"""Manual grid selection module"""

import ImageDraw
from math import sqrt, acos, copysign

from geometry import l2ad, line, intersection

class UserQuitError(Exception):
    pass

class Screen:
    # TODO isn't this a duplicate of something?
    def __init__(self, res):
        pygame.init()
        pygame.display.set_mode(res)
        pygame.display.set_caption("Imago manual mode")
        self._screen = pygame.display.get_surface()

    def display_picture(self, img):
        pg_img = pygame.image.frombuffer(img.tostring(), img.size, img.mode)
        self._screen.blit(pg_img, (0, 0))
        pygame.display.flip()

def find_lines(im_orig):
    # TODO rename, refactor, comment
    import pygame

    im = im_orig.copy()

    screen = Screen(im.size)

    clock = pygame.time.Clock()
    draw = ImageDraw.Draw(im)
    hoshi = lambda c: draw.ellipse((c[0] - 1, c[1] - 1, c[0] + 1, c[1] + 1),
                 fill=(255, 64, 64))
    corners = []
    color = (64, 64, 255)
    line_width = 1
    lines_r = []

    while True:
        for event in pygame.event.get():
            if event.type == pygame.QUIT or event.type == pygame.KEYDOWN:
                pygame.quit()
                if len(corners) == 4:
                    return lines_r
                else:
                    raise UserQuitError 
            if event.type == pygame.MOUSEBUTTONDOWN:
                if len(corners) >= 4: 
                    corners = []
                    im = im_orig.copy()
                    draw = ImageDraw.Draw(im)

                if len(corners) < 4:
                    corners.append(pygame.mouse.get_pos())
                    draw.point(corners[:-1], fill=color)
                    if len(corners) == 4:
                        l_vert, l_hor = lines(corners)
                        for l in l_vert:
                            draw.line(l, fill=color, width=line_width)
                        for l in l_hor:
                            draw.line(l, fill=color, width=line_width)
                        # TODO sort by distance
                        l_vert.sort()
                        l_hor.sort()
                        for i in [3, 9, 15]:
                            for j in [3, 9, 15]:
                                hoshi(intersection(line(l_vert[i][0], l_vert[i][1]),
                                                   line(l_hor[j][0], l_hor[j][1])))
                        lines_r = [[l2ad(l, im.size) for l in l_vert], 
                                   [l2ad(l, im.size) for l in l_hor]]

        screen.display_picture(im)
        clock.tick(15)

def lines(corners):
    # TODO Error on triangle 
    corners.sort() # TODO does this help?
    # TODO refactor this vvv
    cor_d = [(corners[0], (c[0] - corners[0][0], c[1] - corners[0][1]), c) for c in
             corners[1:]]
    cor_d = [(float(a[0] * b[0] + a[1] * b[1]) / (sqrt(a[0] ** 2 + a[1] ** 2) *
              sqrt(b[0] **2 + b[1] ** 2)), a[0] * b[1] - b[0] * a[1], c) for a, b, c in cor_d]
    cor_d = sorted([(copysign(acos(min(a, 1)), b), c) for a, b, c in cor_d])
    corners = [corners[0]] + [c for _, c in cor_d]
    return (_lines(corners, 0) + 
            [(corners[0], corners[3]), (corners[1], corners[2])],
            _lines(corners[1:4] + [corners[0]], 0) + 
            [(corners[0], corners[1]), (corners[2], corners[3])])

def _lines(corners, n):
    # TODO what is this?
    if n == 0:
        x = half_line(corners)
        return (_lines([corners[0], x[0], x[1], corners[3]], 1) + [x] + 
                _lines([x[0], corners[1], corners[2], x[1]], 1))
    else:
        x = half_line(corners)
        c = intersection(line(x[0], corners[2]), line(corners[1], corners[3]))
        d = intersection(line(corners[0], corners[3]), line(corners[1], corners[2]))
        if d:
            l = (intersection(line(corners[0], corners[1]), line(c, d)),
                 intersection(line(corners[2], corners[3]), line(c, d)))
        else:
            lx = line(c, (c[0] + corners[0][0] - corners[3][0], 
                      c[1] + corners[0][1] - corners[3][1]))
            l = (intersection(line(corners[0], corners[1]), lx),
                 intersection(line(corners[2], corners[3]), lx))
        l2 = half_line([corners[0], l[0], l[1], corners[3]])
        if n == 1:
            return ([l, l2] + _lines([l[0], l2[0], l2[1], l[1]], 2)
                    + _lines([corners[0], l2[0], l2[1], corners[3]], 2)
                    + _lines([l[0], corners[1], corners[2], l[1]], 2))
        if n == 2:
            return [l, l2]


def half_line(corners):
    # TODO what is this?
    c = center(corners)
    d = intersection(line(corners[0], corners[3]), line(corners[1], corners[2]))
    if d:
        l = line(c, d)
    else:
        l = line(c, (c[0] + corners[0][0] - corners[3][0], 
                     c[1] + corners[0][1] - corners[3][1]))
    p1 = intersection(l, line(corners[0], corners[1]))
    p2 = intersection(l, line(corners[2], corners[3]))
    return (p1, p2)

def center(corners):
    """Given a list of four corner points, return the center of the square."""
    return intersection(line(corners[0], corners[2]), 
                        line(corners[1], corners[3]))