# Copyright (C) 2023  Loren Eteval <loren.eteval@proton.me>
#
# This file is part of Furious.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

from Furious.Gui.Icon import Icon
from Furious.Utility.Constants import (
    APP,
    PLATFORM,
    PLATFORM_RELEASE,
    ROOT_DIR,
    PYSIDE6_VERSION,
    DEFAULT_TOR_SOCKS_PORT,
    DEFAULT_TOR_HTTPS_PORT,
    DEFAULT_TOR_RELAY_ESTABLISH_TIMEOUT,
)

from PySide6 import QtCore
from PySide6.QtWidgets import QApplication
from PySide6.QtNetwork import (
    QNetworkAccessManager,
    QNetworkReply,
    QNetworkRequest,
    QNetworkProxy,
)

import os
import sys
import time
import copy
import ujson
import queue
import ctypes
import logging
import pybase64
import threading
import functools
import ipaddress
import subprocess
import urllib.parse

logger = logging.getLogger(__name__)


class Base64Encoder:
    @staticmethod
    @functools.lru_cache(128)
    def encode(text):
        return pybase64.b64encode(text)

    @staticmethod
    @functools.lru_cache(128)
    def decode(text):
        return pybase64.b64decode(text, validate=False)


class Protocol:
    VMess = 'VMess'
    VLESS = 'VLESS'
    Shadowsocks = 'Shadowsocks'
    Trojan = 'Trojan'
    Hysteria1 = 'hysteria1'
    Hysteria2 = 'hysteria2'


class StateContext:
    def __init__(self, ob, *args, **kwargs):
        super().__init__(*args, **kwargs)

        assert hasattr(ob, 'setDisabled')

        self._ob = ob

    def __enter__(self):
        self._ob.setDisabled(True)

    def __exit__(self, exceptionType, exceptionValue, tb):
        self._ob.setDisabled(False)


class Storage:
    def __init__(self, emptyObject, getObjectFn, settingName):
        self.emptyObject = emptyObject
        self.getObjectFn = getObjectFn
        self.settingName = settingName

    def init(self):
        return copy.deepcopy(self.emptyObject)

    def sync(self, ob=None):
        if ob is None:
            # Object is up-to-date
            setattr(APP(), self.settingName, Storage.toStorage(self.getObjectFn()))
        else:
            # Object is up-to-date
            setattr(APP(), self.settingName, Storage.toStorage(ob))

    def toObject(self, storage):
        if not storage:
            # Storage does not exist, or is empty
            return self.init()

        return ujson.loads(Base64Encoder.decode(storage))

    @staticmethod
    def toStorage(ob):
        return Base64Encoder.encode(
            ujson.dumps(ob, ensure_ascii=False, escape_forward_slashes=False).encode()
        )

    def clear(self):
        setattr(APP(), self.settingName, '')


class _ServerStorage(Storage):
    # remark, config, subsId. (subsId corresponds to unique in Subscription Object)
    EMPTY_OBJECT = {'model': []}

    def __init__(self):
        super().__init__(
            _ServerStorage.EMPTY_OBJECT,
            lambda: APP().ServerWidget.StorageObj,
            'Configuration',
        )

    def clear(self):
        super().clear()

        APP().ActivatedItemIndex = str(-1)


class _RoutesStorage(Storage):
    # remark, corename, routes
    EMPTY_OBJECT = {'model': []}

    def __init__(self):
        super().__init__(
            _RoutesStorage.EMPTY_OBJECT,
            lambda: APP().RoutesWidget.StorageObj,
            'CustomRouting',
        )


class _SubscriptionStorage(Storage):
    # unique: remark, webURL
    EMPTY_OBJECT = {}

    def __init__(self):
        super().__init__(
            _SubscriptionStorage.EMPTY_OBJECT,
            lambda: APP().SubscriptionWidget.StorageObj,
            'CustomSubscription',
        )


class _TorRelaySettingsStorage(Storage):
    EMPTY_OBJECT = {
        'socksTunnelPort': DEFAULT_TOR_SOCKS_PORT,
        'httpsTunnelPort': DEFAULT_TOR_HTTPS_PORT,
        'useProxy': True,
        'logLevel': 'notice',
        'relayEstablishTimeout': DEFAULT_TOR_RELAY_ESTABLISH_TIMEOUT,
    }

    def __init__(self):
        super().__init__(
            _TorRelaySettingsStorage.EMPTY_OBJECT,
            lambda: APP().TorRelayWidget.StorageObj,
            'TorRelaySettings',
        )


ServerStorage = _ServerStorage()
RoutesStorage = _RoutesStorage()
SubscriptionStorage = _SubscriptionStorage()
TorRelaySettingsStorage = _TorRelaySettingsStorage()


class AsyncSubprocessMessage:
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        self.msgQueue = queue.Queue()
        self.msgTimer = QtCore.QTimer()

        self.daemonThread = None

    def connectTimeoutCallback(self, callback):
        self.msgTimer.timeout.connect(callback)

    def startDaemonThread(self, stdout):
        def enqueue(msgQueue):
            for line in iter(stdout.readline, b''):
                msgQueue.put(line.decode('utf-8', 'replace').strip())

            stdout.close()

        self.daemonThread = threading.Thread(
            target=enqueue, args=(self.msgQueue,), daemon=True
        )
        self.daemonThread.start()

    def startTimer(self, msec=1):
        self.msgTimer.start(msec)

    def stopTimer(self):
        self.msgTimer.stop()

    def getLineNoWait(self):
        try:
            return self.msgQueue.get_nowait()
        except queue.Empty:
            # Queue is empty

            return ''


class Switch:
    OFF = '0'
    ON_ = '1'

    RANGE = [OFF, ON_]


class SupportConnectedCallback:
    Object = list()

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        SupportConnectedCallback.Object.append(self)

    def disconnectedCallback(self):
        raise NotImplementedError

    def connectedCallback(self):
        raise NotImplementedError

    @staticmethod
    def callConnectedCallback():
        for ob in SupportConnectedCallback.Object:
            assert isinstance(ob, SupportConnectedCallback)

            ob.connectedCallback()

    @staticmethod
    def callDisconnectedCallback():
        for ob in SupportConnectedCallback.Object:
            assert isinstance(ob, SupportConnectedCallback)

            ob.disconnectedCallback()


class NeedSyncSettings:
    Object = list()

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        NeedSyncSettings.Object.append(self)

    def syncSettings(self):
        raise NotImplementedError

    @staticmethod
    def syncAll():
        for ob in NeedSyncSettings.Object:
            assert isinstance(ob, NeedSyncSettings)

            ob.syncSettings()


class SupportThemeChangedCallback:
    Object = list()

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        SupportThemeChangedCallback.Object.append(self)

    def themeChangedCallback(self, theme):
        raise NotImplementedError

    @staticmethod
    def callThemeChangedCallback(theme):
        logger.info(f'system theme changed to {theme}')

        for ob in SupportThemeChangedCallback.Object:
            assert isinstance(ob, SupportThemeChangedCallback)

            ob.themeChangedCallback(theme)


class DNSResolver:
    networkAccessManager = QNetworkAccessManager()

    @staticmethod
    def request(address):
        request = QNetworkRequest(
            QtCore.QUrl(f'https://cloudflare-dns.com/dns-query?name={address}')
        )
        request.setRawHeader('accept'.encode(), 'application/dns-json'.encode())

        return request

    @staticmethod
    def handleFinishedByNetworkReply(networkReply, domain, resultMap):
        assert isinstance(networkReply, QNetworkReply)

        if networkReply.error() != QNetworkReply.NetworkError.NoError:
            logger.error(
                f'DNS resolution for \'{domain}\' failed. {networkReply.errorString()}'
            )

            resultMap['error'] = True
        else:
            logger.info(f'DNS resolution for \'{domain}\' success')

            # Unchecked?
            replyObject = ujson.loads(networkReply.readAll().data())

            for record in replyObject['Answer']:
                address = record['data']

                logger.info(f'\'{domain}\' resolved to \'{address}\'')

                if isValidIPAddress(address):
                    resultMap['result'][address] = True
                else:
                    resultMap['depth'] += 1

                    newNetworkReply = DNSResolver.networkAccessManager.get(
                        DNSResolver.request(address)
                    )
                    newNetworkReply.finished.connect(
                        functools.partial(
                            DNSResolver.handleFinishedByNetworkReply,
                            newNetworkReply,
                            address,
                            resultMap,
                        )
                    )

                    resultMap['reference'].append(newNetworkReply)

        resultMap['depth'] -= 1

    @staticmethod
    def resolve(domain, proxyHost=None, proxyPort=None):
        if proxyHost is None or proxyPort is None:
            DNSResolver.networkAccessManager.setProxy(QNetworkProxy.ProxyType.NoProxy)
        else:
            try:
                DNSResolver.networkAccessManager.setProxy(
                    QNetworkProxy(
                        QNetworkProxy.ProxyType.HttpProxy, proxyHost, int(proxyPort)
                    )
                )

                logger.info(f'DNS resolution uses proxy server {proxyHost}:{proxyPort}')
            except Exception as ex:
                # Any non-exit exceptions

                logger.error(
                    f'invalid proxy server {proxyHost}:{proxyPort}. {ex}. '
                    'DNS resolution uses no proxy'
                )

                DNSResolver.networkAccessManager.setProxy(
                    QNetworkProxy.ProxyType.NoProxy
                )

        resultMap = {
            'depth': 0,
            'error': False,
            'reference': [],
            'result': {},
        }

        resultMap['depth'] += 1

        networkReply = DNSResolver.networkAccessManager.get(DNSResolver.request(domain))
        networkReply.finished.connect(
            functools.partial(
                DNSResolver.handleFinishedByNetworkReply,
                networkReply,
                domain,
                resultMap,
            )
        )

        resultMap['reference'].append(networkReply)

        DNSResolver.wait(resultMap)

        return resultMap['error'], list(resultMap['result'].keys())

    @staticmethod
    def wait(resultMap, startCounter=0, timeout=30000, step=100):
        if resultMap['depth'] != 0:
            logger.info('DNS resolution in progress. Wait')
        else:
            return

        while resultMap['depth'] != 0 and startCounter < timeout:
            eventLoopWait(step)

            startCounter += step

        if resultMap['depth'] != 0:
            logger.error('DNS resolution timeout')

            for networkReply in resultMap['reference']:
                if (
                    isinstance(networkReply, QNetworkReply)
                    and not networkReply.isFinished()
                ):
                    networkReply.abort()


def icon(prefix, name):
    if name.startswith('rocket-takeoff'):
        # Colorful. Use default
        return Icon(f':/Icons/bootstrap/{name}')
    else:
        return Icon(f':/Icons/{prefix}/{name}')


bootstrapIcon = functools.partial(icon, 'bootstrap')
bootstrapIconWhite = functools.partial(icon, 'bootstrap/white')


@functools.lru_cache(None)
def protocolRepr(protocol):
    if protocol.lower() == 'vmess':
        return Protocol.VMess

    if protocol.lower() == 'vless':
        return Protocol.VLESS

    if protocol.lower() == 'shadowsocks':
        return Protocol.Shadowsocks

    if protocol.lower() == 'trojan':
        return Protocol.Trojan

    return protocol


@functools.lru_cache(None)
def isValidIPAddress(address):
    try:
        ipaddress.ip_address(address)
    except Exception:
        # Any non-exita exceptions

        return False
    else:
        return True


# Can throw exceptions
def parseHostPort(address):
    if address.count('//') == 0:
        result = urllib.parse.urlsplit('//' + address)
    else:
        result = urllib.parse.urlsplit(address)

    return result.hostname, str(result.port)


def enumValueWrapper(enum):
    # Protect PySide6 enum wrapper behavior changes
    if PYSIDE6_VERSION < '6.2.2':
        return enum
    else:
        return enum.value


def eventLoopWait(ms):
    # Protect qWait method does not exist in some
    # old PySide6 version
    if PYSIDE6_VERSION < '6.3.1':
        for counter in range(0, ms, 1):
            time.sleep(1 / 1000)

            APP().processEvents()
    else:
        from PySide6.QtTest import QTest

        QTest.qWait(ms)

        APP().processEvents()


def runCommand(*args, **kwargs):
    if PLATFORM == 'Windows':
        return subprocess.run(
            *args, creationflags=subprocess.CREATE_NO_WINDOW, **kwargs
        )
    else:
        return subprocess.run(*args, **kwargs)


def getAbsolutePath(path):
    return path if os.path.isabs(path) else str(ROOT_DIR / path)


@functools.lru_cache(None)
def getUbuntuRelease():
    try:
        result = runCommand(
            ['cat', '/etc/lsb-release'],
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE,
            check=True,
        )

        values = dict(
            list(line.split('='))
            for line in filter(lambda x: x != '', result.stdout.decode().split('\n'))
        )

        if values['DISTRIB_ID'] == 'Ubuntu':
            return values['DISTRIB_RELEASE']
        else:
            return ''
    except Exception:
        # Any non-exit exceptions

        return ''


def swapListItem(listOrTuple, index0, index1):
    swap = listOrTuple[index0]

    listOrTuple[index0] = listOrTuple[index1]
    listOrTuple[index1] = swap


@functools.lru_cache(None)
def isAdministrator():
    if PLATFORM == 'Windows':
        return ctypes.windll.shell32.IsUserAnAdmin() == 1
    else:
        return os.geteuid() == 0


def isVPNMode():
    return isAdministrator() and APP().VPNMode == Switch.ON_


def isScriptMode():
    return sys.argv[0].endswith('.py')


def isRealFile(file):
    if not hasattr(file, 'fileno'):
        return False

    try:
        tmp = os.dup(file.fileno())
    except Exception:
        # Any non-exit exceptions

        return False
    else:
        os.close(tmp)

        return True


def isPythonw():
    # pythonw.exe. Also applies to packed GUI application on Windows
    return not isRealFile(sys.__stdout__) or not isRealFile(sys.__stderr__)


def isWindows7():
    return PLATFORM == 'Windows' and PLATFORM_RELEASE == '7'


def moveToCenter(widget, parent=None):
    geometry = widget.geometry()

    if parent is None:
        center = QApplication.primaryScreen().availableGeometry().center()
    else:
        center = parent.geometry().center()

    geometry.moveCenter(center)

    widget.move(geometry.topLeft())