//
//  Copyright (C) 2017 Santiago León O., Adam Bieńkowski
//
//  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/>.
//

public class Gala.Plugins.PIP.SelectionArea : Clutter.Actor
{
	public signal void captured (int x, int y, int width, int height);
	public signal void selected (int x, int y);
	public signal void closed ();

	public Gala.WindowManager wm { get; construct; }

	private Gala.ModalProxy? modal_proxy;
	private Gdk.Point start_point;
	private Gdk.Point end_point;
	private bool dragging = false;
	private bool clicked = false;

	public SelectionArea (Gala.WindowManager wm)
	{
		Object (wm: wm);
	}

	construct
	{
		start_point = { 0, 0 };
		end_point = { 0, 0 };
		visible = true;
		reactive = true;

		int screen_width, screen_height;
		wm.get_screen ().get_size (out screen_width, out screen_height);
		width = screen_width;
		height = screen_height;

		var canvas = new Clutter.Canvas ();
		canvas.set_size (screen_width, screen_height);
		canvas.draw.connect (draw_area);
		set_content (canvas);

		canvas.invalidate ();
	}

	public override bool key_press_event (Clutter.KeyEvent e)
	{
		if (e.keyval == Clutter.Key.Escape) {
			close ();
			closed ();
			return true;
		}

		return false;
	}

	public override bool button_press_event (Clutter.ButtonEvent e)
	{
		if (dragging || e.button != 1) {
			return true;
		}

		clicked = true;

		start_point.x = (int) e.x;
		start_point.y = (int) e.y;

		return true;
	}

	public override bool button_release_event (Clutter.ButtonEvent e)
	{
		if (e.button != 1) {
			return true;
		}

		if (!dragging) {
			selected ((int) e.x, (int) e.y);
			close ();
			return true;
		}

		dragging = false;
		clicked = false;

		int x, y, w, h;
		get_selection_rectangle (out x, out y, out w, out h);
		close ();
		start_point = { 0, 0 };
		end_point = { 0, 0 };
		this.hide ();
		content.invalidate ();

		captured (x, y, w, h);

		return true;
	}

	public override bool motion_event (Clutter.MotionEvent e)
	{
		if (!clicked) {
			return true;
		}

		end_point.x = (int) e.x;
		end_point.y = (int) e.y;
		content.invalidate ();

		if (!dragging) {
			dragging = true;
		}

		return true;
	}

	public void close ()
	{
		wm.get_screen ().set_cursor (Meta.Cursor.DEFAULT);

		if (modal_proxy != null) {
			wm.pop_modal (modal_proxy);
		}
	}

	public void start_selection ()
	{
		wm.get_screen ().set_cursor (Meta.Cursor.CROSSHAIR);
		grab_key_focus ();

		modal_proxy = wm.push_modal ();
	}

	private void get_selection_rectangle (out int x, out int y, out int width, out int height)
	{
		x = int.min (start_point.x, end_point.x);
		y = int.min (start_point.y, end_point.y);
		width = (start_point.x - end_point.x).abs ();
		height = (start_point.y - end_point.y).abs ();
	}

	private bool draw_area (Cairo.Context ctx)
	{
		Clutter.cairo_clear (ctx);

		if (!dragging) {
			return true;
		}

		int x, y, w, h;
		get_selection_rectangle (out x, out y, out w, out h);

		ctx.rectangle (x, y, w, h);
		ctx.set_source_rgba (0.1, 0.1, 0.1, 0.2);
		ctx.fill ();

		ctx.rectangle (x, y, w, h);
		ctx.set_source_rgb (0.7, 0.7, 0.7);
		ctx.set_line_width (1.0);
		ctx.stroke ();

		return true;
	}
}