import abc
from typing import Optional

import cv2
import torch
from loguru import logger
import numpy as np

from lama_cleaner.helper import boxes_from_mask, resize_max_size, pad_img_to_modulo
from lama_cleaner.schema import Config, HDStrategy


class InpaintModel:
    min_size: Optional[int] = None
    pad_mod = 8
    pad_to_square = False

    def __init__(self, device):
        """

        Args:
            device:
        """
        self.device = device
        self.init_model(device)

    @abc.abstractmethod
    def init_model(self, device):
        ...

    @staticmethod
    @abc.abstractmethod
    def is_downloaded() -> bool:
        ...

    @abc.abstractmethod
    def forward(self, image, mask, config: Config):
        """Input images and output images have same size
        images: [H, W, C] RGB
        masks: [H, W] 255 为 masks 区域
        return: BGR IMAGE
        """
        ...

    def _pad_forward(self, image, mask, config: Config):
        origin_height, origin_width = image.shape[:2]
        pad_image = pad_img_to_modulo(image, mod=self.pad_mod, square=self.pad_to_square, min_size=self.min_size)
        pad_mask = pad_img_to_modulo(mask, mod=self.pad_mod, square=self.pad_to_square, min_size=self.min_size)

        logger.info(f"final forward pad size: {pad_image.shape}")

        result = self.forward(pad_image, pad_mask, config)
        result = result[0:origin_height, 0:origin_width, :]

        original_pixel_indices = mask < 127
        result[original_pixel_indices] = image[:, :, ::-1][original_pixel_indices]
        return result

    @torch.no_grad()
    def __call__(self, image, mask, config: Config):
        """
        images: [H, W, C] RGB, not normalized
        masks: [H, W]
        return: BGR IMAGE
        """
        inpaint_result = None
        logger.info(f"hd_strategy: {config.hd_strategy}")
        if config.hd_strategy == HDStrategy.CROP:
            if max(image.shape) > config.hd_strategy_crop_trigger_size:
                logger.info(f"Run crop strategy")
                boxes = boxes_from_mask(mask)
                crop_result = []
                for box in boxes:
                    crop_image, crop_box = self._run_box(image, mask, box, config)
                    crop_result.append((crop_image, crop_box))

                inpaint_result = image[:, :, ::-1]
                for crop_image, crop_box in crop_result:
                    x1, y1, x2, y2 = crop_box
                    inpaint_result[y1:y2, x1:x2, :] = crop_image

        elif config.hd_strategy == HDStrategy.RESIZE:
            if max(image.shape) > config.hd_strategy_resize_limit:
                origin_size = image.shape[:2]
                downsize_image = resize_max_size(image, size_limit=config.hd_strategy_resize_limit)
                downsize_mask = resize_max_size(mask, size_limit=config.hd_strategy_resize_limit)

                logger.info(f"Run resize strategy, origin size: {image.shape} forward size: {downsize_image.shape}")
                inpaint_result = self._pad_forward(downsize_image, downsize_mask, config)

                # only paste masked area result
                inpaint_result = cv2.resize(inpaint_result,
                                            (origin_size[1], origin_size[0]),
                                            interpolation=cv2.INTER_CUBIC)

                original_pixel_indices = mask < 127
                inpaint_result[original_pixel_indices] = image[:, :, ::-1][original_pixel_indices]

        if inpaint_result is None:
            inpaint_result = self._pad_forward(image, mask, config)

        return inpaint_result

    def _run_box(self, image, mask, box, config: Config):
        """

        Args:
            image: [H, W, C] RGB
            mask: [H, W, 1]
            box: [left,top,right,bottom]

        Returns:
            BGR IMAGE
        """
        box_h = box[3] - box[1]
        box_w = box[2] - box[0]
        cx = (box[0] + box[2]) // 2
        cy = (box[1] + box[3]) // 2
        img_h, img_w = image.shape[:2]

        w = box_w + config.hd_strategy_crop_margin * 2
        h = box_h + config.hd_strategy_crop_margin * 2

        _l = cx - w // 2
        _r = cx + w // 2
        _t = cy - h // 2
        _b = cy + h // 2

        l = max(_l, 0)
        r = min(_r, img_w)
        t = max(_t, 0)
        b = min(_b, img_h)

        # try to get more context when crop around image edge 
        if _l < 0:
            r += abs(_l)
        if _r > img_w:
            l -= (_r - img_w)
        if _t < 0:
            b += abs(_t)
        if _b > img_h:
            t -= (_b - img_h)

        l = max(l, 0)
        r = min(r, img_w)
        t = max(t, 0)
        b = min(b, img_h)

        crop_img = image[t:b, l:r, :]
        crop_mask = mask[t:b, l:r]

        logger.info(f"box size: ({box_h},{box_w}) crop size: {crop_img.shape}")

        return self._pad_forward(crop_img, crop_mask, config), [l, t, r, b]