# -*- coding: utf-8 -*-

# Weechat Matrix Protocol Script
# Copyright © 2018 Damir Jelić <poljar@termina.org.uk>
#
# Permission to use, copy, modify, and/or distribute this software for
# any purpose with or without fee is hereby granted, provided that the
# above copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
# SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

from __future__ import unicode_literals

import socket
import ssl
import time
import pprint
import OpenSSL.crypto as crypto
import textwrap
from itertools import chain

# pylint: disable=redefined-builtin
from builtins import str
from future.utils import bytes_to_native_str as n

# pylint: disable=unused-import
from typing import (List, Set, Dict, Tuple, Text, Optional, AnyStr, Deque, Any)
import logbook
from logbook import Logger, StderrHandler, StreamHandler

import nio
from nio import TransportType, RemoteTransportError, RemoteProtocolError

from matrix.colors import Formatted
from matrix.utf import utf8_decode
from matrix.http import HttpResponse
from matrix.api import MatrixSendMessage
from matrix.encryption import matrix_olm_command_cb

# Weechat searches for the registered callbacks in the scope of the main script
# file, import the callbacks here so weechat can find them.
from matrix.commands import (hook_commands, hook_page_up, matrix_command_cb,
                             matrix_command_join_cb, matrix_command_part_cb,
                             matrix_command_invite_cb, matrix_command_topic_cb,
                             matrix_command_pgup_cb, matrix_redact_command_cb,
                             matrix_command_buf_clear_cb, matrix_me_command_cb,
                             matrix_command_kick_cb)
from matrix.buffer import room_buffer_input_cb, room_buffer_close_cb

from matrix.server import (
    MatrixServer,
    create_default_server,
    send_cb,
    matrix_timer_cb,
    matrix_config_server_read_cb,
    matrix_config_server_write_cb,
    matrix_config_server_change_cb,
)

from matrix.bar_items import (init_bar_items, matrix_bar_item_name,
                              matrix_bar_item_plugin, matrix_bar_item_lag,
                              matrix_bar_item_buffer_modes)

from matrix.completion import (
    init_completion, matrix_command_completion_cb,
    matrix_server_command_completion_cb, matrix_debug_completion_cb,
    matrix_message_completion_cb, matrix_server_completion_cb,
    matrix_olm_user_completion_cb, matrix_olm_device_completion_cb)

from matrix.utils import (key_from_value, server_buffer_prnt, prnt_debug,
                          server_buffer_set_title)

from matrix.plugin_options import (DebugType, RedactType)

from matrix.config import (matrix_config_init, matrix_config_read,
                           matrix_config_free, matrix_config_change_cb,
                           matrix_config_reload_cb)

import matrix.globals

from matrix.globals import W, SERVERS, SCRIPT_NAME, OPTIONS

# yapf: disable
WEECHAT_SCRIPT_NAME = SCRIPT_NAME
WEECHAT_SCRIPT_DESCRIPTION = "matrix chat plugin"              # type: str
WEECHAT_SCRIPT_AUTHOR = "Damir Jelić <poljar@termina.org.uk>"  # type: str
WEECHAT_SCRIPT_VERSION = "0.1"                                 # type: str
WEECHAT_SCRIPT_LICENSE = "ISC"                                 # type: str
# yapf: enable


logger = Logger("matrix-cli")


def print_certificate_info(buff, sock, cert):
    cert_pem = ssl.DER_cert_to_PEM_cert(sock.getpeercert(True))

    x509 = crypto.load_certificate(crypto.FILETYPE_PEM, cert_pem)

    public_key = x509.get_pubkey()

    key_type = ("RSA" if public_key.type() == crypto.TYPE_RSA else "DSA")
    key_size = str(public_key.bits())
    sha256_fingerprint = x509.digest(n(b"SHA256"))
    sha1_fingerprint = x509.digest(n(b"SHA1"))
    signature_algorithm = x509.get_signature_algorithm()

    key_info = ("key info: {key_type} key {bits} bits, signed using "
                "{algo}").format(
                    key_type=key_type, bits=key_size, algo=signature_algorithm)

    validity_info = ("        Begins on:  {before}\n"
                     "        Expires on: {after}").format(
                         before=cert["notBefore"], after=cert["notAfter"])

    rdns = chain(*cert["subject"])
    subject = ", ".join(["{}={}".format(name, value) for name, value in rdns])

    rdns = chain(*cert["issuer"])
    issuer = ", ".join(["{}={}".format(name, value) for name, value in rdns])

    subject = "subject: {sub}, serial number {serial}".format(
        sub=subject, serial=cert["serialNumber"])

    issuer = "issuer: {issuer}".format(issuer=issuer)

    fingerprints = ("        SHA1:   {}\n"
                    "        SHA256: {}").format(sha1_fingerprint,
                                                 sha256_fingerprint)

    wrapper = textwrap.TextWrapper(
        initial_indent="    - ", subsequent_indent="        ")

    message = ("{prefix}matrix: received certificate\n"
               " - certificate info:\n"
               "{subject}\n"
               "{issuer}\n"
               "{key_info}\n"
               "    - period of validity:\n{validity_info}\n"
               "    - fingerprints:\n{fingerprints}").format(
                   prefix=W.prefix("network"),
                   subject=wrapper.fill(subject),
                   issuer=wrapper.fill(issuer),
                   key_info=wrapper.fill(key_info),
                   validity_info=validity_info,
                   fingerprints=fingerprints)

    W.prnt(buff, message)

def wrap_socket(server, file_descriptor):
    # type: (MatrixServer, int) -> None
    sock = None  # type: socket.socket

    temp_socket = socket.fromfd(file_descriptor, socket.AF_INET,
                                socket.SOCK_STREAM)

    # For python 2.7 wrap_socket() doesn't work with sockets created from an
    # file descriptor because fromfd() doesn't return a wrapped socket, the bug
    # was fixed for python 3, more info: https://bugs.python.org/issue13942
    # pylint: disable=protected-access,unidiomatic-typecheck
    if type(temp_socket) == socket._socket.socket:
        # pylint: disable=no-member
        sock = socket._socketobject(_sock=temp_socket)
    else:
        sock = temp_socket

    # fromfd() duplicates the file descriptor but doesn't retain it's blocking
    # non-blocking attribute, so mark the socket as non-blocking even though
    # weechat already did that for us
    sock.setblocking(False)

    message = "{prefix}matrix: Doing SSL handshake...".format(
        prefix=W.prefix("network"))
    W.prnt(server.server_buffer, message)

    ssl_socket = server.ssl_context.wrap_socket(
        sock, do_handshake_on_connect=False,
        server_hostname=server.address)  # type: ssl.SSLSocket

    server.socket = ssl_socket

    try_ssl_handshake(server)


@utf8_decode
def ssl_fd_cb(server_name, file_descriptor):
    server = SERVERS[server_name]

    if server.ssl_hook:
        W.unhook(server.ssl_hook)
        server.ssl_hook = None

    try_ssl_handshake(server)

    return W.WEECHAT_RC_OK


def try_ssl_handshake(server):
    sock = server.socket

    while True:
        try:
            sock.do_handshake()

            cipher = sock.cipher()
            cipher_message = ("{prefix}matrix: Connected using {tls}, and "
                              "{bit} bit {cipher} cipher suite.").format(
                                  prefix=W.prefix("network"),
                                  tls=cipher[1],
                                  bit=cipher[2],
                                  cipher=cipher[0])
            W.prnt(server.server_buffer, cipher_message)

            cert = sock.getpeercert()
            if cert:
                print_certificate_info(server.server_buffer, sock, cert)

            finalize_connection(server)

            return True

        except ssl.SSLWantReadError:
            hook = W.hook_fd(server.socket.fileno(), 1, 0, 0, "ssl_fd_cb",
                             server.name)
            server.ssl_hook = hook

            return False

        except ssl.SSLWantWriteError:
            hook = W.hook_fd(server.socket.fileno(), 0, 1, 0, "ssl_fd_cb",
                             server.name)
            server.ssl_hook = hook

            return False

        except ssl.SSLError as error:
            str_error = error.reason if error.reason else "Unknown error"

            message = ("{prefix}Error while doing SSL handshake"
                       ": {error}").format(
                           prefix=W.prefix("network"), error=str_error)

            server_buffer_prnt(server, message)

            server_buffer_prnt(
                server, ("{prefix}matrix: disconnecting from server..."
                        ).format(prefix=W.prefix("network")))

            server.disconnect()
            return False


@utf8_decode
def receive_cb(server_name, file_descriptor):
    server = SERVERS[server_name]

    while True:
        try:
            data = server.socket.recv(4096)
        except ssl.SSLWantReadError:
            break
        except socket.error as error:
            errno = "error" + str(error.errno) + " " if error.errno else ""
            str_error = error.strerror if error.strerror else "Unknown error"
            str_error = errno + str_error

            message = ("{prefix}Error while reading from "
                       "socket: {error}").format(
                           prefix=W.prefix("network"), error=str_error)

            server_buffer_prnt(server, message)

            server_buffer_prnt(
                server, ("{prefix}matrix: disconnecting from server..."
                         ).format(prefix=W.prefix("network")))

            server.disconnect()

            return W.WEECHAT_RC_OK

        if not data:
            server_buffer_prnt(
                server,
                "{prefix}matrix: Error while reading from socket".format(
                    prefix=W.prefix("network")))
            server_buffer_prnt(
                server, ("{prefix}matrix: disconnecting from server..."
                         ).format(prefix=W.prefix("network")))

            server.disconnect()
            break

        try:
            server.client.receive(data)
        except (RemoteTransportError, RemoteProtocolError) as e:
            server.error(str(e))
            server.disconnect()

        response = server.client.next_response()

        # Check if we need to send some data back
        data_to_send = server.client.data_to_send()

        if data_to_send:
            server.send(data_to_send)

        if response:
            server.handle_response(response)
            break

    return W.WEECHAT_RC_OK


def finalize_connection(server):
    hook = W.hook_fd(
        server.socket.fileno(),
        1,
        0,
        0,
        "receive_cb",
        server.name
    )

    server.fd_hook = hook
    server.connected = True
    server.connecting = False

    negotiated_protocol = server.socket.selected_alpn_protocol()

    if negotiated_protocol is None:
        negotiated_protocol = server.socket.selected_npn_protocol()

    transport_type = None

    if negotiated_protocol == "http/1.1":
        transport_type = TransportType.HTTP
    elif negotiated_protocol == "h2":
        transport_type = TransportType.HTTP2

    data = server.client.connect(transport_type)
    server.send(data)

    server.login()


@utf8_decode
def connect_cb(data, status, gnutls_rc, sock, error, ip_address):
    # pylint: disable=too-many-arguments,too-many-branches
    status_value = int(status)  # type: int
    server = SERVERS[data]

    if status_value == W.WEECHAT_HOOK_CONNECT_OK:
        file_descriptor = int(sock)  # type: int
        server.numeric_address = ip_address
        server_buffer_set_title(server)

        wrap_socket(server, file_descriptor)

        return W.WEECHAT_RC_OK

    elif status_value == W.WEECHAT_HOOK_CONNECT_ADDRESS_NOT_FOUND:
        W.prnt(
            server.server_buffer,
            '{address} not found'.format(address=ip_address))

    elif status_value == W.WEECHAT_HOOK_CONNECT_IP_ADDRESS_NOT_FOUND:
        W.prnt(server.server_buffer, 'IP address not found')

    elif status_value == W.WEECHAT_HOOK_CONNECT_CONNECTION_REFUSED:
        W.prnt(server.server_buffer, 'Connection refused')

    elif status_value == W.WEECHAT_HOOK_CONNECT_PROXY_ERROR:
        W.prnt(server.server_buffer,
               'Proxy fails to establish connection to server')

    elif status_value == W.WEECHAT_HOOK_CONNECT_LOCAL_HOSTNAME_ERROR:
        W.prnt(server.server_buffer, 'Unable to set local hostname')

    elif status_value == W.WEECHAT_HOOK_CONNECT_GNUTLS_INIT_ERROR:
        W.prnt(server.server_buffer, 'TLS init error')

    elif status_value == W.WEECHAT_HOOK_CONNECT_GNUTLS_HANDSHAKE_ERROR:
        W.prnt(server.server_buffer, 'TLS Handshake failed')

    elif status_value == W.WEECHAT_HOOK_CONNECT_MEMORY_ERROR:
        W.prnt(server.server_buffer, 'Not enough memory')

    elif status_value == W.WEECHAT_HOOK_CONNECT_TIMEOUT:
        W.prnt(server.server_buffer, 'Timeout')

    elif status_value == W.WEECHAT_HOOK_CONNECT_SOCKET_ERROR:
        W.prnt(server.server_buffer, 'Unable to create socket')
    else:
        W.prnt(
            server.server_buffer,
            'Unexpected error: {status}'.format(status=status_value))

    server.disconnect(reconnect=True)
    return W.WEECHAT_RC_OK


@utf8_decode
def room_close_cb(data, buffer):
    W.prnt("",
           "Buffer '%s' will be closed!" % W.buffer_get_string(buffer, "name"))
    return W.WEECHAT_RC_OK


@utf8_decode
def matrix_unload_cb():
    matrix_config_free(matrix.globals.CONFIG)

    # for server in SERVERS.values():
    #     server.store_olm()

    W.prnt("", "unloading")
    return W.WEECHAT_RC_OK


def autoconnect(servers):
    for server in servers.values():
        if server.autoconnect:
            server.connect()


def debug_buffer_close_cb(data, buffer):
    OPTIONS.debug_buffer_ptr = ""
    return W.WEECHAT_RC_OK


class WeechatHandler(StreamHandler):
    def __init__(self, level=logbook.NOTSET, format_string=None, filter=None,
                 bubble=False):
        StreamHandler.__init__(
            self,
            object(),
            level,
            format_string,
            None,
            filter,
            bubble
        )

    def write(self, item):
        buf = ""

        if OPTIONS.debug_buffer:
            if not OPTIONS.debug_buffer_ptr:
                OPTIONS.debug_buffer_ptr = W.buffer_new(
                    "Matrix Debug", "", "", "debug_buffer_close_cb", "")

            buf = OPTIONS.debug_buffer_ptr

        W.prnt(buf, item)


if __name__ == "__main__":
    if W.register(WEECHAT_SCRIPT_NAME, WEECHAT_SCRIPT_AUTHOR,
                  WEECHAT_SCRIPT_VERSION, WEECHAT_SCRIPT_LICENSE,
                  WEECHAT_SCRIPT_DESCRIPTION, 'matrix_unload_cb', ''):

        if not W.mkdir_home("matrix", 0o700):
            message = ("{prefix}matrix: Error creating session "
                       "directory").format(prefix=W.prefix("error"))
            W.prnt("", message)

        handler = WeechatHandler()
        handler.format_string = "{record.channel}: {record.message}"
        handler.push_application()

        # TODO if this fails we should abort and unload the script.
        matrix.globals.CONFIG = W.config_new("matrix",
                                             "matrix_config_reload_cb", "")
        matrix_config_init(matrix.globals.CONFIG)
        matrix_config_read(matrix.globals.CONFIG)

        hook_commands()
        init_bar_items()
        init_completion()

        if not SERVERS:
            create_default_server(matrix.globals.CONFIG)

        autoconnect(SERVERS)