# Pyrogram - Telegram MTProto API Client Library for Python
# Copyright (C) 2017 Dan Tès <https://github.com/delivrance>
#
# This file is part of Pyrogram.
#
# Pyrogram is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Pyrogram is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with Pyrogram.  If not, see <http://www.gnu.org/licenses/>.

import base64
import json
import logging
import time
from collections import namedtuple
from configparser import ConfigParser
from hashlib import sha256

from pyrogram.extensions import Markdown

from pyrogram.api import functions, types
from pyrogram.api.core import Object
from pyrogram.api.errors import (
    PhoneMigrate, NetworkMigrate, PhoneNumberInvalid,
    PhoneNumberUnoccupied, PhoneCodeInvalid, PhoneCodeHashEmpty,
    PhoneCodeExpired, PhoneCodeEmpty, SessionPasswordNeeded,
    PasswordHashInvalid, FloodWait, PeerIdInvalid
)
from pyrogram.api.types import (
    User, Chat, Channel,
    PeerUser, PeerChat, PeerChannel,
    Dialog, Message,
    InputPeerEmpty, InputPeerSelf,
    InputPeerUser, InputPeerChat, InputPeerChannel)
from pyrogram.session import Auth, Session

log = logging.getLogger(__name__)

Config = namedtuple("Config", ["api_id", "api_hash"])


class Client:
    DIALOGS_AT_ONCE = 100

    def __init__(self, session_name: str, test_mode: bool = False):
        self.session_name = session_name
        self.test_mode = test_mode

        self.dc_id = None
        self.auth_key = None
        self.user_id = None

        self.rnd_id = None

        self.peers_by_id = {}
        self.peers_by_username = {}

        self.config = None
        self.session = None

    def send(self, data: Object):
        return self.session.send(data)

    def authorize(self):
        while True:
            phone_number = input("Enter phone number: ")

            while True:
                confirm = input("Is \"{}\" correct? (y/n): ".format(phone_number))

                if confirm in ("y", "1"):
                    break
                elif confirm in ("n", "2"):
                    phone_number = input("Enter phone number: ")

            try:
                r = self.send(
                    functions.auth.SendCode(
                        phone_number,
                        self.config.api_id,
                        self.config.api_hash
                    )
                )
            except (PhoneMigrate, NetworkMigrate) as e:
                self.session.stop()

                self.dc_id = e.x
                self.auth_key = Auth(self.dc_id, self.test_mode).create()

                self.session = Session(self.dc_id, self.test_mode, self.auth_key, self.config.api_id)
                self.session.start()

                r = self.send(
                    functions.auth.SendCode(
                        phone_number,
                        self.config.api_id,
                        self.config.api_hash
                    )
                )
                break
            except PhoneNumberInvalid as e:
                print(e.MESSAGE)
            except FloodWait as e:
                print(e.MESSAGE.format(x=e.x))
                time.sleep(e.x)
            except Exception as e:
                log.error(e, exc_info=True)
            else:
                break

        phone_registered = r.phone_registered
        phone_code_hash = r.phone_code_hash

        while True:
            phone_code = input("Enter phone code: ")

            try:
                if phone_registered:
                    r = self.send(
                        functions.auth.SignIn(
                            phone_number,
                            phone_code_hash,
                            phone_code
                        )
                    )
                else:
                    try:
                        self.send(
                            functions.auth.SignIn(
                                phone_number,
                                phone_code_hash,
                                phone_code
                            )
                        )
                    except PhoneNumberUnoccupied:
                        pass

                    first_name = input("First name: ")
                    last_name = input("Last name: ")

                    r = self.send(
                        functions.auth.SignUp(
                            phone_number,
                            phone_code_hash,
                            phone_code,
                            first_name,
                            last_name
                        )
                    )
            except (PhoneCodeInvalid, PhoneCodeEmpty, PhoneCodeExpired, PhoneCodeHashEmpty) as e:
                print(e.MESSAGE)
            except SessionPasswordNeeded as e:
                print(e.MESSAGE)

                while True:
                    try:
                        r = self.send(functions.account.GetPassword())

                        print("Hint: {}".format(r.hint))
                        password = input("Enter password: ")  # TODO: Use getpass

                        password = r.current_salt + password.encode() + r.current_salt
                        password_hash = sha256(password).digest()

                        r = self.send(functions.auth.CheckPassword(password_hash))
                    except PasswordHashInvalid as e:
                        print(e.MESSAGE)
                    except FloodWait as e:
                        print(e.MESSAGE.format(x=e.x))
                        time.sleep(e.x)
                    except Exception as e:
                        log.error(e, exc_info=True)
                    else:
                        break
                break
            except FloodWait as e:
                print(e.MESSAGE.format(x=e.x))
                time.sleep(e.x)
            except Exception as e:
                log.error(e, exc_info=True)
            else:
                break

        return r.user.id

    def load_config(self):
        config = ConfigParser()
        config.read("config.ini")

        self.config = Config(
            int(config["pyrogram"]["api_id"]),
            config["pyrogram"]["api_hash"]
        )

    def load_session(self, session_name):
        try:
            with open("{}.session".format(session_name)) as f:
                s = json.load(f)
        except FileNotFoundError:
            self.dc_id = 1
            self.auth_key = Auth(self.dc_id, self.test_mode).create()
        else:
            self.dc_id = s["dc_id"]
            self.test_mode = s["test_mode"]
            self.auth_key = base64.b64decode("".join(s["auth_key"]))
            self.user_id = s["user_id"]

    def save_session(self):
        auth_key = base64.b64encode(self.auth_key).decode()
        auth_key = [auth_key[i: i + 43] for i in range(0, len(auth_key), 43)]

        with open("{}.session".format(self.session_name), "w") as f:
            json.dump(
                dict(
                    dc_id=self.dc_id,
                    test_mode=self.test_mode,
                    auth_key=auth_key,
                    user_id=self.user_id,
                ),
                f,
                indent=4
            )

    def start(self):
        self.load_config()
        self.load_session(self.session_name)

        self.session = Session(self.dc_id, self.test_mode, self.auth_key, self.config.api_id)

        terms = self.session.start()

        if self.user_id is None:
            print(terms, "\n")

            self.user_id = self.authorize()
            self.save_session()

        self.rnd_id = self.session.msg_id
        # self.get_dialogs()

    def get_dialogs(self):
        peers = []

        def parse_dialogs(d) -> int:
            oldest_date = 1 << 32

            for dialog in d.dialogs:  # type: Dialog
                # Only search for Users, Chats and Channels
                if not isinstance(dialog.peer, (PeerUser, PeerChat, PeerChannel)):
                    continue

                if isinstance(dialog.peer, PeerUser):
                    peer_type = "user"
                    peer_id = dialog.peer.user_id
                elif isinstance(dialog.peer, PeerChat):
                    peer_type = "chat"
                    peer_id = dialog.peer.chat_id
                elif isinstance(dialog.peer, PeerChannel):
                    peer_type = "channel"
                    peer_id = dialog.peer.channel_id
                else:
                    continue

                for message in d.messages:  # type: Message
                    # Only search for Messages
                    if not isinstance(message, Message):
                        continue

                    is_this = peer_id == message.from_id or dialog.peer == message.to_id

                    if is_this:
                        for entity in (d.users if peer_type == "user" else d.chats):  # type: User or Chat or Channel
                            if entity.id == peer_id:
                                peers.append(
                                    dict(
                                        id=peer_id,
                                        access_hash=getattr(entity, "access_hash", None),
                                        type=peer_type,
                                        first_name=getattr(entity, "first_name", None),
                                        last_name=getattr(entity, "last_name", None),
                                        title=getattr(entity, "title", None),
                                        username=getattr(entity, "username", None),
                                    )
                                )

                                if message.date < oldest_date:
                                    oldest_date = message.date

                                break
                        break

            return oldest_date

        pinned_dialogs = self.send(functions.messages.GetPinnedDialogs())
        parse_dialogs(pinned_dialogs)

        dialogs = self.send(
            functions.messages.GetDialogs(
                0, 0, InputPeerEmpty(),
                self.DIALOGS_AT_ONCE, True
            )
        )

        offset_date = parse_dialogs(dialogs)
        logging.info("Dialogs count: {}".format(len(peers)))

        while len(dialogs.dialogs) == self.DIALOGS_AT_ONCE:
            dialogs = self.send(
                functions.messages.GetDialogs(
                    offset_date, 0, types.InputPeerEmpty(),
                    self.DIALOGS_AT_ONCE, True
                )
            )

            offset_date = parse_dialogs(dialogs)
            logging.info("Dialogs count: {}".format(len(peers)))

        for i in peers:
            id = i["id"]
            username = i["username"]

            self.peers_by_id[id] = i

            if username:
                username = username.lower()
                self.peers_by_username[username] = i

    def get_me(self):
        return self.send(
            functions.users.GetFullUser(
                InputPeerSelf()
            )
        )

    def send_message(
            self,
            chat_id: int or str,
            text: str,
            disable_web_page_preview: bool = None,
            reply_to_msg_id: int = None,
    ):
        # TODO: Resolve usernames when they don't exists yet (contacts.ResolveUsername)

        if chat_id in ("self", "me"):
            input_peer = InputPeerSelf()
        else:
            try:
                peer = (
                    self.peers_by_username[chat_id.lower()]
                    if isinstance(chat_id, str)
                    else self.peers_by_id[chat_id]
                )
            except KeyError:
                raise PeerIdInvalid

            peer_type = peer["type"]
            peer_id = peer["id"]
            peer_access_hash = peer["access_hash"]

            if peer_type == "user":
                input_peer = InputPeerUser(
                    peer_id,
                    peer_access_hash
                )
            elif peer_type == "chat":
                input_peer = InputPeerChat(
                    peer_id
                )
            elif peer_type == "channel":
                input_peer = InputPeerChannel(
                    peer_id,
                    peer_access_hash
                )
            else:
                raise PeerIdInvalid

        text, entities = Markdown.parse(text)

        return self.send(
            functions.messages.SendMessage(
                peer=input_peer,
                message=text,
                random_id=self.rnd_id(),
                no_webpage=disable_web_page_preview,
                reply_to_msg_id=reply_to_msg_id,
                entities=entities
            )
        )