import asyncio
import json
import pathlib
import shutil
from io import BytesIO
from typing import List, Union

from PIL import Image, ImageChops, ImageColor, ImageDraw, ImageFont, ImageOps
from PIL.ImageDraw import _color_diff


async def composite_regions(im, regions, color, masks_path) -> Union[Image.Image, None]:
    im2 = Image.new("RGB", im.size, color)

    loop = asyncio.get_running_loop()

    combined_mask = None
    for region in regions:
        mask = Image.open(masks_path / f"{region}.png").convert("1")
        if combined_mask is None:
            combined_mask = mask
        else:
            # combined_mask = ImageChops.logical_or(combined_mask, mask)
            combined_mask = await loop.run_in_executor(
                None, ImageChops.logical_and, combined_mask, mask
            )

    if combined_mask is None:  # No regions usually
        return None

    out = await loop.run_in_executor(None, Image.composite, im, im2, combined_mask.convert("L"))

    return out


def get_center(points):
    """
    Taken from https://stackoverflow.com/questions/4355894/how-to-get-center-of-set-of-points-using-python
    """
    x = [p[0] for p in points]
    y = [p[1] for p in points]
    return sum(x) / len(points), sum(y) / len(points)


def recommended_combinations(mask_centers):
    pass  # TODO: Create recommendation algo and test it


def floodfill(image, xy, value, border=None, thresh=0) -> set:
    """
    Taken and modified from PIL.ImageDraw.floodfill

    (experimental) Fills a bounded region with a given color.

    :param image: Target image.
    :param xy: Seed position (a 2-item coordinate tuple). See
        :ref:`coordinate-system`.
    :param value: Fill color.
    :param border: Optional border value.  If given, the region consists of
        pixels with a color different from the border color.  If not given,
        the region consists of pixels having the same color as the seed
        pixel.
    :param thresh: Optional threshold value which specifies a maximum
        tolerable difference of a pixel value from the 'background' in
        order for it to be replaced. Useful for filling regions of
        non-homogeneous, but similar, colors.
    """
    # based on an implementation by Eric S. Raymond
    # amended by yo1995 @20180806
    pixel = image.load()
    x, y = xy
    try:
        background = pixel[x, y]
        if _color_diff(value, background) <= thresh:
            return set()  # seed point already has fill color
        pixel[x, y] = value
    except (ValueError, IndexError):
        return set()  # seed point outside image
    edge = {(x, y)}
    # use a set to keep record of current and previous edge pixels
    # to reduce memory consumption
    filled_pixels = set()
    full_edge = set()
    while edge:
        filled_pixels.update(edge)
        new_edge = set()
        for (x, y) in edge:  # 4 adjacent method
            for (s, t) in ((x + 1, y), (x - 1, y), (x, y + 1), (x, y - 1)):
                # If already processed, or if a coordinate is negative, skip
                if (s, t) in full_edge or s < 0 or t < 0:
                    continue
                try:
                    p = pixel[s, t]
                except (ValueError, IndexError):
                    pass
                else:
                    full_edge.add((s, t))
                    if border is None:
                        fill = _color_diff(p, background) <= thresh
                    else:
                        fill = p != value and p != border
                    if fill:
                        pixel[s, t] = value
                        new_edge.add((s, t))
        full_edge = edge  # discard pixels processed
        edge = new_edge
    return filled_pixels


class ConquestMap:
    def __init__(self, path: pathlib.Path):
        self.path = path

        self.name = None
        self.custom = None
        self.region_max = None
        self.regions = {}

    async def change_name(self, new_name: str, new_path: pathlib.Path):
        if new_path.exists() and new_path.is_dir():
            # This is an overwrite operation
            # await ctx.maybe_send_embed(f"{map_name} already exists, okay to overwrite?")
            #
            # pred = MessagePredicate.yes_or_no(ctx)
            # try:
            #     await self.bot.wait_for("message", check=pred, timeout=30)
            # except TimeoutError:
            #     await ctx.maybe_send_embed("Response timed out, cancelling save")
            #     return
            # if not pred.result:
            #     return
            return False, "Overwrite currently not supported"

        # This is a new name
        new_path.mkdir()

        shutil.copytree(self.path, new_path)

        self.name = new_name
        self.path = new_path

        await self.save_data()

        return True

    def masks_path(self):
        return self.path / "masks"

    def data_path(self):
        return self.path / "data.json"

    def blank_path(self):
        return self.path / "blank.png"  # Everything is png now

    def numbers_path(self):
        return self.path / "numbers.png"

    def numbered_path(self):
        return self.path / "numbered.png"

    async def init_directory(self, name: str, path: pathlib.Path, image: Image.Image):
        if not path.exists() or not path.is_dir():
            path.mkdir()

        self.name = name
        self.path = path

        await self.save_data()

        image.save(self.blank_path(), "PNG")

        return True

    async def save_data(self):
        to_save = self.__dict__.copy()
        to_save.pop("path")
        with self.data_path().open("w+") as dp:
            json.dump(to_save, dp, sort_keys=True, indent=4)

    async def load_data(self):
        with self.data_path().open() as dp:
            data = json.load(dp)

        self.name = data["name"]
        self.custom = data["custom"]
        self.region_max = data["region_max"]

        self.regions = {key: Region(**data) for key, data in data["regions"].items()}

    async def save_region(self, region):
        if not self.custom:
            return False
        pass

    async def generate_masks(self):
        regioner = Regioner(filename="blank.png", filepath=self.path)
        loop = asyncio.get_running_loop()
        regions = await loop.run_in_executor(None, regioner.execute)

        if not regions:
            return regions

        self.regions = regions
        self.region_max = len(regions) + 1

        await self.save_data()

    async def create_number_mask(self):
        regioner = Regioner(filename="blank.png", filepath=self.path)
        loop = asyncio.get_running_loop()
        return await loop.run_in_executor(None, regioner.create_number_mask, self.regions)

    async def combine_masks(self, mask_list: List[int]):
        loop = asyncio.get_running_loop()
        lowest, eliminated = await loop.run_in_executor(None, self._img_combine_masks, mask_list)

        if not lowest:
            return lowest

        elim_regions = [self.regions[n] for n in eliminated]
        lowest_region = self.regions[lowest]

        # points = [self.mm["regions"][f"{n}"]["center"] for n in mask_list]
        #
        # points = [(r.center, r.weight) for r in elim_regions]

        weighted_points = [r.center for r in elim_regions for _ in range(r.weight)]

        lowest_region.center = get_center(weighted_points)

        for key in eliminated:
            self.regions.pop(key)
            # self.mm["regions"].pop(f"{key}")

        if self.region_max in eliminated:  # Max region has changed
            self.region_max = max(self.regions.keys())

        await self.create_number_mask()

        await self.save_data()

    def _img_combine_masks(self, mask_list: List[int]):
        if not mask_list:
            return False, None

        if not self.blank_path().exists():
            return False, None

        if not self.masks_path().exists():
            return False, None

        base_img: Image.Image = Image.open(self.blank_path())
        mask = Image.new("1", base_img.size, 1)

        lowest_num = None
        eliminated_masks = []

        for mask_num in mask_list:
            if lowest_num is None or mask_num < lowest_num:
                lowest_num = mask_num
            else:
                eliminated_masks.append(mask_num)

            mask2 = Image.open(self.masks_path() / f"{mask_num}.png").convert("1")
            mask = ImageChops.logical_and(mask, mask2)

        mask.save(self.masks_path() / f"{lowest_num}.png", "PNG")
        return lowest_num, eliminated_masks

    async def get_sample(self):
        files = [self.blank_path()]

        masks_dir = self.masks_path()
        if masks_dir.exists() and masks_dir.is_dir():
            loop = asyncio.get_running_loop()
            current_map = Image.open(self.blank_path())

            regions = list(self.regions.keys())
            fourth = len(regions) // 4

            current_map = await composite_regions(
                current_map, regions[:fourth], ImageColor.getrgb("red"), self.masks_path()
            )
            current_map = await composite_regions(
                current_map,
                regions[fourth: fourth * 2],
                ImageColor.getrgb("green"),
                self.masks_path(),
            )
            current_map = await composite_regions(
                current_map,
                regions[fourth * 2: fourth * 3],
                ImageColor.getrgb("blue"),
                self.masks_path(),
            )
            current_map = await composite_regions(
                current_map, regions[fourth * 3:], ImageColor.getrgb("yellow"), self.masks_path()
            )

            numbers = Image.open(self.numbers_path()).convert("L")
            inverted_map = ImageOps.invert(current_map)
            current_numbered_img = await loop.run_in_executor(
                None, Image.composite, current_map, inverted_map, numbers
            )

            buffer1 = BytesIO()
            buffer2 = BytesIO()

            current_map.save(buffer1, "png")
            buffer1.seek(0)
            current_numbered_img.save(buffer2, "png")
            buffer2.seek(0)

            files.append(buffer1)
            files.append(buffer2)

        return files


class Region:
    def __init__(self, center, weight, **kwargs):
        self.center = center
        self.weight = weight
        self.data = kwargs


class Regioner:
    def __init__(
            self, filepath: pathlib.Path, filename: str, wall_color="black", region_color="white"
    ):
        self.filepath = filepath
        self.filename = filename
        self.wall_color = ImageColor.getcolor(wall_color, "L")
        self.region_color = ImageColor.getcolor(region_color, "L")

    def execute(self):
        """
        Create the regions of the map

        TODO: Using proper multithreading best practices.
        TODO: This is iterating over a 2d array with some overlap, you went to school for this Bozo

        TODO: Fails on some maps where borders aren't just black (i.e. water borders vs region borders)
        """

        base_img_path = self.filepath / self.filename
        if not base_img_path.exists():
            return False

        masks_path = self.filepath / "masks"

        if not masks_path.exists():
            masks_path.mkdir()

        black = ImageColor.getcolor("black", "L")
        white = ImageColor.getcolor("white", "L")

        base_img: Image.Image = Image.open(base_img_path).convert("L")
        already_processed = set()

        mask_count = 0
        regions = {}

        for y1 in range(base_img.height):
            for x1 in range(base_img.width):
                if (x1, y1) in already_processed:
                    continue
                if base_img.getpixel((x1, y1)) == self.region_color:
                    filled = floodfill(base_img, (x1, y1), black, self.wall_color)
                    if filled:  # Pixels were updated, make them into a mask
                        mask = Image.new("L", base_img.size, 255)
                        for x2, y2 in filled:
                            mask.putpixel((x2, y2), 0)  # TODO: Switch to ImageDraw

                        mask_count += 1
                        mask = mask.convert("L")
                        mask.save(masks_path / f"{mask_count}.png", "PNG")

                        regions[mask_count] = Region(
                            center=get_center(filled), weight=len(filled)
                        )

                        already_processed.update(filled)

        # TODO: save mask_centers

        self.create_number_mask(regions)
        return regions

    def create_number_mask(self, regions):
        base_img_path = self.filepath / self.filename
        if not base_img_path.exists():
            return False

        base_img: Image.Image = Image.open(base_img_path).convert("L")

        number_img = Image.new("L", base_img.size, 255)
        fnt = ImageFont.load_default()
        d = ImageDraw.Draw(number_img)
        for region_num, region in regions.items():
            center = region.center
            text = getattr(region, "center", str(region_num))
            d.text(center, text, font=fnt, fill=0)
        number_img.save(self.filepath / f"numbers.png", "PNG")
        return True