from ..geom import Rect, Polygon
from .. import WIDTH, HEIGHT, get_cursor_pos
from ..colors import *
from ..math import *
from ..draw import *

class SeparatingAxisTheorem:

    title = "Separating Axis Theorem"

    def __init__(self):
        self.shape1 = Polygon(0, 0, [
            (0, 60),
            (60, 0),
            (0, -60),
            (-60, 0)
        ])

        self.shape2 = Polygon(*get_cursor_pos(), [
            (60, 60),
            (60, -60),
            (-60, -60),
            (-60, 60)
        ])

    def render(self, surface):
        self.shape2.set_position(*get_cursor_pos())

        normals = []

        def add_if_not_exists(normal):
            for existing in normals:
                if is_equal(*existing, *normal):
                    return
            normals.append(normal)

        for normal in self.shape1.get_normals() + self.shape2.get_normals():
            add_if_not_exists(normal)

        def get_min_max(normal, vertices):
            _min = float('inf')
            _max = float('-inf')
            for vertex in vertices:
                proj = dot(*normal, *vertex)
                _min = min(_min, proj)
                _max = max(_max, proj)
            return _min, _max

        collisions = []
        for normal in normals:
            min1, max1 = get_min_max(normal,
                                     self.shape1.get_translated_vertices())
            min2, max2 = get_min_max(normal,
                                     self.shape2.get_translated_vertices())

            colliding = max1 > min2 and max2 > min1
            collisions.append(colliding)

            offset = scale(*rnormal(*normal), 300)

            # axis
            line(surface, WHITE,
                 add(*scale(*reverse(*normal), 1000), *offset),
                 add(*scale(*normal, 1000), *offset))

            # shape 1
            line(surface, YELLOW if not colliding else RED,
                      add(*scale(*normal, min1), *offset),
                      add(*scale(*normal, max1), *offset), 5)
            # shape 2
            line(surface, YELLOW if not colliding else RED,
                      add(*scale(*normal, min2), *offset),
                      add(*scale(*normal, max2), *offset), 5)


        self.shape1.draw(surface, YELLOW, 4)
        self.shape2.draw(surface, RED if all(collisions) else WHITE, 4)