from typing import Dict, List, Tuple

import cv2
import numpy as np
import logging

# 尝试延迟引入 pyzbar；在未安装 zbar 运行库的环境下，保证服务可启动，
# 后续仅使用自研 EAN-13 解码或返回空结果。
try:
    from pyzbar.pyzbar import decode as _pyzbar_decode, ZBarSymbol as _ZBarSymbol
    _PYZBAR_AVAILABLE = True
except Exception as _e:  # ImportError 或 zbar 动态库缺失
    _PYZBAR_AVAILABLE = False
    _PYZBAR_IMPORT_ERR = _e
    _pyzbar_decode = None
    _ZBarSymbol = None


def _prepare_images(gray: np.ndarray, try_invert: bool, rotations: List[int]) -> List[Tuple[np.ndarray, int, bool]]:
    # 返回 (图像, 旋转角度, 是否反色)
    images: List[Tuple[np.ndarray, int, bool]] = []
    for ang in rotations:
        if ang % 360 == 0:
            rot = gray
        elif ang % 360 == 90:
            rot = cv2.rotate(gray, cv2.ROTATE_90_CLOCKWISE)
        elif ang % 360 == 180:
            rot = cv2.rotate(gray, cv2.ROTATE_180)
        elif ang % 360 == 270:
            rot = cv2.rotate(gray, cv2.ROTATE_90_COUNTERCLOCKWISE)
        else:
            # 任意角度插值旋转
            h, w = gray.shape[:2]
            M = cv2.getRotationMatrix2D((w / 2, h / 2), ang, 1.0)
            rot = cv2.warpAffine(gray, M, (w, h), flags=cv2.INTER_LINEAR)
        images.append((rot, ang, False))
        if try_invert:
            images.append((cv2.bitwise_not(rot), ang, True))
    return images


def _collect_supported_symbols() -> List["_ZBarSymbol"]:
    names = [
        "EAN13",
        "EAN8",
        "UPCA",
        "UPCE",
        "CODE128",
        "CODE39",
        "QRCODE",
        # 兼容不同版本：有的叫 ITF，有的叫 I25
        "ITF",
        "I25",
    ]
    symbols: List["_ZBarSymbol"] = []
    if not _PYZBAR_AVAILABLE:
        return symbols
    for n in names:
        if hasattr(_ZBarSymbol, n):
            symbols.append(getattr(_ZBarSymbol, n))
    # 若列表为空，退回由 zbar 自行决定的默认集合
    return symbols


def decode_with_pyzbar(image_bgr: np.ndarray, try_invert: bool, rotations: List[int]) -> List[Dict[str, str]]:
    logger = logging.getLogger("pyzbar_engine")
    if not _PYZBAR_AVAILABLE or _pyzbar_decode is None:
        # 缺少 pyzbar/zbar，返回空集合并提示
        logger.warning("pyzbar 或 zbar 未就绪，已跳过 pyzbar 解码: %s", str(locals().get('_PYZBAR_IMPORT_ERR', '')))  # type: ignore
        return []
    # 输入 BGR，转灰度
    gray = cv2.cvtColor(image_bgr, cv2.COLOR_BGR2GRAY)
    results: List[Dict[str, str]] = []
    symbols = _collect_supported_symbols()
    logger.debug("调用 pyzbar: symbols=%d, rotations=%s, try_invert=%s", len(symbols) if symbols else 0, rotations, try_invert)
    for img, ang, inv in _prepare_images(gray, try_invert=try_invert, rotations=rotations):
        # pyzbar 要求 8bit 图像
        decoded = _pyzbar_decode(img, symbols=symbols or None)
        for obj in decoded:
            data = obj.data.decode("utf-8", errors="ignore")
            typ = obj.type
            results.append({"type": typ, "code": data})
        if results:
            # 若当前设置已识别出内容，继续下一个旋转场景以收集更多，但不必反复
            # 这里不提前返回，以便尽量收集多结果
            pass
    # 去重（按 type+code）
    uniq = []
    seen = set()
    for r in results:
        key = (r["type"], r["code"]) if isinstance(r, dict) else (None, None)
        if key not in seen:
            seen.add(key)
            uniq.append(r)
    logger.debug("pyzbar 返回结果数: %d", len(uniq))
    return uniq