"""Detect and decode barcodes / QR codes from an image file using zxing-cpp."""
from __future__ import annotations

import logging
from dataclasses import dataclass, field
from pathlib import Path

logger = logging.getLogger(__name__)

# Human-readable names for zxing BarcodeFormat values
_FORMAT_NAMES: dict[str, str] = {
    "QRCode": "二维码 (QR Code)",
    "DataMatrix": "DataMatrix",
    "Aztec": "Aztec",
    "PDF417": "PDF417",
    "MicroQRCode": "微型二维码",
    "RMQRCode": "R型QR码",
    "EAN8": "EAN-8",
    "EAN13": "EAN-13",
    "UPCE": "UPC-E",
    "UPCA": "UPC-A",
    "Code39": "Code 39",
    "Code93": "Code 93",
    "Code128": "Code 128",
    "ITF": "ITF（交叉二五码）",
    "Codabar": "Codabar",
    "DataBar": "DataBar",
    "DataBarExpanded": "DataBar Expanded",
    "MaxiCode": "MaxiCode",
    "DXFilmEdge": "DXFilmEdge",
    "LinearCodes": "一维码",
    "MatrixCodes": "矩阵码",
}


@dataclass
class BarcodeResult:
    format: str          # zxing format string, e.g. "EAN13"
    format_label: str    # Chinese-friendly label
    text: str            # decoded text / number
    # bounding box in image pixels (top-left origin)
    x0: int
    y0: int
    x1: int
    y1: int
    valid: bool          # zxing isValid


def detect_barcodes(image_path: Path) -> list[BarcodeResult]:
    """Scan *image_path* for all barcodes and QR codes.

    Returns a list of :class:`BarcodeResult`, one entry per detected code.
    Returns an empty list when nothing is found or on error.
    """
    try:
        import zxingcpp
    except ImportError:
        logger.warning("zxing-cpp not installed; barcode detection skipped")
        return []

    try:
        from PIL import Image
        img = Image.open(image_path).convert("RGB")
    except Exception as exc:
        logger.warning("barcode_detector: cannot open image %s: %s", image_path, exc)
        return []

    try:
        results = zxingcpp.read_barcodes(img)
    except Exception as exc:
        logger.warning("barcode_detector: zxing scan failed: %s", exc)
        return []

    output: list[BarcodeResult] = []
    for r in results:
        fmt_str = str(r.format).replace("BarcodeFormat.", "")
        label = _FORMAT_NAMES.get(fmt_str, fmt_str)

        # zxing-cpp position: r.position is a quadrilateral with four points
        try:
            pts = r.position
            xs = [pts.top_left.x, pts.top_right.x, pts.bottom_right.x, pts.bottom_left.x]
            ys = [pts.top_left.y, pts.top_right.y, pts.bottom_right.y, pts.bottom_left.y]
            x0, y0, x1, y1 = int(min(xs)), int(min(ys)), int(max(xs)), int(max(ys))
        except Exception:
            x0 = y0 = x1 = y1 = 0

        output.append(BarcodeResult(
            format=fmt_str,
            format_label=label,
            text=r.text,
            x0=x0, y0=y0, x1=x1, y1=y1,
            valid=r.valid,
        ))
        logger.info(
            "barcode_detector: found %s  text=%r  bbox=(%d,%d,%d,%d)",
            fmt_str, r.text, x0, y0, x1, y1,
        )

    if not output:
        logger.info("barcode_detector: no barcode/QR found in %s", image_path.name)

    return output