"""
check_pdf_size.py – verify that a PDF's page dimensions match 35 mm × 25 mm.

Usage:
    python check_pdf_size.py [path/to/label.pdf]

If no path is given the script operates on every PDF found in pdf_backup/.
Exit code 0 = all OK, 1 = mismatch or error.
"""

import os
import sys

# ── Target dimensions ────────────────────────────────────────────────────────
TARGET_W_MM = 35.0   # width  (landscape, wider side)
TARGET_H_MM = 25.0   # height
TOLERANCE_MM = 0.5   # ± 0.5 mm is acceptable rounding from PDF viewers

PT_PER_MM = 72.0 / 25.4   # 1 mm in points


def read_page_size_pt(pdf_path):
    """
    Return (width_pt, height_pt) of the first page of *pdf_path*.
    Tries pypdf first, then pymupdf (fitz) as a fallback.
    Raises RuntimeError if neither library is available.
    """
    # ── pypdf ────────────────────────────────────────────────────────────────
    try:
        from pypdf import PdfReader                     # type: ignore
        reader = PdfReader(pdf_path)
        page = reader.pages[0]
        w = float(page.mediabox.width)
        h = float(page.mediabox.height)
        return w, h
    except ImportError:
        pass

    # ── pymupdf (fitz) ───────────────────────────────────────────────────────
    try:
        import fitz                                     # type: ignore
        doc = fitz.open(pdf_path)
        rect = doc[0].rect
        return rect.width, rect.height
    except ImportError:
        pass

    raise RuntimeError(
        "Install pypdf or pymupdf:\n"
        "  pip install pypdf\n"
        "  pip install pymupdf"
    )


def check_file(pdf_path):
    """Print a pass/fail line for one PDF.  Returns True if dimensions match."""
    if not os.path.exists(pdf_path):
        print(f"  MISS  {pdf_path}  (file not found)")
        return False

    try:
        w_pt, h_pt = read_page_size_pt(pdf_path)
    except Exception as e:
        print(f"  ERR   {pdf_path}  ({e})")
        return False

    w_mm = w_pt / PT_PER_MM
    h_mm = h_pt / PT_PER_MM

    w_ok = abs(w_mm - TARGET_W_MM) <= TOLERANCE_MM
    h_ok = abs(h_mm - TARGET_H_MM) <= TOLERANCE_MM
    ok = w_ok and h_ok

    status = "PASS" if ok else "FAIL"
    print(
        f"  {status}  {os.path.basename(pdf_path)}"
        f"  {w_mm:.2f}×{h_mm:.2f} mm"
        f"  (target {TARGET_W_MM}×{TARGET_H_MM} mm ±{TOLERANCE_MM} mm)"
    )
    return ok


def main():
    targets = sys.argv[1:]

    if not targets:
        backup_dir = os.path.join(os.path.dirname(__file__), "pdf_backup")
        if os.path.isdir(backup_dir):
            targets = [
                os.path.join(backup_dir, f)
                for f in sorted(os.listdir(backup_dir))
                if f.lower().endswith(".pdf")
            ]
        if not targets:
            # fall back to test_label.pdf in cwd
            targets = ["test_label.pdf"]

    print(f"Checking {len(targets)} PDF(s)…")
    results = [check_file(p) for p in targets]

    total  = len(results)
    passed = sum(results)
    failed = total - passed
    print(f"\n  {passed}/{total} passed" + (f", {failed} FAILED" if failed else ""))
    sys.exit(0 if failed == 0 else 1)


if __name__ == "__main__":
    main()