/*
 * Copyright (C) 2012 - Juan Ferrer Toribio
 *
 * 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 3 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 "vn-handler.h"

#define ACTION_GROUP_NAME "handler"

G_DEFINE_TYPE (VnHandler, vn_handler, GTK_TYPE_BIN);

/**
 * vn_handler_new:
 * 
 * Creates a new handler
 *
 * Return value: #GtkWidget created.  
 **/
GtkWidget * vn_handler_new ()
{
	return g_object_new (VN_TYPE_HANDLER, NULL);
}

/**
 * vn_handler_new_with_form:
 * @form: #DbIterator where the handler will be created
 * 
 * Creates a new handler into a iterator gived
 *
 * Return value: #GtkWidget created.  
 **/
GtkWidget * vn_handler_new_with_iterator (DbIterator * iterator)
{
	return g_object_new (VN_TYPE_HANDLER, "iterator", iterator, NULL);
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Private

static gboolean vn_handler_dialog (VnHandler * obj, gchar * message)
{
	GtkWidget * toplevel = gtk_widget_get_toplevel (GTK_WIDGET (obj)),
		* dialog = gtk_message_dialog_new (GTK_WINDOW (toplevel)
		,GTK_DIALOG_MODAL | GTK_DIALOG_DESTROY_WITH_PARENT
		,GTK_MESSAGE_QUESTION
		,GTK_BUTTONS_OK_CANCEL
		,"%s"
		,message
	);
	gint response = gtk_dialog_run (GTK_DIALOG (dialog));
	gtk_widget_destroy (dialog);
	return response == GTK_RESPONSE_OK;
}

static void vn_handler_on_add_activated (GSimpleAction * a, GVariant * p, gpointer obj)
{
	db_iterator_insert (VN_HANDLER (obj)->iterator);
}

static void vn_handler_on_remove_activated (GSimpleAction * a, GVariant * p, gpointer obj)
{
	if (db_iterator_get_mode (VN_HANDLER (obj)->iterator) == DB_ITERATOR_MODE_ON_DEMAND
	|| vn_handler_dialog (obj, _("Are you sure you want to delete the current selection?")))
		db_iterator_delete (VN_HANDLER (obj)->iterator);
}

static void vn_handler_on_save_activated (GSimpleAction * a, GVariant * p, gpointer obj)
{
	if (db_iterator_get_mode (VN_HANDLER (obj)->iterator) != DB_ITERATOR_MODE_ON_DEMAND)
		db_iterator_perform_operations (VN_HANDLER (obj)->iterator);
	else if (vn_handler_dialog (obj, _("Are you sure you want to save the changes?")))
		db_iterator_perform_operations (VN_HANDLER (obj)->iterator);
}

static void vn_handler_on_undo_activated (GSimpleAction * a, GVariant * p, gpointer obj)
{
	if (vn_handler_dialog (obj, _("Are you sure you want to undo all changes?")))
		db_iterator_reverse_operations (VN_HANDLER (obj)->iterator);
}

static void vn_handler_on_refresh_activated (GSimpleAction * a, GVariant * p, gpointer obj)
{
	db_iterator_refresh (VN_HANDLER (obj)->iterator);
}

static void vn_handler_on_move_activated (GSimpleAction * action, GVariant * p, gpointer o)
{
	VnHandler * obj = o;
	DbIteratorMove move;

	if (action == obj->move_previous)
		move = DB_ITERATOR_MOVE_PREVIOUS;
	else if (action == obj->move_next)
		move = DB_ITERATOR_MOVE_NEXT;
	else if (action == obj->move_last)
		move = DB_ITERATOR_MOVE_LAST;
	else
		move = DB_ITERATOR_MOVE_FIRST;

	db_iterator_move_to (obj->iterator, move);
}

static void vn_handler_refresh_save_undo_status (VnHandler * obj)
{
	gboolean enabled = obj->iterator
		&& db_iterator_has_pending_operations (obj->iterator);

	if (obj->show_flags & VN_HANDLER_SHOW_SAVE)
		g_simple_action_set_enabled (obj->save, enabled);

	if (obj->show_flags & VN_HANDLER_SHOW_UNDO)
		g_simple_action_set_enabled (obj->undo, enabled);
}

static void vn_handler_refresh_scroll_status (VnHandler * obj)
{
	if (obj->show_flags & VN_HANDLER_SHOW_SCROLL)
	{
		gboolean enabled;
		gint row = db_iterator_get_row (obj->iterator);
	
		enabled = row > 0;
		g_simple_action_set_enabled (obj->move_first, enabled);
		g_simple_action_set_enabled (obj->move_previous, enabled);

		enabled = row != -1 && row < db_iterator_get_nrows (obj->iterator) - 1;
		g_simple_action_set_enabled (obj->move_next, enabled);
		g_simple_action_set_enabled (obj->move_last, enabled);
	}
}

static void vn_handler_on_data_changed (DbIterator * iterator, VnHandler * obj)
{
	if (obj->show_flags & VN_HANDLER_SHOW_ADD)
	{
		gboolean enabled =
			db_iterator_get_update_flags (iterator) & DB_MODEL_INSERT
			&& (db_iterator_get_nrows (iterator) < 1 || !obj->simple_record);

		g_simple_action_set_enabled (obj->add, enabled);
	}

	vn_handler_refresh_save_undo_status (obj);
	vn_handler_refresh_scroll_status (obj);
}

static void vn_handler_on_row_num_changed (DbIterator * iterator, VnHandler * obj)
{
	if (obj->show_flags & VN_HANDLER_SHOW_REMOVE)
	{
		gboolean enabled =
			db_iterator_get_update_flags (iterator) & DB_MODEL_DELETE
			&& db_iterator_get_nrows (iterator) > 0;

		g_simple_action_set_enabled (obj->remove, enabled);
	}

	vn_handler_refresh_scroll_status (obj);
}

static void vn_handler_on_operations_done (DbIterator * iterator, VnHandler * obj)
{
	vn_handler_refresh_save_undo_status (obj);
}

static void action_group_set_enabled (GActionGroup * group, gboolean enabled)
{
	gint i;
	gchar ** actions = g_action_group_list_actions (group);

	for (i = 0; actions[i]; i++)
	{
		GAction * a = g_action_map_lookup_action (G_ACTION_MAP (group), actions[i]);
		g_simple_action_set_enabled (G_SIMPLE_ACTION (a), enabled);
	}
}

static void vn_handler_on_status_changed (DbIterator * iterator, gboolean ready, VnHandler * obj)
{
	action_group_set_enabled (obj->group, ready);
	vn_handler_on_row_num_changed (iterator, obj);
	vn_handler_on_data_changed (iterator, obj);
}

static void vn_handler_refresh_status (VnHandler * obj)
{
	if (!obj->iterator)
		action_group_set_enabled (obj->group, FALSE);
	else
		vn_handler_on_status_changed (obj->iterator,
			db_iterator_is_ready (obj->iterator), obj);
}

static struct
{
	gchar * icon;
	gchar * tooltip;
}
actions_data[] =
{
	{
		 "edit-undo-symbolic"
		,N_("Undo changes")
	},{
		 "document-save-symbolic"
		,N_("Save changes")
	},{
		 "view-refresh-symbolic"
		,N_("Refresh data")
	},{
		 "list-remove-symbolic"
		,N_("Remove record")
	},{
		 "list-add-symbolic"
		,N_("Add record")
	},{
		 "go-first-symbolic"
		,N_("Move to the first row")
	},{
		 "go-previous-symbolic"
		,N_("Move to the previous row")
	},{
		 "go-next-symbolic"
		,N_("Move to the next row")
	},{
		 "go-last-symbolic"
		,N_("Move to the last row")
	}
};

static VnHandlerShowFlags entries_flags[] =
{
	 VN_HANDLER_SHOW_UNDO
	,VN_HANDLER_SHOW_SAVE
	,VN_HANDLER_SHOW_REFRESH
	,VN_HANDLER_SHOW_REMOVE
	,VN_HANDLER_SHOW_ADD
	,VN_HANDLER_SHOW_SCROLL
	,VN_HANDLER_SHOW_SCROLL
	,VN_HANDLER_SHOW_SCROLL
	,VN_HANDLER_SHOW_SCROLL
};

static GActionEntry entries[] =
{
	{
		 "undo"
		,vn_handler_on_undo_activated
	},{
		 "save"
		,vn_handler_on_save_activated
	},{
		 "refresh"
		,vn_handler_on_refresh_activated
	},{
		 "remove"
		,vn_handler_on_remove_activated
	},{
		 "add"
		,vn_handler_on_add_activated
	},{
		 "move-first"
		,vn_handler_on_move_activated
	},{
		 "move-previous"
		,vn_handler_on_move_activated
	},{
		 "move-next"
		,vn_handler_on_move_activated
	},{
		 "move-last"
		,vn_handler_on_move_activated
	}
};

static guint n_entries = G_N_ELEMENTS (entries);

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Public

/**
 * vn_handler_set_show_flags:
 * @obj: a #VnHandler
 * @show_flags: the buttons to be shown
 * 
 * Sets the buttons that will be shown on the interface.
 **/
void vn_handler_set_show_flags (VnHandler * obj, VnHandlerShowFlags show_flags)
{
	gint i;
	GList * list = gtk_container_get_children (GTK_CONTAINER (obj->buttons)),
		* l = list;
	obj->show_flags = show_flags;

	for (i = 0; i < n_entries && l; i++)
	{
		GtkWidget * button = l->data;

		if (obj->show_flags & entries_flags[i])
			gtk_widget_show (button);
		else
			gtk_widget_hide (button);

		l = l->next;
	}

	if (obj->show_flags & VN_HANDLER_SHOW_ADD)
		obj->add = G_SIMPLE_ACTION (g_action_map_lookup_action (G_ACTION_MAP (obj->group), "add"));

	if (obj->show_flags & VN_HANDLER_SHOW_REMOVE)
		obj->remove = G_SIMPLE_ACTION (g_action_map_lookup_action (G_ACTION_MAP (obj->group), "remove"));

	if (obj->show_flags & VN_HANDLER_SHOW_SAVE)
		obj->save = G_SIMPLE_ACTION (g_action_map_lookup_action (G_ACTION_MAP (obj->group), "save"));

	if (obj->show_flags & VN_HANDLER_SHOW_UNDO)
		obj->undo = G_SIMPLE_ACTION (g_action_map_lookup_action (G_ACTION_MAP (obj->group), "undo"));

	if (obj->show_flags & VN_HANDLER_SHOW_SCROLL)
	{
		obj->move_first = G_SIMPLE_ACTION (g_action_map_lookup_action (G_ACTION_MAP (obj->group), "move-first"));
		obj->move_previous = G_SIMPLE_ACTION (g_action_map_lookup_action (G_ACTION_MAP (obj->group), "move-previous"));
		obj->move_next = G_SIMPLE_ACTION (g_action_map_lookup_action (G_ACTION_MAP (obj->group), "move-next"));
		obj->move_last = G_SIMPLE_ACTION (g_action_map_lookup_action (G_ACTION_MAP (obj->group), "move-last"));
	}

	vn_handler_refresh_status (obj);
}

/**
 * vn_handler_get_iterator:
 * @obj: a #VnHandler
 * 
 * Gets the iterator handled by #VnHandler
 *
 * Return value: (transfer none) (allow-none): the #DbIterator
 **/
DbIterator * vn_handler_get_iterator (VnHandler * obj)
{
	return obj->iterator;
}

/**
 * vn_handler_set_iterator:
 * @obj: a #VnHandler
 * @iterator: the iterator to be handled
 * 
 * Sets the iterator handled by #VnHandler
 **/
void vn_handler_set_iterator (VnHandler * obj, DbIterator * iterator)
{
	g_return_if_fail (VN_IS_HANDLER (obj));
	g_return_if_fail (DB_IS_ITERATOR (iterator) || !iterator);

	if (obj->iterator)
	{	
		g_object_disconnect (obj->iterator
			,"any-signal", vn_handler_on_status_changed, obj
			,"any-signal", vn_handler_on_data_changed, obj
			,"any-signal", vn_handler_on_row_num_changed, obj
			,"any-signal", vn_handler_on_operations_done, obj
			,NULL
		);
		g_clear_object (&obj->iterator);
	}
	if (iterator)
	{
		obj->iterator = g_object_ref (iterator);
		g_object_connect (iterator
			,"signal::status-changed", vn_handler_on_status_changed, obj
			,"signal::data-changed", vn_handler_on_data_changed, obj
			,"signal::row-num-changed", vn_handler_on_row_num_changed, obj
			,"signal::operations-done", vn_handler_on_operations_done, obj
			,NULL
		);
	}
	
	vn_handler_refresh_status (obj);
}

/**
 * vn_handler_set_simple_record:
 * @obj: a #VnHandler
 * @simple: %FALSE if model allows multiple records, %TRUE otherwise
 * 
 * Sets if it is used to handle a iterator with a single record.
 **/
void vn_handler_set_simple_record (VnHandler * obj, gboolean simple)
{
	g_return_if_fail (VN_IS_HANDLER (obj));
	
	obj->simple_record = simple;
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Properties

enum
{
	  PROP_FORM = 1
	 ,PROP_SHOW_FLAGS
	 ,PROP_SIMPLE_RECORD
};

static void vn_handler_set_property (VnHandler * obj, guint id,
	const GValue * value, GParamSpec * pspec)
{
	switch (id)
	{
		case PROP_FORM:
			vn_handler_set_iterator (obj, g_value_get_object (value));
			break;
		case PROP_SHOW_FLAGS:
			vn_handler_set_show_flags (obj, g_value_get_flags (value));
			break;
		case PROP_SIMPLE_RECORD:
			vn_handler_set_simple_record (obj, g_value_get_boolean (value));
			break;
		default:		
			G_OBJECT_WARN_INVALID_PROPERTY_ID (obj, id, pspec);
	}
}

static void vn_handler_get_property (VnHandler * obj, guint id,
	GValue * value, GParamSpec * pspec)
{
	switch (id)
	{
		case PROP_FORM:
			g_value_set_object (value, obj->iterator);
			break;
		case PROP_SHOW_FLAGS:
			g_value_set_flags (value, obj->show_flags);
			break;
		case PROP_SIMPLE_RECORD:
			g_value_set_boolean (value, obj->simple_record);
			break;
		default:		
			G_OBJECT_WARN_INVALID_PROPERTY_ID (obj, id, pspec);
	}
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Class

static void vn_handler_init (VnHandler * obj)
{
	gint i;
	gchar * css;
	GtkStyleContext * context;
	GtkCssProvider * provider;

	obj->add = NULL;
	obj->remove = NULL;
	obj->move_first = NULL;
	obj->move_previous = NULL;
	obj->move_next = NULL;
	obj->move_last = NULL;
	obj->iterator = NULL;

	obj->group = G_ACTION_GROUP (g_simple_action_group_new ());
	g_action_map_add_action_entries (G_ACTION_MAP (obj->group), entries, n_entries, obj);
	gtk_widget_insert_action_group (GTK_WIDGET (obj), ACTION_GROUP_NAME, obj->group);

	obj->buttons = GTK_WIDGET (g_object_new (GTK_TYPE_BUTTON_BOX
		,"layout-style", GTK_BUTTONBOX_EXPAND
		,"homogeneous", FALSE
		,"halign", GTK_ALIGN_END
		,NULL
	));

	context = gtk_widget_get_style_context (obj->buttons);
	provider = gtk_css_provider_get_default ();
	css =
		"VnHandler GtkButtonBox\n"
		"{\n"
		"	-GtkButtonBox-child-min-width: 0;\n"
		"	-GtkButtonBox-child-internal-pad-x: 0;\n"
		"}";

	if (gtk_css_provider_load_from_data (provider, css, -1, NULL))
		gtk_style_context_add_provider (context, GTK_STYLE_PROVIDER (provider),
			GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
	else
		g_object_unref (provider);

	gtk_container_add (GTK_CONTAINER (obj), obj->buttons);

	for (i = 0; i < n_entries; i++)
	{
		GtkWidget * button = gtk_button_new_from_icon_name (actions_data[i].icon, GTK_ICON_SIZE_BUTTON);
		gchar * action_name = g_strconcat (ACTION_GROUP_NAME, ".", entries[i].name, NULL);
		gtk_actionable_set_action_name (GTK_ACTIONABLE (button), action_name);
		g_free (action_name);
		gtk_widget_set_tooltip_text (button, actions_data[i].tooltip);
		gtk_widget_set_no_show_all (button, TRUE);
		gtk_box_pack_start (GTK_BOX (obj->buttons), button, FALSE, FALSE, 0);
	}
}

static void vn_handler_finalize (VnHandler * obj)
{
	vn_handler_set_iterator (obj, NULL);
	G_OBJECT_CLASS (vn_handler_parent_class)->finalize (G_OBJECT (obj));
}

static void vn_handler_class_init (VnHandlerClass * klass)
{
	GObjectClass * k = G_OBJECT_CLASS (klass);
	k->finalize = (GObjectFinalizeFunc) vn_handler_finalize;
	k->set_property = (GObjectSetPropertyFunc) vn_handler_set_property;
	k->get_property = (GObjectGetPropertyFunc) vn_handler_get_property;

	g_object_class_install_property (k, PROP_FORM,
		g_param_spec_object ("iterator"
			,"Iterator"
			,"The handled iterator"
			,DB_TYPE_ITERATOR
			,G_PARAM_CONSTRUCT | G_PARAM_READWRITE
	));
	g_object_class_install_property (k, PROP_SHOW_FLAGS,
		g_param_spec_flags ("show-flags"
			,_("Show flags")
			,_("Sets the buttons that will be shown on the interface")
			,VN_TYPE_HANDLER_SHOW_FLAGS
			,VN_HANDLER_SHOW_UNDO | VN_HANDLER_SHOW_SAVE | VN_HANDLER_SHOW_REMOVE | VN_HANDLER_SHOW_ADD
			,G_PARAM_CONSTRUCT | G_PARAM_READWRITE
	));
	g_object_class_install_property (k, PROP_SIMPLE_RECORD,
		g_param_spec_boolean ("simple-record"
			,_("Simple record")
			,_("Sets if it is used to handle a iterator with a single record")
			,FALSE
			,G_PARAM_CONSTRUCT | G_PARAM_READWRITE
	));
}

GType vn_handler_show_flags_get_type ()
{
	static GType type = 0;

	if (type == 0)
	{
		static const GFlagsValue values[] =
		{
			 {VN_HANDLER_SHOW_REFRESH, "VN_HANDLER_SHOW_REFRESH", "refresh"}
			,{VN_HANDLER_SHOW_UNDO, "VN_HANDLER_SHOW_UNDO", "undo"}
			,{VN_HANDLER_SHOW_SAVE, "VN_HANDLER_SHOW_SAVE", "save"}
			,{VN_HANDLER_SHOW_REMOVE, "VN_HANDLER_SHOW_REMOVE", "remove"}
			,{VN_HANDLER_SHOW_ADD, "VN_HANDLER_SHOW_ADD", "add"}
			,{VN_HANDLER_SHOW_SCROLL, "VN_HANDLER_SHOW_SCROLL", "scroll"}
			,{0, NULL, NULL}
		};

		type = g_flags_register_static
			(g_intern_static_string ("VnHandlerShowFlags"), values);
	}

	return type;
}