"""水印 调试图保存（由 ocr_utils.watermark_utils 迁入）。"""
from __future__ import annotations

import json
import re
from pathlib import Path
from typing import Any, Dict, Optional, Tuple, Union

import cv2
import numpy as np
from loguru import logger
from PIL import Image

from ocr_utils.watermark.removal import render_watermark_mask_overlay

def _image_to_bgr_for_debug(img: np.ndarray) -> np.ndarray:
    """将 ndarray 转为 BGR，供 cv2.imwrite 使用。"""
    if img.ndim == 2:
        return cv2.cvtColor(img, cv2.COLOR_GRAY2BGR)
    out = img.copy()
    if out.shape[2] == 3:
        return cv2.cvtColor(out, cv2.COLOR_RGB2BGR)
    return out


def save_watermark_removal_debug(
    before: Union[np.ndarray, Image.Image],
    after: Union[np.ndarray, Image.Image],
    output_dir: Union[str, Path],
    page_name: str,
    *,
    processing_params: Optional[Dict[str, Any]] = None,
    image_format: str = "png",
    save_compare: bool = True,
    subdir: str = "watermark_removal",
    mask_overlay: Optional[np.ndarray] = None,
) -> Dict[str, str]:
    """
    保存去水印调试图（before / after / compare / meta.json）。

    与 universal_doc_parser 的 module debug 目录结构一致：
    ``{output_dir}/debug/{subdir}/``

    Args:
        before: 处理前图像（RGB/BGR/灰度）
        after: 处理后图像
        output_dir: 输出根目录（通常为 pipeline 或工具的输出目录）
        page_name: 文件名前缀（如 ``doc_page_002``）
        processing_params: 写入 meta.json 的参数（threshold、contrast_enhancement 等）
        image_format: 图片格式，png/jpg
        save_compare: 是否保存左右拼接对比图
        subdir: debug 根目录下的子目录名（默认 watermark_removal）

    Returns:
        已保存文件路径字典（before/after/compare/meta，未保存的键省略）
    """
    if isinstance(before, Image.Image):
        before = np.array(before)
    if isinstance(after, Image.Image):
        after = np.array(after)

    from ocr_utils.module_debug_viz import resolve_module_debug_dir

    debug_dir = resolve_module_debug_dir(output_dir, subdir)

    fmt = (image_format or "png").lstrip(".")
    before_bgr = _image_to_bgr_for_debug(before)
    after_bgr = _image_to_bgr_for_debug(after)

    paths: Dict[str, str] = {}
    before_path = debug_dir / f"{page_name}_watermark_before.{fmt}"
    after_path = debug_dir / f"{page_name}_watermark_after.{fmt}"
    cv2.imwrite(str(before_path), before_bgr)
    cv2.imwrite(str(after_path), after_bgr)
    paths["before"] = str(before_path)
    paths["after"] = str(after_path)

    if save_compare:
        h = max(before_bgr.shape[0], after_bgr.shape[0])
        if before_bgr.shape[0] != h:
            before_bgr = cv2.resize(before_bgr, (before_bgr.shape[1], h))
        if after_bgr.shape[0] != h:
            after_bgr = cv2.resize(after_bgr, (after_bgr.shape[1], h))
        compare = np.hstack([before_bgr, after_bgr])
        compare_path = debug_dir / f"{page_name}_watermark_compare.{fmt}"
        cv2.imwrite(str(compare_path), compare)
        paths["compare"] = str(compare_path)
        logger.info(f"Saved watermark compare: {compare_path}")

    if mask_overlay is not None:
        mask_bgr = _image_to_bgr_for_debug(mask_overlay)
        mask_path = debug_dir / f"{page_name}_watermark_mask.{fmt}"
        cv2.imwrite(str(mask_path), mask_bgr)
        paths["mask"] = str(mask_path)

    meta: Dict[str, Any] = {"page_name": page_name}
    if processing_params:
        _skip_meta = (
            "midtone_mask",
            "wm_mask",
            "wm_candidate",
            "geom_region",
            "geom_candidate",
            "diag_region",
            "text_protect",
            "seal_protect",
            "hough_lines_bgr",
            "diag_ratio_heatmap",
            "hv_ratio_heatmap",
        )
        meta_params = {
            k: v
            for k, v in processing_params.items()
            if k not in _skip_meta
        }
        meta.update(meta_params)
    else:
        meta.update({})
    meta["before"] = paths["before"]
    meta["after"] = paths["after"]
    if "compare" in paths:
        meta["compare"] = paths["compare"]

    meta_path = debug_dir / f"{page_name}_watermark_meta.json"
    meta_path.write_text(json.dumps(meta, ensure_ascii=False, indent=2), encoding="utf-8")
    paths["meta"] = str(meta_path)

    logger.info(f"Saved watermark debug: {before_path}, {after_path}")
    return paths