"""License status by code. Published 1930 or earlier = US public domain as of 2026. Anything else is unknown."""
import datetime
import os
import re

import pdftext

PATTERNS = [r"first\s+published\s+in\s+(\d{4})", r"(?:©|copyright|\(c\))\s*(\d{4})"]


def find_year(units):
    """Earliest year the book's own front pages give as first publication or copyright: (year, where, text) or None."""
    for pat in PATTERNS:
        for u in units[:8]:
            m = re.search(pat, u["text"], re.I)
            if m:
                return int(m.group(1)), "pdf p.%d" % u["pdf_page"], m.group(0)
    return None


def run(cfg, book_dir, book, pdf):
    found = find_year(pdftext.units(pdf))
    limit = cfg["license"]["public_domain_max_year"]
    if found is None:
        status, reason, year = "unknown", "no publication year found in the book's own text", None
    else:
        year, where, quote = found
        if year <= limit:
            status = "public domain"
            reason = "published %d (book text, %s: \"%s\"), %d or earlier, so US public domain as of 2026" % (year, where, quote, limit)
        else:
            status = "unknown"
            reason = "published %d (book text, %s: \"%s\"), later than %d, so the date rule does not clear it; confirm before sharing" % (year, where, quote, limit)
    today = datetime.date.today().isoformat()
    book["published_year"] = year
    book["license"] = {"status": status, "reason": reason, "checked": today}
    with open(os.path.join(book_dir, "LICENSE_STATUS.md"), "w", encoding="utf-8") as f:
        f.write("# License status\n\nStatus: %s\n\nReason: %s\n\nDate checked: %s\n\n"
                "Rule: published %d or earlier is public domain in the US as of 2026; anything else is unknown until confirmed. "
                "Status never blocks audio production. Nothing is published.\n" % (status, reason, today, limit))