/*
 * gedit-history-entry.c
 * This file is part of gedit
 *
 * Copyright (C) 2006 - Paolo Borelli
 *
 * 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/>.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include "gedit-history-entry.h"

#include <string.h>
#include <glib/gi18n.h>
#include <gtk/gtk.h>

#define MIN_ITEM_LEN 3

#define GEDIT_HISTORY_ENTRY_HISTORY_LENGTH_DEFAULT 10

struct _GeditHistoryEntry
{
	GtkComboBoxText     parent_instance;

	gchar              *history_id;
	guint               history_length;

	GtkEntryCompletion *completion;

	GSettings          *settings;
};

enum {
	PROP_0,
	PROP_HISTORY_ID,
	PROP_HISTORY_LENGTH,
	PROP_ENABLE_COMPLETION,
	LAST_PROP
};

static GParamSpec *properties[LAST_PROP];

G_DEFINE_TYPE (GeditHistoryEntry, gedit_history_entry, GTK_TYPE_COMBO_BOX_TEXT)

static void
gedit_history_entry_set_property (GObject      *object,
				  guint         prop_id,
				  const GValue *value,
				  GParamSpec   *spec)
{
	GeditHistoryEntry *entry;

	g_return_if_fail (GEDIT_IS_HISTORY_ENTRY (object));

	entry = GEDIT_HISTORY_ENTRY (object);

	switch (prop_id)
	{
		case PROP_HISTORY_ID:
			entry->history_id = g_value_dup_string (value);
			break;
		case PROP_HISTORY_LENGTH:
			gedit_history_entry_set_history_length (entry,
								g_value_get_uint (value));
			break;
		case PROP_ENABLE_COMPLETION:
			gedit_history_entry_set_enable_completion (entry,
			                                           g_value_get_boolean (value));
			break;
		default:
			G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, spec);
	}
}

static void
gedit_history_entry_get_property (GObject    *object,
				  guint       prop_id,
				  GValue     *value,
				  GParamSpec *spec)
{
	GeditHistoryEntry *entry;

	g_return_if_fail (GEDIT_IS_HISTORY_ENTRY (object));

	entry = GEDIT_HISTORY_ENTRY (object);

	switch (prop_id)
	{
		case PROP_HISTORY_ID:
			g_value_set_string (value, entry->history_id);
			break;
		case PROP_HISTORY_LENGTH:
			g_value_set_uint (value, entry->history_length);
			break;
		case PROP_ENABLE_COMPLETION:
			g_value_set_boolean (value, gedit_history_entry_get_enable_completion (GEDIT_HISTORY_ENTRY (object)));
			break;
		default:
			G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, spec);
	}
}

static void
gedit_history_entry_dispose (GObject *object)
{
	GeditHistoryEntry *entry = GEDIT_HISTORY_ENTRY (object);

	gedit_history_entry_set_enable_completion (entry, FALSE);

	g_clear_object (&entry->settings);

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

static void
gedit_history_entry_finalize (GObject *object)
{
	GeditHistoryEntry *entry = GEDIT_HISTORY_ENTRY (object);

	g_free (entry->history_id);

	G_OBJECT_CLASS (gedit_history_entry_parent_class)->finalize (object);
}

static void
gedit_history_entry_load_history (GeditHistoryEntry *entry)
{
	gchar **items;
	gsize i;

	items = g_settings_get_strv (entry->settings, entry->history_id);
	i = 0;

	gtk_combo_box_text_remove_all (GTK_COMBO_BOX_TEXT (entry));

	/* Now the default value is an empty string so we have to take care
	   of it to not add the empty string in the search list */
	while (items[i] != NULL && *items[i] != '\0' &&
	       i < entry->history_length)
	{
		gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (entry), items[i]);
		i++;
	}

	g_strfreev (items);
}

static void
gedit_history_entry_class_init (GeditHistoryEntryClass *klass)
{
	GObjectClass *object_class = G_OBJECT_CLASS (klass);

	object_class->set_property = gedit_history_entry_set_property;
	object_class->get_property = gedit_history_entry_get_property;
	object_class->dispose = gedit_history_entry_dispose;
	object_class->finalize = gedit_history_entry_finalize;

	properties[PROP_HISTORY_ID] =
		g_param_spec_string ("history-id",
		                     "History ID",
		                     "History ID",
		                     NULL,
		                     G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS);

	properties[PROP_HISTORY_LENGTH] =
		g_param_spec_uint ("history-length",
		                   "Max History Length",
		                   "Max History Length",
		                   0,
		                   G_MAXUINT,
		                   GEDIT_HISTORY_ENTRY_HISTORY_LENGTH_DEFAULT,
		                   G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);

	properties[PROP_ENABLE_COMPLETION] =
		g_param_spec_boolean ("enable-completion",
		                      "Enable Completion",
		                      "Wether the completion is enabled",
		                      TRUE,
		                      G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);

	g_object_class_install_properties (object_class, LAST_PROP, properties);
}

static GtkListStore *
get_history_store (GeditHistoryEntry *entry)
{
	GtkTreeModel *store;

	store = gtk_combo_box_get_model (GTK_COMBO_BOX (entry));
	g_return_val_if_fail (GTK_IS_LIST_STORE (store), NULL);

	return (GtkListStore *) store;
}

static gchar **
get_history_items (GeditHistoryEntry *entry)
{
	GtkListStore *store;
	GtkTreeIter iter;
	GPtrArray *array;
	gboolean valid;
	gint n_children;
	gint text_column;

	store = get_history_store (entry);
	text_column = gtk_combo_box_get_entry_text_column (GTK_COMBO_BOX (entry));

	valid = gtk_tree_model_get_iter_first (GTK_TREE_MODEL (store),
					       &iter);
	n_children = gtk_tree_model_iter_n_children (GTK_TREE_MODEL (store),
						     NULL);

	array = g_ptr_array_sized_new (n_children + 1);

	while (valid)
	{
		gchar *str;

		gtk_tree_model_get (GTK_TREE_MODEL (store),
				    &iter,
				    text_column, &str,
				    -1);

		g_ptr_array_add (array, str);

		valid = gtk_tree_model_iter_next (GTK_TREE_MODEL (store),
						  &iter);
	}

	g_ptr_array_add (array, NULL);

	return (gchar **)g_ptr_array_free (array, FALSE);
}

static void
gedit_history_entry_save_history (GeditHistoryEntry *entry)
{
	gchar **items;

	g_return_if_fail (GEDIT_IS_HISTORY_ENTRY (entry));

	items = get_history_items (entry);

	g_settings_set_strv (entry->settings,
			     entry->history_id,
			     (const gchar * const *)items);

	g_strfreev (items);
}

static gboolean
remove_item (GeditHistoryEntry *entry,
	     const gchar       *text)
{
	GtkListStore *store;
	GtkTreeIter iter;
	gint text_column;

	g_return_val_if_fail (text != NULL, FALSE);

	store = get_history_store (entry);
	text_column = gtk_combo_box_get_entry_text_column (GTK_COMBO_BOX (entry));

	if (!gtk_tree_model_get_iter_first (GTK_TREE_MODEL (store), &iter))
		return FALSE;

	do
	{
		gchar *item_text;

		gtk_tree_model_get (GTK_TREE_MODEL (store),
				    &iter,
				    text_column,
				    &item_text,
				    -1);

		if (item_text != NULL &&
		    strcmp (item_text, text) == 0)
		{
			gtk_list_store_remove (store, &iter);
			g_free (item_text);
			return TRUE;
		}

		g_free (item_text);

	} while (gtk_tree_model_iter_next (GTK_TREE_MODEL (store), &iter));

	return FALSE;
}

static void
clamp_list_store (GtkListStore *store,
		  guint         max)
{
	GtkTreePath *path;
	GtkTreeIter iter;

	/* -1 because TreePath counts from 0 */
	path = gtk_tree_path_new_from_indices (max - 1, -1);

	if (gtk_tree_model_get_iter (GTK_TREE_MODEL (store), &iter, path))
	{
		while (TRUE)
		{
			if (!gtk_list_store_remove (store, &iter))
				break;
		}
	}

	gtk_tree_path_free (path);
}

static void
insert_history_item (GeditHistoryEntry *entry,
		     const gchar       *text,
		     gboolean           prepend)
{
	GtkListStore *store;

	if (g_utf8_strlen (text, -1) <= MIN_ITEM_LEN)
		return;

	store = get_history_store (entry);

	/* remove the text from the store if it was already
	 * present. If it wasn't, clamp to max history - 1
	 * before inserting the new row, otherwise appending
	 * would not work */

	if (!remove_item (entry, text))
	{
		clamp_list_store (store, entry->history_length - 1);
	}

	if (prepend)
	{
		gtk_combo_box_text_prepend_text (GTK_COMBO_BOX_TEXT (entry), text);
	}
	else
	{
		gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (entry), text);
	}

	gedit_history_entry_save_history (entry);
}

void
gedit_history_entry_prepend_text (GeditHistoryEntry *entry,
				  const gchar       *text)
{
	g_return_if_fail (GEDIT_IS_HISTORY_ENTRY (entry));
	g_return_if_fail (text != NULL);

	insert_history_item (entry, text, TRUE);
}

void
gedit_history_entry_append_text (GeditHistoryEntry *entry,
				 const gchar       *text)
{
	g_return_if_fail (GEDIT_IS_HISTORY_ENTRY (entry));
	g_return_if_fail (text != NULL);

	insert_history_item (entry, text, FALSE);
}

void
gedit_history_entry_clear (GeditHistoryEntry *entry)
{
	g_return_if_fail (GEDIT_IS_HISTORY_ENTRY (entry));

	gtk_combo_box_text_remove_all (GTK_COMBO_BOX_TEXT (entry));

	gedit_history_entry_save_history (entry);
}

static void
gedit_history_entry_init (GeditHistoryEntry *entry)
{
	entry->history_id = NULL;
	entry->history_length = GEDIT_HISTORY_ENTRY_HISTORY_LENGTH_DEFAULT;

	entry->completion = NULL;

	entry->settings = g_settings_new ("org.gnome.gedit.state.history-entry");
}

void
gedit_history_entry_set_history_length (GeditHistoryEntry *entry,
					guint              history_length)
{
	g_return_if_fail (GEDIT_IS_HISTORY_ENTRY (entry));
	g_return_if_fail (history_length > 0);

	entry->history_length = history_length;

	/* TODO: update if we currently have more items than max */
}

guint
gedit_history_entry_get_history_length (GeditHistoryEntry *entry)
{
	g_return_val_if_fail (GEDIT_IS_HISTORY_ENTRY (entry), 0);

	return entry->history_length;
}

void
gedit_history_entry_set_enable_completion (GeditHistoryEntry *entry,
					   gboolean           enable)
{
	g_return_if_fail (GEDIT_IS_HISTORY_ENTRY (entry));

	if (enable)
	{
		if (entry->completion != NULL)
		{
			return;
		}

		entry->completion = gtk_entry_completion_new ();
		gtk_entry_completion_set_model (entry->completion,
						GTK_TREE_MODEL (get_history_store (entry)));

		/* Use model column 0 as the text column */
		gtk_entry_completion_set_text_column (entry->completion, 0);

		gtk_entry_completion_set_minimum_key_length (entry->completion,
							     MIN_ITEM_LEN);

		gtk_entry_completion_set_popup_completion (entry->completion, FALSE);
		gtk_entry_completion_set_inline_completion (entry->completion, TRUE);

		/* Assign the completion to the entry */
		gtk_entry_set_completion (GTK_ENTRY (gedit_history_entry_get_entry (entry)),
					  entry->completion);
	}
	else
	{
		if (entry->completion == NULL)
		{
			return;
		}

		gtk_entry_set_completion (GTK_ENTRY (gedit_history_entry_get_entry (entry)), NULL);
		g_clear_object (&entry->completion);
	}
}

gboolean
gedit_history_entry_get_enable_completion (GeditHistoryEntry *entry)
{
	g_return_val_if_fail (GEDIT_IS_HISTORY_ENTRY (entry), FALSE);

	return entry->completion != NULL;
}

GtkWidget *
gedit_history_entry_new (const gchar *history_id,
			 gboolean     enable_completion)
{
	GeditHistoryEntry *entry;

	g_return_val_if_fail (history_id != NULL, NULL);

	enable_completion = (enable_completion != FALSE);

	entry = g_object_new (GEDIT_TYPE_HISTORY_ENTRY,
	                      "has-entry", TRUE,
	                      "entry-text-column", 0,
	                      "id-column", 1,
	                      "history-id", history_id,
	                      "enable-completion", enable_completion,
	                      NULL);

	/* We must load the history after the object has been constructed,
	 * to ensure that the model is set properly.
	 */
	gedit_history_entry_load_history (entry);

	return GTK_WIDGET (entry);
}

/*
 * Utility function to get the editable text entry internal widget.
 * I would prefer to not expose this implementation detail and
 * simply make the GeditHistoryEntry widget implement the
 * GtkEditable interface. Unfortunately both GtkEditable and
 * GtkComboBox have a "changed" signal and I am not sure how to
 * handle the conflict.
 */
GtkWidget *
gedit_history_entry_get_entry (GeditHistoryEntry *entry)
{
	g_return_val_if_fail (GEDIT_IS_HISTORY_ENTRY (entry), NULL);

	return gtk_bin_get_child (GTK_BIN (entry));
}

/* ex:set ts=8 noet: */
