#!/usr/bin/env python3
'''
Onionr - P2P Microblogging Platform & Social network.

This file contains both the OnionrCommunicate class for communcating with peers
and code to operate as a daemon, getting commands from the command queue database (see core.Core.daemonQueue)
'''
'''
    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 sqlite3, requests, hmac, hashlib, time, sys, os, math, logger, urllib.parse
import core, onionrutils

class OnionrCommunicate:
    def __init__(self, debug, developmentMode):
        '''
            OnionrCommunicate

            This class handles communication with nodes in the Onionr network.
        '''
        self._core = core.Core()
        self._utils = onionrutils.OnionrUtils(self._core)
        blockProcessTimer = 0
        blockProcessAmount = 5
        heartBeatTimer = 0
        heartBeatRate = 10
        logger.debug('Communicator debugging enabled.')
        torID = open('data/hs/hostname').read()

        self.peerData = {} # Session data for peers (recent reachability, speed, etc)

        # get our own PGP fingerprint
        fingerprintFile = 'data/own-fingerprint.txt'
        if not os.path.exists(fingerprintFile):
            self._core.generateMainPGP(torID)
        with open(fingerprintFile,'r') as f:
            self.pgpOwnFingerprint = f.read()
        logger.info('My PGP fingerprint is ' + logger.colors.underline + self.pgpOwnFingerprint + logger.colors.reset + logger.colors.fg.green + '.')
        if os.path.exists(self._core.queueDB):
            self._core.clearDaemonQueue()
        while True:
            command = self._core.daemonQueue()
            # Process blocks based on a timer
            blockProcessTimer += 1
            heartBeatTimer += 1
            if heartBeatRate == heartBeatTimer:
                logger.debug('Communicator heartbeat')
                heartBeatTimer = 0
            if blockProcessTimer == blockProcessAmount:
                self.lookupBlocks()
                self.processBlocks()
                blockProcessTimer = 0
            #logger.debug('Communicator daemon heartbeat')
            if command != False:
                if command[0] == 'shutdown':
                    logger.warn('Daemon recieved exit command.')
                    break
            time.sleep(1)

        return

    def getRemotePeerKey(self, peerID):
        '''
            This function contacts a peer and gets their main PGP key.

            This is safe because Tor or I2P is used, but it does not ensure that the person is who they say they are
        '''
        url = 'http://' + peerID + '/public/?action=getPGP'
        r = requests.get(url, headers=headers)
        response = r.text

        return response

    def shareHMAC(self, peerID, key):
        '''
            This function shares an HMAC key to a peer
        '''

        return

    def getPeerProof(self, peerID):
        '''
            This function gets the current peer proof requirement
        '''

        return

    def sendPeerProof(self, peerID, data):
        '''
            This function sends the proof result to a peer previously fetched with getPeerProof
        '''

        return

    def lookupBlocks(self):
        '''
            Lookup blocks and merge new ones
        '''
        peerList = self._core.listPeers()
        blocks = ''
        for i in peerList:
            lastDB = self._core.getPeerInfo(i, 'blockDBHash')
            if lastDB == None:
                logger.debug('Fetching hash from ' + i + ' No previous known.')
            else:
                logger.debug('Fetching hash from ' + i + ', ' + lastDB + ' last known')
            currentDB = self.performGet('getDBHash', i)
            if currentDB != False:
                logger.debug(i + " hash db (from request): " + currentDB)
            else:
                logger.warn("Error getting hash db status for " + i)
            if currentDB != False:
                if lastDB != currentDB:
                    logger.debug('Fetching hash from ' + i + ' - ' + currentDB + ' current hash.')
                    blocks += self.performGet('getBlockHashes', i)
                if self._utils.validateHash(currentDB):
                    self._core.setPeerInfo(i, "blockDBHash", currentDB)
        logger.debug('BLOCKS: \n' + blocks)
        blockList = blocks.split('\n')
        for i in blockList:
            if len(i.strip()) == 0:
                continue
            if self._utils.hasBlock(i):
                continue
            logger.debug('Exchanged block (blockList): ' + i)
            if not self._utils.validateHash(i):
                # skip hash if it isn't valid
                logger.warn('Hash ' + i + ' is not valid')
                continue
            else:
                logger.debug('Adding ' +  i + ' to hash database...')
                self._core.addToBlockDB(i)

        return

    def processBlocks(self):
        '''
            Work with the block database and download any missing blocks

            This is meant to be called from the communicator daemon on its timer.
        '''
        for i in self._core.getBlockList(True).split("\n"):
            if i != "":
                logger.warn('UNSAVED BLOCK: ' + i)
                data = self.downloadBlock(i)

        return

    def downloadBlock(self, hash):
        '''
            Download a block from random order of peers
        '''
        peerList = self._core.listPeers()
        blocks = ''
        for i in peerList:
            hasher = hashlib.sha3_256()
            data = self.performGet('getData', i, hash)
            if data == False or len(data) > 10000000:
                continue
            hasher.update(data.encode())
            digest = hasher.hexdigest()
            if type(digest) is bytes:
                digest = digest.decode()
            if digest == hash.strip():
                self._core.setData(data)
                if data.startswith('-txt-'):
                    self._core.setBlockType(hash, 'txt')
                logger.info('Successfully obtained data for ' + hash)
                if len(data) < 120:
                    logger.debug('Block text:\n' + data)
            else:
                logger.warn("Failed to validate " + hash)

        return

    def urlencode(self, data):
        '''
            URL encodes the data
        '''
        return urllib.parse.quote_plus(data)

    def performGet(self, action, peer, data=None, type='tor'):
        '''
            Performs a request to a peer through Tor or i2p (currently only Tor)
        '''
        if not peer.endswith('.onion') and not peer.endswith('.onion/'):
            raise PeerError('Currently only Tor .onion peers are supported. You must manually specify .onion')

        # Store peer in peerData dictionary (non permanent)
        if not peer in self.peerData:
            self.peerData[peer] = {'connectCount': 0, 'failCount': 0, 'lastConnectTime': math.floor(time.time())}

        socksPort = sys.argv[2]
        '''We use socks5h to use tor as DNS'''
        proxies = {'http': 'socks5h://127.0.0.1:' + str(socksPort), 'https': 'socks5h://127.0.0.1:' + str(socksPort)}
        headers = {'user-agent': 'PyOnionr'}
        url = 'http://' + peer + '/public/?action=' + self.urlencode(action)
        if data != None:
            url = url + '&data=' + self.urlencode(data)
        try:
            r = requests.get(url, headers=headers, proxies=proxies, timeout=(15, 30))
            retData = r.text
        except requests.exceptions.RequestException as e:
            logger.warn(action + " failed with peer " + peer + ": " + str(e))
            retData = False
        
        if not retData:
            self.peerData[peer]['failCount'] += 1
        else:
            self.peerData[peer]['connectCount'] += 1
            self.peerData[peer]['lastConnectTime'] = math.floor(time.time())
        return retData


shouldRun = False
debug = True
developmentMode = False
if os.path.exists('dev-enabled'):
    developmentMode = True
try:
    if sys.argv[1] == 'run':
        shouldRun = True
except IndexError:
    pass
if shouldRun:
    try:
        OnionrCommunicate(debug, developmentMode)
    except KeyboardInterrupt:
        pass