'''
    Onionr - Private P2P Communication

    Netcontroller library, used to control/work with Tor/I2P and send requests through them
'''
'''
    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/>.
'''
import os, sys, base64, subprocess, signal, time
import multiprocessing
import platform # For windows sigkill workaround
import config, logger
from . import getopenport
from utils import identifyhome
from . import watchdog
config.reload()
TOR_KILL_WAIT = 3

def add_bridges(torrc: str)->str:
    """Configure tor to use a bridge using Onionr config keys"""
    if config.get('tor.use_bridge', False) == True:
        bridge = config.get('tor.bridge_ip', None)
        if not bridge is None:
            fingerprint = config.get('tor.bridge_fingerprint', '') # allow blank fingerprint purposefully
            torrc += '\nUseBridges 1\nBridge %s %s\n' % (bridge, fingerprint)
        else:
            logger.warn('bridge was enabled but not specified in config')

    return torrc

class NetController:
    '''
        This class handles hidden service setup on Tor and I2P
    '''

    def __init__(self, hsPort, apiServerIP='127.0.0.1'):
        # set data dir
        self.dataDir = identifyhome.identify_home()

        self.torConfigLocation = self.dataDir + 'torrc'
        self.readyState = False
        self.socksPort = getopenport.get_open_port()
        self.hsPort = hsPort
        self._torInstnace = ''
        self.myID = ''
        self.apiServerIP = apiServerIP

        if os.path.exists('./tor'):
            self.torBinary = './tor'
        elif os.path.exists('/usr/bin/tor'):
            self.torBinary = '/usr/bin/tor'
        else:
            self.torBinary = 'tor'

    def generateTorrc(self):
        '''
            Generate a torrc file for our tor instance
        '''
        hsVer = '# v2 onions'
        if config.get('tor.v3onions'):
            hsVer = 'HiddenServiceVersion 3'

        if os.path.exists(self.torConfigLocation):
            os.remove(self.torConfigLocation)

        # Set the Tor control password. Meant to make it harder to manipulate our Tor instance
        plaintext = base64.b64encode(os.urandom(50)).decode()
        config.set('tor.controlpassword', plaintext, savefile=True)
        config.set('tor.socksport', self.socksPort, savefile=True)

        controlPort = getopenport.get_open_port()

        config.set('tor.controlPort', controlPort, savefile=True)

        hashedPassword = subprocess.Popen([self.torBinary, '--hash-password', plaintext], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        for line in iter(hashedPassword.stdout.readline, b''):
            password = line.decode()
            if 'warn' not in password:
                break

        torrcData = '''SocksPort ''' + str(self.socksPort) + ''' OnionTrafficOnly
DataDirectory ''' + self.dataDir + '''tordata/
CookieAuthentication 1
KeepalivePeriod 40
CircuitsAvailableTimeout 86400
ControlPort ''' + str(controlPort) + '''
HashedControlPassword ''' + str(password) + '''
        '''
        if config.get('general.security_level', 1) == 0:
            torrcData += '''\nHiddenServiceDir ''' + self.dataDir + '''hs/
\n''' + hsVer + '''\n
HiddenServiceNumIntroductionPoints 6
HiddenServiceMaxStreams 100
HiddenServiceMaxStreamsCloseCircuit 1
HiddenServicePort 80 ''' + self.apiServerIP + ''':''' + str(self.hsPort)

        torrcData = add_bridges(torrcData)

        torrc = open(self.torConfigLocation, 'w')
        torrc.write(torrcData)
        torrc.close()
        return

    def startTor(self, gen_torrc=True):
        '''
            Start Tor with onion service on port 80 & socks proxy on random port
        '''
        if gen_torrc:
            self.generateTorrc()

        if os.path.exists('./tor'):
            self.torBinary = './tor'
        elif os.path.exists('/usr/bin/tor'):
            self.torBinary = '/usr/bin/tor'
        else:
            self.torBinary = 'tor'

        try:
            tor = subprocess.Popen([self.torBinary, '-f', self.torConfigLocation], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        except FileNotFoundError:
            logger.fatal("Tor was not found in your path or the Onionr directory. Please install Tor and try again.", terminal=True)
            return False
        else:
            # Test Tor Version
            torVersion = subprocess.Popen([self.torBinary, '--version'], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
            for line in iter(torVersion.stdout.readline, b''):
                if 'Tor 0.2.' in line.decode():
                    logger.fatal('Tor 0.3+ required', terminal=True)
                    return False
            torVersion.kill()

        # wait for tor to get to 100% bootstrap
        try:
            for line in iter(tor.stdout.readline, b''):
                if 'bootstrapped 100' in line.decode().lower():
                    logger.info(line.decode())
                    break
                elif 'opening socks listener' in line.decode().lower():
                    logger.debug(line.decode().replace('\n', ''))
                else:
                    if 'err' in line.decode():
                        logger.error(line.decode().replace('\n', ''))
                    elif 'warn' in line.decode():
                        logger.warn(line.decode().replace('\n', ''))
                    else:
                        logger.debug(line.decode().replace('\n', ''))
            else:
                logger.fatal('Failed to start Tor. Maybe a stray instance of Tor used by Onionr is still running? This can also be a result of file permissions being too open', terminal=True)
                return False
        except KeyboardInterrupt:
            logger.fatal('Got keyboard interrupt. Onionr will exit soon.', timestamp = False, terminal=True)
            return False

        logger.info('Finished starting Tor.', terminal=True)

        self.readyState = True

        try:
            myID = open(self.dataDir + 'hs/hostname', 'r')
            self.myID = myID.read().replace('\n', '')
            myID.close()
        except FileNotFoundError:
            self.myID = ""

        torPidFile = open(self.dataDir + 'torPid.txt', 'w')
        torPidFile.write(str(tor.pid))
        torPidFile.close()

        multiprocessing.Process(target=watchdog.watchdog, args=[os.getpid(), tor.pid]).start()

        return True

    def killTor(self):
        '''
            Properly kill tor based on pid saved to file
        '''

        try:
            pid = open(self.dataDir + 'torPid.txt', 'r')
            pidN = pid.read()
            pid.close()
        except FileNotFoundError:
            return

        try:
            int(pidN)
        except:
            return

        try:
            try:
                os.kill(int(pidN), signal.SIGTERM)
            except PermissionError:
                # seems to happen on win 10
                pass
            os.remove(self.dataDir + 'torPid.txt')
        except ProcessLookupError:
            pass
        except FileNotFoundError:
            pass
        
        try:
            time.sleep(TOR_KILL_WAIT)
        except KeyboardInterrupt:
            pass

        if 'windows' == platform.system().lower():
            os.system('taskkill /PID %s /F' % (pidN,))
            time.sleep(0.5)
            return
        try:
            os.kill(int(pidN), signal.SIGKILL)
        except (ProcessLookupError, PermissionError) as e:
            pass
        try:
            os.remove(self.dataDir + 'tordata/lock')
        except FileNotFoundError:
            pass