# -*- coding: utf-8 -*-
# vi:si:et:sw=4:sts=4:ts=4


from queue import Queue
from threading import Thread
import json
from io import BytesIO
import gzip
import urllib.request, urllib.error, urllib.parse
from datetime import datetime
import os
import time

import ox
from tornado.ioloop import PeriodicCallback

import settings
import user.models
from changelog import Changelog

from websocket import trigger_event
from localnodes import LocalNodes
from tor_request import get_opener
import state
import db

import logging
logger = logging.getLogger(__name__)

ENCODING='base64'

class Node(Thread):
    _running = True
    host = None
    local = None
    _online = None
    download_speed = 0
    TIMEOUT = 5

    def __init__(self, nodes, user):
        self._nodes = nodes
        self.user = user
        self.user_id = user.id
        self._opener = get_opener(self.user_id)
        self._q = Queue()
        Thread.__init__(self)
        self.daemon = True
        self.start()
        self.ping()

    def run(self):
        while self._running:
            action = self._q.get()
            if not self._running:
                break
            if action == 'send_response':
                self._send_response()
            elif action == 'ping':
                self.online = self.can_connect()
            else:
                logger.debug('unknown action %s', action)

    def join(self):
        self._running = False
        self._q.put('')
        #return Thread.join(self)


    def ping(self):
        if state.online:
            self._q.put('ping')

    @property
    def url(self):
        url = None
        if self.local:
            if ':' in self.local:
                url = 'https://[%s]:%s' % (self.local, self.port)
            else:
                url = 'https://%s:%s' % (self.local, self.port)
        elif len(self.user_id) == 16:
            url = 'https://%s.onion:9851' % self.user_id
        return url

    @property
    def online(self):
        return self._online

    @online.setter
    def online(self, online):
        if self._online != online:
            self._online = online
            self.trigger_status()
        else:
            self._online = online

    def resolve(self):
        #logger.debug('resolve node %s', self.user_id)
        r = self.get_local()
        if r:
            self.local = r['host']
            if 'port' in r:
                self.port = r['port']
        else:
            self.local = None
            self.port = 9851
        if len(self.user_id) == 43:
            self.migrate_id()


    def migrate_id(self):
        import ed25519
        from . import directory
        key = self.user_id.encode()
        vk = ed25519.VerifyingKey(key, encoding=ENCODING)
        try:
            r = directory.get(vk)
        except:
            logger.debug('directory failed', exc_info=1)
            r = None
        if r and 'id' in r and len(r['id']) == 16:
            u = self.user
            self.user_id = r['id']
            u.migrate_id(self.user_id)
            self._opener = get_opener(self.user_id)

    def get_local(self):
        if self._nodes and self._nodes._local:
            return self._nodes._local.get(self.user_id)
        return None

    def request(self, action, *args):
        logger.debug('request[%s] %s%s', self.user_id, action, args)
        self.resolve()
        url = self.url
        if not url:
            logger.debug('unable to find host %s', self.user_id)
            self.online = False
            return None
        #logger.debug('url=%s', url)
        content = json.dumps([action, args]).encode()
        headers = {
            'User-Agent': settings.USER_AGENT,
            'X-Node-Protocol': settings.NODE_PROTOCOL,
            'Accept': 'text/plain',
            'Accept-Encoding': 'gzip',
            'Content-Type': 'application/json',
        }
        self._opener.addheaders = list(zip(headers.keys(), headers.values()))
        #logger.debug('headers: %s', self._opener.addheaders)
        try:
            self._opener.timeout = self.TIMEOUT
            r = self._opener.open(url, data=content)
        except urllib.error.HTTPError as e:
            if e.code == 403:
                logger.debug('403: %s (%s)', url, self.user_id)
                self._running = False
                if state.tasks:
                    state.tasks.queue('peering', (self.user_id, False))
                del self._nodes[self.user_id]
                self.online = False
                return None
            logger.debug('urllib2.HTTPError %s %s', e, e.code)
            self.online = False
            return None
        except urllib.error.URLError as e:
            logger.debug('urllib2.URLError %s', e)
            self.online = False
            return None
        except:
            logger.debug('unknown url error', exc_info=1)
            self.online = False
            return None
        data = r.read()
        if r.headers.get('content-encoding', None) == 'gzip':
            data = gzip.GzipFile(fileobj=BytesIO(data)).read()

        version = r.headers.get('X-Node-Protocol', None)
        if version != settings.NODE_PROTOCOL:
            logger.debug('version does not match local: %s remote %s (%s)', settings.NODE_PROTOCOL, version, self.user_id)
            self.online = False
            if version > settings.NODE_PROTOCOL:
                state.update_required = True
            return None

        response = json.loads(data.decode('utf-8'))
        return response

    def can_connect(self):
        self.resolve()
        url = self.url
        try:
            if url:
                headers = {
                    'User-Agent': settings.USER_AGENT,
                    'X-Node-Protocol': settings.NODE_PROTOCOL,
                    'Accept-Encoding': 'gzip',
                }
                self._opener.addheaders = list(zip(headers.keys(), headers.values()))
                self._opener.timeout = 2
                r = self._opener.open(url)
                version = r.headers.get('X-Node-Protocol', None)
                if version != settings.NODE_PROTOCOL:
                    logger.debug('version does not match local: %s remote %s', settings.NODE_PROTOCOL, version)
                    return False
                c = r.read()
                logger.debug('can connect to: %s', url)
                return True
        except:
            logger.debug('can not connect to: %s', url)
            pass
        return False

    def is_online(self):
        return self.online or self.get_local() != None

    def send_response(self):
        self._q.put('send_response')

    def _send_response(self):
        with db.session():
            u = user.models.User.get_or_create(self.user_id)
            if u.peered or u.queued:
                logger.debug('go online peered=%s queued=%s %s (%s)', u.peered, u.queued, u.id, u.nickname)
                try:
                    self.online = self.can_connect()
                    if self.online:
                        logger.debug('connected to %s', self.url)
                        if u.queued:
                            logger.debug('queued peering event pending=%s peered=%s', u.pending, u.peered)
                            if u.pending == 'sent':
                                self.peering('requestPeering')
                            elif u.pending == '' and u.peered:
                                self.peering('acceptPeering')
                            else:
                                #fixme, what about cancel/reject peering here?
                                self.peering('removePeering')
                except:
                    logger.debug('failed to connect to %s', self.user_id)
                    self.online = False

    def trigger_status(self):
        if self.online is not None:
            trigger_event('status', {
                'id': self.user_id,
                'online': self.online
            })

    def pullChanges(self):
        with db.session():
            u = user.models.User.get_or_create(self.user_id)
            if not self.online or not u.peered:
                return True
            last = Changelog.query.filter_by(user_id=self.user_id).order_by('-revision').first()
            from_revision = last.revision + 1 if last else 0
            try:
                changes = self.request('pullChanges', from_revision)
            except:
                self.online = False
                logger.debug('%s went offline', u.name)
                return False
            if not changes:
                return False
            try:
                r = Changelog.apply_changes(u, changes, first=from_revision == 0)
            except:
                logger.debug('apply_changes failed', exc_info=True)
                r = False
            return r

    def peering(self, action):
        with db.session():
            u = user.models.User.get_or_create(self.user_id)
            if action in ('requestPeering', 'acceptPeering'):
                r = self.request(action, settings.preferences['username'], u.info.get('message'))
            else:
                r = self.request(action, u.info.get('message'))
            if r != None:
                u.queued = False
                if 'message' in u.info:
                    del u.info['message']
                u.save()
            else:
                logger.debug('peering failed? %s %s', action, r)
            if action in ('cancelPeering', 'rejectPeering', 'removePeering'):
                self.online = False
            trigger_event('peering.%s'%action.replace('Peering', ''), u.json())
            return True

    headers = {
        'X-Node-Protocol': settings.NODE_PROTOCOL,
        'User-Agent': settings.USER_AGENT,
        'Accept-Encoding': 'gzip',
    }

    def download(self, item):
        from item.models import Transfer
        self.resolve()
        url = '%s/get/%s' % (self.url, item.id)
        t1 = datetime.utcnow()
        logger.debug('download %s', url)
        self._opener.addheaders = list(zip(self.headers.keys(), self.headers.values()))
        try:
            r = self._opener.open(url, timeout=self.TIMEOUT*5)
        except:
            logger.debug('openurl failed %s', url, exc_info=1)
            return False
        if r.getcode() == 200:
            try:
                fileobj = r
                if r.headers.get('content-encoding', None) == 'gzip':
                    fileobj = gzip.GzipFile(fileobj=r)
                content = b''
                ct = datetime.utcnow()
                size = 0
                chunk_size = 16*1024
                for chunk in iter(lambda: fileobj.read(chunk_size), b''):
                    content += chunk
                    size += len(chunk)
                    since_ct = (datetime.utcnow() - ct).total_seconds()
                    if since_ct > 1:
                        ct = datetime.utcnow()
                        t = Transfer.get(item.id)
                        if not t.added:
                            # transfer was canceled
                            trigger_event('transfer', {
                                'id': item.id, 'progress': -1
                            })
                            return False
                        else:
                            t.progress = size / item.info['size']
                            t.save()
                            trigger_event('transfer', {
                                'id': item.id, 'progress': t.progress
                            })
                    if state.bandwidth:
                        while not state.bandwidth.download(chunk_size) and self._running:
                            time.sleep(0.1)
                t2 = datetime.utcnow()
                duration = (t2-t1).total_seconds()
                if duration:
                    self.download_speed = size / duration
                return item.save_file(content)
            except:
                logger.debug('download failed %s', url, exc_info=1)
                return False
        else:
            logger.debug('FAILED %s', url)
            return False

    def download_preview(self, item_id):
        logger.debug('trying to download preview from %s for %s', self.url, item_id)
        from item.icons import icons
        self.resolve()
        url = '%s/preview/%s' % (self.url, item_id)
        self._opener.addheaders = list(zip(self.headers.keys(), self.headers.values()))
        try:
            r = self._opener.open(url, timeout=self.TIMEOUT*2)
        except:
            logger.debug('openurl failed %s', url, exc_info=1)
            return False
        code = r.getcode()
        if code == 200:
            try:
                fileobj = r
                if r.headers.get('content-encoding', None) == 'gzip':
                    fileobj = gzip.GzipFile(fileobj=r)
                content = fileobj.read()
                key = 'preview:' + item_id
                icons[key] = content
                icons.clear(key+':')
                return True
            except:
                logger.debug('preview download failed %s', url, exc_info=1)
        elif code == 404:
            pass
        else:
            logger.debug('FAILED %s', url)
        return False

    def download_upgrade(self, release):
        for module in release['modules']:
            path = os.path.join(settings.update_path, release['modules'][module]['name'])
            if not os.path.exists(path):
                url = '%s/oml/%s' % (self.url, release['modules'][module]['name'])
                sha1 = release['modules'][module]['sha1']
                headers = {
                    'User-Agent': settings.USER_AGENT,
                }
                self._opener.addheaders = list(zip(headers.keys(), headers.values()))
                r = self._opener.open(url)
                if r.getcode() == 200:
                    with open(path, 'w') as fd:
                        fd.write(r.read())
                        if (ox.sha1sum(path) != sha1):
                            logger.error('invalid update!')
                            os.unlink(path)
                            return False
                else:
                    return False

class Nodes(Thread):
    _nodes = {}
    _local = None
    _pulling = False

    def __init__(self):
        self._q = Queue()
        self._running = True
        with db.session():
            for u in user.models.User.query.filter_by(peered=True):
                if 'local' in u.info:
                    del u.info['local']
                    u.save()
                self.queue('add', u.id)
            for u in user.models.User.query.filter_by(queued=True):
                logger.debug('adding queued node... %s', u.id)
                self.queue('add', u.id, True)
        self._local = LocalNodes()
        self._cleanup = PeriodicCallback(lambda: self.queue('cleanup'), 120000)
        self._cleanup.start()
        self._pullcb = PeriodicCallback(self.pull, 60000)
        self._pullcb.start()
        Thread.__init__(self)
        self.daemon = True
        self.start()

    def cleanup(self):
        if self._running and self._local:
            self._local.cleanup()

    def pull(self):
        if state.online and not self._pulling:
            self.queue('pull')

    def queue(self, *args):
        self._q.put(list(args))

    def is_online(self, id):
        return id in self._nodes and self._nodes[id].is_online()

    def download(self, id, item):
        return id in self._nodes and self._nodes[id].download(item)

    def download_preview(self, id, item):
        return id in self._nodes and \
            self._nodes[id].is_online() and \
            self._nodes[id].download_preview(item)

    def _call(self, target, action, *args):
        if target == 'all':
            nodes = list(self._nodes.values())
        elif target == 'peered':
            nodes = [n for n in list(self._nodes.values()) if n.user.peered]
        elif target == 'online':
            nodes = [n for n in list(self._nodes.values()) if n.online]
        else:
            if not target in self._nodes:
                self._add(target)
            nodes = [self._nodes[target]]
        for node in nodes:
            r = getattr(node, action)(*args)
            logger.debug('call node api %s->%s%s = %s', node.user_id, action, args, r)

    def _add(self, user_id, send_response=False):
        if user_id not in self._nodes:
            from user.models import User
            with db.session():
                self._nodes[user_id] = Node(self, User.get_or_create(user_id))
        else:
            if not self._nodes[user_id].online:
                self._nodes[user_id].ping()
        if send_response:
            self._nodes[user_id].send_response()

    def _pull(self):
        if state.activity and state.activity.get('activity') == 'import':
            return
        self._pulling = True
        for node in list(self._nodes.values()):
            node.online = node.can_connect()
            if node.online:
                node.pullChanges()
        self._pulling = False

    def run(self):
        while self._running:
            args = self._q.get()
            if args:
                if args[0] == 'cleanup':
                    self.cleanup()
                elif args[0] == 'add':
                    self._add(*args[1:])
                elif args[0] == 'pull':
                    self._pull()
                else:
                    self._call(*args)

    def join(self):
        self._running = False
        self._q.put(None)
        for node in list(self._nodes.values()):
            node.join()
        if self._local:
            self._local.join()
        return Thread.join(self)

def publish_node():
    update_online()
    state.check_nodes = PeriodicCallback(check_nodes, 120000)
    state.check_nodes.start()
    state._online = PeriodicCallback(update_online, 60000)
    state._online.start()

def update_online():
    online = state.tor and state.tor.is_online()
    if online != state.online:
        state.online = online
        trigger_event('status', {
            'id': settings.USER_ID,
            'online': state.online
        })
        if state.online and state.nodes:
            state.nodes.pull()

    if settings.OLD_USER_ID and not settings.server.get('migrated_id', False):
        from . import directory
        r = directory.put(settings.sk, {
            'id': settings.USER_ID,
        })
        logger.debug('push id to directory %s', r)
        if r:
            settings.server['migrated_id'] = True

def check_nodes():
    if state.online:
        with db.session():
            for u in user.models.User.query.filter_by(queued=True):
                if not state.nodes.is_online(u.id):
                    logger.debug('queued peering message for %s trying to connect...', u.id)
                    state.nodes.queue('add', u.id, True)