#!/usr/bin/env python3
"""Local static server for this project with HTTP and HTTPS support."""

from __future__ import annotations

import argparse
import ssl
import sys
import threading
import time
from functools import partial
from http.server import SimpleHTTPRequestHandler, ThreadingHTTPServer
from pathlib import Path


PROJECT_ROOT = Path(__file__).resolve().parent
DEFAULT_WEB_DIR = PROJECT_ROOT / "www"
DEFAULT_SSL_DIR = Path.home() / ".ssl_for_local_servers"
DEFAULT_CERT_PATH = DEFAULT_SSL_DIR / "cert.pem"
DEFAULT_KEY_PATH = DEFAULT_SSL_DIR / "key.pem"


def make_handler(directory: Path):
    return partial(SimpleHTTPRequestHandler, directory=str(directory))


def start_http_server(host: str, port: int, directory: Path) -> ThreadingHTTPServer:
    server = ThreadingHTTPServer((host, port), make_handler(directory))
    thread = threading.Thread(target=server.serve_forever, daemon=True)
    thread.start()
    print(f"[HTTP ] Serving {directory} at http://{host}:{port}")
    return server


def start_https_server(
    host: str,
    port: int,
    directory: Path,
    cert_path: Path,
    key_path: Path,
) -> ThreadingHTTPServer:
    server = ThreadingHTTPServer((host, port), make_handler(directory))

    context = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
    context.load_cert_chain(certfile=str(cert_path), keyfile=str(key_path))
    server.socket = context.wrap_socket(server.socket, server_side=True)

    thread = threading.Thread(target=server.serve_forever, daemon=True)
    thread.start()
    print(f"[HTTPS] Serving {directory} at https://{host}:{port}")
    print(f"[HTTPS] Using cert: {cert_path}")
    print(f"[HTTPS] Using key : {key_path}")
    return server


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(
        description="Serve this project locally over HTTP and/or HTTPS."
    )
    parser.add_argument(
        "--mode",
        choices=["http", "https", "both"],
        default="both",
        help="Which protocol(s) to serve (default: both).",
    )
    parser.add_argument(
        "--host",
        default="127.0.0.1",
        help="Host/interface to bind (default: 127.0.0.1).",
    )
    parser.add_argument(
        "--http-port",
        type=int,
        default=8080,
        help="HTTP port (default: 8080).",
    )
    parser.add_argument(
        "--https-port",
        type=int,
        default=8443,
        help="HTTPS port (default: 8443).",
    )
    parser.add_argument(
        "--dir",
        default=str(DEFAULT_WEB_DIR),
        help=f"Directory to serve (default: {DEFAULT_WEB_DIR}).",
    )
    parser.add_argument(
        "--cert",
        default=str(DEFAULT_CERT_PATH),
        help=f"TLS cert path (default: {DEFAULT_CERT_PATH}).",
    )
    parser.add_argument(
        "--key",
        default=str(DEFAULT_KEY_PATH),
        help=f"TLS key path (default: {DEFAULT_KEY_PATH}).",
    )
    return parser.parse_args()


def validate_mode_and_paths(args: argparse.Namespace) -> tuple[Path, Path, Path]:
    directory = Path(args.dir).expanduser().resolve()
    cert_path = Path(args.cert).expanduser().resolve()
    key_path = Path(args.key).expanduser().resolve()

    if not directory.exists() or not directory.is_dir():
        print(f"Error: directory does not exist or is not a directory: {directory}", file=sys.stderr)
        raise SystemExit(2)

    if args.mode in {"https", "both"}:
        if not cert_path.exists():
            print(f"Error: cert file not found: {cert_path}", file=sys.stderr)
            raise SystemExit(2)
        if not key_path.exists():
            print(f"Error: key file not found: {key_path}", file=sys.stderr)
            raise SystemExit(2)

    return directory, cert_path, key_path


def main() -> None:
    args = parse_args()
    directory, cert_path, key_path = validate_mode_and_paths(args)

    servers: list[ThreadingHTTPServer] = []

    try:
        if args.mode in {"http", "both"}:
            servers.append(start_http_server(args.host, args.http_port, directory))

        if args.mode in {"https", "both"}:
            if args.mode == "both" and args.http_port == args.https_port:
                print("Error: --http-port and --https-port must differ in mode=both.", file=sys.stderr)
                raise SystemExit(2)
            servers.append(
                start_https_server(
                    args.host,
                    args.https_port,
                    directory,
                    cert_path,
                    key_path,
                )
            )

        print("Press Ctrl+C to stop.")
        while True:
            time.sleep(1)

    except KeyboardInterrupt:
        print("\nShutting down...")
    finally:
        for server in servers:
            server.shutdown()
            server.server_close()
        print("Stopped.")


if __name__ == "__main__":
    main()