# Copyright (C) 2020 by ÿnérant, eichhornchen, nicomarg, charlse
# SPDX-License-Identifier: GPL-3.0-or-later

from enum import auto, Enum
from random import choice, random, randint, shuffle

from ..interfaces import Map, Tile


DEFAULT_PARAMS = {
        "width" : 80,
        "height" : 40,
        "tries" : 600,
        "max_rooms" : 99,
        "max_room_tries" : 15,
        "cross_room" : 1,
        "corridor_chance" : .8,
        "min_v_corr" : 2,
        "max_v_corr" : 6,
        "min_h_corr" : 4,
        "max_h_corr" : 12,
        "large_circular_room" : .10,
        "circular_holes" : .5,
}

class Generator:
    def __init__(self, params: dict = DEFAULT_PARAMS):
        self.params = params

    @staticmethod
    def room_fits(level, y, x, room, door_y, door_x, dy, dx):
        if level[y][x] != Tile.EMPTY or level[y-dy][x-dx] != Tile.FLOOR:
            return False
        lh, lw = len(level), len(level[0])
        rh, rw = len(room), len(room[0])
        for ry in range(rh):
            for rx in range(rw):
                if room[ry][rx] == Tile.FLOOR:
                    ly, lx = y + ry - door_y, x + rx - door_x
                    if not(0 <= ly <= rh and 0 <= lx <= rw) or \
                            level[ly][lx] == Tile.FLOOR:
                        return False
        return True

    @staticmethod
    def place_room(level, y, x, door_y, door_x, room):
        rh, rw = len(room), len(room[0])
        # maybe place Tile.DOOR here ?
        level[door_y][door_x] = Tile.FLOOR
        for ry in range(rh):
            for rx in range(rw):
                if room[ry][rx] == Tile.FLOOR:
                    level[y-door_y+ry][y-door_x+rx] = Tile.FLOOR

    @staticmethod
    def place_walls(level):
        h, w = len(level), len(level[0])
        for y in range(h):
            for x in range(w):
                if level[y][x] == Tile.FLOOR:
                    for dy, dx in Map.neighbourhood(level, y, x):
                        if level[y+dy][x+dx] == Tile.EMPTY:
                            level[y+dy][x+dx] = Tile.FLOOR
 
    def corr_meta_info(self):
        if random() < self.params["corridor_chance"]:
            h_sup = randint(self.params["min_h_corr"], \
                    self.params["max_h_corr"]) if random() < .5 else 0
            w_sup = 0 if h_sup else randint(self.params["min_w_corr"], \
                    self.params["max_w_coor"])
            h_off = h_sup if random() < .5 else 0
            w_off = w_sup if random() < .5 else 0
            return h_sup, w_sup, h_off, w_off
        return 0, 0, 0, 0

    def attach_door(self, room, h_sup, w_sup, h_off, w_off):
        l = h_sup + w_sup
        dy, dx = 0, 0
        if l > 0:
            if h_sup:
                dy = -1 if h_off else 1
            else:
                dx = -1 if w_off else 1
        else:
            if random() < .5:
                dy = -1 if random() < .5 else 1
            else:
                dx = -1 if random() < .5 else 1

        yxs = [i for i in range(len(room) * len(room[0]))]
        shuffle(yxs)
        for pos in yxs:
            y, x = pos // len(room), pos % len(room)
            if room[y][x] == Tile.EMPTY:
                if room[y-dy][x-dx] == Tile.FLOOR:
                    build_here = True
                    for i in range(l):
                        if room[y+i*dy][x+i*dx] != Tile.EMPTY:
                            build_here = False
                            break
                    if build_here:
                        for i in range(l):
                            room[y+i*dy][x+i*dx] == Tile.FLOOR
                        break
        return y+l*dy, x+l*dx, dy, dx


    def create_circular_room(self):
        if random() < self.params["large_circular_room"]:
            r = randint(5, 10)
        else:
            r = randint(2, 4)

        room = []
        
        h_sup, w_sup, h_off, w_off = self.corr_meta_info()

        height = 2*r+2
        width = 2*r+2
        make_hole = r > 6 and random() < self.params["circular_holes"]
        if make_hole:
            r2 = randint(3, r-3)
        for i in range(height+h_sup):
            room.append([])
            d = (i-h_off-height//2)**2
            for j in range(width+w_sup):
                if d + (j-w_off-width//2)**2 < r**2 and \
                        (not(make_hole) or d + (j-w_off-width//2)**2 >= r2**2):
                    room[-1].append(Tile.FLOOR)
                else:
                    room[-1].append(Tile.EMPTY)

        door_y, door_x, dy, dx = self.attach_door(room, h_sup, w_sup, h_off, w_off)

        return room, door_y, door_x, dy, dx

    def create_random_room(self):
        return self.create_circular_room()
    
    def run(self):
        height, width = self.params["height"], self.params["width"]
        level = [[Tile.EMPTY for i in range(width)] for j in range(height)]

        # the starting room must have no corridor
        mem, self.params["corridor_chance"] = self.params["corridor_chance"], 0
        starting_room, _, _, _, _ = self.create_random_room()
        self.place_room(level, height//2, width//2, 0, 0, starting_room)
        self.params["corridor_chance"] = mem

        # find a starting position
        sy, sx = randint(0, height-1), randint(0, width-1)
        while level[sy][sx] != Tile.FLOOR:
            sy, sx = randint(0, height-1), randint(0, width-1)

        # now we loop until we've tried enough, or we've added enough rooms
        tries, rooms_built = 0, 0
        while tries < self.params["tries"] and rooms_built < self.params["max_rooms"]:

            room, door_y, door_x, dy, dx = self.create_random_room()
            positions = [i for i in range()]
            shuffle(positions)
            for pos in positions:
                y, x = pos // height, pos % width
                if self.room_fits(level, y, x, room, door_y, door_x, dy, dx):
                    self.place_room(level, y, x, door_y, door_x, room)

        # post-processing
        self.place_walls(level)

        return Map(width, height, level, sy, sx)