#!/usr/bin/env python3
"""
issue_index.py — rebuild tmp/issues/INDEX.md from what is on disk. No network.

The index is a map of the cache, nothing else: issues that were never fetched
do not appear. issue_get.py and issue_push.py call it automatically; run it by
hand only after deleting files.

Usage:
    issue_index.py [--out tmp/issues]
"""
import argparse
import os
import re
import sys

sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
from _tea import ISSUE_ROOT, parse_meta, read_file, write_file  # noqa: E402


def cell(v):
    if isinstance(v, list):
        return ", ".join(v) or "—"
    v = (v or "").strip()
    return v.replace("|", "\\|") or "—"


def build(root):
    rows = []
    for name in sorted(os.listdir(root)) if os.path.isdir(root) else []:
        m = re.match(r'^(\d+)\.md$', name)
        if not m:
            continue
        n = int(m.group(1))
        meta, title, _ = parse_meta(read_file(os.path.join(root, name)))
        labels = meta.get("labels") or []
        if isinstance(labels, str):
            labels = [labels]
        types = [l for l in labels if l.startswith("type/")]
        rest = [l for l in labels if not l.startswith("type/")]
        has_comments = os.path.isfile(os.path.join(root, "%d.comments.md" % n))
        rows.append({
            "n": n,
            "state": cell(meta.get("state")),
            "type": cell(types[0].split("/", 1)[1] if types else ""),
            "labels": cell(rest),
            "title": cell(title),
            "milestone": cell(meta.get("milestone")),
            "depends": cell(meta.get("depends")),
            "comments": ("[%s](%d.comments.md)" % (cell(meta.get("comments")), n)
                         if has_comments else "—"),
            "fetched": cell(meta.get("fetched"))[:10],
        })
    rows.sort(key=lambda r: r["n"])

    trees = sorted(f for f in (os.listdir(root) if os.path.isdir(root) else [])
                   if re.match(r'^tree-\d+\.md$', f))

    out = ["# Issue cache", "",
           "Local cache of fetched issues — not a mirror. Refresh with "
           "`issue_get.py <n>`; issues absent here were never fetched.", ""]
    if rows:
        out += ["| # | state | type | labels | title | milestone | depends | comments | fetched |",
                "|---|---|---|---|---|---|---|---|---|"]
        out += ["| [#%d](%d.md) | %s | %s | %s | %s | %s | %s | %s | %s |" % (
            r["n"], r["n"], r["state"], r["type"], r["labels"], r["title"],
            r["milestone"], r["depends"], r["comments"], r["fetched"]) for r in rows]
    else:
        out.append("_empty_")
    if trees:
        out += ["", "## Dependency trees", ""]
        out += ["- [%s](%s)" % (t, t) for t in trees]

    drafts_dir = os.path.join(root, "drafts")
    drafts = sorted(f for f in (os.listdir(drafts_dir) if os.path.isdir(drafts_dir) else [])
                    if f.endswith(".md"))
    if drafts:
        out += ["", "## Drafts (not yet pushed)", ""]
        out += ["- [drafts/%s](drafts/%s)" % (d, d) for d in drafts]

    out.append("")
    return write_file(os.path.join(root, "INDEX.md"), "\n".join(out)), len(rows)


def main():
    ap = argparse.ArgumentParser(description="Rebuild the issue cache index (no network)")
    ap.add_argument("--out", default=ISSUE_ROOT, help="cache root (default: tmp/issues)")
    args = ap.parse_args()
    path, n = build(args.out)
    print("%s — %d issue(s)" % (path, n))


if __name__ == "__main__":
    main()