ZeroNet/src/Site/Site.py

import os
import json
import logging
import hashlib
import re
import time
import random
import sys
import binascii
import struct
import socket
import urllib
import urllib2

import gevent

import util
from lib import bencode
from lib.subtl.subtl import UdpTrackerClient
from Config import config
from Peer import Peer
from Worker import WorkerManager
from Debug import Debug
from Content import ContentManager
from SiteStorage import SiteStorage
from Crypt import CryptHash
from util import helper
import SiteManager


class Site:

    def __init__(self, address, allow_create=True):
        self.address = re.sub("[^A-Za-z0-9]", "", address)  # Make sure its correct address
        self.address_short = "%s..%s" % (self.address[:6], self.address[-4:])  # Short address for logging
        self.log = logging.getLogger("Site:%s" % self.address_short)
        self.addEventListeners()

        self.content = None  # Load content.json
        self.peers = {}  # Key: ip:port, Value: Peer.Peer
        self.peer_blacklist = SiteManager.peer_blacklist  # Ignore this peers (eg. myself)
        self.last_announce = 0  # Last announce time to tracker
        self.last_tracker_id = random.randint(0, 10)  # Last announced tracker id
        self.worker_manager = WorkerManager(self)  # Handle site download from other peers
        self.bad_files = {}  # SHA check failed files, need to redownload {"inner.content": 1} (key: file, value: failed accept)
        self.content_updated = None  # Content.js update time
        self.notifications = []  # Pending notifications displayed once on page load [error|ok|info, message, timeout]
        self.page_requested = False  # Page viewed in browser

        self.storage = SiteStorage(self, allow_create=allow_create)  # Save and load site files
        self.loadSettings()  # Load settings from sites.json
        self.content_manager = ContentManager(self)  # Load contents
        self.connection_server = None
        if "main" in sys.modules and "file_server" in dir(sys.modules["main"]):  # Use global file server by default if possible
            self.connection_server = sys.modules["main"].file_server
        else:
            self.connection_server = None
        if not self.settings.get("auth_key"):  # To auth user in site (Obsolete, will be removed)
            self.settings["auth_key"] = CryptHash.random()
            self.log.debug("New auth key: %s" % self.settings["auth_key"])
            self.saveSettings()

        if not self.settings.get("wrapper_key"):  # To auth websocket permissions
            self.settings["wrapper_key"] = CryptHash.random()
            self.log.debug("New wrapper key: %s" % self.settings["wrapper_key"])
            self.saveSettings()

        self.websockets = []  # Active site websocket connections

    def __str__(self):
        return "Site %s" % self.address_short

    def __repr__(self):
        return "<%s>" % self.__str__()

    # Load site settings from data/sites.json
    def loadSettings(self):
        sites_settings = json.load(open("%s/sites.json" % config.data_dir))
        if self.address in sites_settings:
            self.settings = sites_settings[self.address]
        else:
            if self.address == config.homepage:  # Add admin permissions to homepage
                permissions = ["ADMIN"]
            else:
                permissions = []
            self.settings = {"own": False, "serving": True, "permissions": permissions}  # Default
        return

    # Save site settings to data/sites.json
    def saveSettings(self):
        sites_settings = json.load(open("%s/sites.json" % config.data_dir))
        sites_settings[self.address] = self.settings
        helper.atomicWrite("%s/sites.json" % config.data_dir, json.dumps(sites_settings, indent=2, sort_keys=True))

    # Max site size in MB
    def getSizeLimit(self):
        return self.settings.get("size_limit", config.size_limit)

    # Next size limit based on current size
    def getNextSizeLimit(self):
        size_limits = [10, 20, 50, 100, 200, 500, 1000, 2000, 5000, 10000, 20000, 50000, 100000]
        size = self.settings.get("size", 0)
        for size_limit in size_limits:
            if size * 1.2 < size_limit * 1024 * 1024:
                return size_limit
        return 999999

    # Download all file from content.json
    def downloadContent(self, inner_path, download_files=True, peer=None, check_modifications=False):
        s = time.time()
        self.log.debug("Downloading %s..." % inner_path)
        found = self.needFile(inner_path, update=self.bad_files.get(inner_path))
        content_inner_dir = helper.getDirname(inner_path)
        if not found:
            self.log.debug("Download %s failed, check_modifications: %s" % (inner_path, check_modifications))
            if check_modifications:  # Download failed, but check modifications if its succed later
                self.onFileDone.once(lambda file_name: self.checkModifications(0), "check_modifications")
            return False  # Could not download content.json

        self.log.debug("Got %s" % inner_path)
        changed, deleted = self.content_manager.loadContent(inner_path, load_includes=False)

        # Start download files
        file_threads = []
        if download_files:
            for file_relative_path in self.content_manager.contents[inner_path].get("files", {}).keys():
                file_inner_path = content_inner_dir + file_relative_path
                # Start download and dont wait for finish, return the event
                res = self.needFile(file_inner_path, blocking=False, update=self.bad_files.get(file_inner_path), peer=peer)
                if res is not True and res is not False:  # Need downloading and file is allowed
                    file_threads.append(res)  # Append evt

        # Wait for includes download
        include_threads = []
        for file_relative_path in self.content_manager.contents[inner_path].get("includes", {}).keys():
            file_inner_path = content_inner_dir + file_relative_path
            include_thread = gevent.spawn(self.downloadContent, file_inner_path, download_files=download_files, peer=peer)
            include_threads.append(include_thread)

        self.log.debug("%s: Downloading %s includes..." % (inner_path, len(include_threads)))
        gevent.joinall(include_threads)
        self.log.debug("%s: Includes download ended" % inner_path)

        if check_modifications:  # Check if every file is up-to-date
            self.checkModifications(0)

        self.log.debug("%s: Downloading %s files, changed: %s..." % (inner_path, len(file_threads), len(changed)))
        gevent.joinall(file_threads)
        self.log.debug("%s: DownloadContent ended in %.2fs" % (inner_path, time.time() - s))

        return True

    # Return bad files with less than 3 retry
    def getReachableBadFiles(self):
        if not self.bad_files:
            return False
        return [bad_file for bad_file, retry in self.bad_files.iteritems() if retry < 3]

    # Retry download bad files
    def retryBadFiles(self):
        for bad_file in self.bad_files.keys():
            self.needFile(bad_file, update=True, blocking=False)

    # Download all files of the site
    @util.Noparallel(blocking=False)
    def download(self, check_size=False, blind_includes=False):
        self.log.debug(
            "Start downloading, bad_files: %s, check_size: %s, blind_includes: %s" %
            (self.bad_files, check_size, blind_includes)
        )
        gevent.spawn(self.announce)
        if check_size:  # Check the size first
            valid = self.downloadContent("content.json", download_files=False)  # Just download content.json files
            if not valid:
                return False  # Cant download content.jsons or size is not fits

        # Download everything
        valid = self.downloadContent("content.json", check_modifications=blind_includes)

        self.retryBadFiles()

        return valid

    # Update worker, try to find client that supports listModifications command
    def updater(self, peers_try, queried, since):
        while 1:
            if not peers_try or len(queried) >= 3:  # Stop after 3 successful query
                break
            peer = peers_try.pop(0)
            if not peer.connection and len(queried) < 2:
                peer.connect()  # Only open new connection if less than 2 queried already
            if not peer.connection or peer.connection.handshake.get("rev", 0) < 126:
                continue  # Not compatible
            res = peer.listModified(since)
            if not res or "modified_files" not in res:
                continue  # Failed query

            queried.append(peer)
            for inner_path, modified in res["modified_files"].iteritems():  # Check if the peer has newer files than we
                content = self.content_manager.contents.get(inner_path)
                if (not content or modified > content["modified"]) and inner_path not in self.bad_files:
                    self.log.debug("New modified file from %s: %s" % (peer, inner_path))
                    # We dont have this file or we have older
                    self.bad_files[inner_path] = self.bad_files.get(inner_path, 0) + 1  # Mark as bad file
                    gevent.spawn(self.downloadContent, inner_path)  # Download the content.json + the changed files

    # Check modified content.json files from peers and add modified files to bad_files
    # Return: Successfully queried peers [Peer, Peer...]
    def checkModifications(self, since=None):
        peers_try = []  # Try these peers
        queried = []  # Successfully queried from these peers

        peers = self.peers.values()
        random.shuffle(peers)
        for peer in peers:  # Try to find connected good peers, but we must have at least 5 peers
            if peer.findConnection() and peer.connection.handshake.get("rev", 0) > 125:  # Add to the beginning if rev125
                peers_try.insert(0, peer)
            elif len(peers_try) < 5:  # Backup peers, add to end of the try list
                peers_try.append(peer)

        if since is None:  # No since definied, download from last modification time-1day
            since = self.settings.get("modified", 60 * 60 * 24) - 60 * 60 * 24
        self.log.debug("Try to get listModifications from peers: %s since: %s" % (peers_try, since))

        updaters = []
        for i in range(3):
            updaters.append(gevent.spawn(self.updater, peers_try, queried, since))

        gevent.joinall(updaters, timeout=10)  # Wait 10 sec to workers done query modifications
        time.sleep(0.1)
        self.log.debug("Queried listModifications from: %s" % queried)
        return queried

    # Update content.json from peers and download changed files
    # Return: None
    @util.Noparallel()
    def update(self, announce=False):
        self.content_manager.loadContent("content.json")  # Reload content.json
        self.content_updated = None  # Reset content updated time
        self.updateWebsocket(updating=True)
        if announce:
            self.announce()

        queried = self.checkModifications()

        if not queried:  # Not found any client that supports listModifications
            self.log.debug("Fallback to old-style update")
            self.redownloadContents()

        if not self.settings["own"]:
            self.storage.checkFiles(quick_check=True)  # Quick check files based on file size

        changed, deleted = self.content_manager.loadContent("content.json")

        if self.bad_files:
            self.download()

        self.settings["size"] = self.content_manager.getTotalSize()  # Update site size
        self.updateWebsocket(updated=True)

    # Update site by redownload all content.json
    def redownloadContents(self):
        # Download all content.json again
        content_threads = []
        for inner_path in self.content_manager.contents.keys():
            content_threads.append(self.needFile(inner_path, update=True, blocking=False))

        self.log.debug("Waiting %s content.json to finish..." % len(content_threads))
        gevent.joinall(content_threads)

    # Publish worker
    def publisher(self, inner_path, peers, published, limit, event_done=None):
        file_size = self.storage.getSize(inner_path)
        body = self.storage.read(inner_path)
        while 1:
            if not peers or len(published) >= limit:
                if event_done:
                    event_done.set(True)
                break  # All peers done, or published engouht
            peer = peers.pop(0)
            if peer.connection and peer.connection.last_ping_delay:  # Peer connected
                # Timeout: 5sec + size in kb + last_ping
                timeout = timeout = 5 + int(file_size / 1024) + peer.connection.last_ping_delay
            else:  # Peer not connected
                # Timeout: 5sec + size in kb
                timeout = timeout = 5 + int(file_size / 1024)
            result = {"exception": "Timeout"}

            for retry in range(2):
                try:
                    with gevent.Timeout(timeout, False):
                        result = peer.request("update", {
                            "site": self.address,
                            "inner_path": inner_path,
                            "body": body,
                            "peer": (config.ip_external, config.fileserver_port)
                        })
                    if result:
                        break
                except Exception, err:
                    result = {"exception": Debug.formatException(err)}

            if result and "ok" in result:
                published.append(peer)
                self.log.info("[OK] %s: %s" % (peer.key, result["ok"]))
            else:
                if result == {"exception": "Timeout"}:
                    peer.onConnectionError()
                self.log.info("[FAILED] %s: %s" % (peer.key, result))

    # Update content.json on peers
    @util.Noparallel()
    def publish(self, limit=5, inner_path="content.json"):
        published = []  # Successfully published (Peer)
        publishers = []  # Publisher threads

        connected_peers = self.getConnectedPeers()
        if len(connected_peers) > limit * 2:  # Publish to already connected peers if possible
            peers = connected_peers
        else:
            peers = self.peers.values()

        self.log.info("Publishing to %s/%s peers (connected: %s)..." % (
            min(len(self.peers), limit), len(self.peers), len(connected_peers)
        ))

        if not peers:
            return 0  # No peers found

        random.shuffle(peers)
        event_done = gevent.event.AsyncResult()
        for i in range(min(len(self.peers), limit, 5)):  # Max 5 thread
            publisher = gevent.spawn(self.publisher, inner_path, peers, published, limit, event_done)
            publishers.append(publisher)

        event_done.get()  # Wait for done
        if len(published) < min(len(self.peers), limit):
            time.sleep(0.2)  # If less than we need sleep a bit
        if len(published) == 0:
            gevent.joinall(publishers)  # No successful publish, wait for all publisher

        # Make sure the connected passive peers got the update
        passive_peers = [
            peer for peer in peers
            if peer.connection and not peer.connection.closed and peer.key.endswith(":0") and peer not in published
        ]  # Every connected passive peer that we not published to

        self.log.info(
            "Successfuly published to %s peers, publishing to %s more passive peers" %
            (len(published), len(passive_peers))
        )

        for peer in passive_peers:
            gevent.spawn(self.publisher, inner_path, passive_peers, published, limit=10)

        return len(published)

    # Copy this site
    def clone(self, address, privatekey=None, address_index=None, overwrite=False):
        import shutil
        new_site = SiteManager.site_manager.need(address, all_file=False)
        default_dirs = []  # Dont copy these directories (has -default version)
        for dir_name in os.listdir(self.storage.directory):
            if "-default" in dir_name:
                default_dirs.append(dir_name.replace("-default", ""))

        self.log.debug("Cloning to %s, ignore dirs: %s" % (address, default_dirs))

        # Copy root content.json
        if not new_site.storage.isFile("content.json") and not overwrite:
            # Content.json not exist yet, create a new one from source site
            content_json = self.storage.loadJson("content.json")
            if "domain" in content_json:
                del content_json["domain"]
            content_json["title"] = "my" + content_json["title"]
            content_json["cloned_from"] = self.address
            if address_index:
                content_json["address_index"] = address_index  # Site owner's BIP32 index
            new_site.storage.writeJson("content.json", content_json)
            new_site.content_manager.loadContent(
                "content.json", add_bad_files=False, delete_removed_files=False, load_includes=False
            )

        # Copy files
        for content_inner_path, content in self.content_manager.contents.items():
            for file_relative_path in sorted(content["files"].keys()):
                file_inner_path = helper.getDirname(content_inner_path) + file_relative_path  # Relative to content.json
                file_inner_path = file_inner_path.strip("/")  # Strip leading /
                if file_inner_path.split("/")[0] in default_dirs:  # Dont copy directories that has -default postfixed alternative
                    self.log.debug("[SKIP] %s (has default alternative)" % file_inner_path)
                    continue
                file_path = self.storage.getPath(file_inner_path)

                # Copy the file normally to keep the -default postfixed dir and file to allow cloning later
                file_path_dest = new_site.storage.getPath(file_inner_path)
                self.log.debug("[COPY] %s to %s..." % (file_inner_path, file_path_dest))
                dest_dir = os.path.dirname(file_path_dest)
                if not os.path.isdir(dest_dir):
                    os.makedirs(dest_dir)
                shutil.copy(file_path, file_path_dest)

                # If -default in path, create a -default less copy of the file
                if "-default" in file_inner_path:
                    file_path_dest = new_site.storage.getPath(file_inner_path.replace("-default", ""))
                    if new_site.storage.isFile(file_path_dest) and not overwrite:  # Don't overwrite site files with default ones
                        self.log.debug("[SKIP] Default file: %s (already exist)" % file_inner_path)
                        continue
                    self.log.debug("[COPY] Default file: %s to %s..." % (file_inner_path, file_path_dest))
                    dest_dir = os.path.dirname(file_path_dest)
                    if not os.path.isdir(dest_dir):
                        os.makedirs(dest_dir)
                    shutil.copy(file_path, file_path_dest)
                    # Sign if content json
                    if file_path_dest.endswith("/content.json"):
                        new_site.storage.onUpdated(file_inner_path.replace("-default", ""))
                        new_site.content_manager.loadContent(
                            file_inner_path.replace("-default", ""), add_bad_files=False,
                            delete_removed_files=False, load_includes=False
                        )
                        if privatekey:
                            new_site.content_manager.sign(file_inner_path.replace("-default", ""), privatekey)
                            new_site.content_manager.loadContent(
                                file_inner_path, add_bad_files=False, delete_removed_files=False, load_includes=False
                            )

        if privatekey:
            new_site.content_manager.sign("content.json", privatekey)
            new_site.content_manager.loadContent(
                "content.json", add_bad_files=False, delete_removed_files=False, load_includes=False
            )

        # Rebuild DB
        if new_site.storage.isFile("dbschema.json"):
            new_site.storage.closeDb()
            new_site.storage.rebuildDb()

        return new_site

    # Check and download if file not exist
    def needFile(self, inner_path, update=False, blocking=True, peer=None, priority=0):
        if self.storage.isFile(inner_path) and not update:  # File exist, no need to do anything
            return True
        elif self.settings["serving"] is False:  # Site not serving
            return False
        else:  # Wait until file downloaded
            self.bad_files[inner_path] = self.bad_files.get(inner_path, 0) + 1  # Mark as bad file
            if not self.content_manager.contents.get("content.json"):  # No content.json, download it first!
                self.log.debug("Need content.json first")
                gevent.spawn(self.announce)
                if inner_path != "content.json":  # Prevent double download
                    task = self.worker_manager.addTask("content.json", peer)
                    task.get()
                    self.content_manager.loadContent()
                    if not self.content_manager.contents.get("content.json"):
                        return False  # Content.json download failed

            if not inner_path.endswith("content.json") and not self.content_manager.getFileInfo(inner_path):
                # No info for file, download all content.json first
                self.log.debug("No info for %s, waiting for all content.json" % inner_path)
                success = self.downloadContent("content.json", download_files=False)
                if not success:
                    return False
                if not self.content_manager.getFileInfo(inner_path):
                    return False  # Still no info for file

            task = self.worker_manager.addTask(inner_path, peer, priority=priority)
            if blocking:
                return task.get()
            else:
                return task

    # Add or update a peer to site
    # return_peer: Always return the peer even if it was already present
    def addPeer(self, ip, port, return_peer=False):
        if not ip:
            return False
        if (ip, port) in self.peer_blacklist:
            return False  # Ignore blacklist (eg. myself)
        key = "%s:%s" % (ip, port)
        if key in self.peers:  # Already has this ip
            self.peers[key].found()
            if return_peer:  # Always return peer
                return self.peers[key]
            else:
                return False
        else:  # New peer
            peer = Peer(ip, port, self)
            self.peers[key] = peer
            return peer

    # Gather peer from connected peers
    @util.Noparallel(blocking=False)
    def announcePex(self, query_num=2, need_num=5):
        peers = [peer for peer in self.peers.values() if peer.connection and peer.connection.connected]  # Connected peers
        if len(peers) == 0:  # Small number of connected peers for this site, connect to any
            self.log.debug("Small number of peers detected...query all of peers using pex")
            peers = self.peers.values()
            need_num = 10

        random.shuffle(peers)
        done = 0
        added = 0
        for peer in peers:
            if peer.connection:  # Has connection
                if "port_opened" in peer.connection.handshake:  # This field added recently, so probably has has peer exchange
                    res = peer.pex(need_num=need_num)
                else:
                    res = False
            else:  # No connection
                res = peer.pex(need_num=need_num)
            if type(res) == int:  # We have result
                done += 1
                added += res
                if res:
                    self.worker_manager.onPeers()
                    self.updateWebsocket(peers_added=res)
            if done == query_num:
                break
        self.log.debug("Queried pex from %s peers got %s new peers." % (done, added))

    # Gather peers from tracker
    # Return: Complete time or False on error
    def announceTracker(self, protocol, address, fileserver_port, address_hash, my_peer_id):
        s = time.time()
        if protocol == "udp":  # Udp tracker
            if config.disable_udp:
                return False  # No udp supported
            ip, port = address.split(":")
            tracker = UdpTrackerClient(ip, int(port))
            tracker.peer_port = fileserver_port
            try:
                tracker.connect()
                tracker.poll_once()
                tracker.announce(info_hash=address_hash, num_want=50)
                back = tracker.poll_once()
                peers = back["response"]["peers"]
            except Exception, err:
                return False

        else:  # Http tracker
            params = {
                'info_hash': binascii.a2b_hex(address_hash),
                'peer_id': my_peer_id, 'port': fileserver_port,
                'uploaded': 0, 'downloaded': 0, 'left': 0, 'compact': 1, 'numwant': 30,
                'event': 'started'
            }
            req = None
            try:
                url = "http://" + address + "?" + urllib.urlencode(params)
                # Load url
                with gevent.Timeout(10, False):  # Make sure of timeout
                    req = urllib2.urlopen(url, timeout=8)
                    response = req.read()
                    req.fp._sock.recv = None  # Hacky avoidance of memory leak for older python versions
                    req.close()
                    req = None
                if not response:
                    self.log.debug("Http tracker %s response error" % url)
                    return False
                # Decode peers
                peer_data = bencode.decode(response)["peers"]
                response = None
                peer_count = len(peer_data) / 6
                peers = []
                for peer_offset in xrange(peer_count):
                    off = 6 * peer_offset
                    peer = peer_data[off:off + 6]
                    addr, port = struct.unpack('!LH', peer)
                    peers.append({"addr": socket.inet_ntoa(struct.pack('!L', addr)), "port": port})
            except Exception, err:
                self.log.debug("Http tracker %s error: %s" % (url, err))
                if req:
                    req.close()
                    req = None
                return False

        # Adding peers
        added = 0
        for peer in peers:
            if not peer["port"]:
                continue  # Dont add peers with port 0
            if self.addPeer(peer["addr"], peer["port"]):
                added += 1
        if added:
            self.worker_manager.onPeers()
            self.updateWebsocket(peers_added=added)
            self.log.debug("Found %s peers, new: %s" % (len(peers), added))
        return time.time() - s

    # Add myself and get other peers from tracker
    def announce(self, force=False, num=5, pex=True):
        if time.time() < self.last_announce + 30 and not force:
            return  # No reannouncing within 30 secs
        self.last_announce = time.time()

        trackers = config.trackers
        if num == 1:  # Only announce on one tracker, increment the queried tracker id
            self.last_tracker_id += 1
            self.last_tracker_id = self.last_tracker_id % len(trackers)
            trackers = [trackers[self.last_tracker_id]]  # We only going to use this one

        errors = []
        slow = []
        address_hash = hashlib.sha1(self.address).hexdigest()  # Site address hash
        my_peer_id = sys.modules["main"].file_server.peer_id

        if sys.modules["main"].file_server.port_opened:
            fileserver_port = config.fileserver_port
        else:  # Port not opened, report port 0
            fileserver_port = 0

        s = time.time()
        announced = 0
        threads = []

        for tracker in trackers:  # Start announce threads
            protocol, address = tracker.split("://")
            thread = gevent.spawn(self.announceTracker, protocol, address, fileserver_port, address_hash, my_peer_id)
            threads.append(thread)
            thread.address = address
            thread.protocol = protocol
            if len(threads) > num:  # Announce limit
                break

        gevent.joinall(threads)  # Wait for announce finish

        for thread in threads:
            if thread.value:
                if thread.value > 1:
                    slow.append("%.2fs %s://%s" % (thread.value, thread.protocol, thread.address))
                announced += 1
            else:
                errors.append("%s://%s" % (thread.protocol, thread.address))

        # Save peers num
        self.settings["peers"] = len(self.peers)
        self.saveSettings()

        if len(errors) < min(num, len(trackers)):  # Less errors than total tracker nums
            self.log.debug(
                "Announced port %s to %s trackers in %.3fs, errors: %s, slow: %s" %
                (fileserver_port, announced, time.time() - s, errors, slow)
            )
        else:
            self.log.error("Announce to %s trackers in %.3fs, failed" % (announced, time.time() - s))

        if pex:
            if not [peer for peer in self.peers.values() if peer.connection and peer.connection.connected]:
                # If no connected peer yet then wait for connections
                gevent.spawn_later(3, self.announcePex, need_num=10)  # Spawn 3 secs later
            else:  # Else announce immediately
                self.announcePex()

    # Keep connections to get the updates (required for passive clients)
    def needConnections(self, num=3):
        need = min(len(self.peers), num)  # Need 3 peer, but max total peers

        connected = 0
        for peer in self.peers.values():  # Check current connected number
            if peer.connection and peer.connection.connected:
                connected += 1

        self.log.debug("Need connections: %s, Current: %s, Total: %s" % (need, connected, len(self.peers)))

        if connected < need:  # Need more than we have
            for peer in self.peers.values():
                if not peer.connection or not peer.connection.connected:  # No peer connection or disconnected
                    peer.pex()  # Initiate peer exchange
                    if peer.connection and peer.connection.connected:
                        connected += 1  # Successfully connected
                if connected >= need:
                    break
        return connected

    # Return: Probably working, connectable Peers
    def getConnectablePeers(self, need_num=5, ignore=[]):
        peers = self.peers.values()
        random.shuffle(peers)
        found = []
        for peer in peers:
            if peer.key.endswith(":0"):
                continue  # Not connectable
            if not peer.connection:
                continue  # No connection
            if peer.key in ignore:
                continue  # The requester has this peer
            if time.time() - peer.connection.last_recv_time > 60 * 60 * 2:  # Last message more than 2 hours ago
                peer.connection = None  # Cleanup: Dead connection
                continue
            found.append(peer)
            if len(found) >= need_num:
                break  # Found requested number of peers

        if (not found and not ignore) or (need_num > 5 and need_num < 100 and len(found) < need_num):
            # Return not that good peers: Not found any peer and the requester dont have any or cant give enough peer
            found = [peer for peer in peers if not peer.key.endswith(":0") and peer.key not in ignore][0:need_num - len(found)]

        return found

    def getConnectedPeers(self):
        return [peer for peer in self.peers.values() if peer.connection and peer.connection.connected]

    # Cleanup probably dead peers
    def cleanupPeers(self):
        peers = self.peers.values()
        if len(peers) < 20:
            return False
        removed = 0

        for peer in peers:
            if peer.connection and peer.connection.connected:
                continue
            if peer.connection and not peer.connection.connected:
                peer.connection = None  # Dead connection
            if time.time() - peer.last_found > 60 * 60 * 4:  # Not found on tracker or via pex in last 4 hour
                peer.remove()
                removed += 1
            if removed > 5:  # Don't remove too much at once
                break

        if removed:
            self.log.debug("Cleanup peers result: Removed %s, left: %s" % (removed, len(self.peers)))

    # - Events -

    # Add event listeners
    def addEventListeners(self):
        self.onFileStart = util.Event()  # If WorkerManager added new task
        self.onFileDone = util.Event()  # If WorkerManager successfully downloaded a file
        self.onFileFail = util.Event()  # If WorkerManager failed to download a file
        self.onComplete = util.Event()  # All file finished

        self.onFileStart.append(lambda inner_path: self.fileStarted())  # No parameters to make Noparallel batching working
        self.onFileDone.append(lambda inner_path: self.fileDone(inner_path))
        self.onFileFail.append(lambda inner_path: self.fileFailed(inner_path))

    # Send site status update to websocket clients
    def updateWebsocket(self, **kwargs):
        if kwargs:
            param = {"event": kwargs.items()[0]}
        else:
            param = None
        for ws in self.websockets:
            ws.event("siteChanged", self, param)

    # File download started
    @util.Noparallel(blocking=False)
    def fileStarted(self):
        time.sleep(0.001)  # Wait for other files adds
        self.updateWebsocket(file_started=True)

    # File downloaded successful
    def fileDone(self, inner_path):
        # File downloaded, remove it from bad files
        if inner_path in self.bad_files:
            self.log.debug("Bad file solved: %s" % inner_path)
            del(self.bad_files[inner_path])

        # Update content.json last downlad time
        if inner_path == "content.json":
            self.content_updated = time.time()

        self.updateWebsocket(file_done=inner_path)

    # File download failed
    def fileFailed(self, inner_path):
        if inner_path == "content.json":
            self.content_updated = False
            self.log.debug("Can't update content.json")
        if inner_path in self.bad_files:
            self.bad_files[inner_path] = self.bad_files.get(inner_path, 0) + 1

        self.updateWebsocket(file_failed=inner_path)