/* This file is part of Cinaest.
 *
 * Copyright (C) 2010 Philipp Zabel
 *
 * Cinaest 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.
 *
 * Cinaest 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 Cinaest. If not, see <http://www.gnu.org/licenses/>.
 */

using Gtk;

public class RatingWidget : DrawingArea {
	private int rating;
	private bool button_pressed;
	private Gdk.Color active_color;
	private Gdk.Color disabled_color;

	public RatingWidget () {
		var style = Gtk.rc_get_style_by_paths (this.get_settings (), "GtkButton", null, typeof (Gtk.Button));
		if (!style.lookup_color ("ActiveTextColor", out active_color))
			Gdk.Color.parse ("white", out active_color);
		if (!style.lookup_color ("DisabledTextColor", out disabled_color))
			Gdk.Color.parse ("black", out disabled_color);

		add_events (Gdk.EventMask.BUTTON_PRESS_MASK
		            | Gdk.EventMask.BUTTON_RELEASE_MASK
		            | Gdk.EventMask.POINTER_MOTION_MASK);

		set_size_request (640, 70);
	}

	public override bool expose_event (Gdk.EventExpose event) {
		var cr = Gdk.cairo_create (this.window);
		cr.rectangle (event.area.x, event.area.y, event.area.width, event.area.height);
		cr.clip ();

		for (int i = 0; i < 10; i++) {
			draw_star (cr, i, (i >= rating) ? disabled_color : active_color);
		}

		return false;
	}

	private void draw_star (Cairo.Context cr, int n, Gdk.Color color) {
		var radius = double.min (this.allocation.width / 20,
		                         this.allocation.height / 2);
		var x = radius * (2 * n + 1);
		var y = this.allocation.height / 2;

		cr.set_source_rgb (color.red / 65535.0, color.green / 65535.0, color.blue / 65535.0);
		cr.new_path ();
		for (int i = 0; i <= 10; i++) {
			double r = radius * (5 + 8 * (i % 2)) / 13.0;
			double a = x + r * Math.cos (i * 2*Math.PI/10.0 + Math.PI/2.0);
			double b = y + r * Math.sin (i * 2*Math.PI/10.0 + Math.PI/2.0);
			if (i == 0)
				cr.move_to (a, b);
			else
				cr.line_to (a, b);
		}
		cr.close_path ();
		cr.fill_preserve ();
	}

	public override bool button_press_event (Gdk.EventButton event) {
		button_pressed = true;
		rate (10 * event.x / this.allocation.width);

		return false;
	}

	public override bool button_release_event (Gdk.EventButton event) {
		button_pressed = false;

		return false;
	}

	public override bool motion_notify_event (Gdk.EventMotion event) {
		if (button_pressed)
			rate (10 * event.x / this.allocation.width);

		return false;
	}

	private void rate (double r) {
		if (r <= 0)
			rating = 0;
		else
			rating = (int) r + 1;
		if (rating > 10)
			rating = 10;

		unowned Gdk.Region region = this.window.get_clip_region ();
		// redraw the cairo canvas completely by exposing it
		this.window.invalidate_region (region, true);
		this.window.process_updates (true);
	}

	public int get_rating () {
		return rating;
	}
}