#!/usr/bin/env python3
import argparse
import sys
import os.path
import http.server
import ssl


def check_cert(dir):
    try:
        for i in 'cert', 'key':
            open(os.path.join(dir, 'https-%s.pem' % i)).close()
    except (FileNotFoundError, PermissionError) as e:
        print('Could not use %s: %s. Using http only.' % (dir, e.args[1]))
        return False
    except Exception as e:
        print('Error %d: %s' % e.args)
        sys.exit(e.errno)
    return True


def main(address, port, tls_dir):
    use_tls = check_cert(tls_dir)
    port = 80 if port == 443 and not use_tls else port
    try:
        server = http.server.HTTPServer((address, port),
                http.server.SimpleHTTPRequestHandler)
        if use_tls:
            tls_socket = ssl.wrap_socket(server.socket, server_side=True,
                    certfile=os.path.join(tls_dir, 'https-cert.pem'),
                    keyfile=os.path.join(tls_dir,'https-key.pem'),
                    ssl_version=ssl.PROTOCOL_TLSv1_2)
            server.socket = tls_socket
    except Exception as e:
        print('Error %d: %s' % e.args)
        sys.exit(e.errno)

    print('Serving on %s:%d...' % (address, port))

    try:
        server.serve_forever()
    except KeyboardInterrupt:
        print(' Bye.')
        server.socket.close()


if __name__ == '__main__':
    parser = argparse.ArgumentParser(description="Hyperminimal https server")
    parser.add_argument('address', nargs='?',
                        type=str, default='0.0.0.0',
                        help='bind ip address (default: 0.0.0.0)')
    parser.add_argument('port', nargs='?',
                        type=int, default=443,
                        help='bind port number (default: 80 or 443)')
    parser.add_argument('-t', '--tls', type=str,
                        default='/usr/local/etc/openssl',
                        help='cert/key couple directory. Must be PEM \
                        formatted and named https-key.pem, https-cert.pem \
                        (default: /usr/local/etc/openssl)')
    args = parser.parse_args()
    main(args.address, args.port, args.tls)