# -*- coding: utf-8 -*-
"""定标授权书扫描件：找纸张／版心边界，反推公章、印鉴、签名的真实毫米数。"""
import io
import os
import sys

import numpy as np
from PIL import Image

sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding="utf-8")

HERE = os.path.dirname(os.path.abspath(__file__))
SRC = os.path.join(HERE, "_bid_assets", "seal_src", "p1_img1.png")
SEAL = os.path.join(HERE, "_bid_assets", "seal")
OUT = os.path.join(HERE, "_tmp_inspect")
os.makedirs(OUT, exist_ok=True)

im = Image.open(SRC).convert("RGB")
a = np.asarray(im.convert("L"))
h, w = a.shape
print(f"扫描件 {w}×{h} px，宽高比 {w / h:.4f}"
      f"（A4 竖版应为 {210 / 297:.4f}）")

# 纸张边界：扫描仪底色通常明显暗于纸面
row_med = np.median(a, axis=1)
col_med = np.median(a, axis=0)
print(f"行中位亮度：首 {row_med[:8].astype(int)} … 末 {row_med[-8:].astype(int)}")
print(f"列中位亮度：首 {col_med[:8].astype(int)} … 末 {col_med[-8:].astype(int)}")

# 版心（印刷内容）边界：按暗像素投影
dark = a < 170
cols = dark.sum(axis=0)
rows = dark.sum(axis=1)
thr_c, thr_r = max(6, h // 400), max(6, w // 400)
xs = np.nonzero(cols > thr_c)[0]
ys = np.nonzero(rows > thr_r)[0]
print(f"\n内容范围 x[{xs.min()}, {xs.max()}]  y[{ys.min()}, {ys.max()}]"
      f"  即 {xs.max() - xs.min() + 1}×{ys.max() - ys.min() + 1} px")

# 假定纸张为 A4 且扫描件已裁到纸张边缘
for label, paper_w in (("按整幅=A4宽210mm", 210.0),
                       ("按整幅=A4高297mm定标", 297.0 * w / h)):
    mm_px = paper_w / w
    print(f"\n【{label}】1 px = {mm_px:.4f} mm  → 整幅 "
          f"{w * mm_px:.0f}×{h * mm_px:.0f} mm")
    for name in ("gongzhang", "yinjian", "signature"):
        p = os.path.join(SEAL, f"{name}.png")
        if not os.path.exists(p):
            continue
        al = np.asarray(Image.open(p))[..., 3]
        ys2, xs2 = np.nonzero(al > 8)
        bw, bh = xs2.max() - xs2.min() + 1, ys2.max() - ys2.min() + 1
        print(f"    {name:10s} {bw:4d}×{bh:4d} px = "
              f"{bw * mm_px:5.1f}×{bh * mm_px:5.1f} mm")

im.resize((w // 3, h // 3), Image.LANCZOS).save(
    os.path.join(OUT, "seal_src_thumb.jpg"), quality=80)
print(f"\n缩略图 → {os.path.join(OUT, 'seal_src_thumb.jpg')}")