#!/usr/bin/env python3
# =============================================================================
# skills/ingest/scripts/index-append.py
# Insert an entry line into the correct section of wiki/index.md and keep that
# section's entries alphabetically ordered. Bumps frontmatter last_updated.
#
#   index-append.py --section Sources \
#       --entry '- [[sources/foo]] — One-line summary. `maturity: draft`'
# =============================================================================
import argparse
import datetime
import re
import sys

ENTRY_RE = re.compile(r"^- \[\[")
LINK_RE = re.compile(r"^- \[\[([^\]]+)\]\]")
HEADER_RE = re.compile(r"^## ")


def main() -> int:
    ap = argparse.ArgumentParser()
    ap.add_argument("--section", required=True,
                    help="Section name, e.g. Sources / Entities / Concepts / Queries / Conflicts")
    ap.add_argument("--entry", required=True, help="Full index line to insert")
    ap.add_argument("--file", default="wiki/index.md")
    args = ap.parse_args()

    try:
        with open(args.file, encoding="utf-8") as fh:
            lines = fh.read().splitlines()
    except FileNotFoundError:
        print(f"index-append: not found: {args.file}", file=sys.stderr)
        return 1

    today = datetime.date.today().isoformat()

    # 1. Bump last_updated inside the first frontmatter block
    fm_open = False
    fm_close_idx = None
    bumped = False
    for i, ln in enumerate(lines):
        if ln.strip() == "---":
            if not fm_open:
                fm_open = True
                continue
            fm_close_idx = i  # the closing ---
            break
        if fm_open and ln.startswith("last_updated:"):
            lines[i] = f"last_updated: {today}"
            bumped = True

    if not fm_open:
        print("index-append: warning: no frontmatter found, last_updated not bumped",
              file=sys.stderr)
    elif not bumped and fm_close_idx is not None:
        # self-heal: frontmatter present but missing the key — insert it before the close
        lines.insert(fm_close_idx, f"last_updated: {today}")
        print("index-append: last_updated key was missing — inserted", file=sys.stderr)

    # 2. Locate the target section [start, end)
    start = None
    for i, ln in enumerate(lines):
        if HEADER_RE.match(ln) and ln[3:].startswith(args.section):
            start = i
            break
    if start is None:
        print(f"index-append: section '{args.section}' not found in {args.file}",
              file=sys.stderr)
        return 1

    end = len(lines)
    for i in range(start + 1, len(lines)):
        if HEADER_RE.match(lines[i]):
            end = i
            break

    # 3. Split the section body into intro (non-entry) and entries
    body = lines[start + 1:end]
    intro = [ln for ln in body if not ENTRY_RE.match(ln)]
    entries = [ln for ln in body if ENTRY_RE.match(ln)]

    # Deduplicate by wikilink PATH, not by exact line: a re-ingest with a changed
    # summary/maturity should UPDATE the existing entry, not add a duplicate line.
    new_m = LINK_RE.match(args.entry)
    new_link = new_m.group(1) if new_m else None

    if new_link is not None:
        replaced = False
        for idx, ln in enumerate(entries):
            m = LINK_RE.match(ln)
            if m and m.group(1) == new_link:
                if ln == args.entry:
                    print("index-append: entry already present, skipping")
                    return 0
                entries[idx] = args.entry          # same page, refreshed text
                replaced = True
                break
        if not replaced:
            entries.append(args.entry)
    else:
        # No parseable wikilink — fall back to exact-line dedup.
        if args.entry in entries:
            print("index-append: entry already present, skipping")
            return 0
        entries.append(args.entry)

    entries.sort(key=str.casefold)

    # Normalise intro: drop trailing blanks, keep header + comment(s)
    while intro and intro[-1].strip() == "":
        intro.pop()

    new_section = intro + [""] + entries + [""]
    lines = lines[:start + 1] + new_section + lines[end:]

    with open(args.file, "w", encoding="utf-8") as fh:
        fh.write("\n".join(lines) + "\n")

    print(f"index-append: added to {args.section}")
    return 0


if __name__ == "__main__":
    sys.exit(main())