#!/usr/bin/env python3
"""Tiny Plan F3 CLI: create/update/rebuild/sync-refs/images."""
from __future__ import annotations

import sys
from datetime import datetime, timezone
from pathlib import Path

ROOT = Path(__file__).resolve().parents[1]
PLANS = ROOT / "plans"


def plan_dir(product_id: str) -> Path:
    return PLANS / product_id


def create(product_id: str, purpose: str) -> Path:
    d = plan_dir(product_id)
    d.mkdir(parents=True, exist_ok=True)
    md = (PLANS / "templates" / "plan.template.md").read_text(encoding="utf-8")
    html = (PLANS / "templates" / "plan.template.html").read_text(encoding="utf-8")
    for p, text in [(d / "plan.md", md), (d / "plan.html", html)]:
        p.write_text(text.replace("{{product_id}}", product_id).replace("{{purpose}}", purpose), encoding="utf-8")
    return d / "plan.md"


def update(product_id: str, note: str) -> Path:
    p = plan_dir(product_id) / "plan.md"
    ts = datetime.now(timezone.utc).isoformat()
    with p.open("a", encoding="utf-8") as f:
        f.write(f"\n## Amendment {ts}\n{note}\n")
    return p


def rebuild(product_id: str) -> Path:
    p = plan_dir(product_id) / "plan.md"
    text = p.read_text(encoding="utf-8")
    html = "<pre>" + text.replace("&", "&amp;").replace("<", "&lt;") + "</pre>\n"
    out = p.with_suffix(".html")
    out.write_text(html, encoding="utf-8")
    return out


def main(argv=None) -> int:
    argv = argv or sys.argv[1:]
    if len(argv) < 2 or argv[0] not in {"create", "update", "rebuild", "sync-refs", "images"}:
        print("usage: plan_skill.py create PRODUCT PURPOSE | update PRODUCT NOTE | rebuild PRODUCT | sync-refs PRODUCT | images PRODUCT", file=sys.stderr)
        return 2
    cmd, product_id, *rest = argv
    if cmd == "create":
        print(create(product_id, " ".join(rest) or product_id))
    elif cmd == "update":
        print(update(product_id, " ".join(rest) or "updated"))
    elif cmd == "rebuild":
        print(rebuild(product_id))
    else:
        print(plan_dir(product_id) / "plan.md")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())