// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "include/file_selector_linux/file_selector_plugin.h"

#include <flutter_linux/flutter_linux.h>
#include <gtk/gtk.h>

#include "file_selector_plugin_private.h"
#include "messages.g.h"

// Error codes.
const char kBadArgumentsError[] = "Bad Arguments";
const char kNoScreenError[] = "No Screen";

struct _FlFileSelectorPlugin {
  GObject parent_instance;

  FlPluginRegistrar* registrar;
};

G_DEFINE_TYPE(FlFileSelectorPlugin, fl_file_selector_plugin, G_TYPE_OBJECT)

// Converts a type group received from Flutter into a GTK file filter.
static GtkFileFilter* type_group_to_filter(FfsPlatformTypeGroup* group) {
  g_autoptr(GtkFileFilter) filter = gtk_file_filter_new();

  const gchar* label = ffs_platform_type_group_get_label(group);
  gtk_file_filter_set_name(filter, label);

  FlValue* extensions = ffs_platform_type_group_get_extensions(group);
  for (size_t i = 0; i < fl_value_get_length(extensions); i++) {
    FlValue* v = fl_value_get_list_value(extensions, i);
    const gchar* pattern = fl_value_get_string(v);
    gtk_file_filter_add_pattern(filter, pattern);
  }
  FlValue* mime_types = ffs_platform_type_group_get_mime_types(group);
  for (size_t i = 0; i < fl_value_get_length(mime_types); i++) {
    FlValue* v = fl_value_get_list_value(mime_types, i);
    const gchar* pattern = fl_value_get_string(v);
    gtk_file_filter_add_mime_type(filter, pattern);
  }

  return GTK_FILE_FILTER(g_object_ref(filter));
}

// Creates a GtkFileChooserNative for the given method call details.
static GtkFileChooserNative* create_dialog(
    GtkWindow* window, GtkFileChooserAction action, const gchar* title,
    const gchar* default_confirm_button_text,
    FfsPlatformFileChooserOptions* options) {
  const gchar* confirm_button_text =
      ffs_platform_file_chooser_options_get_accept_button_label(options);
  if (confirm_button_text == nullptr) {
    confirm_button_text = default_confirm_button_text;
  }

  g_autoptr(GtkFileChooserNative) dialog =
      GTK_FILE_CHOOSER_NATIVE(gtk_file_chooser_native_new(
          title, window, action, confirm_button_text, "_Cancel"));

  const gboolean* select_multiple =
      ffs_platform_file_chooser_options_get_select_multiple(options);
  if (select_multiple != nullptr) {
    gtk_file_chooser_set_select_multiple(GTK_FILE_CHOOSER(dialog),
                                         *select_multiple);
  }

  const gchar* current_folder =
      ffs_platform_file_chooser_options_get_current_folder_path(options);
  if (current_folder != nullptr) {
    gtk_file_chooser_set_current_folder(GTK_FILE_CHOOSER(dialog),
                                        current_folder);
  }

  const gchar* current_name =
      ffs_platform_file_chooser_options_get_current_name(options);
  if (current_name != nullptr) {
    gtk_file_chooser_set_current_name(GTK_FILE_CHOOSER(dialog), current_name);
  }

  FlValue* type_groups =
      ffs_platform_file_chooser_options_get_allowed_file_types(options);
  if (type_groups != nullptr) {
    for (size_t i = 0; i < fl_value_get_length(type_groups); i++) {
      FlValue* type_group = fl_value_get_list_value(type_groups, i);
      GtkFileFilter* filter = type_group_to_filter(FFS_PLATFORM_TYPE_GROUP(
          fl_value_get_custom_value_object(type_group)));
      if (filter == nullptr) {
        return nullptr;
      }
      gtk_file_chooser_add_filter(GTK_FILE_CHOOSER(dialog), filter);
    }
  }

  return GTK_FILE_CHOOSER_NATIVE(g_object_ref(dialog));
}

GtkFileChooserNative* create_dialog_of_type(
    GtkWindow* window, FfsPlatformFileChooserActionType type,
    FfsPlatformFileChooserOptions* options) {
  switch (type) {
    case FILE_SELECTOR_LINUX_PLATFORM_FILE_CHOOSER_ACTION_TYPE_OPEN:
      return create_dialog(window, GTK_FILE_CHOOSER_ACTION_OPEN, "Open File",
                           "_Open", options);
    case FILE_SELECTOR_LINUX_PLATFORM_FILE_CHOOSER_ACTION_TYPE_CHOOSE_DIRECTORY:
      return create_dialog(window, GTK_FILE_CHOOSER_ACTION_SELECT_FOLDER,
                           "Choose Directory", "_Open", options);
    case FILE_SELECTOR_LINUX_PLATFORM_FILE_CHOOSER_ACTION_TYPE_SAVE:
      return create_dialog(window, GTK_FILE_CHOOSER_ACTION_SAVE, "Save File",
                           "_Save", options);
  }
  return nullptr;
}

// Shows the requested dialog type.
static FfsFileSelectorApiShowFileChooserResponse* handle_show_file_chooser(
    FfsPlatformFileChooserActionType type,
    FfsPlatformFileChooserOptions* options, gpointer user_data) {
  FlFileSelectorPlugin* self = FL_FILE_SELECTOR_PLUGIN(user_data);

  FlView* view = fl_plugin_registrar_get_view(self->registrar);
  if (view == nullptr) {
    return ffs_file_selector_api_show_file_chooser_response_new_error(
        kNoScreenError, nullptr, nullptr);
  }
  GtkWindow* window = GTK_WINDOW(gtk_widget_get_toplevel(GTK_WIDGET(view)));

  g_autoptr(GtkFileChooserNative) dialog =
      create_dialog_of_type(window, type, options);

  if (dialog == nullptr) {
    return ffs_file_selector_api_show_file_chooser_response_new_error(
        kBadArgumentsError, "Unable to create dialog from arguments", nullptr);
  }

  gint response = gtk_native_dialog_run(GTK_NATIVE_DIALOG(dialog));
  g_autoptr(FlValue) result = nullptr;
  if (response == GTK_RESPONSE_ACCEPT) {
    result = fl_value_new_list();
    g_autoptr(GSList) filenames =
        gtk_file_chooser_get_filenames(GTK_FILE_CHOOSER(dialog));
    for (GSList* link = filenames; link != nullptr; link = link->next) {
      g_autofree gchar* filename = static_cast<gchar*>(link->data);
      fl_value_append_take(result, fl_value_new_string(filename));
    }
  }

  return ffs_file_selector_api_show_file_chooser_response_new(result);
}

static void fl_file_selector_plugin_dispose(GObject* object) {
  FlFileSelectorPlugin* self = FL_FILE_SELECTOR_PLUGIN(object);

  ffs_file_selector_api_clear_method_handlers(
      fl_plugin_registrar_get_messenger(self->registrar), nullptr);
  g_clear_object(&self->registrar);

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

static void fl_file_selector_plugin_class_init(
    FlFileSelectorPluginClass* klass) {
  G_OBJECT_CLASS(klass)->dispose = fl_file_selector_plugin_dispose;
}

static void fl_file_selector_plugin_init(FlFileSelectorPlugin* self) {}

FlFileSelectorPlugin* fl_file_selector_plugin_new(
    FlPluginRegistrar* registrar) {
  FlFileSelectorPlugin* self = FL_FILE_SELECTOR_PLUGIN(
      g_object_new(fl_file_selector_plugin_get_type(), nullptr));

  self->registrar = FL_PLUGIN_REGISTRAR(g_object_ref(registrar));

  static FfsFileSelectorApiVTable api_vtable = {
      .show_file_chooser = handle_show_file_chooser,
  };
  ffs_file_selector_api_set_method_handlers(
      fl_plugin_registrar_get_messenger(registrar), nullptr, &api_vtable,
      g_object_ref(self), g_object_unref);

  return self;
}

void file_selector_plugin_register_with_registrar(
    FlPluginRegistrar* registrar) {
  FlFileSelectorPlugin* plugin = fl_file_selector_plugin_new(registrar);
  g_object_unref(plugin);
}