'''
    Onionr - P2P Microblogging Platform & Social network

    OnionrUtils offers various useful functions to Onionr. Relatively misc.
'''
'''
    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/>.
'''
# Misc functions that do not fit in the main api, but are useful
import getpass, sys, requests, os, socket, hashlib, logger, sqlite3, config, binascii, time, base64
import nacl.signing, nacl.encoding

if sys.version_info < (3, 6):
    try:
        import sha3
    except ModuleNotFoundError:
        logger.fatal('On Python 3 versions prior to 3.6.x, you need the sha3 module')
        sys.exit(1)

class OnionrUtils:
    '''
        Various useful function
    '''
    def __init__(self, coreInstance):
        self.fingerprintFile = 'data/own-fingerprint.txt'
        self._core = coreInstance

        self.timingToken = ''

        return

    def getTimeBypassToken(self):
        if os.path.exists('data/time-bypass.txt'):
            with open('data/time-bypass.txt', 'r') as bypass:
                self.timingToken = bypass.read()

    def sendPM(self, pubkey, message):
        '''
            High level function to encrypt a message to a peer and insert it as a block
        '''

        encrypted = self._core._crypto.pubKeyEncrypt(message, pubkey, anonymous=True, encodedData=True).decode()
        block = self._core.insertBlock(encrypted, header='pm')

        if block == '':
            logger.error('Could not send PM')
        else:
            logger.info('Sent PM, hash: ' + block)

        return

    def incrementAddressSuccess(self, address):
        '''
            Increase the recorded sucesses for an address
        '''
        increment = self._core.getAddressInfo(address, 'success') + 1
        self._core.setAddressInfo(address, 'success', increment)
        return

    def decrementAddressSuccess(self, address):
        '''
            Decrease the recorded sucesses for an address
        '''
        increment = self._core.getAddressInfo(address, 'success') - 1
        self._core.setAddressInfo(address, 'success', increment)
        return

    def mergeKeys(self, newKeyList):
        '''
            Merge ed25519 key list to our database
        '''
        retVal = False
        if newKeyList != False:
            for key in newKeyList.split(','):
                if not key in self._core.listPeers(randomOrder=False) and type(key) != None and key != self._core._crypto.pubKey:
                    if self._core.addPeer(key):
                        retVal = True
        return retVal


    def mergeAdders(self, newAdderList):
        '''
            Merge peer adders list to our database
        '''
        retVal = False
        if newAdderList != False:
            for adder in newAdderList.split(','):
                if not adder in self._core.listAdders(randomOrder=False) and adder.strip() != self.getMyAddress():
                    if self._core.addAddress(adder):
                        logger.info('Added ' + adder + ' to db.', timestamp=True)
                        input()
                        retVal = True
                else:
                    logger.debug(adder + " is either our address or already in our DB")
        return retVal

    def getMyAddress(self):
        myAddressFile = open("data/hs/hostname", 'r')
        myAddress = myAddressFile.read()
        myAddressFile.close()
        return myAddress.strip()

    def localCommand(self, command):
        '''
            Send a command to the local http API server, securely. Intended for local clients, DO NOT USE for remote peers.
        '''

        config.reload()
        self.getTimeBypassToken()
        # TODO: URL encode parameters, just as an extra measure. May not be needed, but should be added regardless.
        try:
            retData = requests.get('http://' + open('data/host.txt', 'r').read() + ':' + str(config.get('client')['port']) + '/client/?action=' + command + '&token=' + str(config.get('client')['client_hmac']) + '&timingToken=' + self.timingToken).text
        except requests.ConnectionError:
            retData = False

        return retData

    def getPassword(self, message='Enter password: ', confirm = True):
        '''
            Get a password without showing the users typing and confirm the input
        '''
        # Get a password safely with confirmation and return it
        while True:
            print(message)
            pass1 = getpass.getpass()
            if confirm:
                print('Confirm password: ')
                pass2 = getpass.getpass()
                if pass1 != pass2:
                    logger.error("Passwords do not match.")
                    logger.readline()
                else:
                    break
            else:
                break

        return pass1

    def checkPort(self, port, host=''):
        '''
            Checks if a port is available, returns bool
        '''
        # inspired by https://www.reddit.com/r/learnpython/comments/2i4qrj/how_to_write_a_python_script_that_checks_to_see/ckzarux/
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        retVal = False
        try:
            sock.bind((host, port))
        except OSError as e:
            if e.errno is 98:
                retVal = True
        finally:
            sock.close()

        return retVal

    def checkIsIP(self, ip):
        '''
            Check if a string is a valid IPv4 address
        '''
        try:
            socket.inet_aton(ip)
        except:
            return False
        else:
            return True

    def getBlockDBHash(self):
        '''
            Return a sha3_256 hash of the blocks DB
        '''
        with open(self._core.blockDB, 'rb') as data:
            data = data.read()
        hasher = hashlib.sha3_256()
        hasher.update(data)
        dataHash = hasher.hexdigest()

        return dataHash

    def hasBlock(self, hash):
        '''
            Check for new block in the list
        '''
        conn = sqlite3.connect(self._core.blockDB)
        c = conn.cursor()
        if not self.validateHash(hash):
            raise Exception("Invalid hash")
        for result in c.execute("SELECT COUNT() FROM hashes where hash='" + hash + "'"):
            if result[0] >= 1:
                conn.commit()
                conn.close()
                return True
            else:
                conn.commit()
                conn.close()
                return False

    def validateHash(self, data, length=64):
        '''
            Validate if a string is a valid hex formatted hash
        '''
        retVal = True
        if data == False or data == True:
            return False
        data = data.strip()
        if len(data) != length:
            retVal = False
        else:
            try:
                int(data, 16)
            except ValueError:
                retVal = False

        return retVal

    def validatePubKey(self, key):
        '''Validate if a string is a valid base32 encoded Ed25519 key'''
        retVal = False
        try:
            nacl.signing.SigningKey(seed=key, encoder=nacl.encoding.Base32Encoder)
        except nacl.exceptions.ValueError:
            pass
        except base64.binascii.Error as err:
            pass
        else:
            retVal = True
        return retVal


    def validateID(self, id):
        '''
            Validate if an address is a valid tor or i2p hidden service
        '''
        idLength = len(id)
        retVal = True
        idNoDomain = ''
        peerType = ''
        # i2p b32 addresses are 60 characters long (including .b32.i2p)
        if idLength == 60:
            peerType = 'i2p'
            if not id.endswith('.b32.i2p'):
                retVal = False
            else:
                idNoDomain = id.split('.b32.i2p')[0]
        # Onion v2's are 22 (including .onion), v3's are 62 with .onion
        elif idLength == 22 or idLength == 62:
            peerType = 'onion'
            if not id.endswith('.onion'):
                retVal = False
            else:
                idNoDomain = id.split('.onion')[0]
        else:
            retVal = False
        if retVal:
            if peerType == 'i2p':
                try:
                    id.split('.b32.i2p')[2]
                except:
                    pass
                else:
                    retVal = False
            elif peerType == 'onion':
                try:
                    id.split('.onion')[2]
                except:
                    pass
                else:
                    retVal = False
            if not idNoDomain.isalnum():
                retVal = False

        return retVal

    def loadPMs(self):
        '''
            Find, decrypt, and return array of PMs (array of dictionary, {from, text})
        '''
        blocks = self._core.getBlockList().split('\n')
        message = ''
        sender = ''
        for i in blocks:
            if len (i) == 0:
                continue
            with open('data/blocks/' + i + '.dat', 'r') as potentialMessage:
                message = potentialMessage.read()
                if message.startswith('-pm-'):
                    try:
                        message = self._core._crypto.pubKeyDecrypt(message.replace('-pm-', ''), encodedData=True, anonymous=True)
                    except nacl.exceptions.CryptoError as e:
                        #logger.debug('Unable to decrypt ' + i)
                        #logger.debug(str(e))
                        pass
                    else:
                        logger.info('Recieved message: ' + message.decode())
        return