#!/usr/bin/env python3
"""Validate commit messages for GRM.

Rules:
- On feature branches: conventional commits ONLY, must NOT include GRM-N prefix.
- On master branch: must follow '<task-id>: <conventional commit>' pattern,
  e.g. 'GRM-24: fix: resolve timeout'.
"""

import re
import subprocess  # nosec B404

import click

from gitea_runner_manager.config import CONVENTIONAL_RE
from gitea_runner_manager.i18n import _

MASTER_TASK_ID_RE = re.compile(r"^GRM-\d+:")


def first_line(text: str) -> str:
    return text.split("\n")[0]


def get_branch() -> str:
    try:
        result = subprocess.run(  # nosec
            ["git", "symbolic-ref", "--short", "HEAD"],
            capture_output=True,
            text=True,
            check=True,
        )
        return result.stdout.strip()
    except subprocess.CalledProcessError:
        return ""


@click.command()
@click.argument("commit_msg_file")
@click.option("--branch", default=None, help="Override branch detection (for CI use).")
def main(commit_msg_file: str, branch: str | None) -> None:
    with open(commit_msg_file) as f:
        msg = f.read().strip()

    if branch is None:
        branch = get_branch()
    subject = first_line(msg)

    if branch == "master":
        if not MASTER_TASK_ID_RE.match(subject):
            raise click.ClickException(
                _(
                    "Oops! Master branch commits must start with a task ID.\n"
                    "  Expected: GRM-N: <conventional commit message>\n"
                    "  Got:      {subject}",
                    subject=subject,
                )
            )
        remainder = MASTER_TASK_ID_RE.sub("", subject).strip()
        if not CONVENTIONAL_RE.match(remainder):
            raise click.ClickException(
                _(
                    "Oops! Master branch commit must follow conventional format after task ID.\n"
                    "  Expected: GRM-N: <type>: <description>\n"
                    "  Got:      {subject}",
                    subject=subject,
                )
            )
        return

    if MASTER_TASK_ID_RE.match(subject):
        raise click.ClickException(
            _(
                "Oops! Do not include task ID (GRM-N) in feature branch commits.\n"
                "  The task ID will be added automatically on merge via CI."
            )
        )

    if not CONVENTIONAL_RE.match(subject):
        raise click.ClickException(
            _(
                "Oops! Commit message must follow conventional commit format.\n"
                "  Expected: <type>: <description>\n"
                "  Got:      {subject}\n"
                "  Allowed types: feat, fix, chore, docs, style, refactor,\n"
                "                 perf, test, ci, build, revert, BREAKING CHANGE",
                subject=subject,
            )
        )


if __name__ == "__main__":  # pragma: no cover
    main()