"""
openapi_first.cli
========================

Command-line interface for FastAPI OpenAPI-first scaffolding utilities.

This CLI bootstraps OpenAPI-first FastAPI applications from versioned,
bundled templates packaged with the library.
"""

import argparse
import shutil
from pathlib import Path
from importlib import resources


DEFAULT_TEMPLATE = "health_app"


def available_templates() -> list[str]:
    """
    Return a list of available application templates.
    """
    root = resources.files("openapi_first.templates")
    return sorted(
        item.name
        for item in root.iterdir()
        if item.is_dir() and not item.name.startswith("_")
    )


def copy_template(template: str, target_dir: Path) -> None:
    """
    Copy a bundled OpenAPI-first application template into a directory.
    """
    target_dir = target_dir.resolve()
    target_dir.mkdir(parents=True, exist_ok=True)

    root = resources.files("openapi_first.templates")
    src = root / template

    if not src.exists():
        raise FileNotFoundError(
            f"Template '{template}' not found. "
            f"Available templates: {', '.join(available_templates())}"
        )

    with resources.as_file(src) as path:
        shutil.copytree(path, target_dir, dirs_exist_ok=True)


def main() -> None:
    parser = argparse.ArgumentParser(
        description="FastAPI OpenAPI-first scaffolding tools"
    )
    parser.add_argument(
        "template",
        nargs="?",
        default=DEFAULT_TEMPLATE,
        help=f"Template name (default: {DEFAULT_TEMPLATE})",
    )
    parser.add_argument(
        "path",
        nargs="?",
        default=None,
        help="Target directory (defaults to template name)",
    )
    parser.add_argument(
        "--list",
        action="store_true",
        help="List available templates and exit",
    )

    args = parser.parse_args()

    if args.list:
        for name in available_templates():
            print(name)
        return

    target = Path(args.path or args.template.replace("_", "-"))

    try:
        copy_template(args.template, target)
    except Exception as exc:
        raise SystemExit(str(exc)) from exc

    print(f"Template '{args.template}' created at {target}")