#!/usr/bin/env python3
"""deploy-plan.py — map changed paths to deployable services.

Thin wrapper over scripts/service-map.py, which owns the path->service
semantics in the shared inventory (shared/services.yml): per-service path
rules, the quadlet netns/network coupling graph, host scoping (a host's
directory can only select that host's services), and canonical restart
order. This file keeps the deployer's CLI contract only.

Usage:
  deploy-plan.py --target NAME --repo DIR --base REV --head REV
  deploy-plan.py --target NAME [paths...]        (paths also on stdin)

Prints one service name per line (canonical restart order); exit 0 with no
output when nothing relevant changed.
"""
import os
import subprocess
import sys

SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
SERVICE_MAP = os.path.join(SCRIPT_DIR, "service-map.py")


def git_paths(repo: str, base: str, head: str) -> list[str]:
    proc = subprocess.run(
        ["git", "-C", repo, "diff", "--name-only", base, head],
        text=True, capture_output=True)
    if proc.returncode != 0:
        sys.stderr.write(f"deploy-plan: git diff failed: {proc.stderr}")
        raise SystemExit(1)
    return [line for line in proc.stdout.splitlines() if line]


def main() -> int:
    args = sys.argv[1:]
    if not args or args[0] != "--target":
        print(__doc__, file=sys.stderr)
        return 2
    if len(args) < 2:
        print("missing target name after --target", file=sys.stderr)
        return 2
    target = args[1]
    # `--paths` is the historic seam keyword: a flag, not an option — the
    # paths are the positional arguments that follow it.
    rest = [a for a in args[2:] if a != "--paths"]
    if "--repo" in rest:
        try:
            repo = rest[rest.index("--repo") + 1]
            base = rest[rest.index("--base") + 1]
            head = rest[rest.index("--head") + 1]
        except (ValueError, IndexError):
            print("--repo, --base and --head must appear together", file=sys.stderr)
            return 2
        paths = git_paths(repo, base, head)
    else:
        paths = rest or [line.strip() for line in sys.stdin if line.strip()]
    if not paths:
        return 0
    proc = subprocess.run([sys.executable, SERVICE_MAP, "plan", "--host", target] + paths,
                          text=True, capture_output=True)
    if proc.returncode != 0:
        sys.stderr.write(proc.stderr)
        return proc.returncode
    sys.stdout.write(proc.stdout)
    return 0


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