/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */

/*
 * Copyright (C) 2017 Red Hat
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"

#include "backends/meta-monitor-config-store.h"

#include <gio/gio.h>
#include <string.h>

#include "backends/meta-monitor-config-manager.h"
#include "backends/meta-monitor-config-utils.h"

#define MONITORS_CONFIG_XML_FORMAT_VERSION 2

#define QUOTE1(a) #a
#define QUOTE(a) QUOTE1(a)

/*
 * Example configuration:
 *
 * <monitors version="2">
 *   <configuration>
 *     <logicalmonitor>
 *       <x>0</x>
 *       <y>0</y>
 *       <scale>1</scale>
 *       <monitor>
 *         <monitorspec>
 *           <connector>LVDS1</connector>
 *           <vendor>Vendor A</vendor>
 *           <product>Product A</product>
 *           <serial>Serial A</serial>
 *         </monitorspec>
 *         <mode>
 *           <width>1920</width>
 *           <height>1080</height>
 *           <rate>60.049972534179688</rate>
 *           <flag>interlace</flag>
 *         </mode>
 *       </monitor>
 *       <transform>
 *         <rotation>right</rotation>
 *         <flipped>no</flipped>
 *       </transform>
 *       <primary>yes</primary>
 *       <presentation>no</presentation>
 *     </logicalmonitor>
 *     <logicalmonitor>
 *       <x>1920</x>
 *       <y>1080</y>
 *       <monitor>
 *         <monitorspec>
 *           <connector>LVDS2</connector>
 *           <vendor>Vendor B</vendor>
 *           <product>Product B</product>
 *           <serial>Serial B</serial>
 *         </monitorspec>
 *         <mode>
 *           <width>1920</width>
 *           <height>1080</height>
 *           <rate>60.049972534179688</rate>
 *         </mode>
 *         <underscanning>yes</underscanning>
 *       </monitor>
 *       <presentation>yes</presentation>
 *     </logicalmonitor>
 *     <disabled>
 *       <monitorspec>
 *         <connector>LVDS3</connector>
 *         <vendor>Vendor C</vendor>
 *         <product>Product C</product>
 *         <serial>Serial C</serial>
 *       </monitorspec>
 *     </disabled>
 *     <forlease>
 *       <monitorspec>
 *         <connector>LVDS3</connector>
 *         <vendor>Vendor C</vendor>
 *         <product>Product C</product>
 *         <serial>Serial C</serial>
 *       </monitorspec>
 *     </forlease>
 *   </configuration>
 * </monitors>
 *
 */

enum
{
  PROP_0,

  PROP_MONITOR_MANAGER,

  PROP_LAST
};

static GParamSpec *obj_props[PROP_LAST];

struct _MetaMonitorConfigStore
{
  GObject parent;

  MetaMonitorManager *monitor_manager;

  GHashTable *configs;

  GCancellable *save_cancellable;

  GFile *user_file;
  GFile *custom_read_file;
  GFile *custom_write_file;

  gboolean has_stores_policy;
  GList *stores_policy;

  gboolean has_dbus_policy;
  MetaMonitorConfigPolicy policy;
};

typedef enum
{
  STATE_INITIAL,
  STATE_UNKNOWN,
  STATE_MONITORS,
  STATE_CONFIGURATION,
  STATE_LAYOUT_MODE,
  STATE_LOGICAL_MONITOR,
  STATE_LOGICAL_MONITOR_X,
  STATE_LOGICAL_MONITOR_Y,
  STATE_LOGICAL_MONITOR_PRIMARY,
  STATE_LOGICAL_MONITOR_PRESENTATION,
  STATE_LOGICAL_MONITOR_SCALE,
  STATE_TRANSFORM,
  STATE_TRANSFORM_ROTATION,
  STATE_TRANSFORM_FLIPPED,
  STATE_MONITOR,
  STATE_MONITOR_SPEC,
  STATE_MONITOR_SPEC_CONNECTOR,
  STATE_MONITOR_SPEC_VENDOR,
  STATE_MONITOR_SPEC_PRODUCT,
  STATE_MONITOR_SPEC_SERIAL,
  STATE_MONITOR_MODE,
  STATE_MONITOR_MODE_WIDTH,
  STATE_MONITOR_MODE_HEIGHT,
  STATE_MONITOR_MODE_RATE,
  STATE_MONITOR_MODE_RATE_MODE,
  STATE_MONITOR_MODE_FLAG,
  STATE_MONITOR_UNDERSCANNING,
  STATE_MONITOR_MAXBPC,
  STATE_MONITOR_RGB_RANGE,
  STATE_MONITOR_COLOR_MODE,
  STATE_DISABLED,
  STATE_FOR_LEASE,
  STATE_POLICY,
  STATE_STORES,
  STATE_STORE,
  STATE_DBUS,
} ParserState;

typedef struct
{
  ParserState state;
  MetaMonitorConfigStore *config_store;
  GFile *file;

  GHashTable *pending_configs;

  ParserState monitor_spec_parent_state;

  gboolean is_current_layout_mode_valid;
  MetaLogicalMonitorLayoutMode current_layout_mode;
  GList *current_logical_monitor_configs;
  MetaMonitorSpec *current_monitor_spec;
  gboolean current_transform_flipped;
  MtkMonitorTransform current_transform;
  MetaMonitorModeSpec *current_monitor_mode_spec;
  MetaMonitorConfig *current_monitor_config;
  MetaLogicalMonitorConfig *current_logical_monitor_config;
  GList *current_disabled_monitor_specs;
  GList *current_for_lease_monitor_specs;
  gboolean seen_policy;
  gboolean seen_stores;
  gboolean seen_dbus;
  MetaConfigStore pending_store;
  GList *stores;

  gboolean enable_dbus_set;
  gboolean enable_dbus;

  ParserState unknown_state_root;
  int unknown_level;

  MetaMonitorsConfigFlag extra_config_flags;
  gboolean should_update_file;
} ConfigParser;

G_DEFINE_TYPE (MetaMonitorConfigStore, meta_monitor_config_store,
               G_TYPE_OBJECT)

static void
meta_monitor_config_init (MetaMonitorConfig *config)
{
  config->enable_underscanning = FALSE;
  config->has_max_bpc = FALSE;
  config->max_bpc = 0;
  config->rgb_range = META_OUTPUT_RGB_RANGE_AUTO;
}

static gboolean
text_equals (const char *text,
             int         len,
             const char *expect)
{
  if (strlen (expect) != len)
    return FALSE;

  return strncmp (text, expect, len) == 0;
}

static void
enter_unknown_element (ConfigParser *parser,
                       const char   *element_name,
                       const char   *root_element_name,
                       ParserState   root_state)
{
  parser->state = STATE_UNKNOWN;
  parser->unknown_level = 1;
  parser->unknown_state_root = root_state;
  g_warning ("Unknown element <%s> under <%s>, ignoring",
             element_name, root_element_name);
}

static void
handle_start_element (GMarkupParseContext  *context,
                      const char           *element_name,
                      const char          **attribute_names,
                      const char          **attribute_values,
                      gpointer              user_data,
                      GError              **error)
{
  ConfigParser *parser = user_data;

  switch (parser->state)
    {
    case STATE_INITIAL:
      {
        char *version;

        if (!g_str_equal (element_name, "monitors"))
          {
            g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                         "Invalid document element '%s'", element_name);
            return;
          }

        if (!g_markup_collect_attributes (element_name, attribute_names, attribute_values,
                                          error,
                                          G_MARKUP_COLLECT_STRING, "version", &version,
                                          G_MARKUP_COLLECT_INVALID))
          {
            g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_INVALID_CONTENT,
                         "Missing config file format version");
          }

        if (!g_str_equal (version, QUOTE (MONITORS_CONFIG_XML_FORMAT_VERSION)))
          {
            g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_INVALID_CONTENT,
                         "Invalid or unsupported version '%s'", version);
            return;
          }

        parser->state = STATE_MONITORS;
        return;
      }

    case STATE_MONITORS:
      {
        if (g_str_equal (element_name, "configuration"))
          {
            parser->state = STATE_CONFIGURATION;
            parser->is_current_layout_mode_valid = FALSE;
          }
        else if (g_str_equal (element_name, "policy"))
          {
            if (parser->seen_policy)
              {
                g_set_error (error,
                             G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                             "Multiple policy definitions");
                return;
              }

            parser->seen_policy = TRUE;
            parser->state = STATE_POLICY;
          }
        else
          {
            enter_unknown_element (parser, element_name,
                                   "monitors", STATE_MONITORS);
            return;
          }

        return;
      }

    case STATE_UNKNOWN:
      {
        parser->unknown_level++;

        return;
      }

    case STATE_CONFIGURATION:
      {
        if (g_str_equal (element_name, "logicalmonitor"))
          {
            parser->current_logical_monitor_config =
              g_new0 (MetaLogicalMonitorConfig, 1);

            parser->state = STATE_LOGICAL_MONITOR;
          }
        else if (g_str_equal (element_name, "layoutmode"))
          {
            parser->state = STATE_LAYOUT_MODE;
          }
        else if (g_str_equal (element_name, "disabled"))
          {
            parser->state = STATE_DISABLED;
          }
        else if (g_str_equal (element_name, "forlease"))
          {
            parser->state = STATE_FOR_LEASE;
          }
        else
          {
            enter_unknown_element (parser, element_name,
                                   "configuration", STATE_CONFIGURATION);
          }

        return;
      }

    case STATE_LAYOUT_MODE:
      {
        g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                     "Unexpected element '%s'", element_name);
        return;
      }

    case STATE_LOGICAL_MONITOR:
      {
        if (g_str_equal (element_name, "x"))
          {
            parser->state = STATE_LOGICAL_MONITOR_X;
          }
        else if (g_str_equal (element_name, "y"))
          {
            parser->state = STATE_LOGICAL_MONITOR_Y;
          }
        else if (g_str_equal (element_name, "scale"))
          {
            parser->state = STATE_LOGICAL_MONITOR_SCALE;
          }
        else if (g_str_equal (element_name, "primary"))
          {
            parser->state = STATE_LOGICAL_MONITOR_PRIMARY;
          }
        else if (g_str_equal (element_name, "presentation"))
          {
            parser->state = STATE_LOGICAL_MONITOR_PRESENTATION;
          }
        else if (g_str_equal (element_name, "transform"))
          {
            parser->state = STATE_TRANSFORM;
          }
        else if (g_str_equal (element_name, "monitor"))
          {
            parser->current_monitor_config = g_new0 (MetaMonitorConfig, 1);
            meta_monitor_config_init (parser->current_monitor_config);

            parser->state = STATE_MONITOR;
          }
        else
          {
            enter_unknown_element (parser, element_name,
                                   "logicalmonitor", STATE_LOGICAL_MONITOR);
          }

        return;
      }

    case STATE_LOGICAL_MONITOR_X:
    case STATE_LOGICAL_MONITOR_Y:
    case STATE_LOGICAL_MONITOR_SCALE:
    case STATE_LOGICAL_MONITOR_PRIMARY:
    case STATE_LOGICAL_MONITOR_PRESENTATION:
      {
        g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                     "Invalid logical monitor element '%s'", element_name);
        return;
      }

    case STATE_TRANSFORM:
      {
        if (g_str_equal (element_name, "rotation"))
          {
            parser->state = STATE_TRANSFORM_ROTATION;
          }
        else if (g_str_equal (element_name, "flipped"))
          {
            parser->state = STATE_TRANSFORM_FLIPPED;
          }

        return;
      }

    case STATE_TRANSFORM_ROTATION:
    case STATE_TRANSFORM_FLIPPED:
      {
        g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                     "Invalid transform element '%s'", element_name);
        return;
      }

    case STATE_MONITOR:
      {
        if (g_str_equal (element_name, "monitorspec"))
          {
            parser->current_monitor_spec = g_new0 (MetaMonitorSpec, 1);
            parser->monitor_spec_parent_state = STATE_MONITOR;
            parser->state = STATE_MONITOR_SPEC;
          }
        else if (g_str_equal (element_name, "mode"))
          {
            parser->current_monitor_mode_spec = g_new0 (MetaMonitorModeSpec, 1);

            parser->state = STATE_MONITOR_MODE;
          }
        else if (g_str_equal (element_name, "underscanning"))
          {
            parser->state = STATE_MONITOR_UNDERSCANNING;
          }
        else if (g_str_equal (element_name, "maxbpc"))
          {
            parser->state = STATE_MONITOR_MAXBPC;
          }
        else if (g_str_equal (element_name, "rgbrange"))
          {
            parser->state = STATE_MONITOR_RGB_RANGE;
          }
        else if (g_str_equal (element_name, "colormode"))
          {
            parser->state = STATE_MONITOR_COLOR_MODE;
          }
        else
          {
            g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                         "Invalid monitor element '%s'", element_name);
            return;
          }

        return;
      }

    case STATE_MONITOR_SPEC:
      {
        if (g_str_equal (element_name, "connector"))
          {
            parser->state = STATE_MONITOR_SPEC_CONNECTOR;
          }
        else if (g_str_equal (element_name, "vendor"))
          {
            parser->state = STATE_MONITOR_SPEC_VENDOR;
          }
        else if (g_str_equal (element_name, "product"))
          {
            parser->state = STATE_MONITOR_SPEC_PRODUCT;
          }
        else if (g_str_equal (element_name, "serial"))
          {
            parser->state = STATE_MONITOR_SPEC_SERIAL;
          }
        else
          {
            g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                         "Invalid monitor spec element '%s'", element_name);
            return;
          }

        return;
      }

    case STATE_MONITOR_SPEC_CONNECTOR:
    case STATE_MONITOR_SPEC_VENDOR:
    case STATE_MONITOR_SPEC_PRODUCT:
    case STATE_MONITOR_SPEC_SERIAL:
      {
        g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                     "Invalid monitor spec element '%s'", element_name);
        return;
      }

    case STATE_MONITOR_MODE:
      {
        if (g_str_equal (element_name, "width"))
          {
            parser->state = STATE_MONITOR_MODE_WIDTH;
          }
        else if (g_str_equal (element_name, "height"))
          {
            parser->state = STATE_MONITOR_MODE_HEIGHT;
          }
        else if (g_str_equal (element_name, "rate"))
          {
            parser->state = STATE_MONITOR_MODE_RATE;
          }
        else if (g_str_equal (element_name, "ratemode"))
          {
            parser->state = STATE_MONITOR_MODE_RATE_MODE;
          }
        else if (g_str_equal (element_name, "flag"))
          {
            parser->state = STATE_MONITOR_MODE_FLAG;
          }
        else
          {
            g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                         "Invalid mode element '%s'", element_name);
            return;
          }

        return;
      }

    case STATE_MONITOR_MODE_WIDTH:
    case STATE_MONITOR_MODE_HEIGHT:
    case STATE_MONITOR_MODE_RATE:
    case STATE_MONITOR_MODE_RATE_MODE:
    case STATE_MONITOR_MODE_FLAG:
      {
        g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                     "Invalid mode sub element '%s'", element_name);
        return;
      }

    case STATE_MONITOR_UNDERSCANNING:
      {
        g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                     "Invalid element '%s' under underscanning", element_name);
        return;
      }

    case STATE_MONITOR_MAXBPC:
      {
        g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                     "Invalid element '%s' under maxbpc", element_name);
        return;
      }

    case STATE_MONITOR_RGB_RANGE:
      {
        g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                     "Invalid element '%s' under rgbrange", element_name);
        return;
      }

    case STATE_MONITOR_COLOR_MODE:
      {
        g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                     "Invalid element '%s' under colormode", element_name);
        return;
      }

    case STATE_DISABLED:
      {
        if (!g_str_equal (element_name, "monitorspec"))
          {
            g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                         "Invalid element '%s' under disabled", element_name);
            return;
          }

        parser->current_monitor_spec = g_new0 (MetaMonitorSpec, 1);
        parser->monitor_spec_parent_state = STATE_DISABLED;
        parser->state = STATE_MONITOR_SPEC;

        return;
      }

    case STATE_FOR_LEASE:
      {
        if (!g_str_equal (element_name, "monitorspec"))
          {
            g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                         "Invalid element '%s' under forlease", element_name);
            return;
          }

        parser->current_monitor_spec = g_new0 (MetaMonitorSpec, 1);
        parser->monitor_spec_parent_state = STATE_FOR_LEASE;
        parser->state = STATE_MONITOR_SPEC;

        return;
      }

    case STATE_POLICY:
      {
        if (!(parser->extra_config_flags &
              META_MONITORS_CONFIG_FLAG_SYSTEM_CONFIG))
          {
            g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_INVALID_CONTENT,
                         "Policy can only be defined in system level configurations");
            return;
          }

        if (g_str_equal (element_name, "stores"))
          {
            if (parser->seen_stores)
              {
                g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                             "Multiple stores elements under policy");
                return;
              }

            parser->seen_stores = TRUE;
            parser->state = STATE_STORES;
          }
        else if (g_str_equal (element_name, "dbus"))
          {
            if (parser->seen_dbus)
              {
                g_set_error (error,
                             G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                             "Multiple dbus elements under policy");
                return;
              }

            parser->seen_dbus = TRUE;
            parser->state = STATE_DBUS;
          }
        else
          {
            enter_unknown_element (parser, element_name,
                                   "policy", STATE_POLICY);
          }

        return;
      }

    case STATE_STORES:
      {
        if (g_str_equal (element_name, "store"))
          {
            parser->state = STATE_STORE;
          }
        else
          {
            enter_unknown_element (parser, element_name,
                                   "stores", STATE_STORES);
          }

        return;
      }

    case STATE_STORE:
      {
        g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                     "Invalid store sub element '%s'", element_name);
        return;
      }

    case STATE_DBUS:
      {
        g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_UNKNOWN_ELEMENT,
                     "Invalid dbus sub element '%s'", element_name);
        return;
      }
    }
}

static void
finish_monitor_spec (ConfigParser *parser)
{
  switch (parser->monitor_spec_parent_state)
    {
    case STATE_MONITOR:
      {
        parser->current_monitor_config->monitor_spec =
          parser->current_monitor_spec;
        parser->current_monitor_spec = NULL;

        return;
      }
    case STATE_DISABLED:
      {
        parser->current_disabled_monitor_specs =
          g_list_prepend (parser->current_disabled_monitor_specs,
                          parser->current_monitor_spec);
        parser->current_monitor_spec = NULL;

        return;
      }
    case STATE_FOR_LEASE:
      {
        parser->current_for_lease_monitor_specs =
          g_list_prepend (parser->current_for_lease_monitor_specs,
                          parser->current_monitor_spec);
        parser->current_monitor_spec = NULL;

        return;
      }

    default:
      g_assert_not_reached ();
    }
}

static void
get_monitor_size_with_rotation (MetaLogicalMonitorConfig *logical_monitor_config,
                                unsigned int             *width_out,
                                unsigned int             *height_out)
{
  MetaMonitorConfig *monitor_config =
    logical_monitor_config->monitor_configs->data;

  if (mtk_monitor_transform_is_rotated (logical_monitor_config->transform))
    {
      *width_out = monitor_config->mode_spec->height;
      *height_out = monitor_config->mode_spec->width;
    }
  else
    {
      *width_out = monitor_config->mode_spec->width;
      *height_out = monitor_config->mode_spec->height;
    }
}

static void
derive_logical_monitor_layouts (GList                       *logical_monitor_configs,
                                MetaLogicalMonitorLayoutMode layout_mode)
{
  GList *l;

  for (l = logical_monitor_configs; l; l = l->next)
    {
      MetaLogicalMonitorConfig *logical_monitor_config = l->data;
      unsigned int width, height;

      get_monitor_size_with_rotation (logical_monitor_config, &width, &height);

      if (layout_mode == META_LOGICAL_MONITOR_LAYOUT_MODE_LOGICAL)
        {
          width = (int) roundf (width / logical_monitor_config->scale);
          height = (int) roundf (height / logical_monitor_config->scale);
        }

      logical_monitor_config->layout.width = width;
      logical_monitor_config->layout.height = height;
    }
}

static gboolean
detect_layout_mode_configs (MetaMonitorManager      *monitor_manager,
                            GList                   *logical_monitor_configs,
                            GList                   *disabled_monitor_specs,
                            GList                   *for_lease_monitor_specs,
                            MetaMonitorsConfigFlag   config_flags,
                            MetaMonitorsConfig     **physical_layout_mode_config,
                            MetaMonitorsConfig     **logical_layout_mode_config,
                            GError                 **error)
{
  GList *logical_monitor_configs_copy;
  GList *disabled_monitor_specs_copy;
  GList *for_lease_monitor_specs_copy;
  MetaMonitorsConfig *physical_config, *logical_config;
  g_autoptr (GError) local_error_physical = NULL;
  g_autoptr (GError) local_error_logical = NULL;

  logical_monitor_configs_copy =
    meta_clone_logical_monitor_config_list (logical_monitor_configs);
  disabled_monitor_specs_copy =
    g_list_copy_deep (disabled_monitor_specs, (GCopyFunc) meta_monitor_spec_clone, NULL);
  for_lease_monitor_specs_copy =
    g_list_copy_deep (for_lease_monitor_specs, (GCopyFunc) meta_monitor_spec_clone, NULL);

  derive_logical_monitor_layouts (logical_monitor_configs,
                                  META_LOGICAL_MONITOR_LAYOUT_MODE_PHYSICAL);
  physical_config =
    meta_monitors_config_new_full (g_steal_pointer (&logical_monitor_configs),
                                   g_steal_pointer (&disabled_monitor_specs),
                                   g_steal_pointer (&for_lease_monitor_specs),
                                   META_LOGICAL_MONITOR_LAYOUT_MODE_PHYSICAL,
                                   config_flags);

  if (!meta_verify_monitors_config (physical_config, monitor_manager,
                                    &local_error_physical))
    g_clear_object (&physical_config);

  derive_logical_monitor_layouts (logical_monitor_configs_copy,
                                  META_LOGICAL_MONITOR_LAYOUT_MODE_LOGICAL);
  logical_config =
    meta_monitors_config_new_full (g_steal_pointer (&logical_monitor_configs_copy),
                                   g_steal_pointer (&disabled_monitor_specs_copy),
                                   g_steal_pointer (&for_lease_monitor_specs_copy),
                                   META_LOGICAL_MONITOR_LAYOUT_MODE_LOGICAL,
                                   config_flags);

  if (!meta_verify_monitors_config (logical_config, monitor_manager,
                                    &local_error_logical))
    g_clear_object (&logical_config);

  if (!physical_config && !logical_config)
    {
      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
                   "Detected neither physical (%s) nor logical (%s) layout mode",
                   local_error_physical->message, local_error_logical->message);
      return  FALSE;
    }

  *physical_layout_mode_config = physical_config;
  *logical_layout_mode_config = logical_config;

  return TRUE;
}

static void
maybe_convert_scales (GList *logical_monitor_configs)
{
  GList *l;

  for (l = logical_monitor_configs; l; l = l->next)
    {
      MetaLogicalMonitorConfig *logical_monitor_config = l->data;
      unsigned int width, height;
      float existing_scale = logical_monitor_config->scale;
      float existing_scaled_width, existing_scaled_height;
      float new_scale = 0.0f;

      get_monitor_size_with_rotation (logical_monitor_config, &width, &height);

      existing_scaled_width = width / existing_scale;
      existing_scaled_height = height / existing_scale;

      if (floorf (existing_scaled_width) == existing_scaled_width &&
          floorf (existing_scaled_height) == existing_scaled_height)
        continue;

      new_scale =
        meta_get_closest_monitor_scale_factor_for_resolution (width,
                                                              height,
                                                              existing_scale,
                                                              0.1f);
      if (new_scale == 0.0f)
        new_scale = 1.0f;

      logical_monitor_config->scale = new_scale;
    }
}

static gboolean
try_convert_1_dimensional_line (GList    *logical_monitor_configs,
                                gboolean  horizontal)
{
  int i;
  unsigned int n_monitors = g_list_length (logical_monitor_configs);
  unsigned int n_monitors_found;
  unsigned int looking_for;
  unsigned int accumulated;
  MetaLogicalMonitorConfig *prev_logical_monitor_config;

  /* Before we change any values, make sure monitors are actually aligned on a
   * straight line.
   */
  looking_for = 0;
  n_monitors_found = 0;
  for (i = 0; i < n_monitors; i++)
    {
      GList *l;

      for (l = logical_monitor_configs; l; l = l->next)
        {
          MetaLogicalMonitorConfig *logical_monitor_config = l->data;
          unsigned int width, height;

          if ((horizontal && logical_monitor_config->layout.x != looking_for) ||
              (!horizontal && logical_monitor_config->layout.y != looking_for))
            continue;

          get_monitor_size_with_rotation (logical_monitor_config, &width, &height);

          looking_for += horizontal ? width : height;

          n_monitors_found++;
        }
    }

  if (n_monitors_found != n_monitors)
    {
      /* If we haven't found all the monitors on our straight line, we can't
       * run the algorithm.
       */
      return FALSE;
    }

  looking_for = 0;
  accumulated = 0;
  prev_logical_monitor_config = NULL;
  for (i = 0; i < n_monitors; i++)
    {
      GList *l;

      for (l = logical_monitor_configs; l; l = l->next)
        {
          MetaLogicalMonitorConfig *logical_monitor_config = l->data;
          unsigned int width, height;
          float scale = logical_monitor_config->scale;

          if ((horizontal && logical_monitor_config->layout.x != looking_for) ||
              (!horizontal && logical_monitor_config->layout.y != looking_for))
            continue;

          get_monitor_size_with_rotation (logical_monitor_config, &width, &height);

          if (horizontal)
            {
              logical_monitor_config->layout.x = accumulated;

              /* In the other dimension, always center in relation to the previous
               * monitor.
               */
              if (prev_logical_monitor_config)
                {
                  unsigned int prev_width, prev_height;
                  float centerline;

                  get_monitor_size_with_rotation (prev_logical_monitor_config,
                                                  &prev_width, &prev_height);

                  centerline = prev_logical_monitor_config->layout.y +
                    (int) roundf ((prev_height / prev_logical_monitor_config->scale) / 2.0f);

                  logical_monitor_config->layout.y =
                    (int) (centerline - roundf ((height / scale) / 2.0f));
                }
            }
          else
            {
              logical_monitor_config->layout.y = accumulated;

              /* See comment above */
              if (prev_logical_monitor_config)
                {
                  unsigned int prev_width, prev_height;
                  float centerline;

                  get_monitor_size_with_rotation (prev_logical_monitor_config,
                                                  &prev_width, &prev_height);

                  centerline = prev_logical_monitor_config->layout.x +
                    roundf ((prev_width / prev_logical_monitor_config->scale) / 2.0f);

                  logical_monitor_config->layout.x =
                    (int) (centerline - roundf ((width / scale) / 2.0f));
                }
            }

          looking_for += horizontal ? width : height;
          accumulated += (int) roundf ((horizontal ? width : height) / scale);

          prev_logical_monitor_config = logical_monitor_config;
          break;
        }
    }

  return TRUE;
}

static gboolean
try_convert_2d_with_baseline (GList    *logical_monitor_configs,
                              gboolean  horizontal)
{
  /* Look for a shared baseline which every monitor is aligned to,
   * then calculate the new layout keeping that baseline.
   *
   * This one consists of a lot of steps, to make explanations easier,
   * we'll assume a horizontal baseline for all explanations in comments.
   */

  int i;
  unsigned int n_monitors = g_list_length (logical_monitor_configs);
  MetaLogicalMonitorConfig *first_logical_monitor_config =
    logical_monitor_configs->data;
  unsigned int width, height;
  unsigned int looking_for_1, looking_for_2;
  gboolean baseline_is_1, baseline_is_2;
  GList *l;
  unsigned int baseline;
  unsigned int cur_side_1, cur_side_2;

  get_monitor_size_with_rotation (first_logical_monitor_config,
                                  &width, &height);

  /* Step 1: We don't know whether the first monitor is above or below the
   * baseline, so there are two possible baselines: Top or bottom edge of
   * the first monitor.
   *
   * Find out which one the actual baseline is, top or bottom edge!
   */

  looking_for_1 = horizontal
    ? first_logical_monitor_config->layout.y
    : first_logical_monitor_config->layout.x;
  looking_for_2 = horizontal
    ? first_logical_monitor_config->layout.y + height
    : first_logical_monitor_config->layout.x + width;

  baseline_is_1 = baseline_is_2 = TRUE;

  for (l = logical_monitor_configs; l; l = l->next)
    {
      MetaLogicalMonitorConfig *logical_monitor_config = l->data;

      get_monitor_size_with_rotation (logical_monitor_config,
                                      &width, &height);

      if ((horizontal &&
           logical_monitor_config->layout.y != looking_for_1 &&
           logical_monitor_config->layout.y + height != looking_for_1) ||
          (!horizontal &&
           logical_monitor_config->layout.x != looking_for_1 &&
           logical_monitor_config->layout.x + width != looking_for_1))
        baseline_is_1 = FALSE;

      if ((horizontal &&
           logical_monitor_config->layout.y != looking_for_2 &&
           logical_monitor_config->layout.y + height != looking_for_2) ||
          (!horizontal &&
           logical_monitor_config->layout.x != looking_for_2 &&
           logical_monitor_config->layout.x + width != looking_for_2))
        baseline_is_2 = FALSE;
    }

  if (!baseline_is_1 && !baseline_is_2)
    {
      /* We couldn't find a clear baseline which all monitors are aligned with,
       * this conversion won't work!
       */
      return FALSE;
    }

  baseline = baseline_is_1 ? looking_for_1 : looking_for_2;

  /* Step 2: Now that we have a baseline, go through the monitors
   * above the baseline which need to be scaled, and move their top
   * edge so that their bottom edge is still aligned with the baseline.
   *
   * For the monitors below the baseline there's no such need, because
   * even with scale, their top edge will remain aligned with the
   * baseline.
   */

  for (l = logical_monitor_configs; l; l = l->next)
    {
      MetaLogicalMonitorConfig *logical_monitor_config = l->data;

      if (logical_monitor_config->scale == 1.0f)
        continue;

      /* Filter out all the monitors below the baseline */
      if ((horizontal && logical_monitor_config->layout.y == baseline) ||
          (!horizontal && logical_monitor_config->layout.x == baseline))
        continue;

      get_monitor_size_with_rotation (logical_monitor_config,
                                      &width, &height);

      if (horizontal)
        {
          logical_monitor_config->layout.y =
            baseline - (int) roundf (height / logical_monitor_config->scale);
        }
      else
        {
          logical_monitor_config->layout.x =
            baseline - (int) roundf (width / logical_monitor_config->scale);
        }
    }

  /* Step 3: Still not done... Now we're done aligning monitors with the
   * baseline, but the scaling might also have opened holes in the horizontal
   * direction.
   *
   * We need to "walk along" the monitor strips above and below the baseline
   * and make sure everything is adjacent on both sides of the baseline.
   */

  cur_side_1 = 0;
  cur_side_2 = 0;

  for (i = 0; i < n_monitors; i++)
    {
      unsigned int min_side_1 = G_MAXUINT;
      unsigned int min_side_2 = G_MAXUINT;
      MetaLogicalMonitorConfig *lowest_mon_side_1 = NULL;
      MetaLogicalMonitorConfig *lowest_mon_side_2 = NULL;

      for (l = logical_monitor_configs; l; l = l->next)
        {
          MetaLogicalMonitorConfig *logical_monitor_config = l->data;

          if ((horizontal && logical_monitor_config->layout.y != baseline) ||
              (!horizontal && logical_monitor_config->layout.x != baseline))
            {
              /* above the baseline */

              if (horizontal)
                {
                  if (logical_monitor_config->layout.x >= cur_side_1 &&
                      logical_monitor_config->layout.x < min_side_1)
                    {
                      min_side_1 = logical_monitor_config->layout.x;
                      lowest_mon_side_1 = logical_monitor_config;
                    }
                }
              else
                {
                  if (logical_monitor_config->layout.y >= cur_side_1 &&
                      logical_monitor_config->layout.y < min_side_1)
                    {
                      min_side_1 = logical_monitor_config->layout.y;
                      lowest_mon_side_1 = logical_monitor_config;
                    }
                }
            }
          else
            {
              /* below the baseline */

              if (horizontal)
                {
                  if (logical_monitor_config->layout.x >= cur_side_2 &&
                      logical_monitor_config->layout.x < min_side_2)
                    {
                      min_side_2 = logical_monitor_config->layout.x;
                      lowest_mon_side_2 = logical_monitor_config;
                    }
                }
              else
                {
                  if (logical_monitor_config->layout.y >= cur_side_2 &&
                      logical_monitor_config->layout.y < min_side_2)
                    {
                      min_side_2 = logical_monitor_config->layout.y;
                      lowest_mon_side_2 = logical_monitor_config;
                    }
                }
            }
        }

      if (lowest_mon_side_1)
        {
          get_monitor_size_with_rotation (lowest_mon_side_1, &width, &height);

          if (horizontal)
            {
              lowest_mon_side_1->layout.x = cur_side_1;
              cur_side_1 += (int) roundf (width / lowest_mon_side_1->scale);
            }
          else
            {
              lowest_mon_side_1->layout.y = cur_side_1;
              cur_side_1 += (int) roundf (height / lowest_mon_side_1->scale);
            }
        }

      if (lowest_mon_side_2)
        {
          get_monitor_size_with_rotation (lowest_mon_side_2, &width, &height);

          if (horizontal)
            {
              lowest_mon_side_2->layout.x = cur_side_2;
              cur_side_2 += (int) roundf (width / lowest_mon_side_2->scale);
            }
          else
            {
              lowest_mon_side_2->layout.y = cur_side_2;
              cur_side_2 += (int) roundf (height / lowest_mon_side_2->scale);
            }
        }
    }

  return TRUE;
}

static void
convert_align_on_horizontal_line (GList *logical_monitor_configs)
{
  GList *l;
  unsigned int accumulated_x = 0;

  for (l = logical_monitor_configs; l; l = l->next)
    {
      MetaLogicalMonitorConfig *logical_monitor_config = l->data;
      unsigned int width, height;

      get_monitor_size_with_rotation (logical_monitor_config, &width, &height);

      logical_monitor_config->layout.x = accumulated_x;
      logical_monitor_config->layout.y = 0;

      accumulated_x += (int) roundf (width / logical_monitor_config->scale);
    }
}

static void
adjust_for_offset (GList *logical_monitor_configs)
{
  GList *l;
  int offset_x, offset_y;

  offset_x = offset_y = G_MAXINT;

  for (l = logical_monitor_configs; l; l = l->next)
    {
      MetaLogicalMonitorConfig *logical_monitor_config = l->data;

      offset_x = MIN (offset_x, logical_monitor_config->layout.x);
      offset_y = MIN (offset_y, logical_monitor_config->layout.y);
    }

  if (offset_x == G_MAXINT && offset_y == G_MAXINT)
    return;

  for (l = logical_monitor_configs; l; l = l->next)
    {
      MetaLogicalMonitorConfig *logical_monitor_config = l->data;

      if (offset_x != G_MAXINT)
        logical_monitor_config->layout.x -= offset_x;

      if (offset_y != G_MAXINT)
        logical_monitor_config->layout.y -= offset_y;
    }
}

static MetaMonitorsConfig *
attempt_layout_mode_conversion (MetaMonitorManager     *monitor_manager,
                                GList                  *logical_monitor_configs,
                                GList                  *disabled_monitor_specs,
                                GList                  *for_lease_monitor_specs,
                                MetaMonitorsConfigFlag  config_flags)
{
  GList *logical_monitor_configs_copy;
  g_autoptr (MetaMonitorsConfig) new_logical_config = NULL;
  g_autoptr (GError) local_error = NULL;

  logical_monitor_configs_copy =
    meta_clone_logical_monitor_config_list (logical_monitor_configs);

  maybe_convert_scales (logical_monitor_configs_copy);
  derive_logical_monitor_layouts (logical_monitor_configs_copy,
                                  META_LOGICAL_MONITOR_LAYOUT_MODE_LOGICAL);

  if (meta_verify_logical_monitor_config_list (logical_monitor_configs,
                                               META_LOGICAL_MONITOR_LAYOUT_MODE_LOGICAL,
                                               monitor_manager,
                                               &local_error))
    {
      /* Great, it was enough to convert the scales and the config is now already
       * valid in LOGICAL mode, can skip the fallible conversion paths.
       */
      goto create_full_config;
    }

  if (!try_convert_1_dimensional_line (logical_monitor_configs_copy, TRUE) &&
      !try_convert_1_dimensional_line (logical_monitor_configs_copy, FALSE) &&
      !try_convert_2d_with_baseline (logical_monitor_configs_copy, TRUE) &&
      !try_convert_2d_with_baseline (logical_monitor_configs_copy, FALSE))
    {
      /* All algorithms we have to convert failed, this is expected for complex
       * layouts, so fall back to the simple method and align all monitors on
       * a horizontal line.
       */
      convert_align_on_horizontal_line (logical_monitor_configs_copy);
    }

  adjust_for_offset (logical_monitor_configs_copy);

create_full_config:
  new_logical_config =
    meta_monitors_config_new_full (g_steal_pointer (&logical_monitor_configs_copy),
                                   g_list_copy_deep (disabled_monitor_specs,
                                                     (GCopyFunc) meta_monitor_spec_clone,
                                                     NULL),
                                   g_list_copy_deep (for_lease_monitor_specs,
                                                     (GCopyFunc) meta_monitor_spec_clone,
                                                     NULL),
                                   META_LOGICAL_MONITOR_LAYOUT_MODE_LOGICAL,
                                   config_flags);

  if (!meta_verify_monitors_config (new_logical_config, monitor_manager, &local_error))
    {
      /* Verification of the converted config failed, this should not happen as the
       * conversion functions should give up in case conversion is not possible.
       */
      g_warning ("Verification of converted monitor config failed: %s",
                 local_error->message);
      return NULL;
    }

  return g_steal_pointer (&new_logical_config);
}

static void
handle_end_element (GMarkupParseContext  *context,
                    const char           *element_name,
                    gpointer              user_data,
                    GError              **error)
{
  ConfigParser *parser = user_data;

  switch (parser->state)
    {
    case STATE_LOGICAL_MONITOR_X:
    case STATE_LOGICAL_MONITOR_Y:
    case STATE_LOGICAL_MONITOR_SCALE:
    case STATE_LOGICAL_MONITOR_PRIMARY:
    case STATE_LOGICAL_MONITOR_PRESENTATION:
      {
        parser->state = STATE_LOGICAL_MONITOR;
        return;
      }

    case STATE_TRANSFORM:
      {
        g_assert (g_str_equal (element_name, "transform"));

        parser->current_logical_monitor_config->transform =
          parser->current_transform;
        if (parser->current_transform_flipped)
          {
            parser->current_logical_monitor_config->transform +=
              MTK_MONITOR_TRANSFORM_FLIPPED;
          }

        parser->current_transform = MTK_MONITOR_TRANSFORM_NORMAL;
        parser->current_transform_flipped = FALSE;

        parser->state = STATE_LOGICAL_MONITOR;
        return;
      }

    case STATE_TRANSFORM_ROTATION:
    case STATE_TRANSFORM_FLIPPED:
      {
        parser->state = STATE_TRANSFORM;
        return;
      }

    case STATE_MONITOR_SPEC_CONNECTOR:
    case STATE_MONITOR_SPEC_VENDOR:
    case STATE_MONITOR_SPEC_PRODUCT:
    case STATE_MONITOR_SPEC_SERIAL:
      {
        parser->state = STATE_MONITOR_SPEC;
        return;
      }

    case STATE_MONITOR_SPEC:
      {
        g_assert (g_str_equal (element_name, "monitorspec"));

        if (!meta_verify_monitor_spec (parser->current_monitor_spec, error))
          return;

        finish_monitor_spec (parser);

        parser->state = parser->monitor_spec_parent_state;
        return;
      }

    case STATE_MONITOR_MODE_WIDTH:
    case STATE_MONITOR_MODE_HEIGHT:
    case STATE_MONITOR_MODE_RATE:
    case STATE_MONITOR_MODE_RATE_MODE:
    case STATE_MONITOR_MODE_FLAG:
      {
        parser->state = STATE_MONITOR_MODE;
        return;
      }

    case STATE_MONITOR_MODE:
      {
        g_assert (g_str_equal (element_name, "mode"));

        if (!meta_verify_monitor_mode_spec (parser->current_monitor_mode_spec,
                                            error))
          return;

        parser->current_monitor_config->mode_spec =
          parser->current_monitor_mode_spec;
        parser->current_monitor_mode_spec = NULL;

        parser->state = STATE_MONITOR;
        return;
      }

    case STATE_MONITOR_UNDERSCANNING:
      {
        g_assert (g_str_equal (element_name, "underscanning"));

        parser->state = STATE_MONITOR;
        return;
      }

    case STATE_MONITOR_MAXBPC:
      {
        g_assert (g_str_equal (element_name, "maxbpc"));

        parser->state = STATE_MONITOR;
        return;
      }

    case STATE_MONITOR_RGB_RANGE:
      {
        g_assert (g_str_equal (element_name, "rgbrange"));

        parser->state = STATE_MONITOR;
        return;
      }

    case STATE_MONITOR_COLOR_MODE:
      {
        g_assert (g_str_equal (element_name, "colormode"));

        parser->state = STATE_MONITOR;
        return;
      }

    case STATE_MONITOR:
      {
        MetaLogicalMonitorConfig *logical_monitor_config;

        g_assert (g_str_equal (element_name, "monitor"));

        if (!meta_verify_monitor_config (parser->current_monitor_config, error))
          return;

        logical_monitor_config = parser->current_logical_monitor_config;

        logical_monitor_config->monitor_configs =
          g_list_append (logical_monitor_config->monitor_configs,
                         parser->current_monitor_config);
        parser->current_monitor_config = NULL;

        parser->state = STATE_LOGICAL_MONITOR;
        return;
      }

    case STATE_LOGICAL_MONITOR:
      {
        MetaLogicalMonitorConfig *logical_monitor_config =
          parser->current_logical_monitor_config;

        g_assert (g_str_equal (element_name, "logicalmonitor"));

        if (logical_monitor_config->scale == 0)
          logical_monitor_config->scale = 1;

        parser->current_logical_monitor_configs =
          g_list_append (parser->current_logical_monitor_configs,
                         logical_monitor_config);
        parser->current_logical_monitor_config = NULL;

        parser->state = STATE_CONFIGURATION;
        return;
      }

    case STATE_LAYOUT_MODE:
      {
        parser->state = STATE_CONFIGURATION;
        return;
      }

    case STATE_DISABLED:
      {
        g_assert (g_str_equal (element_name, "disabled"));

        parser->state = STATE_CONFIGURATION;
        return;
      }

    case STATE_FOR_LEASE:
      {
        g_assert (g_str_equal (element_name, "forlease"));

        parser->state = STATE_CONFIGURATION;
        return;
      }

    case STATE_CONFIGURATION:
      {
        MetaMonitorConfigStore *store = parser->config_store;
        g_autoptr (MetaMonitorsConfig) config = NULL;
        MetaMonitorsConfigKey *config_key;
        MetaLogicalMonitorLayoutMode layout_mode = parser->current_layout_mode;
        MetaMonitorsConfigFlag config_flags = META_MONITORS_CONFIG_FLAG_NONE;

        g_assert (g_str_equal (element_name, "configuration"));

        config_flags |= parser->extra_config_flags;

        if (!parser->is_current_layout_mode_valid)
          {
            MetaMonitorsConfig *physical_layout_mode_config;
            MetaMonitorsConfig *logical_layout_mode_config;

            if (!detect_layout_mode_configs (store->monitor_manager,
                                             parser->current_logical_monitor_configs,
                                             parser->current_disabled_monitor_specs,
                                             parser->current_for_lease_monitor_specs,
                                             config_flags,
                                             &physical_layout_mode_config,
                                             &logical_layout_mode_config,
                                             error))
              {
                parser->current_logical_monitor_configs = NULL;
                parser->current_disabled_monitor_specs = NULL;
                parser->current_for_lease_monitor_specs = NULL;
                return;
              }

            parser->current_logical_monitor_configs = NULL;
            parser->current_disabled_monitor_specs = NULL;
            parser->current_for_lease_monitor_specs = NULL;

            if (physical_layout_mode_config)
              {
                g_hash_table_replace (parser->pending_configs,
                                      physical_layout_mode_config->key,
                                      physical_layout_mode_config);

                /* If the config only works with PHYSICAL layout mode, we'll attempt to
                 * convert the PHYSICAL config to LOGICAL. This will fail for
                 * more complex configurations though.
                 */
                if (!logical_layout_mode_config)
                  {
                    logical_layout_mode_config =
                      attempt_layout_mode_conversion (store->monitor_manager,
                                                      physical_layout_mode_config->logical_monitor_configs,
                                                      physical_layout_mode_config->disabled_monitor_specs,
                                                      physical_layout_mode_config->for_lease_monitor_specs,
                                                      config_flags);
                  }
              }

            if (logical_layout_mode_config)
              {
                g_hash_table_replace (parser->pending_configs,
                                      logical_layout_mode_config->key,
                                      logical_layout_mode_config);
              }

            parser->should_update_file = TRUE;
          }
        else
          {
            derive_logical_monitor_layouts (parser->current_logical_monitor_configs,
                                            layout_mode);

            config =
              meta_monitors_config_new_full (parser->current_logical_monitor_configs,
                                             parser->current_disabled_monitor_specs,
                                             parser->current_for_lease_monitor_specs,
                                             layout_mode,
                                             config_flags);

            parser->current_logical_monitor_configs = NULL;
            parser->current_disabled_monitor_specs = NULL;
            parser->current_for_lease_monitor_specs = NULL;

            if (!meta_verify_monitors_config (config, store->monitor_manager,
                                              error))
              return;

            config_key = config->key;
            g_hash_table_replace (parser->pending_configs,
                                  config_key, g_steal_pointer (&config));
          }

        parser->state = STATE_MONITORS;
        return;
      }

    case STATE_STORE:
      {
        g_assert (g_str_equal (element_name, "store"));

        if (parser->pending_store == -1)
          {
            g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_INVALID_CONTENT,
                         "Got an empty store");
            return;
          }

        if (g_list_find (parser->stores,
                         GINT_TO_POINTER (parser->pending_store)))
          {
            g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_INVALID_CONTENT,
                         "Multiple identical stores in policy");
            return;
          }

        parser->stores =
          g_list_append (parser->stores,
                         GINT_TO_POINTER (parser->pending_store));
        parser->pending_store = -1;

        parser->state = STATE_STORES;
        return;
      }

    case STATE_STORES:
      {
        g_assert (g_str_equal (element_name, "stores"));

        if (parser->config_store->has_stores_policy)
          {
            g_warning ("Ignoring stores policy from '%s', "
                       "it has already been configured",
                       g_file_peek_path (parser->file));
            g_clear_pointer (&parser->stores, g_list_free);
          }
        else
          {
            parser->config_store->stores_policy =
              g_steal_pointer (&parser->stores);
            parser->config_store->has_stores_policy = TRUE;
          }

        parser->state = STATE_POLICY;
        return;
      }

    case STATE_DBUS:
      {
        if (!parser->config_store->has_dbus_policy)
          {
            parser->config_store->has_dbus_policy = TRUE;
            parser->config_store->policy.enable_dbus = parser->enable_dbus;
            parser->enable_dbus_set = FALSE;
          }
        else
          {
            g_warning ("Policy for monitor configuration via D-Bus "
                       "has already been set, ignoring policy from '%s'",
                       g_file_get_path (parser->file));
          }
        parser->state = STATE_POLICY;

        return;
      }

    case STATE_POLICY:
      {
        g_assert (g_str_equal (element_name, "policy"));

        parser->state = STATE_MONITORS;
        return;
      }

    case STATE_UNKNOWN:
      {
        parser->unknown_level--;
        if (parser->unknown_level == 0)
          {
            g_assert (parser->unknown_state_root >= 0);
            parser->state = parser->unknown_state_root;
            parser->unknown_state_root = -1;
          }
        return;
      }

    case STATE_MONITORS:
      {
        g_assert (g_str_equal (element_name, "monitors"));

        parser->state = STATE_INITIAL;
        return;
      }

    case STATE_INITIAL:
      {
        g_assert_not_reached ();
      }
    }
}

static gboolean
read_int (const char  *text,
          gsize        text_len,
          gint        *out_value,
          GError     **error)
{
  char buf[64];
  int64_t value;
  char *end;

  strncpy (buf, text, text_len);
  buf[MIN (63, text_len)] = 0;

  value = g_ascii_strtoll (buf, &end, 10);

  if (*end || value < 0 || value > G_MAXINT16)
    {
      g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_INVALID_CONTENT,
                   "Expected a number, got %s", buf);
      return FALSE;
    }
  else
    {
      *out_value = value;
      return TRUE;
    }
}

static gboolean
read_float (const char  *text,
            gsize        text_len,
            float       *out_value,
            GError     **error)
{
  char buf[64];
  float value;
  char *end;

  strncpy (buf, text, text_len);
  buf[MIN (63, text_len)] = 0;

  value = (float) g_ascii_strtod (buf, &end);

  if (*end)
    {
      g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_INVALID_CONTENT,
                   "Expected a number, got %s", buf);
      return FALSE;
    }
  else
    {
      *out_value = value;
      return TRUE;
    }
}

static gboolean
read_bool (const char  *text,
           gsize        text_len,
           gboolean    *out_value,
           GError     **error)
{
  if (text_equals (text, text_len, "no"))
    {
      *out_value = FALSE;
      return TRUE;
    }
  else if (text_equals (text, text_len, "yes"))
    {
      *out_value = TRUE;
      return TRUE;
    }
  else
    {
      g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_INVALID_CONTENT,
                   "Invalid boolean value '%.*s'", (int) text_len, text);
      return FALSE;
    }
}

static gboolean
is_all_whitespace (const char *text,
                   gsize       text_len)
{
  gsize i;

  for (i = 0; i < text_len; i++)
    if (!g_ascii_isspace (text[i]))
      return FALSE;

  return TRUE;
}

static void
handle_text (GMarkupParseContext *context,
             const gchar         *text,
             gsize                text_len,
             gpointer             user_data,
             GError             **error)
{
  ConfigParser *parser = user_data;

  switch (parser->state)
    {
    case STATE_UNKNOWN:
      return;

    case STATE_INITIAL:
    case STATE_MONITORS:
    case STATE_CONFIGURATION:
    case STATE_LOGICAL_MONITOR:
    case STATE_MONITOR:
    case STATE_MONITOR_SPEC:
    case STATE_MONITOR_MODE:
    case STATE_TRANSFORM:
    case STATE_DISABLED:
    case STATE_FOR_LEASE:
    case STATE_POLICY:
    case STATE_STORES:
      {
        if (!is_all_whitespace (text, text_len))
          g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_INVALID_CONTENT,
                       "Unexpected content at this point");
        return;
      }

    case STATE_LAYOUT_MODE:
      {
        if (text_equals (text, text_len, "logical"))
          {
            parser->current_layout_mode = META_LOGICAL_MONITOR_LAYOUT_MODE_LOGICAL;
            parser->is_current_layout_mode_valid = TRUE;
          }
        else if (text_equals (text, text_len, "physical"))
          {
            parser->current_layout_mode = META_LOGICAL_MONITOR_LAYOUT_MODE_PHYSICAL;
            parser->is_current_layout_mode_valid = TRUE;
          }
        else
          {
            g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_INVALID_CONTENT,
                         "Invalid layout mode %.*s", (int)text_len, text);
          }

        return;
      }

    case STATE_MONITOR_SPEC_CONNECTOR:
      {
        parser->current_monitor_spec->connector = g_strndup (text, text_len);
        return;
      }

    case STATE_MONITOR_SPEC_VENDOR:
      {
        parser->current_monitor_spec->vendor = g_strndup (text, text_len);
        return;
      }

    case STATE_MONITOR_SPEC_PRODUCT:
      {
        parser->current_monitor_spec->product = g_strndup (text, text_len);
        return;
      }

    case STATE_MONITOR_SPEC_SERIAL:
      {
        parser->current_monitor_spec->serial = g_strndup (text, text_len);
        return;
      }

    case STATE_LOGICAL_MONITOR_X:
      {
        read_int (text, text_len,
                  &parser->current_logical_monitor_config->layout.x, error);
        return;
      }

    case STATE_LOGICAL_MONITOR_Y:
      {
        read_int (text, text_len,
                  &parser->current_logical_monitor_config->layout.y, error);
        return;
      }

    case STATE_LOGICAL_MONITOR_SCALE:
      {
        if (!read_float (text, text_len,
                         &parser->current_logical_monitor_config->scale, error))
          return;

        if (parser->current_logical_monitor_config->scale <= 0.0)
          {
            g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
                         "Logical monitor scale '%g' invalid",
                         parser->current_logical_monitor_config->scale);
            return;
          }

        return;
      }

    case STATE_LOGICAL_MONITOR_PRIMARY:
      {
        read_bool (text, text_len,
                   &parser->current_logical_monitor_config->is_primary,
                   error);
        return;
      }

    case STATE_LOGICAL_MONITOR_PRESENTATION:
      {
        read_bool (text, text_len,
                   &parser->current_logical_monitor_config->is_presentation,
                   error);
        return;
      }

    case STATE_TRANSFORM_ROTATION:
      {
        if (text_equals (text, text_len, "normal"))
          parser->current_transform = MTK_MONITOR_TRANSFORM_NORMAL;
        else if (text_equals (text, text_len, "left"))
          parser->current_transform = MTK_MONITOR_TRANSFORM_90;
        else if (text_equals (text, text_len, "upside_down"))
          parser->current_transform = MTK_MONITOR_TRANSFORM_180;
        else if (text_equals (text, text_len, "right"))
          parser->current_transform = MTK_MONITOR_TRANSFORM_270;
        else
          g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_INVALID_CONTENT,
                       "Invalid rotation type %.*s", (int)text_len, text);

        return;
      }

    case STATE_TRANSFORM_FLIPPED:
      {
        read_bool (text, text_len,
                   &parser->current_transform_flipped,
                   error);
        return;
      }

    case STATE_MONITOR_MODE_WIDTH:
      {
        read_int (text, text_len,
                  &parser->current_monitor_mode_spec->width,
                  error);
        return;
      }

    case STATE_MONITOR_MODE_HEIGHT:
      {
        read_int (text, text_len,
                  &parser->current_monitor_mode_spec->height,
                  error);
        return;
      }

    case STATE_MONITOR_MODE_RATE:
      {
        read_float (text, text_len,
                    &parser->current_monitor_mode_spec->refresh_rate,
                    error);
        return;
      }

    case STATE_MONITOR_MODE_RATE_MODE:
      {
        if (text_equals (text, text_len, "fixed"))
          {
            parser->current_monitor_mode_spec->refresh_rate_mode =
              META_CRTC_REFRESH_RATE_MODE_FIXED;
          }
        else if (text_equals (text, text_len, "variable"))
          {
            parser->current_monitor_mode_spec->refresh_rate_mode =
              META_CRTC_REFRESH_RATE_MODE_VARIABLE;
          }
        else
          {
            g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_INVALID_CONTENT,
                         "Invalid refresh rate mode %.*s", (int) text_len, text);
          }

        return;
      }

    case STATE_MONITOR_MODE_FLAG:
      {
        if (text_equals (text, text_len, "interlace"))
          {
            parser->current_monitor_mode_spec->flags |=
              META_CRTC_MODE_FLAG_INTERLACE;
          }
        else
          {
            g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_INVALID_CONTENT,
                         "Invalid mode flag %.*s", (int) text_len, text);
          }

        return;
      }

    case STATE_MONITOR_UNDERSCANNING:
      {
        read_bool (text, text_len,
                   &parser->current_monitor_config->enable_underscanning,
                   error);
        return;
      }

    case STATE_MONITOR_MAXBPC:
      {
        int signed_max_bpc;

        if (read_int (text, text_len, &signed_max_bpc, error))
          {
            if (signed_max_bpc >= 0)
              {
                parser->current_monitor_config->has_max_bpc = TRUE;
                parser->current_monitor_config->max_bpc = signed_max_bpc;
              }
            else
              {
                g_set_error (error, G_MARKUP_ERROR,
                             G_MARKUP_ERROR_INVALID_CONTENT,
                             "Invalid negative maxbpc value \"%s\"",
                             text);
              }
          }

        return;
      }

    case STATE_MONITOR_RGB_RANGE:
      {
        if (text_equals (text, text_len, "auto"))
          parser->current_monitor_config->rgb_range = META_OUTPUT_RGB_RANGE_AUTO;
        else if (text_equals (text, text_len, "full"))
          parser->current_monitor_config->rgb_range = META_OUTPUT_RGB_RANGE_FULL;
        else if (text_equals (text, text_len, "limited"))
          parser->current_monitor_config->rgb_range = META_OUTPUT_RGB_RANGE_LIMITED;
        else
          g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_INVALID_CONTENT,
                       "Invalid RGB Range type %.*s", (int)text_len, text);

        return;
      }

    case STATE_MONITOR_COLOR_MODE:
      {
        if (text_equals (text, text_len, "default"))
          {
            parser->current_monitor_config->color_mode =
              META_COLOR_MODE_DEFAULT;
          }
        else if (text_equals (text, text_len, "bt2100"))
          {
            parser->current_monitor_config->color_mode =
              META_COLOR_MODE_BT2100;
          }
        else
          {
            g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_INVALID_CONTENT,
                         "Invalid color mode %.*s", (int)text_len, text);
          }
        return;
      }

    case STATE_STORE:
      {
        MetaConfigStore store;

        if (parser->pending_store != -1)
          {
            g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_INVALID_CONTENT,
                         "Multiple store strings");
            return;
          }

        if (text_equals (text, text_len, "system"))
          {
            store = META_CONFIG_STORE_SYSTEM;
          }
        else if (text_equals (text, text_len, "user"))
          {
            store = META_CONFIG_STORE_USER;
          }
        else
          {
            g_set_error (error, G_MARKUP_ERROR, G_MARKUP_ERROR_INVALID_CONTENT,
                         "Invalid store %.*s", (int) text_len, text);
            return;
          }

        parser->pending_store = store;
        return;
      }

    case STATE_DBUS:
      {
        parser->enable_dbus_set = TRUE;
        read_bool (text, text_len,
                   &parser->enable_dbus,
                   error);
        return;
      }
    }
}

static const GMarkupParser config_parser = {
  .start_element = handle_start_element,
  .end_element = handle_end_element,
  .text = handle_text
};

static gboolean
read_config_file (MetaMonitorConfigStore  *config_store,
                  GFile                   *file,
                  MetaMonitorsConfigFlag   extra_config_flags,
                  GHashTable             **out_configs,
                  gboolean                *should_update_file,
                  GError                 **error)
{
  char *buffer;
  gsize size;
  ConfigParser parser;
  GMarkupParseContext *parse_context;

  if (!g_file_load_contents (file, NULL, &buffer, &size, NULL, error))
    return FALSE;

  parser = (ConfigParser) {
    .state = STATE_INITIAL,
    .file = file,
    .config_store = config_store,
    .pending_configs = g_hash_table_new_full (meta_monitors_config_key_hash,
                                              meta_monitors_config_key_equal,
                                              NULL,
                                              g_object_unref),
    .extra_config_flags = extra_config_flags,
    .unknown_state_root = -1,
    .pending_store = -1,
    .should_update_file = FALSE
  };

  parse_context = g_markup_parse_context_new (&config_parser,
                                              G_MARKUP_TREAT_CDATA_AS_TEXT |
                                              G_MARKUP_PREFIX_ERROR_POSITION,
                                              &parser, NULL);
  if (!g_markup_parse_context_parse (parse_context, buffer, size, error))
    {
      g_list_free_full (parser.current_logical_monitor_configs,
                        (GDestroyNotify) meta_logical_monitor_config_free);
      g_clear_pointer (&parser.current_monitor_spec,
                       meta_monitor_spec_free);
      g_free (parser.current_monitor_mode_spec);
      g_clear_pointer (&parser.current_monitor_config,
                      meta_monitor_config_free);
      g_clear_pointer (&parser.current_logical_monitor_config,
                       meta_logical_monitor_config_free);
      g_list_free (parser.stores);
      g_hash_table_unref (parser.pending_configs);
      return FALSE;
    }

  *out_configs = g_steal_pointer (&parser.pending_configs);
  *should_update_file = parser.should_update_file;

  g_markup_parse_context_free (parse_context);
  g_free (buffer);

  return TRUE;
}

MetaMonitorsConfig *
meta_monitor_config_store_lookup (MetaMonitorConfigStore *config_store,
                                  MetaMonitorsConfigKey  *key)
{
  return META_MONITORS_CONFIG (g_hash_table_lookup (config_store->configs,
                                                    key));
}

static void
append_monitor_spec (GString         *buffer,
                     MetaMonitorSpec *monitor_spec,
                     const char      *indentation)
{
  char *escaped;

  g_string_append_printf (buffer, "%s<monitorspec>\n", indentation);

  escaped = g_markup_escape_text (monitor_spec->connector, -1);
  g_string_append_printf (buffer, "%s  <connector>%s</connector>\n",
                          indentation,
                          escaped);
  g_free (escaped);

  escaped = g_markup_escape_text (monitor_spec->vendor, -1);
  g_string_append_printf (buffer, "%s  <vendor>%s</vendor>\n",
                          indentation,
                          escaped);
  g_free (escaped);

  escaped = g_markup_escape_text (monitor_spec->product, -1);
  g_string_append_printf (buffer, "%s  <product>%s</product>\n",
                          indentation,
                          escaped);
  g_free (escaped);

  escaped = g_markup_escape_text (monitor_spec->serial, -1);
  g_string_append_printf (buffer, "%s  <serial>%s</serial>\n",
                          indentation,
                          escaped);
  g_free (escaped);

  g_string_append_printf (buffer, "%s</monitorspec>\n", indentation);
}

static void
append_rgb_range (GString            *buffer,
                  MetaOutputRGBRange  rgb_range,
                  const char         *indentation)
{
  const char *rgb_range_str;

  switch (rgb_range)
    {
    case META_OUTPUT_RGB_RANGE_FULL:
      rgb_range_str = "full";
      break;
    case META_OUTPUT_RGB_RANGE_LIMITED:
      rgb_range_str = "limited";
      break;
    default:
      return;
    }

  g_string_append_printf (buffer, "%s<rgbrange>%s</rgbrange>\n",
                          indentation,
                          rgb_range_str);
}

static void
append_color_mode (GString       *buffer,
                   MetaColorMode  rgb_range,
                   const char    *indentation)
{
  const char *color_mode_str;

  switch (rgb_range)
    {
    case META_COLOR_MODE_BT2100:
      color_mode_str = "bt2100";
      break;
    case META_COLOR_MODE_DEFAULT:
    default:
      return;
    }

  g_string_append_printf (buffer, "%s<colormode>%s</colormode>\n",
                          indentation,
                          color_mode_str);
}

static void
append_monitors (GString *buffer,
                 GList   *monitor_configs)
{
  GList *l;

  for (l = monitor_configs; l; l = l->next)
    {
      MetaMonitorConfig *monitor_config = l->data;
      char rate_str[G_ASCII_DTOSTR_BUF_SIZE];

      g_ascii_formatd (rate_str, sizeof (rate_str),
                       "%.3f", monitor_config->mode_spec->refresh_rate);

      g_string_append (buffer, "      <monitor>\n");
      append_monitor_spec (buffer, monitor_config->monitor_spec, "        ");
      g_string_append (buffer, "        <mode>\n");
      g_string_append_printf (buffer, "          <width>%d</width>\n",
                              monitor_config->mode_spec->width);
      g_string_append_printf (buffer, "          <height>%d</height>\n",
                              monitor_config->mode_spec->height);
      g_string_append_printf (buffer, "          <rate>%s</rate>\n",
                              rate_str);
      if (monitor_config->mode_spec->refresh_rate_mode ==
          META_CRTC_REFRESH_RATE_MODE_VARIABLE)
        g_string_append_printf (buffer, "          <ratemode>variable</ratemode>\n");
      if (monitor_config->mode_spec->flags & META_CRTC_MODE_FLAG_INTERLACE)
        g_string_append_printf (buffer, "          <flag>interlace</flag>\n");
      g_string_append (buffer, "        </mode>\n");
      if (monitor_config->enable_underscanning)
        g_string_append (buffer, "        <underscanning>yes</underscanning>\n");
      append_rgb_range (buffer, monitor_config->rgb_range, "        ");
      append_color_mode (buffer, monitor_config->color_mode, "        ");

      if (monitor_config->has_max_bpc)
        {
          g_string_append_printf (buffer, "        <maxbpc>%u</maxbpc>\n",
                                  monitor_config->max_bpc);
        }
      g_string_append (buffer, "      </monitor>\n");
    }
}

static const char *
bool_to_string (gboolean value)
{
  return value ? "yes" : "no";
}

static void
append_transform (GString             *buffer,
                  MtkMonitorTransform  transform)
{
  const char *rotation = NULL;
  gboolean flipped = FALSE;

  switch (transform)
    {
    case MTK_MONITOR_TRANSFORM_NORMAL:
      return;
    case MTK_MONITOR_TRANSFORM_90:
      rotation = "left";
      break;
    case MTK_MONITOR_TRANSFORM_180:
      rotation = "upside_down";
      break;
    case MTK_MONITOR_TRANSFORM_270:
      rotation = "right";
      break;
    case MTK_MONITOR_TRANSFORM_FLIPPED:
      rotation = "normal";
      flipped = TRUE;
      break;
    case MTK_MONITOR_TRANSFORM_FLIPPED_90:
      rotation = "left";
      flipped = TRUE;
      break;
    case MTK_MONITOR_TRANSFORM_FLIPPED_180:
      rotation = "upside_down";
      flipped = TRUE;
      break;
    case MTK_MONITOR_TRANSFORM_FLIPPED_270:
      rotation = "right";
      flipped = TRUE;
      break;
    }

  g_string_append (buffer, "      <transform>\n");
  g_string_append_printf (buffer, "        <rotation>%s</rotation>\n",
                          rotation);
  g_string_append_printf (buffer, "        <flipped>%s</flipped>\n",
                          bool_to_string (flipped));
  g_string_append (buffer, "      </transform>\n");
}

static void
append_logical_monitor_xml (GString                  *buffer,
                            MetaMonitorsConfig       *config,
                            MetaLogicalMonitorConfig *logical_monitor_config)
{
  char scale_str[G_ASCII_DTOSTR_BUF_SIZE];

  g_string_append (buffer, "    <logicalmonitor>\n");
  g_string_append_printf (buffer, "      <x>%d</x>\n",
                          logical_monitor_config->layout.x);
  g_string_append_printf (buffer, "      <y>%d</y>\n",
                          logical_monitor_config->layout.y);
  g_ascii_dtostr (scale_str, G_ASCII_DTOSTR_BUF_SIZE,
                  logical_monitor_config->scale);
  g_string_append_printf (buffer, "      <scale>%s</scale>\n",
                          scale_str);
  if (logical_monitor_config->is_primary)
    g_string_append (buffer, "      <primary>yes</primary>\n");
  if (logical_monitor_config->is_presentation)
    g_string_append (buffer, "      <presentation>yes</presentation>\n");
  append_transform (buffer, logical_monitor_config->transform);
  append_monitors (buffer, logical_monitor_config->monitor_configs);
  g_string_append (buffer, "    </logicalmonitor>\n");
}

static GString *
generate_config_xml (MetaMonitorConfigStore *config_store)
{
  GString *buffer;
  GHashTableIter iter;
  MetaMonitorsConfig *config;

  buffer = g_string_new ("");
  g_string_append_printf (buffer, "<monitors version=\"%d\">\n",
                          MONITORS_CONFIG_XML_FORMAT_VERSION);

  g_hash_table_iter_init (&iter, config_store->configs);
  while (g_hash_table_iter_next (&iter, NULL, (gpointer *) &config))
    {
      GList *l;

      if (config->flags & META_MONITORS_CONFIG_FLAG_SYSTEM_CONFIG)
        continue;

      g_string_append (buffer, "  <configuration>\n");

      switch (config->layout_mode)
        {
        case META_LOGICAL_MONITOR_LAYOUT_MODE_LOGICAL:
          g_string_append (buffer, "    <layoutmode>logical</layoutmode>\n");
          break;
        case META_LOGICAL_MONITOR_LAYOUT_MODE_PHYSICAL:
          g_string_append (buffer, "    <layoutmode>physical</layoutmode>\n");
          break;
        }

      for (l = config->logical_monitor_configs; l; l = l->next)
        {
          MetaLogicalMonitorConfig *logical_monitor_config = l->data;

          append_logical_monitor_xml (buffer, config, logical_monitor_config);
        }

      if (config->disabled_monitor_specs)
        {
          g_string_append (buffer, "    <disabled>\n");
          for (l = config->disabled_monitor_specs; l; l = l->next)
            {
              MetaMonitorSpec *monitor_spec = l->data;

              append_monitor_spec (buffer, monitor_spec, "      ");
            }
          g_string_append (buffer, "    </disabled>\n");
        }

      if (config->for_lease_monitor_specs)
        {
          g_string_append (buffer, "    <forlease>\n");
          for (l = config->for_lease_monitor_specs; l; l = l->next)
            {
              MetaMonitorSpec *monitor_spec = l->data;

              append_monitor_spec (buffer, monitor_spec, "      ");
            }
          g_string_append (buffer, "    </forlease>\n");
        }

      g_string_append (buffer, "  </configuration>\n");
    }

  g_string_append (buffer, "</monitors>\n");

  return buffer;
}

typedef struct _SaveData
{
  MetaMonitorConfigStore *config_store;
  GString *buffer;
} SaveData;

static void
saved_cb (GObject      *object,
          GAsyncResult *result,
          gpointer      user_data)
{
  SaveData *data = user_data;
  GError *error = NULL;

  if (!g_file_replace_contents_finish (G_FILE (object), result, NULL, &error))
    {
      if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
        {
          g_warning ("Saving monitor configuration failed: %s", error->message);
          g_clear_object (&data->config_store->save_cancellable);
        }

      g_error_free (error);
    }
  else
    {
      g_clear_object (&data->config_store->save_cancellable);
    }

  g_clear_object (&data->config_store);
  g_string_free (data->buffer, TRUE);
  g_free (data);
}

static void
meta_monitor_config_store_save_sync (MetaMonitorConfigStore *config_store)
{
  GError *error = NULL;
  GFile *file;
  GString *buffer;

  if (config_store->custom_write_file)
    file = config_store->custom_write_file;
  else
    file = config_store->user_file;

  buffer = generate_config_xml (config_store);

  if (!g_file_replace_contents (file,
                                buffer->str, buffer->len,
                                NULL,
                                FALSE,
                                G_FILE_CREATE_REPLACE_DESTINATION,
                                NULL,
                                NULL,
                                &error))
    {
      g_warning ("Saving monitor configuration failed: %s",
                 error->message);
      g_error_free (error);
    }

  g_string_free (buffer, TRUE);
}

static void
meta_monitor_config_store_save (MetaMonitorConfigStore *config_store)
{
  GString *buffer;
  SaveData *data;

  if (config_store->save_cancellable)
    {
      g_cancellable_cancel (config_store->save_cancellable);
      g_clear_object (&config_store->save_cancellable);
    }

  /*
   * Custom write file is only ever used by the test suite, and the test suite
   * will want to have be able to read back the content immediately, so for
   * custom write files, do the content replacement synchronously.
   */
  if (config_store->custom_write_file)
    {
      meta_monitor_config_store_save_sync (config_store);
      return;
    }

  if (config_store->has_stores_policy &&
      !g_list_find (config_store->stores_policy,
                    GINT_TO_POINTER (META_CONFIG_STORE_USER)))
    return;

  config_store->save_cancellable = g_cancellable_new ();

  buffer = generate_config_xml (config_store);

  data = g_new0 (SaveData, 1);
  *data = (SaveData) {
    .config_store = g_object_ref (config_store),
    .buffer = buffer
  };

  g_file_replace_contents_async (config_store->user_file,
                                 buffer->str, buffer->len,
                                 NULL,
                                 TRUE,
                                 G_FILE_CREATE_REPLACE_DESTINATION,
                                 config_store->save_cancellable,
                                 saved_cb, data);
}

static void
maybe_save_configs (MetaMonitorConfigStore *config_store)
{
  /*
   * If a custom file is used, it means we are run by the test suite. When this
   * is done, avoid replacing the user configuration file with test data,
   * except if a custom write file is set as well.
   */
  if (!config_store->custom_read_file || config_store->custom_write_file)
    meta_monitor_config_store_save (config_store);
}

static gboolean
is_system_config (MetaMonitorsConfig *config)
{
  return !!(config->flags & META_MONITORS_CONFIG_FLAG_SYSTEM_CONFIG);
}

void
meta_monitor_config_store_add (MetaMonitorConfigStore *config_store,
                               MetaMonitorsConfig     *config)
{
  g_hash_table_replace (config_store->configs,
                        config->key, g_object_ref (config));

  if (!is_system_config (config))
    maybe_save_configs (config_store);
}

void
meta_monitor_config_store_remove (MetaMonitorConfigStore *config_store,
                                  MetaMonitorsConfig     *config)
{
  g_hash_table_remove (config_store->configs, config->key);

  if (!is_system_config (config))
    maybe_save_configs (config_store);
}

gboolean
meta_monitor_config_store_set_custom (MetaMonitorConfigStore  *config_store,
                                      const char              *read_path,
                                      const char              *write_path,
                                      MetaMonitorsConfigFlag   config_flags,
                                      GError                 **error)
{
  GHashTable *new_configs = NULL;
  gboolean should_save_configs = FALSE;

  g_clear_object (&config_store->custom_read_file);
  g_clear_object (&config_store->custom_write_file);

  config_store->custom_read_file = g_file_new_for_path (read_path);
  if (write_path)
    config_store->custom_write_file = g_file_new_for_path (write_path);

  g_clear_pointer (&config_store->stores_policy, g_list_free);
  config_store->has_stores_policy = FALSE;
  config_store->policy.enable_dbus = TRUE;
  config_store->has_dbus_policy = FALSE;

  if (!read_config_file (config_store,
                         config_store->custom_read_file,
                         config_flags,
                         &new_configs,
                         &should_save_configs,
                         error))
    return FALSE;

  g_clear_pointer (&config_store->configs, g_hash_table_unref);
  config_store->configs = g_steal_pointer (&new_configs);

  if (should_save_configs)
    maybe_save_configs (config_store);

  return TRUE;
}

int
meta_monitor_config_store_get_config_count (MetaMonitorConfigStore *config_store)
{
  return (int) g_hash_table_size (config_store->configs);
}

GList *
meta_monitor_config_store_get_stores_policy (MetaMonitorConfigStore *config_store)
{
  return config_store->stores_policy;
}

MetaMonitorManager *
meta_monitor_config_store_get_monitor_manager (MetaMonitorConfigStore *config_store)
{
  return config_store->monitor_manager;
}

MetaMonitorConfigStore *
meta_monitor_config_store_new (MetaMonitorManager *monitor_manager)
{
  return g_object_new (META_TYPE_MONITOR_CONFIG_STORE,
                       "monitor-manager", monitor_manager,
                       NULL);
}

static void
meta_monitor_config_store_constructed (GObject *object)
{
  MetaMonitorConfigStore *config_store = META_MONITOR_CONFIG_STORE (object);

  meta_monitor_config_store_reset (config_store);

  G_OBJECT_CLASS (meta_monitor_config_store_parent_class)->constructed (object);
}

static void
meta_monitor_config_store_dispose (GObject *object)
{
  MetaMonitorConfigStore *config_store = META_MONITOR_CONFIG_STORE (object);

  if (config_store->save_cancellable)
    {
      g_cancellable_cancel (config_store->save_cancellable);
      g_clear_object (&config_store->save_cancellable);

      meta_monitor_config_store_save_sync (config_store);
    }

  g_clear_pointer (&config_store->configs, g_hash_table_destroy);

  g_clear_object (&config_store->user_file);
  g_clear_object (&config_store->custom_read_file);
  g_clear_object (&config_store->custom_write_file);
  g_clear_pointer (&config_store->stores_policy, g_list_free);

  G_OBJECT_CLASS (meta_monitor_config_store_parent_class)->dispose (object);
}

static void
meta_monitor_config_store_get_property (GObject    *object,
                                        guint       prop_id,
                                        GValue     *value,
                                        GParamSpec *pspec)
{
  MetaMonitorConfigStore *config_store = META_MONITOR_CONFIG_STORE (object);

  switch (prop_id)
    {
    case PROP_MONITOR_MANAGER:
      g_value_set_object (value, &config_store->monitor_manager);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
    }
}

static void
meta_monitor_config_store_set_property (GObject      *object,
                                        guint         prop_id,
                                        const GValue *value,
                                        GParamSpec   *pspec)
{
  MetaMonitorConfigStore *config_store = META_MONITOR_CONFIG_STORE (object);

  switch (prop_id)
    {
    case PROP_MONITOR_MANAGER:
      config_store->monitor_manager = g_value_get_object (value);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
    }
}

static void
meta_monitor_config_store_init (MetaMonitorConfigStore *config_store)
{
  config_store->configs = g_hash_table_new_full (meta_monitors_config_key_hash,
                                                 meta_monitors_config_key_equal,
                                                 NULL,
                                                 g_object_unref);
  config_store->policy.enable_dbus = TRUE;
}

static void
meta_monitor_config_store_class_init (MetaMonitorConfigStoreClass *klass)
{
  GObjectClass *object_class = G_OBJECT_CLASS (klass);

  object_class->constructed = meta_monitor_config_store_constructed;
  object_class->dispose = meta_monitor_config_store_dispose;
  object_class->get_property = meta_monitor_config_store_get_property;
  object_class->set_property = meta_monitor_config_store_set_property;

  obj_props[PROP_MONITOR_MANAGER] =
    g_param_spec_object ("monitor-manager", NULL, NULL,
                         META_TYPE_MONITOR_MANAGER,
                         G_PARAM_READWRITE |
                         G_PARAM_STATIC_STRINGS |
                         G_PARAM_CONSTRUCT_ONLY);

  g_object_class_install_properties (object_class, PROP_LAST, obj_props);
}

static void
replace_configs (MetaMonitorConfigStore *config_store,
                 GHashTable             *configs)
{
  GHashTableIter iter;
  MetaMonitorsConfigKey *key;
  MetaMonitorsConfig *config;

  g_hash_table_iter_init (&iter, configs);
  while (g_hash_table_iter_next (&iter,
                                 (gpointer *) &key,
                                 (gpointer *) &config))
    {
      g_hash_table_iter_steal (&iter);
      g_hash_table_replace (config_store->configs, key, config);
    }
}

void
meta_monitor_config_store_reset (MetaMonitorConfigStore *config_store)
{
  g_autoptr (GHashTable) system_configs = NULL;
  g_autoptr (GHashTable) user_configs = NULL;
  const char * const *system_dirs;
  char *user_file_path;
  GError *error = NULL;
  gboolean should_save_configs = FALSE;

  g_clear_object (&config_store->user_file);
  g_clear_object (&config_store->custom_read_file);
  g_clear_object (&config_store->custom_write_file);
  g_hash_table_remove_all (config_store->configs);

  for (system_dirs = g_get_system_config_dirs ();
       system_dirs && *system_dirs;
       system_dirs++)
    {
      g_autofree char *system_file_path = NULL;

      system_file_path = g_build_filename (*system_dirs, "monitors.xml", NULL);
      if (g_file_test (system_file_path, G_FILE_TEST_EXISTS))
        {
          g_autoptr (GFile) system_file = NULL;

          system_file = g_file_new_for_path (system_file_path);
          if (!read_config_file (config_store,
                                 system_file,
                                 META_MONITORS_CONFIG_FLAG_SYSTEM_CONFIG,
                                 &system_configs,
                                 &should_save_configs,
                                 &error))
            {
              g_warning ("Failed to read monitors config file '%s': %s",
                         system_file_path, error->message);
              g_clear_error (&error);
            }

          if (should_save_configs)
            {
              g_warning ("System monitor configuration file (%s) needs "
                         "updating; ask your administrator to migrate "
                         "the system monitor configuration.",
                         system_file_path);
              should_save_configs = FALSE;
            }
        }
    }

  user_file_path = g_build_filename (g_get_user_config_dir (),
                                     "monitors.xml",
                                     NULL);
  config_store->user_file = g_file_new_for_path (user_file_path);

  if (g_file_test (user_file_path, G_FILE_TEST_EXISTS))
    {
      if (!read_config_file (config_store,
                             config_store->user_file,
                             META_MONITORS_CONFIG_FLAG_NONE,
                             &user_configs,
                             &should_save_configs,
                             &error))
        {
          g_warning ("Failed to read monitors config file '%s': %s",
                     user_file_path, error->message);
          g_error_free (error);
        }
    }

  if (config_store->has_stores_policy)
    {
      GList *l;

      for (l = g_list_last (config_store->stores_policy); l; l = l->prev)
        {
          MetaConfigStore store = GPOINTER_TO_INT (l->data);

          switch (store)
            {
            case META_CONFIG_STORE_SYSTEM:
              if (system_configs)
                replace_configs (config_store, system_configs);
              break;
            case META_CONFIG_STORE_USER:
              if (user_configs)
                replace_configs (config_store, user_configs);
            }
        }
    }
  else
    {
      if (system_configs)
        replace_configs (config_store, system_configs);
      if (user_configs)
        replace_configs (config_store, user_configs);
    }

  if (should_save_configs)
    maybe_save_configs (config_store);

  g_free (user_file_path);
}

const MetaMonitorConfigPolicy *
meta_monitor_config_store_get_policy (MetaMonitorConfigStore *config_store)
{
  return &config_store->policy;
}
