/*
 * mainwindow.c
 *
 * Colloquium - A tiny presentation program
 *
 * Copyright (c) 2011 Thomas White <taw@bitwiz.org.uk>
 *
 * 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/>.
 *
 */


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

#include <stdlib.h>
#include <string.h>
#include <gtk/gtk.h>
#include <assert.h>
#include <gdk/gdkkeysyms.h>

#include "presentation.h"
#include "mainwindow.h"
#include "slide_render.h"
#include "objects.h"


static void add_ui_sig(GtkUIManager *ui, GtkWidget *widget,
                       GtkContainer *container)
{
	gtk_box_pack_start(GTK_BOX(container), widget, FALSE, FALSE, 0);
	if ( GTK_IS_TOOLBAR(widget) ) {
		gtk_toolbar_set_show_arrow(GTK_TOOLBAR(widget), TRUE);
	}
}


static gint quit_sig(GtkWidget *widget, struct presentation *p)
{
	gtk_main_quit();
	return 0;
}


static gint about_sig(GtkWidget *widget, struct presentation *p)
{
	GtkWidget *window;

	const gchar *authors[] = {
		"Thomas White <taw@bitwiz.org.uk>",
		NULL
	};

	window = gtk_about_dialog_new();
	gtk_window_set_transient_for(GTK_WINDOW(window), GTK_WINDOW(p->window));

	gtk_about_dialog_set_name(GTK_ABOUT_DIALOG(window), "Colloquium");
	gtk_about_dialog_set_version(GTK_ABOUT_DIALOG(window), PACKAGE_VERSION);
	gtk_about_dialog_set_copyright(GTK_ABOUT_DIALOG(window),
		"(c) 2011 Thomas White <taw@bitwiz.org.uk>");
	gtk_about_dialog_set_comments(GTK_ABOUT_DIALOG(window),
		"A tiny presentation program");
	gtk_about_dialog_set_license(GTK_ABOUT_DIALOG(window),
		"(c) 2011 Thomas White <taw@bitwiz.org.uk>\n");
	gtk_about_dialog_set_website(GTK_ABOUT_DIALOG(window),
		"http://www.bitwiz.org.uk/");
	gtk_about_dialog_set_authors(GTK_ABOUT_DIALOG(window), authors);

	g_signal_connect(window, "response", G_CALLBACK(gtk_widget_destroy),
			 NULL);

	gtk_widget_show_all(window);

	return 0;
}


static void update_toolbar(struct presentation *p)
{
	GtkWidget *d;

	d = gtk_ui_manager_get_widget(p->ui, "/ui/displaywindowtoolbar/first");
	gtk_widget_set_sensitive(GTK_WIDGET(d), TRUE);
	d = gtk_ui_manager_get_widget(p->ui, "/ui/displaywindowtoolbar/prev");
	gtk_widget_set_sensitive(GTK_WIDGET(d), TRUE);
	d = gtk_ui_manager_get_widget(p->ui, "/ui/displaywindowtoolbar/next");
	gtk_widget_set_sensitive(GTK_WIDGET(d), TRUE);
	d = gtk_ui_manager_get_widget(p->ui, "/ui/displaywindowtoolbar/last");
	gtk_widget_set_sensitive(GTK_WIDGET(d), TRUE);

	if ( p->view_slide_number == 0 ) {

		d = gtk_ui_manager_get_widget(p->ui,
					"/ui/displaywindowtoolbar/first");
		gtk_widget_set_sensitive(GTK_WIDGET(d), FALSE);
		d = gtk_ui_manager_get_widget(p->ui,
					"/ui/displaywindowtoolbar/prev");
		gtk_widget_set_sensitive(GTK_WIDGET(d), FALSE);

	}

	if ( p->view_slide_number == p->num_slides-1 ) {

		d = gtk_ui_manager_get_widget(p->ui,
					"/ui/displaywindowtoolbar/next");
		gtk_widget_set_sensitive(GTK_WIDGET(d), FALSE);
		d = gtk_ui_manager_get_widget(p->ui,
					"/ui/displaywindowtoolbar/last");
		gtk_widget_set_sensitive(GTK_WIDGET(d), FALSE);

	}
}


static gint add_slide_sig(GtkWidget *widget, struct presentation *p)
{
	struct slide *new;

	new = add_slide(p, p->view_slide_number);
	p->view_slide = new;
	p->view_slide_number++;
	p->editing_object = NULL;

	update_toolbar(p);

	gdk_window_invalidate_rect(p->drawingarea->window, NULL, FALSE);

	return FALSE;
}


static gint first_slide_sig(GtkWidget *widget, struct presentation *p)
{
	p->view_slide_number = 0;
	p->view_slide = p->slides[0];
	p->editing_object = NULL;

	update_toolbar(p);

	gdk_window_invalidate_rect(p->drawingarea->window, NULL, FALSE);

	return FALSE;
}


static gint prev_slide_sig(GtkWidget *widget, struct presentation *p)
{
	if ( p->view_slide_number == 0 ) return FALSE;

	p->view_slide_number--;
	p->view_slide = p->slides[p->view_slide_number];
	p->editing_object = NULL;

	update_toolbar(p);

	gdk_window_invalidate_rect(p->drawingarea->window, NULL, FALSE);

	return FALSE;
}


static gint next_slide_sig(GtkWidget *widget, struct presentation *p)
{
	if ( p->view_slide_number == p->num_slides-1 ) return FALSE;

	p->view_slide_number++;
	p->view_slide = p->slides[p->view_slide_number];
	p->editing_object = NULL;

	update_toolbar(p);

	gdk_window_invalidate_rect(p->drawingarea->window, NULL, FALSE);

	return FALSE;
}


static gint last_slide_sig(GtkWidget *widget, struct presentation *p)
{
	p->view_slide_number = p->num_slides-1;
	p->view_slide = p->slides[p->view_slide_number];
	p->editing_object = NULL;

	update_toolbar(p);

	gdk_window_invalidate_rect(p->drawingarea->window, NULL, FALSE);

	return FALSE;
}


static void add_menu_bar(struct presentation *p, GtkWidget *vbox)
{
	GError *error = NULL;
	GtkActionEntry entries[] = {

		{ "FileAction", NULL, "_File", NULL, NULL, NULL },
		{ "QuitAction", GTK_STOCK_QUIT, "_Quit", NULL, NULL,
			G_CALLBACK(quit_sig) },

		{ "HelpAction", NULL, "_Help", NULL, NULL, NULL },
		{ "AboutAction", GTK_STOCK_ABOUT, "_About...",
			NULL, NULL,  G_CALLBACK(about_sig) },

		{ "AddSlideAction", GTK_STOCK_ADD, "Add Slide",
			NULL, NULL, G_CALLBACK(add_slide_sig) },
		{ "ButtonFirstSlideAction", GTK_STOCK_GOTO_FIRST, "First Slide",
			NULL, NULL, G_CALLBACK(first_slide_sig) },
		{ "ButtonPrevSlideAction", GTK_STOCK_GO_BACK, "Previous Slide",
			NULL, NULL, G_CALLBACK(prev_slide_sig) },
		{ "ButtonNextSlideAction", GTK_STOCK_GO_FORWARD, "Next Slide",
			NULL, NULL, G_CALLBACK(next_slide_sig) },
		{ "ButtonLastSlideAction", GTK_STOCK_GOTO_LAST, "Last Slide",
			NULL, NULL, G_CALLBACK(last_slide_sig) },

	};
	guint n_entries = G_N_ELEMENTS(entries);

	p->action_group = gtk_action_group_new("mainwindow");
	gtk_action_group_add_actions(p->action_group, entries, n_entries, p);

	p->ui = gtk_ui_manager_new();
	gtk_ui_manager_insert_action_group(p->ui, p->action_group, 0);
	g_signal_connect(p->ui, "add_widget", G_CALLBACK(add_ui_sig), vbox);
	if ( gtk_ui_manager_add_ui_from_file(p->ui,
	     DATADIR"/colloquium/colloquium.ui", &error) == 0 ) {
		fprintf(stderr, "Error loading main window menu bar: %s\n",
			error->message);
		return;
	}

	gtk_window_add_accel_group(GTK_WINDOW(p->window),
				   gtk_ui_manager_get_accel_group(p->ui));
	gtk_ui_manager_ensure_update(p->ui);

	update_toolbar(p);
}


static gint close_sig(GtkWidget *window, struct presentation *p)
{
	gtk_main_quit();
	return 0;
}


static gboolean im_commit_sig(GtkIMContext *im, gchar *str,
                              struct presentation *p)
{
	if ( p->editing_object == NULL ) return FALSE;
	if ( p->editing_object->type != TEXT ) return FALSE;

	insert_text(p->editing_object, str);

	/* FIXME: Invalidate only the necessary region */
	gdk_window_invalidate_rect(p->drawingarea->window, NULL, FALSE);

	return FALSE;
}


static gboolean key_press_sig(GtkWidget *da, GdkEventKey *event,
                              struct presentation *p)
{
	gboolean r;

	/* Throw the event to the IM context and let it sort things out */
	r = gtk_im_context_filter_keypress(GTK_IM_CONTEXT(p->im_context),
	                                   event);

	if ( r ) return FALSE;  /* IM ate it */

	if ( (p->editing_object != NULL)
	  && (p->editing_object->type == TEXT) )
	{
		switch ( event->keyval ) {

		case GDK_KEY_BackSpace :
			handle_text_backspace(p->editing_object);
			break;

		case GDK_KEY_Left :
			move_cursor_left(p->editing_object);
			break;

		case GDK_KEY_Right :
			move_cursor_right(p->editing_object);
			break;

		}
	}

	switch ( event->keyval ) {

	case GDK_KEY_Page_Up :
		prev_slide_sig(NULL, p);
		break;

	case GDK_KEY_Page_Down :
		next_slide_sig(NULL, p);
		break;

	}

	/* FIXME: Invalidate only the necessary region */
	gdk_window_invalidate_rect(p->drawingarea->window, NULL, FALSE);

	return FALSE;
}


static gboolean button_press_sig(GtkWidget *da, GdkEventButton *event,
                                 struct presentation *p)
{
	struct object *clicked;
	gdouble x, y;

	x = event->x - p->border_offs_x;
	y = event->y - p->border_offs_y;

	if ( p->editing_object && p->editing_object->empty ) {
		delete_object(p->editing_object);
	}
	p->editing_object = NULL;

	if ( (x>0.0) && (x<p->view_slide->slide_width)
	  && (y>0.0) && (y<p->view_slide->slide_height) )
	{
		clicked = find_object_at_position(p->view_slide, x, y);
		if ( !clicked ) {
			p->editing_object = add_text_object(p->view_slide,
			                                    x, y);
		} else {
			p->editing_object = clicked;
			position_caret(clicked, x, y);
		}

	}

	gtk_widget_grab_focus(GTK_WIDGET(da));

	/* FIXME: Invalidate only the necessary region */
	gdk_window_invalidate_rect(p->drawingarea->window, NULL, FALSE);

	return FALSE;
}


static void draw_editing_box(cairo_t *cr, double xmin, double ymin,
                                          double width, double height)
{
	cairo_new_path(cr);
	cairo_rectangle(cr, xmin-5.0, ymin-5.0, width+10.0, height+10.0);
	cairo_set_source_rgb(cr, 1.0, 0.0, 0.0);
	cairo_set_line_width(cr, 0.5);
	cairo_stroke(cr);
}


static void draw_editing_bits(cairo_t *cr, struct object *o)
{
	draw_editing_box(cr, o->x, o->y, o->bb_width, o->bb_height);

	switch ( o->type ) {

	case TEXT :

		draw_caret(cr, o);
		break;

	}
}


static void check_redraw_slide(struct slide *s)
{
	/* Update necessary? */
	if ( s->object_seq <= s->render_cache_seq ) return;

	render_slide(s);
}


static gboolean expose_sig(GtkWidget *da, GdkEventExpose *event,
                           struct presentation *p)
{
	cairo_t *cr;
	GtkAllocation allocation;
	double xoff, yoff;

	check_redraw_slide(p->view_slide);

	cr = gdk_cairo_create(da->window);

	/* Overall background */
	cairo_rectangle(cr, event->area.x, event->area.y,
	                event->area.width, event->area.height);
	cairo_set_source_rgb(cr, 0.9, 0.9, 0.9);
	cairo_fill(cr);

	/* Get the overall size */
	gtk_widget_get_allocation(da, &allocation);
	xoff = (allocation.width - p->slide_width)/2.0;
	yoff = (allocation.height - p->slide_height)/2.0;
	p->border_offs_x = xoff;  p->border_offs_y = yoff;

	/* Draw the slide from the cache */
	cairo_rectangle(cr, event->area.x, event->area.y,
	                event->area.width, event->area.height);
	cairo_set_source_surface(cr, p->view_slide->render_cache, xoff, yoff);
	cairo_fill(cr);

	cairo_translate(cr, xoff, yoff);

	/* Draw editing bits for selected object */
	if ( p->editing_object != NULL ) {
		draw_editing_bits(cr, p->editing_object);
	}

	cairo_destroy(cr);

	return FALSE;
}


int open_mainwindow(struct presentation *p)
{
	GtkWidget *window;
	GtkWidget *vbox;
	char *title;
	GtkWidget *sw;

	if ( p->window != NULL ) {
		fprintf(stderr, "Presentation window is already open!\n");
		return 1;
	}

	window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
	p->window = window;

	title = malloc(strlen(p->titlebar)+14);
	sprintf(title, "%s - Colloquium", p->titlebar);
	gtk_window_set_title(GTK_WINDOW(window), title);
	free(title);

	g_signal_connect(G_OBJECT(window), "destroy", G_CALLBACK(close_sig), p);

	vbox = gtk_vbox_new(FALSE, 0);
	gtk_container_add(GTK_CONTAINER(window), vbox);
	add_menu_bar(p, vbox);

	p->drawingarea = gtk_drawing_area_new();
	sw = gtk_scrolled_window_new(NULL, NULL);
	gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(sw),
	                               GTK_POLICY_AUTOMATIC,
	                               GTK_POLICY_AUTOMATIC);
	gtk_scrolled_window_add_with_viewport(GTK_SCROLLED_WINDOW(sw),
	                                      p->drawingarea);
	gtk_box_pack_start(GTK_BOX(vbox), sw, TRUE, TRUE, 0);
	gtk_widget_set_size_request(GTK_WIDGET(p->drawingarea),
	                            p->slide_width + 20,
	                            p->slide_height + 20);

	gtk_widget_set_can_focus(GTK_WIDGET(p->drawingarea), TRUE);
	gtk_widget_add_events(GTK_WIDGET(p->drawingarea),
	                      GDK_POINTER_MOTION_HINT_MASK
	                       | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK
	                       | GDK_KEY_PRESS_MASK | GDK_KEY_RELEASE_MASK);

	g_signal_connect(G_OBJECT(p->drawingarea), "button-press-event",
			 G_CALLBACK(button_press_sig), p);
	g_signal_connect(G_OBJECT(p->drawingarea), "key-press-event",
			 G_CALLBACK(key_press_sig), p);
	g_signal_connect(G_OBJECT(p->drawingarea), "expose-event",
			 G_CALLBACK(expose_sig), p);

	p->im_context = gtk_im_multicontext_new();
	gtk_im_context_set_client_window(GTK_IM_CONTEXT(p->im_context),
	                                 p->drawingarea->window);
	g_signal_connect(G_OBJECT(p->im_context), "commit",
			 G_CALLBACK(im_commit_sig), p);

	gtk_window_set_default_size(GTK_WINDOW(p->window), 1024+100, 768+100);
	gtk_window_set_resizable(GTK_WINDOW(p->window), TRUE);

	assert(p->num_slides > 0);
	check_redraw_slide(p->view_slide);

	gtk_widget_grab_focus(GTK_WIDGET(p->drawingarea));

	gtk_widget_show_all(window);
	return 0;
}