# MIT License
# Copyright (c) Kentaro Wada

from __future__ import annotations

import math
import uuid

import numpy as np
import PIL.Image
import PIL.ImageDraw
from numpy.typing import NDArray

from labelme._label_file import ShapeDict


def shape_to_mask(
    img_shape: tuple[int, ...],
    points: list[list[float]],
    shape_type: str | None = None,
    line_width: int = 10,
    point_size: int = 5,
) -> NDArray[np.bool_]:
    mask = PIL.Image.fromarray(np.zeros(img_shape[:2], dtype=np.uint8))
    draw = PIL.ImageDraw.Draw(mask)
    xy = [tuple(point) for point in points]
    if shape_type == "circle":
        assert len(xy) == 2, "Shape of shape_type=circle must have 2 points"
        (cx, cy), (px, py) = xy
        d = math.sqrt((cx - px) ** 2 + (cy - py) ** 2)
        draw.ellipse([cx - d, cy - d, cx + d, cy + d], outline=1, fill=1)
    elif shape_type == "rectangle":
        assert len(xy) == 2, "Shape of shape_type=rectangle must have 2 points"
        (x0, y0), (x1, y1) = xy
        draw.rectangle(
            ((min(x0, x1), min(y0, y1)), (max(x0, x1), max(y0, y1))),
            outline=1,
            fill=1,
        )
    elif shape_type == "line":
        assert len(xy) == 2, "Shape of shape_type=line must have 2 points"
        draw.line(xy=xy, fill=1, width=line_width)  # type: ignore[arg-type]
    elif shape_type == "linestrip":
        draw.line(xy=xy, fill=1, width=line_width)  # type: ignore[arg-type]
    elif shape_type == "point":
        assert len(xy) == 1, "Shape of shape_type=point must have 1 points"
        cx, cy = xy[0]
        r = point_size
        draw.ellipse([cx - r, cy - r, cx + r, cy + r], outline=1, fill=1)
    elif shape_type in [None, "polygon"]:
        assert len(xy) > 2, "Polygon must have points more than 2"
        draw.polygon(xy=xy, outline=1, fill=1)  # type: ignore[arg-type]
    else:
        raise ValueError(f"shape_type={shape_type!r} is not supported.")
    return np.array(mask, dtype=bool)


def shapes_to_label(
    img_shape: tuple[int, ...],
    shapes: list[ShapeDict],
    label_name_to_value: dict[str, int],
) -> tuple[NDArray[np.int32], NDArray[np.int32]]:
    cls = np.zeros(img_shape[:2], dtype=np.int32)
    ins = np.zeros_like(cls)
    instances = []
    for shape in shapes:
        points = shape["points"]
        label = shape["label"]
        group_id = shape.get("group_id")
        if group_id is None:
            group_id = uuid.uuid1()
        shape_type = shape.get("shape_type", None)

        cls_name = label
        instance = (cls_name, group_id)

        if instance not in instances:
            instances.append(instance)
        ins_id = instances.index(instance) + 1
        cls_id = label_name_to_value[cls_name]

        mask: NDArray[np.bool_]
        if shape_type == "mask":
            if not isinstance(shape["mask"], np.ndarray):
                raise ValueError("shape['mask'] must be numpy.ndarray")
            mask = np.zeros(img_shape[:2], dtype=bool)
            (x1, y1), (x2, y2) = np.asarray(points).astype(int)
            mask[y1 : y2 + 1, x1 : x2 + 1] = shape["mask"]
        else:
            mask = shape_to_mask(img_shape[:2], points, shape_type)

        cls[mask] = cls_id
        ins[mask] = ins_id

    return cls, ins


def masks_to_bboxes(masks: NDArray[np.bool_]) -> NDArray[np.float32]:
    if masks.ndim != 3:
        raise ValueError(f"masks.ndim must be 3, but it is {masks.ndim}")
    if masks.dtype != bool:
        raise ValueError(f"masks.dtype must be bool type, but it is {masks.dtype}")
    bboxes = []
    for mask in masks:
        where = np.argwhere(mask)
        (y1, x1), (y2, x2) = where.min(0), where.max(0) + 1
        bboxes.append((y1, x1, y2, x2))
    return np.asarray(bboxes, dtype=np.float32)
