#!/usr/bin/env python3
"""Automated release: calculate next version, update files, tag, and push.

Uses git-cliff to determine the next semver version from conventional commits
since the last tag.  Updates ``__version__`` in ``__init__.py`` (the single
source of truth, read by setuptools via ``dynamic = ["version"]``), creates a
release commit, tags it with the changelog as the tag message, and pushes the
tag to trigger the publish workflow.

This script is idempotent: if there are no new conventional commits since the
last tag, it exits with a message and does nothing.

Usage:
  REPO_TOKEN=<token> python3 scripts/release.py [--dry-run]
"""

from __future__ import annotations

import re
import subprocess  # nosec B404

import click
from dotenv import load_dotenv  # pyright: ignore[reportMissingImports,reportUnknownVariableType]

from gitea_runner_manager.i18n import _

load_dotenv(override=True)

INIT_FILE = "src/gitea_runner_manager/__init__.py"
CLIFF_CONFIG = "cliff.toml"


def run_cmd(args: list[str], check: bool = True, capture: bool = True) -> subprocess.CompletedProcess[str]:
    """Run a command and return the completed process."""
    result = subprocess.run(  # nosec B603
        args,
        capture_output=capture,
        text=True,
        check=False,
    )
    if check and result.returncode != 0:
        raise click.ClickException(
            _(
                "Command failed ({cmd}): {stderr}",
                cmd=" ".join(args),
                stderr=result.stderr.strip() if result.stderr else result.stdout.strip(),
            )
        )
    return result


def get_latest_tag() -> str:
    """Get the latest git tag, or empty string if none exists."""
    result = run_cmd(["git", "describe", "--tags", "--abbrev=0"], check=False)
    if result.returncode != 0:
        return ""
    return result.stdout.strip()


def get_bumped_version() -> str:
    """Use git-cliff to calculate the next version from conventional commits."""
    result = run_cmd(["git-cliff", "--bumped-version", "--config", CLIFF_CONFIG])
    version = result.stdout.strip()
    if not version:
        raise click.ClickException(_("git-cliff returned empty version."))
    # git-cliff may return with or without 'v' prefix
    return version.lstrip("v")


def get_changelog(new_version: str) -> str:
    """Generate changelog content for the new version using git-cliff."""
    result = run_cmd(
        [
            "git-cliff",
            "--config",
            CLIFF_CONFIG,
            "--tag",
            f"v{new_version}",
            "--unreleased",
            "--bump",
        ]
    )
    return result.stdout.strip()


def has_unreleased_changes() -> bool:
    """Check if there are conventional commits since the last tag."""
    result = run_cmd(
        ["git-cliff", "--bumped-version", "--config", CLIFF_CONFIG],
        check=False,
    )
    if result.returncode != 0:
        return False
    latest = get_latest_tag()
    if not latest:
        return True
    bumped = result.stdout.strip().lstrip("v")
    current = latest.lstrip("v")
    return bumped != current


def update_init_version(new_version: str) -> None:
    """Update __version__ in __init__.py."""
    with open(INIT_FILE) as f:
        content = f.read()
    updated = re.sub(
        r'^__version__\s*=\s*"[^"]*"',
        f'__version__ = "{new_version}"',
        content,
        count=1,
        flags=re.MULTILINE,
    )
    if updated == content:
        raise click.ClickException(_("Could not find __version__ in {file}", file=INIT_FILE))
    with open(INIT_FILE, "w") as f:
        f.write(updated)


def create_release_commit(new_version: str) -> None:
    """Stage version file and create a release commit."""
    run_cmd(["git", "add", INIT_FILE])
    run_cmd(["git", "commit", "-m", f"chore(release): prepare for v{new_version}"])


def create_and_push_tag(new_version: str, changelog: str, dry_run: bool) -> None:
    """Create an annotated tag with the changelog as message and push it."""
    tag = f"v{new_version}"
    tag_msg = f"Release v{new_version}\n\n{changelog}"
    run_cmd(["git", "tag", "-a", tag, "-m", tag_msg])
    if dry_run:
        click.echo(_("[dry-run] Would push tag {tag}", tag=tag))
        return
    run_cmd(["git", "push", "origin", tag])


@click.command()
@click.option("--dry-run", is_flag=True, default=False, help="Show what would happen without making changes.")
def main(dry_run: bool) -> None:
    # Ensure we're on master
    branch = run_cmd(["git", "rev-parse", "--abbrev-ref", "HEAD"]).stdout.strip()
    if branch != "master":
        raise click.ClickException(_("Release must be run on master, currently on '{branch}'.", branch=branch))

    # Check for unreleased changes
    if not has_unreleased_changes():
        click.echo(_("No unreleased changes found. Nothing to release."))
        return

    # Calculate next version
    new_version = get_bumped_version()
    current_tag = get_latest_tag()
    click.echo(
        _(
            "Bumping version: {current} -> v{new_version}",
            current=current_tag or "(none)",
            new_version=new_version,
        )
    )

    # Generate changelog
    changelog = get_changelog(new_version)
    if not changelog:
        click.echo(_("Warning: git-cliff generated empty changelog."))

    if dry_run:
        click.echo(_("\n[dry-run] Changelog:\n{changelog}", changelog=changelog))
        click.echo(_("[dry-run] Would update {init}", init=INIT_FILE))
        click.echo(_("[dry-run] Would create commit: chore(release): prepare for v{version}", version=new_version))
        click.echo(_("[dry-run] Would create tag: v{version}", version=new_version))
        return

    # Update version file
    update_init_version(new_version)
    click.echo(_("Updated version in {init}", init=INIT_FILE))

    # Create release commit
    create_release_commit(new_version)
    click.echo(_("Created release commit."))

    # Push commit to master
    run_cmd(["git", "push", "origin", "master"])
    click.echo(_("Pushed release commit to master."))

    # Create and push tag
    create_and_push_tag(new_version, changelog, dry_run)
    click.echo(
        _(
            "Nice! Release v{version} tagged and pushed. The publish workflow will be triggered.",
            version=new_version,
        )
    )


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