"""S1 替代真值：DOCX 目录里缓存的页码（生成文档的软件排版时写入）。
比较「各标题之间相隔的页数」，消除页码起始值的影响。"""
import json, re, sys, zipfile, pathlib
import pdfplumber

OUT = pathlib.Path(__file__).parent / "out"
norm = lambda s: re.sub(r"[\s　·.…\-—_]", "", s)

def toc_entries(docx):
    x = zipfile.ZipFile(docx).read("word/document.xml").decode()
    ents = []
    for p in re.findall(r"<w:p[ >].*?</w:p>", x, re.S):
        if "PAGEREF" not in p:
            continue
        # 段落里 PAGEREF 字段之前的文字是标题，字段结果是缓存页码
        before, after = p.split("PAGEREF", 1)
        title = norm("".join(re.findall(r"<w:t[^>]*>([^<]*)</w:t>", before)))
        num = re.findall(r"<w:t[^>]*>(\d+)</w:t>", after)
        if title and num:
            ents.append((title, int(num[0])))
    return ents

def heading_pages(pdf_path, titles):
    with pdfplumber.open(pdf_path) as pdf:
        texts = [norm(pg.extract_text() or "") for pg in pdf.pages]
    found = {}
    for t in titles:
        key = t[:18]
        hits = [i for i, tx in enumerate(texts) if key in tx]
        # 跳过目录页本身：取最后一个出现位置之前、且不在前 6 页的第一个命中
        body = [i for i in hits if i >= 4]
        found[t] = body[0] + 1 if body else None
    return found

rows = {}
for sid in ["S03", "S04", "S06"]:
    ents = toc_entries(OUT / "fixed-docx" / f"{sid}.docx")
    rows[sid] = {"entries": len(ents)}
    for cfg in ["A-fixed", "B-fixed", "C10-fixed", "C13-fixed"]:
        hp = heading_pages(OUT / cfg / f"{sid}.pdf", [t for t, _ in ents])
        pairs = [(n, hp[t]) for t, n in ents if hp[t]]
        if len(pairs) < 2:
            rows[sid][cfg] = None; continue
        (c0, p0), (c1, p1) = pairs[0], pairs[-1]
        span_t, span_p = c1 - c0, p1 - p0
        dev = [abs((p - p0) - (c - c0)) for c, p in pairs]
        rows[sid][cfg] = {"matched": len(pairs), "span_truth": span_t, "span_pdf": span_p,
                          "span_err_pct": round(100 * (span_p - span_t) / span_t, 1), "max_dev_pages": max(dev)}
    print(sid, json.dumps(rows[sid], ensure_ascii=False))
(OUT / "toc_truth.json").write_text(json.dumps(rows, ensure_ascii=False, indent=1))