/*
 * e-image-chooser.c
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) version 3.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 */

#include <config.h>

#include <stdio.h>
#include <string.h>

#include <glib/gi18n.h>

#include "e-image-chooser.h"
#include "e-util/e-util.h"

#define E_IMAGE_CHOOSER_GET_PRIVATE(obj) \
	(G_TYPE_INSTANCE_GET_PRIVATE \
	((obj), E_TYPE_IMAGE_CHOOSER, EImageChooserPrivate))

struct _EImageChooserPrivate {
	GtkWidget *frame;
	GtkWidget *image;

	gchar *image_buf;
	gint image_buf_size;
	gint image_width;
	gint image_height;
};

enum {
	CHANGED,
	LAST_SIGNAL
};

static gpointer parent_class;
static guint signals[LAST_SIGNAL];

#define URI_LIST_TYPE "text/uri-list"

static gboolean
set_image_from_data (EImageChooser *chooser,
                     gchar *data,
                     gint length)
{
	GdkPixbufLoader *loader;
	GdkPixbuf *pixbuf;
	gfloat scale;
	gint new_height;
	gint new_width;

	loader = gdk_pixbuf_loader_new ();
	gdk_pixbuf_loader_write (loader, (guchar *) data, length, NULL);
	gdk_pixbuf_loader_close (loader, NULL);

	pixbuf = gdk_pixbuf_loader_get_pixbuf (loader);
	if (pixbuf)
		g_object_ref (pixbuf);

	g_object_unref (loader);

	if (pixbuf == NULL)
		return FALSE;

	new_height = gdk_pixbuf_get_height (pixbuf);
	new_width = gdk_pixbuf_get_width (pixbuf);

	if (chooser->priv->image_height == 0
	    && chooser->priv->image_width == 0) {
		scale = 1.0;
	} else if (chooser->priv->image_height < new_height
		 || chooser->priv->image_width < new_width) {
		/* we need to scale down */
		if (new_height > new_width)
			scale = (gfloat)chooser->priv->image_height / new_height;
		else
			scale = (gfloat)chooser->priv->image_width / new_width;
	} else {
		/* we need to scale up */
		if (new_height > new_width)
			scale = (gfloat)new_height / chooser->priv->image_height;
		else
			scale = (gfloat)new_width / chooser->priv->image_width;
	}

	if (scale == 1.0) {
		gtk_image_set_from_pixbuf (
			GTK_IMAGE (chooser->priv->image), pixbuf);
		chooser->priv->image_width = new_width;
		chooser->priv->image_height = new_height;
	} else {
		GdkPixbuf *scaled;
		GdkPixbuf *composite;

		new_width *= scale;
		new_height *= scale;
		new_width = MIN (new_width, chooser->priv->image_width);
		new_height = MIN (new_height, chooser->priv->image_height);

		scaled = gdk_pixbuf_scale_simple (
			pixbuf, new_width, new_height,
			GDK_INTERP_BILINEAR);

		composite = gdk_pixbuf_new (
			GDK_COLORSPACE_RGB, TRUE,
			gdk_pixbuf_get_bits_per_sample (pixbuf),
			chooser->priv->image_width,
			chooser->priv->image_height);

		gdk_pixbuf_fill (composite, 0x00000000);

		gdk_pixbuf_copy_area (
			scaled, 0, 0, new_width, new_height,
			composite,
			chooser->priv->image_width / 2 - new_width / 2,
			chooser->priv->image_height / 2 - new_height / 2);

		gtk_image_set_from_pixbuf (
			GTK_IMAGE (chooser->priv->image), composite);

		g_object_unref (scaled);
		g_object_unref (composite);
	}

	g_object_unref (pixbuf);

	g_free (chooser->priv->image_buf);
	chooser->priv->image_buf = data;
	chooser->priv->image_buf_size = length;

	g_signal_emit (chooser, signals[CHANGED], 0);

	return TRUE;
}

static gboolean
image_drag_motion_cb (GtkWidget *widget,
                      GdkDragContext *context,
                      gint x,
                      gint y,
                      guint time,
                      EImageChooser *chooser)
{
	GtkFrame *frame;
	GList *p;

	frame = GTK_FRAME (chooser->priv->frame);

	for (p = context->targets; p != NULL; p = p->next) {
		gchar *possible_type;

		possible_type = gdk_atom_name (GDK_POINTER_TO_ATOM (p->data));
		if (!strcmp (possible_type, URI_LIST_TYPE)) {
			g_free (possible_type);
			gdk_drag_status (context, GDK_ACTION_COPY, time);
			gtk_frame_set_shadow_type (frame, GTK_SHADOW_IN);
			return TRUE;
		}

		g_free (possible_type);
	}

	gtk_frame_set_shadow_type (frame, GTK_SHADOW_NONE);

	return FALSE;
}

static void
image_drag_leave_cb (GtkWidget *widget,
                     GdkDragContext *context,
                     guint time,
                     EImageChooser *chooser)
{
	GtkFrame *frame;

	frame = GTK_FRAME (chooser->priv->frame);
	gtk_frame_set_shadow_type (frame, GTK_SHADOW_NONE);
}

static gboolean
image_drag_drop_cb (GtkWidget *widget,
                    GdkDragContext *context,
                    gint x,
                    gint y,
                    guint time,
                    EImageChooser *chooser)
{
	GtkFrame *frame;
	GList *p;

	frame = GTK_FRAME (chooser->priv->frame);

	if (context->targets == NULL) {
		gtk_frame_set_shadow_type (frame, GTK_SHADOW_NONE);
		return FALSE;
	}

	for (p = context->targets; p != NULL; p = p->next) {
		gchar *possible_type;

		possible_type = gdk_atom_name (GDK_POINTER_TO_ATOM (p->data));
		if (!strcmp (possible_type, URI_LIST_TYPE)) {
			g_free (possible_type);
			gtk_drag_get_data (
				widget, context,
				GDK_POINTER_TO_ATOM (p->data), time);
			gtk_frame_set_shadow_type (frame, GTK_SHADOW_NONE);
			return TRUE;
		}

		g_free (possible_type);
	}

	gtk_frame_set_shadow_type (frame, GTK_SHADOW_NONE);

	return FALSE;
}

static void
image_drag_data_received_cb (GtkWidget *widget,
                             GdkDragContext *context,
                             gint x,
                             gint y,
                             GtkSelectionData *selection_data,
                             guint info,
                             guint time,
                             EImageChooser *chooser)
{
	gboolean handled = FALSE;
	gchar **uris;
	gchar *buf = NULL;
	gsize read = 0;
	GError *error = NULL;

	uris = gtk_selection_data_get_uris (selection_data);

	if (uris == NULL)
		goto exit;

	if (e_util_read_file (uris[0], TRUE, &buf, &read, &error) && read > 0 && buf)
		handled = set_image_from_data (chooser, buf, read);

	g_free (buf);

	g_strfreev (uris);

	if (error) {
		g_warning ("%s", error->message);
		g_error_free (error);
	}

exit:
	gtk_drag_finish (context, handled, FALSE, time);
}

static void
image_chooser_dispose (GObject *object)
{
	EImageChooserPrivate *priv;

	priv = E_IMAGE_CHOOSER_GET_PRIVATE (object);

	if (priv->frame != NULL) {
		g_object_unref (priv->frame);
		priv->frame = NULL;
	}

	if (priv->image != NULL) {
		g_object_unref (priv->image);
		priv->image = NULL;
	}

	/* Chain up to parent's dispose() method. */
	G_OBJECT_CLASS (parent_class)->dispose (object);
}

static void
image_chooser_finalize (GObject *object)
{
	EImageChooserPrivate *priv;

	priv = E_IMAGE_CHOOSER_GET_PRIVATE (object);

	g_free (priv->image_buf);

	/* Chain up to parent's finalize() method. */
	G_OBJECT_CLASS (parent_class)->finalize (object);
}

static void
e_image_chooser_class_init (EImageChooserClass *class)
{
	GObjectClass *object_class = G_OBJECT_CLASS (class);

	parent_class = g_type_class_peek_parent (class);
	g_type_class_add_private (class, sizeof (EImageChooserPrivate));

	object_class = G_OBJECT_CLASS (class);
	object_class->dispose = image_chooser_dispose;
	object_class->finalize = image_chooser_finalize;

	signals[CHANGED] = g_signal_new (
		"changed",
		G_OBJECT_CLASS_TYPE (object_class),
		G_SIGNAL_RUN_FIRST,
		G_STRUCT_OFFSET (EImageChooserClass, changed),
		NULL, NULL,
		g_cclosure_marshal_VOID__VOID,
		G_TYPE_NONE, 0);
}

static void
e_image_chooser_init (EImageChooser *chooser)
{
	GtkWidget *container;
	GtkWidget *widget;

	chooser->priv = E_IMAGE_CHOOSER_GET_PRIVATE (chooser);

	container = GTK_WIDGET (chooser);

	widget = gtk_frame_new ("");
	gtk_frame_set_shadow_type (GTK_FRAME (widget), GTK_SHADOW_NONE);
	gtk_box_pack_start (GTK_BOX (container), widget, TRUE, TRUE, 0);
	chooser->priv->frame = g_object_ref (widget);
	gtk_widget_show (widget);

	container = widget;

	widget = gtk_alignment_new (0, 0, 0, 0);
	gtk_container_add (GTK_CONTAINER (container), widget);
	gtk_widget_show (widget);

	container = widget;

	widget = gtk_image_new ();
	gtk_container_add (GTK_CONTAINER (container), widget);
	chooser->priv->image = g_object_ref (widget);
	gtk_widget_show (widget);

	gtk_drag_dest_set (widget, 0, NULL, 0, GDK_ACTION_COPY);
	gtk_drag_dest_add_uri_targets (widget);

	g_signal_connect (
		widget, "drag-motion",
		G_CALLBACK (image_drag_motion_cb), chooser);
	g_signal_connect (
		widget, "drag-leave",
		G_CALLBACK (image_drag_leave_cb), chooser);
	g_signal_connect (
		widget, "drag-drop",
		G_CALLBACK (image_drag_drop_cb), chooser);
	g_signal_connect (
		widget, "drag-data-received",
		G_CALLBACK (image_drag_data_received_cb), chooser);
}

GType
e_image_chooser_get_type (void)
{
	static GType type = 0;

	if (G_UNLIKELY (type == 0)) {
		static const GTypeInfo type_info =  {
			sizeof (EImageChooserClass),
			(GBaseInitFunc) NULL,
			(GBaseFinalizeFunc) NULL,
			(GClassInitFunc) e_image_chooser_class_init,
			(GClassFinalizeFunc) NULL,
			NULL, /* class_data */
			sizeof (EImageChooser),
			0,    /* n_preallocs */
			(GInstanceInitFunc) e_image_chooser_init,
			NULL  /* value_table */
		};

		type = g_type_register_static (
			GTK_TYPE_VBOX, "EImageChooser", &type_info, 0);
	}

	return type;
}

GtkWidget *
e_image_chooser_new (void)
{
	return g_object_new (E_TYPE_IMAGE_CHOOSER, NULL);
}

gboolean
e_image_chooser_set_from_file (EImageChooser *chooser,
                               const gchar *filename)
{
	gchar *data;
	gsize data_length;

	g_return_val_if_fail (E_IS_IMAGE_CHOOSER (chooser), FALSE);
	g_return_val_if_fail (filename != NULL, FALSE);

	if (!g_file_get_contents (filename, &data, &data_length, NULL))
		return FALSE;

	if (!set_image_from_data (chooser, data, data_length))
		g_free (data);

	return TRUE;
}

gboolean
e_image_chooser_get_image_data (EImageChooser *chooser,
                                gchar **data,
                                gsize *data_length)
{
	g_return_val_if_fail (E_IS_IMAGE_CHOOSER (chooser), FALSE);
	g_return_val_if_fail (data != NULL, FALSE);
	g_return_val_if_fail (data_length != NULL, FALSE);

	*data_length = chooser->priv->image_buf_size;
	*data = g_malloc (*data_length);
	memcpy (*data, chooser->priv->image_buf, *data_length);

	return TRUE;
}

gboolean
e_image_chooser_set_image_data (EImageChooser *chooser,
                                gchar *data,
                                gsize data_length)
{
	gchar *buf;

	g_return_val_if_fail (E_IS_IMAGE_CHOOSER (chooser), FALSE);
	g_return_val_if_fail (data != NULL, FALSE);

	/* yuck, a copy... */
	buf = g_malloc (data_length);
	memcpy (buf, data, data_length);

	if (!set_image_from_data (chooser, buf, data_length)) {
		g_free (buf);
		return FALSE;
	}

	return TRUE;
}