import pygame
import pygame.locals as pgl

from nagslang.resources import resources

POLY_COLORS = {
    1: pygame.color.THECOLORS['red'],
    2: pygame.color.THECOLORS['green'],
    3: pygame.color.THECOLORS['yellow'],
    4: pygame.color.THECOLORS['blue'],
    5: pygame.color.THECOLORS['lightblue'],
    6: pygame.color.THECOLORS['magenta'],
}


class Level(object):

    def __init__(self, name):
        self.name = name
        # defaults
        self.x = 800
        self.y = 600
        self.polygons = {}
        self.basetile = 'tiles/floor.png'
        self._tile_image = None
        self._surface = None
        self._exterior = False

    def load(self):

        def add_polygon(polygon, index, num_points):
            self.polygons[index] = polygon
            if len(polygon) != num_points:
                print 'Error - incorrect polygon size'
                print 'Expected: %d, got %d' % (num_points, len(polygon))

        inpoly = False
        polygon = []
        index = 0
        num_points = 0
        with resources.get_file('levels', self.name) as f:
            for line in f:
                if inpoly:
                    if not line.startswith('Point:'):
                        add_polygon(polygon, index, num_points)
                        polygon = []
                        inpoly = False
                        index = 0
                    else:
                        point = line.split(':', 1)[1]
                        x, y = [int(i) for i in point.split()]
                        polygon.append((x, y))
                if line.startswith('X-Size:'):
                    self.x = int(line.split(':', 1)[1])
                elif line.startswith('Y-Size:'):
                    self.y = int(line.split(':', 1)[1])
                elif line.startswith('Base tile:'):
                    self.basetile = line.split(':', 1)[1].strip()
                elif line.startswith('Polygon'):
                    rest = line.split(' ', 1)[1]
                    index, num_points = [int(x) for x in rest.split(':', 1)]
                    inpoly = True
        if index:
            add_polygon(polygon, index, num_points)

    def all_closed(self):
        """Check if all the polygons are closed"""
        closed = True
        for poly in self.polygons.values():
            if len(poly) == 0:
                # We ignore empty polygons
                continue
            elif len(poly) == 1:
                closed = False
                print "\033[31mError: polygon too small\033[0m"
            elif poly[-1] != poly[0]:
                closed = False
                print "\033[31mError: polygon not closed\033[0m"
        return closed

    def save(self):
        closed = self.all_closed()
        if not closed:
            print 'Not saving the level'
            return
        with resources.get_file('levels', self.name, mode='w') as f:
            f.write('X-Size: %s\n' % self.x)
            f.write('Y-Size: %s\n' % self.y)
            f.write('Base tile: %s\n' % self.basetile)
            for i, poly in self.polygons.items():
                if len(poly) == 0:
                    continue
                f.write('Polygon %d : %d\n' % (i, len(poly)))
                for point in poly:
                    f.write('Point: %d %d\n' % point)
        print 'level %s saved' % self.name

    def get_size(self):
        return self.x, self.y

    def set_base_tile(self, new_tile):
        self.basetile = new_tile
        self._tile_image = None

    def point_to_pygame(self, pos):
        # Convert a point from pymunk (which is what we store)
        # to pygame for drawing
        return (pos[0], self.y - pos[1])

    def get_walls(self):
        return self.polygons.values()

    def _draw_walls(self):
        for index, polygon in self.polygons.items():
            color = POLY_COLORS[index]
            if len(polygon) > 1:
                pointlist = [self.point_to_pygame(p) for p in polygon]
                pygame.draw.lines(self._surface, color, False, pointlist, 2)

    def get_background(self):
        self._draw_background()
        self._draw_exterior()
        # Draw polygons
        self._draw_walls()
        return self._surface

    def _draw_exterior(self, force=False):
        """Fill the exterior of the level with black"""
        if self._exterior and not force:
            return
        surface = pygame.surface.Surface((self.x, self.y), pgl.SRCALPHA)
        surface.fill(pygame.color.THECOLORS["black"])
        for index, polygon in self.polygons.items():
            if len(polygon) > 1:
                pointlist = [self.point_to_pygame(p) for p in polygon]
                # filled polygons
                pygame.draw.polygon(surface, pygame.color.THECOLORS['white'],
                                    pointlist, 0)
        self._surface.blit(surface, (0, 0), special_flags=pgl.BLEND_RGBA_MULT)
        self._exterior = True

    def _draw_background(self, force=False):
        if self._tile_image is None:
            self._tile_image = resources.get_image(self.basetile)
        if self._surface is not None and not force:
            # We assume we don't change
            return self._surface
        self._surface = pygame.surface.Surface((self.x, self.y), pgl.SRCALPHA)
        self._surface.fill(pygame.color.THECOLORS['black'])
        x_step = self._tile_image.get_rect().width
        y_step = self._tile_image.get_rect().height
        x_count = self.x // x_step + 1
        y_count = self.y / y_step + 1
        for x in range(x_count):
            for y in range(y_count):
                tile_rect = pygame.rect.Rect(x * x_step, y * y_step,
                                             x_step, y_step)
                self._surface.blit(self._tile_image, tile_rect)
        return self._surface