import typing
from typing import Optional, Sequence, Tuple, Union

import cv2
import numpy as np

from ...core.bbox_utils import denormalize_bbox, normalize_bbox
from ...core.transforms_interface import BoxType, KeypointType
from ..functional import _maybe_process_in_chunks, pad_with_params, preserve_channel_dim
from ..geometric import functional as FGeometric

__all__ = [
    "get_random_crop_coords",
    "random_crop",
    "crop_bbox_by_coords",
    "bbox_random_crop",
    "crop_keypoint_by_coords",
    "keypoint_random_crop",
    "get_center_crop_coords",
    "center_crop",
    "bbox_center_crop",
    "keypoint_center_crop",
    "crop",
    "bbox_crop",
    "clamping_crop",
    "crop_and_pad",
    "crop_and_pad_bbox",
    "crop_and_pad_keypoint",
]


def get_random_crop_coords(height: int, width: int, crop_height: int, crop_width: int, h_start: float, w_start: float):
    # h_start is [0, 1) and should map to [0, (height - crop_height)]  (note inclusive)
    # This is conceptually equivalent to mapping onto `range(0, (height - crop_height + 1))`
    # See: https://github.com/albumentations-team/albumentations/pull/1080
    y1 = int((height - crop_height + 1) * h_start)
    y2 = y1 + crop_height
    x1 = int((width - crop_width + 1) * w_start)
    x2 = x1 + crop_width
    return x1, y1, x2, y2


def random_crop(img: np.ndarray, crop_height: int, crop_width: int, h_start: float, w_start: float):
    height, width = img.shape[:2]
    if height < crop_height or width < crop_width:
        raise ValueError(
            "Requested crop size ({crop_height}, {crop_width}) is "
            "larger than the image size ({height}, {width})".format(
                crop_height=crop_height, crop_width=crop_width, height=height, width=width
            )
        )
    x1, y1, x2, y2 = get_random_crop_coords(height, width, crop_height, crop_width, h_start, w_start)
    img = img[y1:y2, x1:x2]
    return img


def crop_bbox_by_coords(
    bbox: BoxType, crop_coords: Tuple[int, int, int, int], crop_height: int, crop_width: int, rows: int, cols: int
):
    """Crop a bounding box using the provided coordinates of bottom-left and top-right corners in pixels and the
    required height and width of the crop.

    Args:
        bbox (tuple): A cropped box `(x_min, y_min, x_max, y_max)`.
        crop_coords (tuple): Crop coordinates `(x1, y1, x2, y2)`.
        crop_height (int):
        crop_width (int):
        rows (int): Image rows.
        cols (int): Image cols.

    Returns:
        tuple: A cropped bounding box `(x_min, y_min, x_max, y_max)`.

    """
    bbox = typing.cast(BoxType, denormalize_bbox(bbox, rows, cols))
    x_min, y_min, x_max, y_max = bbox[:4]
    x1, y1, _, _ = crop_coords
    cropped_bbox = x_min - x1, y_min - y1, x_max - x1, y_max - y1
    return normalize_bbox(cropped_bbox, crop_height, crop_width)


def bbox_random_crop(
    bbox: BoxType, crop_height: int, crop_width: int, h_start: float, w_start: float, rows: int, cols: int
):
    crop_coords = get_random_crop_coords(rows, cols, crop_height, crop_width, h_start, w_start)
    return crop_bbox_by_coords(bbox, crop_coords, crop_height, crop_width, rows, cols)


def crop_keypoint_by_coords(keypoint: KeypointType, crop_coords: Tuple[int, int, int, int]):  # skipcq: PYL-W0613
    """Crop a keypoint using the provided coordinates of bottom-left and top-right corners in pixels and the
    required height and width of the crop.

    Args:
        keypoint (tuple): A keypoint `(x, y, angle, scale)`.
        crop_coords (tuple): Crop box coords `(x1, x2, y1, y2)`.

    Returns:
        A keypoint `(x, y, angle, scale)`.

    """
    x, y, angle, scale = keypoint[:4]
    x1, y1, _, _ = crop_coords
    return x - x1, y - y1, angle, scale


def keypoint_random_crop(
    keypoint: KeypointType, crop_height: int, crop_width: int, h_start: float, w_start: float, rows: int, cols: int
):
    """Keypoint random crop.

    Args:
        keypoint: (tuple): A keypoint `(x, y, angle, scale)`.
        crop_height (int): Crop height.
        crop_width (int): Crop width.
        h_start (int): Crop height start.
        w_start (int): Crop width start.
        rows (int): Image height.
        cols (int): Image width.

    Returns:
        A keypoint `(x, y, angle, scale)`.

    """
    crop_coords = get_random_crop_coords(rows, cols, crop_height, crop_width, h_start, w_start)
    return crop_keypoint_by_coords(keypoint, crop_coords)


def get_center_crop_coords(height: int, width: int, crop_height: int, crop_width: int):
    y1 = (height - crop_height) // 2
    y2 = y1 + crop_height
    x1 = (width - crop_width) // 2
    x2 = x1 + crop_width
    return x1, y1, x2, y2


def center_crop(img: np.ndarray, crop_height: int, crop_width: int):
    height, width = img.shape[:2]
    if height < crop_height or width < crop_width:
        raise ValueError(
            "Requested crop size ({crop_height}, {crop_width}) is "
            "larger than the image size ({height}, {width})".format(
                crop_height=crop_height, crop_width=crop_width, height=height, width=width
            )
        )
    x1, y1, x2, y2 = get_center_crop_coords(height, width, crop_height, crop_width)
    img = img[y1:y2, x1:x2]
    return img


def bbox_center_crop(bbox: BoxType, crop_height: int, crop_width: int, rows: int, cols: int):
    crop_coords = get_center_crop_coords(rows, cols, crop_height, crop_width)
    return crop_bbox_by_coords(bbox, crop_coords, crop_height, crop_width, rows, cols)


def keypoint_center_crop(keypoint: KeypointType, crop_height: int, crop_width: int, rows: int, cols: int):
    """Keypoint center crop.

    Args:
        keypoint (tuple): A keypoint `(x, y, angle, scale)`.
        crop_height (int): Crop height.
        crop_width (int): Crop width.
        rows (int): Image height.
        cols (int): Image width.

    Returns:
        tuple: A keypoint `(x, y, angle, scale)`.

    """
    crop_coords = get_center_crop_coords(rows, cols, crop_height, crop_width)
    return crop_keypoint_by_coords(keypoint, crop_coords)


def crop(img: np.ndarray, x_min: int, y_min: int, x_max: int, y_max: int):
    height, width = img.shape[:2]
    if x_max <= x_min or y_max <= y_min:
        raise ValueError(
            "We should have x_min < x_max and y_min < y_max. But we got"
            " (x_min = {x_min}, y_min = {y_min}, x_max = {x_max}, y_max = {y_max})".format(
                x_min=x_min, x_max=x_max, y_min=y_min, y_max=y_max
            )
        )

    if x_min < 0 or x_max > width or y_min < 0 or y_max > height:
        raise ValueError(
            "Values for crop should be non negative and equal or smaller than image sizes"
            "(x_min = {x_min}, y_min = {y_min}, x_max = {x_max}, y_max = {y_max}, "
            "height = {height}, width = {width})".format(
                x_min=x_min, x_max=x_max, y_min=y_min, y_max=y_max, height=height, width=width
            )
        )

    return img[y_min:y_max, x_min:x_max]


def bbox_crop(bbox: BoxType, x_min: int, y_min: int, x_max: int, y_max: int, rows: int, cols: int):
    """Crop a bounding box.

    Args:
        bbox (tuple): A bounding box `(x_min, y_min, x_max, y_max)`.
        x_min (int):
        y_min (int):
        x_max (int):
        y_max (int):
        rows (int): Image rows.
        cols (int): Image cols.

    Returns:
        tuple: A cropped bounding box `(x_min, y_min, x_max, y_max)`.

    """
    crop_coords = x_min, y_min, x_max, y_max
    crop_height = y_max - y_min
    crop_width = x_max - x_min
    return crop_bbox_by_coords(bbox, crop_coords, crop_height, crop_width, rows, cols)


def clamping_crop(img: np.ndarray, x_min: int, y_min: int, x_max: int, y_max: int):
    h, w = img.shape[:2]
    if x_min < 0:
        x_min = 0
    if y_min < 0:
        y_min = 0
    if y_max >= h:
        y_max = h - 1
    if x_max >= w:
        x_max = w - 1
    return img[int(y_min) : int(y_max), int(x_min) : int(x_max)]


@preserve_channel_dim
def crop_and_pad(
    img: np.ndarray,
    crop_params: Sequence[int],
    pad_params: Sequence[int],
    pad_value: Union[int, float],
    rows: int,
    cols: int,
    interpolation: int,
    pad_mode: int,
    keep_size: bool,
) -> np.ndarray:
    if crop_params is not None and any(i != 0 for i in crop_params):
        img = crop(img, *crop_params)
    if pad_params is not None and any(i != 0 for i in pad_params):
        img = pad_with_params(img, *pad_params, border_mode=pad_mode, value=pad_value)

    if keep_size:
        resize_fn = _maybe_process_in_chunks(cv2.resize, dsize=(cols, rows), interpolation=interpolation)
        img = resize_fn(img)

    return img


def crop_and_pad_bbox(
    bbox: BoxType,
    crop_params: Optional[Sequence[int]],
    pad_params: Optional[Sequence[int]],
    rows,
    cols,
    result_rows,
    result_cols,
    keep_size: bool,
) -> BoxType:
    x1, y1, x2, y2 = denormalize_bbox(bbox, rows, cols)

    if crop_params is not None:
        crop_x, crop_y = crop_params[:2]
        x1, y1, x2, y2 = x1 - crop_x, y1 - crop_y, x2 - crop_x, y2 - crop_y
    if pad_params is not None:
        top, bottom, left, right = pad_params
        x1, y1, x2, y2 = x1 + left, y1 + top, x2 + left, y2 + top

    bbox = typing.cast(BoxType, normalize_bbox((x1, y1, x2, y2), result_rows, result_cols))

    return bbox


def crop_and_pad_keypoint(
    keypoint: KeypointType,
    crop_params: Optional[Sequence[int]],
    pad_params: Optional[Sequence[int]],
    rows: int,
    cols: int,
    result_rows: int,
    result_cols: int,
    keep_size: bool,
) -> KeypointType:
    x, y, angle, scale = keypoint

    if crop_params is not None:
        crop_x1, crop_y1, crop_x2, crop_y2 = crop_params
        x, y = x - crop_x1, y - crop_y1
    if pad_params is not None:
        top, bottom, left, right = pad_params
        x, y = x + left, y + top

    if keep_size and (result_cols != cols or result_rows != rows):
        scale_x = cols / result_cols
        scale_y = rows / result_rows
        return FGeometric.keypoint_scale((x, y, angle, scale), scale_x, scale_y)

    return x, y, angle, scale
