"""CLI: python -m rtut {list,validate,show,render} ..."""
from __future__ import annotations

import argparse
import sys
from pathlib import Path

from . import pack as P


def _packs(root: str) -> list[P.Pack]:
    return [P.load(p) for p in P.discover(Path(root))]


def main(argv: list[str] | None = None) -> int:
    ap = argparse.ArgumentParser(prog="rtut")
    sub = ap.add_subparsers(dest="cmd", required=True)
    for name in ("list", "validate"):
        sp = sub.add_parser(name)
        sp.add_argument("root", nargs="?", default=".")
    sp = sub.add_parser("launch"); sp.add_argument("manifest")
    sp.add_argument("--timeout", type=float, default=30.0)
    sp = sub.add_parser("show"); sp.add_argument("manifest")
    sp = sub.add_parser("render"); sp.add_argument("manifest"); sp.add_argument("step")
    sp.add_argument("--param", "-p", action="append", default=[], help="name=value")
    a = ap.parse_args(argv)

    if a.cmd in ("list", "validate"):
        packs = _packs(a.root)
        if not packs:
            print("no packs found", file=sys.stderr)
            return 1
        bad = 0
        for p in packs:
            d = p.data
            if a.cmd == "list":
                print(f"{p.id}\t{d.get('engine')}\t{d.get('exercise_status')}\t{d.get('title')}")
            else:
                print(f"{'ok  ' if p.ok else 'FAIL'} {p.id}")
                for e in p.errors:
                    print(f"     - {e}")
            bad += not p.ok
        return 1 if bad and a.cmd == "validate" else 0
    pk = P.load(Path(a.manifest))
    if not pk.ok:
        print("\n".join(pk.errors), file=sys.stderr)
        return 1
    if a.cmd == "launch":
        from . import legacy
        try:
            proc = legacy.launch(pk, a.timeout)
        except (ValueError, TimeoutError) as e:
            print(f"error: {e}", file=sys.stderr)
            return 1
        print(f"running: {pk.data['legacy'].get('url', '(no url)')}  (Ctrl-C stops it)")
        try:
            return proc.wait()
        except KeyboardInterrupt:
            proc.terminate()
            return 0
    if a.cmd == "show":
        d = pk.data
        print(f"{d['title']}  [{d['exercise_status']}]  engine={d['engine']}")
        for i, s in enumerate(d.get("steps", []), 1):
            print(f"{i}. [{s['owner']}] {s['title']}  ({s.get('risk', 'read-only')})")
            print(f"     done when: {s['verify']['done_when']}")
        return 0
    values = dict(kv.split("=", 1) for kv in a.param)
    step = next((s for s in pk.data.get("steps", []) if s["id"] == a.step), None)
    if not step or "command" not in step:
        print("no such step or step has no command", file=sys.stderr)
        return 1
    try:
        print(P.render(step["command"], values, pk))
    except (KeyError, ValueError) as e:
        print(f"error: {e}", file=sys.stderr)
        return 1
    return 0


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