#!/usr/bin/env python
from __future__ import division
import gtk
from threading import Thread
from math import pi, tan

import src as mt
from utils import BoundingBoxArea, Flick, FlickThread, GtkEventWindow
from hand import HandTracker

mt.register_tracker(HandTracker)


RED = 1, 0, 0
GREEN = 0, 1, 0
BLUE = 0, 0, 1
WHITE = 1, 1, 1
BLACK = 0, 0, 0


class Rectangle(mt.RectangularArea):
    def __init__(self, x, y, width, height, color=(1, 0, 0)):
        super(Rectangle, self).__init__(x, y, width, height)
        self.color = color
        self.on_drag(self.handle_drag)

    def handle_drag(self, g):
        tx, ty = g.get_translation()
        self.translate(tx, ty)
        refresh()

    def draw(self, cr):
        cr.rectangle(self.x, self.y, self.width, self.height)
        cr.set_source_rgb(*self.color)
        cr.fill()


class Polygon(BoundingBoxArea):
    def __init__(self, x, y, points, margin=0, color=BLUE, border_color=RED):
        super(Polygon, self).__init__(x, y, points)
        self.color = color
        self.border_color = border_color
        self.margin = margin

        self.on_drag(self.handle_drag)
        self.on_pinch(self.handle_pinch)
        self.on_rotate(self.handle_rotate)
        self.on_flick(self.handle_flick)
        self.on_tap(self.circulate_color)

    def circulate_color(self, g):
        self.color = self.color[2:] + self.color[:2]
        refresh()

    def flick_drag(self, amt):
        tx, ty = self.flick_direction
        self.translate(tx * amt, ty * amt)
        refresh()

    def handle_flick(self, g):
        trans = g.get_translation()

        if trans.distance_to((0, 0)) > 10:
            self.flick_direction = trans
            flicks.add(Flick(self.flick_drag, 0.7, 0.4))

    def margin_contains(self, x, y):
        m = self.margin
        return self.x - m <= x < self.x + self.width + m \
               and self.y - m <= y < self.y + self.height + m

    def contains(self, x, y):
        if draw_bounding_boxes:
            return self.margin_contains(self, x, y)

        return BoundingBoxArea.contains(self, x, y)

    def handle_drag(self, g):
        tx, ty = g.get_translation()
        self.translate(tx, ty)
        refresh()

    def handle_pinch(self, g):
        cx, cy = g.get_position()
        self.scale_points(g.get_scale(), cx, cy)
        self.update_bounds()
        refresh()

    def handle_rotate(self, g):
        cx, cy = g.get_position()
        self.rotate_points(g.get_angle(), cx, cy)
        self.update_bounds()
        refresh()

    def draw(self, cr):
        # Draw bounding box
        if draw_bounding_boxes:
            m = self.margin
            cr.rectangle(self.x - m, self.y - m,
                         self.width + 2 * m, self.height + 2 * m)
            cr.set_source_rgb(*self.border_color)
            cr.set_line_width(3)
            cr.stroke()

        # Fill polygon
        rx, ry = self.get_offset(root)
        cr.translate(rx, ry)
        cr.new_path()

        for x, y in zip(*self.points):
            cr.line_to(x, y)

        cr.set_source_rgb(*self.color)
        cr.fill()


fullscreen = False
draw_bounding_boxes = False
draw_touch_objects = True
W, H = mt.screen.screen_size


def toggle_fullscreen():
    global fullscreen
    (window.unfullscreen if fullscreen else window.fullscreen)()
    fullscreen = not fullscreen
    refresh()


def create_context_window(w, h, callback):
    def create_context(area, event):
        """Add Cairo context to GTK window and draw state."""
        global cr
        cr = area.window.cairo_create()
        draw()

    def handle_key(win, event):
        """Handle key event. 'f' toggles fullscreen, 'b' toggles bounding
        boxes, 'i' toggles input points, 'q' exits the program."""
        if event.keyval >= 256:
            return

        key = chr(event.keyval)

        if key == 'f':
            toggle_fullscreen()
        elif key == 'b':
            global draw_bounding_boxes
            draw_bounding_boxes = not draw_bounding_boxes
            refresh()
        elif key == 'i':
            global draw_touch_objects
            draw_touch_objects = not draw_touch_objects
            refresh()
        elif key == 'q':
            quit()

    def redraw_updated_window():
        refresh()
        return True

    # GTK window
    global window, root
    window = GtkEventWindow()
    window.set_title('Cairo test')
    window.connect('destroy', quit)
    window.connect('key-press-event', handle_key)
    window.connect('show', callback)
    window.on_update(redraw_updated_window)
    root = window.get_area()

    if fullscreen:
        window.fullscreen()

    # Drawing area, needed by cairo context for drawing
    area = gtk.DrawingArea()
    area.set_size_request(w, h)
    area.connect('expose-event', create_context)

    window.add(area)
    area.show()
    window.show()


def draw():
    if not cr:
        return

    # Background
    cr.rectangle(0, 0, *root.get_size())
    cr.set_source_rgb(*BLACK)
    cr.fill()

    # Drawable objects (use save and restore to allow transformations)
    for obj in draw_objects:
        cr.save()
        obj.draw(cr)
        cr.restore()

    if draw_touch_objects:
        ox, oy = root.get_position()
        cr.set_source_rgb(*WHITE)

        for hand in touch_hands:
            centroid = hand.get_centroid()

            # Check if all fingers have not been removed already
            if not centroid:
                continue

            cx, cy = centroid

            # Filled centroid circle
            if len(hand) > 1:
                cr.arc(cx - ox, cy - oy, 20, 0, 2 * pi)
                cr.fill()

            for x, y in hand:
                x -= ox
                y -= oy

                # Circle outline
                cr.set_line_width(3)
                cr.arc(x, y, 20, 0, 2 * pi)
                cr.stroke()

                # Line to centroid
                if len(hand) > 1:
                    cr.move_to(x, y)
                    cr.line_to(cx - ox, cy - oy)
                    cr.set_line_width(2)
                    cr.stroke()

                # Cross
                cr.set_line_width(1)
                cr.move_to(x - 8, y)
                cr.line_to(x + 8, y)
                cr.move_to(x, y - 8)
                cr.line_to(x, y + 8)
                cr.stroke()


def refresh(*args):
    window.queue_draw()


def quit(*args):
    gtk.main_quit()


# Global variables
window = cr = root = overlay = flicks = None
draw_objects = []
touch_hands = []


def triangle_height(width):
    return abs(.5 * width * tan(2 / 3 * pi))


def on_show(window):
    # Toggle fullscreen on double tap
    root.on_double_tap(lambda g: toggle_fullscreen())

    # Create blue rectangle
    x, y, w, h = 0, 0, 250, 150
    rect = Polygon(x, y, [(0, 0), (0, h), (w, h), (w, 0)], margin=20)
    draw_objects.append(rect)
    root.add_area(rect)

    # Create green triangle
    x, y, w = 400, 400, 200
    h = triangle_height(w)
    triangle = Polygon(x, y, [(0, h), (w, h), (w / 2, 0)],
                       margin=20, color=GREEN)
    draw_objects.append(triangle)
    root.add_area(triangle)

    # Overlay catches finger events to be able to draw touch points
    def handle_down(gesture):
        touch_hands.append(gesture.get_hand())

        if draw_touch_objects:
            refresh()

    def handle_up(gesture):
        touch_hands.remove(gesture.get_hand())

        if draw_touch_objects:
            refresh()

    global screen, overlay
    screen = mt.FullscreenArea()
    overlay = mt.FullscreenArea()
    screen.add_area(root)
    screen.add_area(overlay)

    overlay.on_hand_down(handle_down)
    overlay.on_finger_move(lambda g: draw_touch_objects and refresh())
    overlay.on_hand_up(handle_up)


    # Root area rotation leads to rotation of all polygons around the centroid
    def move_to_polygons(g):
        gx, gy = g.get_position()

        for obj in draw_objects:
            x, y = obj.get_position()
            g.set_position(gx - x, gy - y)
            yield obj, g

    def rotate_root(g):
        for obj, gesture in move_to_polygons(g):
            obj.handle_rotate(gesture)

    def scale_root(g):
        for obj, gesture in move_to_polygons(g):
            obj.handle_pinch(gesture)

    def drag_root(g):
        for obj, gesture in move_to_polygons(g):
            obj.handle_drag(gesture)

    root.on_rotate(rotate_root)
    root.on_pinch(scale_root)
    root.on_drag(drag_root)


if __name__ == '__main__':
    from parse_arguments import create_parser, parse_args

    # Parse arguments
    parser = create_parser()
    parser.add_argument('-f', '--fullscreen', action='store_true',
            default=False, help='run in fullscreen initially')
    args = parse_args(parser)

    fullscreen = args.fullscreen

    # Create a window with a Cairo context in it and a multi-touch area
    # syncronized with it
    create_context_window(800, 600, on_show)

    # Run multi-touch gesture server in separate thread
    driver = mt.create_driver(screen)
    mt_thread = Thread(target=driver.start)
    mt_thread.daemon = True
    mt_thread.start()

    # Flick movement is also handled in a separate thread
    flicks = FlickThread()
    flicks.daemon = True
    flicks.start()

    # Initialize threads in GTK so that the thread started above will work
    gtk.gdk.threads_init()

    # Start main loop in current thread
    gtk.main()