# Licensed to the Software Freedom Conservancy (SFC) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The SFC licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.

"""Utility functions."""

import socket
import urllib.request
from collections.abc import Iterable
from typing import Optional, Union

from selenium.types import AnyKey
from selenium.webdriver.common.keys import Keys

_is_connectable_exceptions = (socket.error, ConnectionResetError)


def free_port() -> int:
    """Determines a free port using sockets.

    First try IPv4, but use IPv6 if it can't bind (IPv6-only system).
    """
    free_socket = None
    try:
        # IPv4
        free_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        free_socket.bind(("127.0.0.1", 0))
    except OSError:
        if free_socket:
            free_socket.close()
        # IPv6
        try:
            free_socket = socket.socket(socket.AF_INET6, socket.SOCK_STREAM)
            free_socket.bind(("::1", 0))
        except OSError:
            if free_socket:
                free_socket.close()
            raise RuntimeError("Can't find free port (Unable to bind to IPv4 or IPv6)")
    try:
        port: int = free_socket.getsockname()[1]
    except Exception as e:
        raise RuntimeError(f"Can't find free port: ({e})")
    finally:
        free_socket.close()
    return port


def find_connectable_ip(host: Union[str, bytes, bytearray, None], port: Optional[int] = None) -> Optional[str]:
    """Resolve a hostname to an IP, preferring IPv4 addresses.

    We prefer IPv4 so that we don't change behavior from previous IPv4-only
    implementations, and because some drivers (e.g., FirefoxDriver) do not
    support IPv6 connections.

    If the optional port number is provided, only IPs that listen on the given
    port are considered.

    :Args:
        - host - hostname
        - port - port number

    :Returns:
        A single IP address, as a string. If any IPv4 address is found, one is
        returned. Otherwise, if any IPv6 address is found, one is returned. If
        neither, then None is returned.
    """
    try:
        addrinfos = socket.getaddrinfo(host, None)
    except socket.gaierror:
        return None

    ip = None
    for family, _, _, _, sockaddr in addrinfos:
        connectable = True
        if port:
            connectable = is_connectable(port, str(sockaddr[0]))

        if connectable and family == socket.AF_INET:
            return str(sockaddr[0])
        if connectable and not ip and family == socket.AF_INET6:
            ip = str(sockaddr[0])
    return ip


def join_host_port(host: str, port: int) -> str:
    """Joins a hostname and port together.

    This is a minimal implementation intended to cope with IPv6 literals. For
    example, _join_host_port('::1', 80) == '[::1]:80'.

    :Args:
        - host - hostname or IP
        - port - port number
    """
    if ":" in host and not host.startswith("["):
        return f"[{host}]:{port}"
    return f"{host}:{port}"


def is_connectable(port: int, host: Optional[str] = "localhost") -> bool:
    """Tries to connect to the server at port to see if it is running.

    :Args:
        - port - port number
        - host - hostname or IP
    """
    socket_ = None
    try:
        socket_ = socket.create_connection((host, port), 1)
        result = True
    except _is_connectable_exceptions:
        result = False
    finally:
        if socket_:
            try:
                socket_.shutdown(socket.SHUT_RDWR)
            except Exception:
                pass
            socket_.close()
    return result


def is_url_connectable(
    port: Union[int, str],
    host: Optional[str] = "127.0.0.1",
    scheme: Optional[str] = "http",
) -> bool:
    """Sends a request to the HTTP server at the /status endpoint to see if it
    responds successfully.

    :Args:
        - port - port number
        - host - hostname or IP
        - scheme - URL scheme
    """
    try:
        with urllib.request.urlopen(f"{scheme}://{host}:{port}/status") as res:
            return res.getcode() == 200
    except Exception:
        return False


def keys_to_typing(value: Iterable[AnyKey]) -> list[str]:
    """Processes the values that will be typed in the element."""
    characters: list[str] = []
    for val in value:
        if isinstance(val, Keys):
            # Todo: Does this even work?
            characters.append(str(val))
        elif isinstance(val, (int, float)):
            characters.extend(str(val))
        else:
            characters.extend(val)
    return characters