#!/usr/bin/env python3
"""
Helper script for the release workflow (.github/workflows/release.yml).

Subcommands:

  build-payload [--github]   Build the JSON payload for creating a release.
                             Reads TAG, GH_SHA from env.
                             With --github, includes generate_release_notes=True.
                             Writes JSON to stdout.

  extract-id < response.json   Print the release id from a release API response.
  extract-upload-url < response.json   Print the upload_url from a GitHub release
                             response (used as the asset upload endpoint template).

This script exists to avoid bash heredoc-inside-YAML-literal indentation traps.
"""

import json
import os
import sys


def build_payload(github: bool) -> int:
    tag = os.environ.get("TAG", "")
    sha = os.environ.get("GH_SHA", "unknown")
    payload = {
        "tag_name": tag,
        "name": tag,
        "body": (
            "Automated release.\n\n"
            f"Built from commit {sha}.\n\n"
            "See the workflow run for the artifact."
        ),
        "draft": False,
        "prerelease": False,
    }
    if github:
        payload["generate_release_notes"] = True
    print(json.dumps(payload))
    return 0


def extract_field(field: str) -> int:
    raw = sys.stdin.read()
    try:
        data = json.loads(raw)
    except json.JSONDecodeError as e:
        print(f"::error::Failed to parse JSON response: {e}", file=sys.stderr)
        return 1
    value = data.get(field, "")
    if not value:
        print(f"::error::Field {field!r} missing from response: {raw}", file=sys.stderr)
        return 1
    print(value)
    return 0


def usage() -> int:
    print(__doc__, file=sys.stderr)
    return 2


def main() -> int:
    if len(sys.argv) < 2:
        return usage()
    cmd = sys.argv[1]
    if cmd == "build-payload":
        return build_payload(github="--github" in sys.argv)
    if cmd == "extract-id":
        return extract_field("id")
    if cmd == "extract-upload-url":
        return extract_field("upload_url")
    if cmd == "extract-tag":
        return extract_field("tag_name")
    return usage()


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