#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Scaffold a deploy / QA note from a git commit range.

Usage (from repo root):
  python scripts/generate_deploy_test_plan.py HEAD~5..HEAD
  python scripts/generate_deploy_test_plan.py abc1234..def5678 --out docs/deploy/20260801_example.md

The script lists commits and touched files. You (or the agent) still fill
test steps and expected results after reading the diffs.
"""

from __future__ import annotations

import argparse
import subprocess
import sys
from datetime import date
from pathlib import Path

ROOT = Path(__file__).resolve().parents[1]


def run(args: list[str]) -> str:
    r = subprocess.run(
        args,
        cwd=ROOT,
        capture_output=True,
        text=True,
        encoding="utf-8",
        errors="replace",
    )
    if r.returncode != 0:
        raise SystemExit(r.stderr or r.stdout or f"command failed: {args}")
    return r.stdout.strip()


def main() -> None:
    p = argparse.ArgumentParser(description="Scaffold deploy test plan from git range")
    p.add_argument(
        "range",
        help="Git revision range, e.g. HEAD~5..HEAD or origin/production..HEAD",
    )
    p.add_argument(
        "--out",
        type=Path,
        default=None,
        help="Optional output path under docs/deploy/",
    )
    p.add_argument("--title", default="Deploy note (draft)", help="Document title")
    args = p.parse_args()

    log = run(["git", "log", "--oneline", args.range])
    if not log:
        print("No commits in range.", file=sys.stderr)
        sys.exit(1)

    stat = run(["git", "diff", "--stat", args.range])
    name_status = run(["git", "diff", "--name-status", args.range])

    commits = [ln for ln in log.splitlines() if ln.strip()]
    commit_bullets = "\n".join(f"- `{c[:7]}` — {c[8:]}" for c in commits)

    body = f"""# {args.title}
Date: {date.today().isoformat()}
Branch / build: (fill)
Range: `{args.range}`
Author: (fill)

> Auto-scaffolded from git. **Replace the Test plan with real steps** after reviewing the diff.

## Summary
- (TODO: 1–3 bullets — user-facing impact)

## Scope
- Backend: (see files below)
- Frontend: (check paired repo if UI)
- DB / Liquibase: (none / list changelog files)
- Config / ops: (none / list)

## Commits
{commit_bullets}

## Files touched
```
{name_status}
```

### Diffstat
```
{stat}
```

## Test plan
| # | Steps (who / where / data) | Expected result |
|---|----------------------------|-----------------|
| 1 | TODO — happy path | TODO |
| 2 | TODO — edge / failure case | TODO |
| 3 | TODO — regression on related screen | TODO |

## Out of scope / not tested
- (TODO)

## Rollback
- Revert range `{args.range}` / redeploy previous build
"""

    if args.out:
        out = args.out if args.out.is_absolute() else ROOT / args.out
        out.parent.mkdir(parents=True, exist_ok=True)
        out.write_text(body, encoding="utf-8")
        print(f"Wrote {out.relative_to(ROOT)}")
    else:
        sys.stdout.reconfigure(encoding="utf-8")
        print(body)


if __name__ == "__main__":
    main()