server.py

from math import floor
from world import World
import queue
import socketserver
import datetime
import random
import re
import requests
import sqlite3
import sys
import threading
import time
import traceback

DEFAULT_HOST = '0.0.0.0'
DEFAULT_PORT = 4080

DB_PATH = 'craft.db'
LOG_PATH = 'log.txt'

CHUNK_SIZE = 32
BUFFER_SIZE = 4096
COMMIT_INTERVAL = 5

AUTH_REQUIRED = True
AUTH_URL = 'https://craft.michaelfogleman.com/api/1/access'

DAY_LENGTH = 600
SPAWN_POINT = (0, 0, 0, 0, 0)
RATE_LIMIT = False
RECORD_HISTORY = False
INDESTRUCTIBLE_ITEMS = set([16])
ALLOWED_ITEMS = set([
    0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
    17, 18, 19, 20, 21, 22, 23,
    32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
    48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63])

AUTHENTICATE = 'A'
BLOCK = 'B'
CHUNK = 'C'
DISCONNECT = 'D'
KEY = 'K'
LIGHT = 'L'
NICK = 'N'
POSITION = 'P'
REDRAW = 'R'
SIGN = 'S'
TALK = 'T'
TIME = 'E'
VERSION = 'V'
YOU = 'U'

try:
    from config import *
except ImportError:
    pass


def log(*args):
    now = datetime.datetime.utcnow()
    line = ' '.join(map(str, (now,) + args))
    print(line)
    with open(LOG_PATH, 'a') as fp:
        fp.write('%s\n' % line)


def chunked(x):
    return int(floor(round(x) / CHUNK_SIZE))


def packet(*args):
    return ('%s\n' % ','.join(map(str, args))).encode("UTF-8")


class RateLimiter(object):
    def __init__(self, rate, per):
        self.rate = float(rate)
        self.per = float(per)
        self.allowance = self.rate
        self.last_check = time.time()

    def tick(self):
        if not RATE_LIMIT:
            return False
        now = time.time()
        elapsed = now - self.last_check
        self.last_check = now
        self.allowance += elapsed * (self.rate / self.per)
        if self.allowance > self.rate:
            self.allowance = self.rate
        if self.allowance < 1:
            return True  # too fast
        else:
            self.allowance -= 1
            return False  # okay


class Server(socketserver.ThreadingMixIn, socketserver.TCPServer):
    allow_reuse_address = True
    daemon_threads = True


class Handler(socketserver.BaseRequestHandler):
    def setup(self):
        self.position_limiter = RateLimiter(100, 5)
        self.limiter = RateLimiter(1000, 10)
        self.version = None
        self.client_id = None
        self.user_id = None
        self.nick = None
        self.queue = queue.Queue()
        self.running = True
        self.start()

    def handle(self):
        model = self.server.model
        model.enqueue(model.on_connect, self)
        try:
            buf = b''
            while True:
                data = self.request.recv(BUFFER_SIZE)
                if not data:
                    break
                buf += data.replace(b'\r\n', b'\n')
                while b'\n' in buf:
                    index = buf.index(b'\n')
                    line = buf[:index]
                    buf = buf[index + 1:]
                    if not line:
                        continue

                    command = line.decode("utf-8")
                    if command[0] == POSITION:
                        if self.position_limiter.tick():
                            log('RATE', self.client_id)
                            self.stop()
                            return
                    else:
                        if self.limiter.tick():
                            log('RATE', self.client_id)
                            self.stop()
                            return
                    model.enqueue(model.on_data, self, command)
        finally:
            model.enqueue(model.on_disconnect, self)

    def finish(self):
        self.running = False

    def stop(self):
        self.request.close()

    def start(self):
        thread = threading.Thread(target=self.run)
        thread.setDaemon(True)
        thread.start()

    def run(self):
        while self.running:
            try:
                buf = b''
                try:
                    buf += self.queue.get(timeout=5)
                    try:
                        while True:
                            buf += self.queue.get_nowait()
                    except queue.Empty:
                        pass
                except queue.Empty:
                    continue
                self.request.sendall(buf)
            except Exception:
                self.request.close()
                raise

    def send_raw(self, data):
        if data:
            self.queue.put(data)

    def send(self, *args):
        self.send_raw(packet(*args))


class Model(object):
    def __init__(self, seed):
        self.world = World(seed)
        self.clients = []
        self.queue = queue.Queue()
        self.commands = {
            AUTHENTICATE: self.on_authenticate,
            CHUNK: self.on_chunk,
            BLOCK: self.on_block,
            LIGHT: self.on_light,
            POSITION: self.on_position,
            TALK: self.on_talk,
            SIGN: self.on_sign,
            VERSION: self.on_version,
        }
        self.patterns = [
            (re.compile(r'^/nick(?:\s+([^,\s]+))?$'), self.on_nick),
            (re.compile(r'^/spawn$'), self.on_spawn),
            (re.compile(r'^/goto(?:\s+(\S+))?$'), self.on_goto),
            (re.compile(r'^/pq\s+(-?[0-9]+)\s*,?\s*(-?[0-9]+)$'), self.on_pq),
            (re.compile(r'^/help(?:\s+(\S+))?$'), self.on_help),
            (re.compile(r'^/list$'), self.on_list),
        ]

    def start(self):
        thread = threading.Thread(target=self.run)
        thread.setDaemon(True)
        thread.start()

    def run(self):
        self.connection = sqlite3.connect(DB_PATH)
        self.create_tables()
        self.commit()
        while True:
            try:
                if time.time() - self.last_commit > COMMIT_INTERVAL:
                    self.commit()
                self.dequeue()
            except Exception:
                traceback.print_exc()

    def enqueue(self, func, *args, **kwargs):
        self.queue.put((func, args, kwargs))

    def dequeue(self):
        try:
            func, args, kwargs = self.queue.get(timeout=5)
            func(*args, **kwargs)
        except queue.Empty:
            pass

    def execute(self, *args, **kwargs):
        return self.connection.execute(*args, **kwargs)

    def commit(self):
        self.last_commit = time.time()
        self.connection.commit()

    def create_tables(self):
        queries = [
            'create table if not exists block ('
            '    p int not null,'
            '    q int not null,'
            '    x int not null,'
            '    y int not null,'
            '    z int not null,'
            '    w int not null'
            ');',
            'create unique index if not exists block_pqxyz_idx on '
            '    block (p, q, x, y, z);',
            'create table if not exists light ('
            '    p int not null,'
            '    q int not null,'
            '    x int not null,'
            '    y int not null,'
            '    z int not null,'
            '    w int not null'
            ');',
            'create unique index if not exists light_pqxyz_idx on '
            '    light (p, q, x, y, z);',
            'create table if not exists sign ('
            '    p int not null,'
            '    q int not null,'
            '    x int not null,'
            '    y int not null,'
            '    z int not null,'
            '    face int not null,'
            '    text text not null'
            ');',
            'create index if not exists sign_pq_idx on sign (p, q);',
            'create unique index if not exists sign_xyzface_idx on '
            '    sign (x, y, z, face);',
            'create table if not exists block_history ('
            '   timestamp real not null,'
            '   user_id int not null,'
            '   x int not null,'
            '   y int not null,'
            '   z int not null,'
            '   w int not null'
            ');',
        ]
        for query in queries:
            self.execute(query)

    def get_default_block(self, x, y, z):
        p, q = chunked(x), chunked(z)
        chunk = self.world.get_chunk(p, q)
        return chunk.get((x, y, z), 0)

    def get_block(self, x, y, z):
        query = (
            'select w from block where '
            'p = :p and q = :q and x = :x and y = :y and z = :z;'
        )
        p, q = chunked(x), chunked(z)
        rows = list(self.execute(query, dict(p=p, q=q, x=x, y=y, z=z)))
        if rows:
            return rows[0][0]
        return self.get_default_block(x, y, z)

    def next_client_id(self):
        result = 1
        client_ids = set(x.client_id for x in self.clients)
        while result in client_ids:
            result += 1
        return result

    def on_connect(self, client):
        client.client_id = self.next_client_id()
        client.nick = 'guest%d' % client.client_id
        log('CONN', client.client_id, *client.client_address)
        client.position = SPAWN_POINT
        self.clients.append(client)
        client.send(YOU, client.client_id, *client.position)
        client.send(TIME, time.time(), DAY_LENGTH)
        client.send(TALK, 'Welcome to Craft!')
        client.send(TALK, 'Type "/help" for a list of commands.')
        self.send_position(client)
        self.send_positions(client)
        self.send_nick(client)
        self.send_nicks(client)

    def on_data(self, client, data: str):
        #log('RECV', client.client_id, data)
        args = data.split(',')
        command, args = args[0], args[1:]
        if command in self.commands:
            func = self.commands[command]
            func(client, *args)

    def on_disconnect(self, client):
        log('DISC', client.client_id, *client.client_address)
        self.clients.remove(client)
        self.send_disconnect(client)
        self.send_talk('%s has disconnected from the server.' % client.nick)

    def on_version(self, client, version):
        if client.version is not None:
            return
        version = int(version)
        if version != 1:
            client.stop()
            return
        client.version = version
        # TODO: client.start() here

    def on_authenticate(self, client, username, access_token):
        print(client, username, access_token)
        user_id = None
        if username and access_token:
            payload = {
                'username': username,
                'access_token': access_token,
            }
            response = requests.post(AUTH_URL, data=payload)
            if response.status_code == 200 and response.text.isdigit():
                user_id = int(response.text)
        client.user_id = user_id
        if user_id is None:
            client.nick = 'guest%d' % client.client_id
            client.send(TALK, 'Visit craft.michaelfogleman.com to register!')
        else:
            client.nick = username
        self.send_nick(client)
        # TODO: has left message if was already authenticated
        self.send_talk('%s has joined the game.' % client.nick)

    def on_chunk(self, client, p, q, key=0):
        packets = b''
        p, q, key = map(int, (p, q, key))
        query = (
            'select rowid, x, y, z, w from block where '
            'p = :p and q = :q and rowid > :key;'
        )
        rows = self.execute(query, dict(p=p, q=q, key=key))
        max_rowid = 0
        blocks = 0
        for rowid, x, y, z, w in rows:
            blocks += 1
            packets += packet(BLOCK, p, q, x, y, z, w)
            max_rowid = max(max_rowid, rowid)
        query = (
            'select x, y, z, w from light where '
            'p = :p and q = :q;'
        )
        rows = self.execute(query, dict(p=p, q=q))
        lights = 0
        for x, y, z, w in rows:
            lights += 1
            packets += packet(LIGHT, p, q, x, y, z, w)
        query = (
            'select x, y, z, face, text from sign where '
            'p = :p and q = :q;'
        )
        rows = self.execute(query, dict(p=p, q=q))
        signs = 0
        for x, y, z, face, text in rows:
            signs += 1
            packets += packet(SIGN, p, q, x, y, z, face, text)
        if blocks:
            packets += packet(KEY, p, q, max_rowid)
        if blocks or lights or signs:
            packets += packet(REDRAW, p, q)
        packets += packet(CHUNK, p, q)
        client.send_raw(packets)

    def on_block(self, client, x, y, z, w):
        x, y, z, w = map(int, (x, y, z, w))
        p, q = chunked(x), chunked(z)
        previous = self.get_block(x, y, z)
        message = None
        if AUTH_REQUIRED and client.user_id is None:
            message = 'Only logged in users are allowed to build.'
        elif y <= 0 or y > 255:
            message = 'Invalid block coordinates.'
        elif w not in ALLOWED_ITEMS:
            message = 'That item is not allowed.'
        elif w and previous:
            message = 'Cannot create blocks in a non-empty space.'
        elif not w and not previous:
            message = 'That space is already empty.'
        elif previous in INDESTRUCTIBLE_ITEMS:
            message = 'Cannot destroy that type of block.'
        if message is not None:
            client.send(BLOCK, p, q, x, y, z, previous)
            client.send(REDRAW, p, q)
            client.send(TALK, message)
            return
        query = (
            'insert into block_history (timestamp, user_id, x, y, z, w) '
            'values (:timestamp, :user_id, :x, :y, :z, :w);'
        )
        if RECORD_HISTORY:
            self.execute(query, dict(timestamp=time.time(),
                                     user_id=client.user_id, x=x, y=y, z=z, w=w))
        query = (
            'insert or replace into block (p, q, x, y, z, w) '
            'values (:p, :q, :x, :y, :z, :w);'
        )
        self.execute(query, dict(p=p, q=q, x=x, y=y, z=z, w=w))
        self.send_block(client, p, q, x, y, z, w)
        for dx in range(-1, 2):
            for dz in range(-1, 2):
                if dx == 0 and dz == 0:
                    continue
                if dx and chunked(x + dx) == p:
                    continue
                if dz and chunked(z + dz) == q:
                    continue
                np, nq = p + dx, q + dz
                self.execute(query, dict(p=np, q=nq, x=x, y=y, z=z, w=-w))
                self.send_block(client, np, nq, x, y, z, -w)
        if w == 0:
            query = (
                'delete from sign where '
                'x = :x and y = :y and z = :z;'
            )
            self.execute(query, dict(x=x, y=y, z=z))
            query = (
                'update light set w = 0 where '
                'x = :x and y = :y and z = :z;'
            )
            self.execute(query, dict(x=x, y=y, z=z))

    def on_light(self, client, x, y, z, w):
        x, y, z, w = map(int, (x, y, z, w))
        p, q = chunked(x), chunked(z)
        block = self.get_block(x, y, z)
        message = None
        if AUTH_REQUIRED and client.user_id is None:
            message = 'Only logged in users are allowed to build.'
        elif block == 0:
            message = 'Lights must be placed on a block.'
        elif w < 0 or w > 15:
            message = 'Invalid light value.'
        if message is not None:
            # TODO: client.send(LIGHT, p, q, x, y, z, previous)
            client.send(REDRAW, p, q)
            client.send(TALK, message)
            return
        query = (
            'insert or replace into light (p, q, x, y, z, w) '
            'values (:p, :q, :x, :y, :z, :w);'
        )
        self.execute(query, dict(p=p, q=q, x=x, y=y, z=z, w=w))
        self.send_light(client, p, q, x, y, z, w)

    def on_sign(self, client, x, y, z, face, *args):
        if AUTH_REQUIRED and client.user_id is None:
            client.send(TALK, 'Only logged in users are allowed to build.')
            return
        text = ','.join(args)
        x, y, z, face = map(int, (x, y, z, face))
        if y <= 0 or y > 255:
            return
        if face < 0 or face > 7:
            return
        if len(text) > 48:
            return
        p, q = chunked(x), chunked(z)
        if text:
            query = (
                'insert or replace into sign (p, q, x, y, z, face, text) '
                'values (:p, :q, :x, :y, :z, :face, :text);'
            )
            self.execute(query,
                         dict(p=p, q=q, x=x, y=y, z=z, face=face, text=text))
        else:
            query = (
                'delete from sign where '
                'x = :x and y = :y and z = :z and face = :face;'
            )
            self.execute(query, dict(x=x, y=y, z=z, face=face))
        self.send_sign(client, p, q, x, y, z, face, text)

    def on_position(self, client, x, y, z, rx, ry):
        x, y, z, rx, ry = map(float, (x, y, z, rx, ry))
        client.position = (x, y, z, rx, ry)
        self.send_position(client)

    def on_talk(self, client, *args):
        text = ','.join(args)
        if text.startswith('/'):
            for pattern, func in self.patterns:
                match = pattern.match(text)
                if match:
                    func(client, *match.groups())
                    break
            else:
                client.send(TALK, 'Unrecognized command: "%s"' % text)
        elif text.startswith('@'):
            nick = text[1:].split(' ', 1)[0]
            for other in self.clients:
                if other.nick == nick:
                    client.send(TALK, '%s> %s' % (client.nick, text))
                    other.send(TALK, '%s> %s' % (client.nick, text))
                    break
            else:
                client.send(TALK, 'Unrecognized nick: "%s"' % nick)
        else:
            self.send_talk('%s> %s' % (client.nick, text))

    def on_nick(self, client, nick=None):
        if AUTH_REQUIRED:
            client.send(TALK, 'You cannot change your nick on this server.')
            return
        if nick is None:
            client.send(TALK, 'Your nickname is %s' % client.nick)
        else:
            self.send_talk('%s is now known as %s' % (client.nick, nick))
            client.nick = nick
            self.send_nick(client)

    def on_spawn(self, client):
        client.position = SPAWN_POINT
        client.send(YOU, client.client_id, *client.position)
        self.send_position(client)

    def on_goto(self, client, nick=None):
        if nick is None:
            clients = [x for x in self.clients if x != client]
            other = random.choice(clients) if clients else None
        else:
            nicks = dict((client.nick, client) for client in self.clients)
            other = nicks.get(nick)
        if other:
            client.position = other.position
            client.send(YOU, client.client_id, *client.position)
            self.send_position(client)

    def on_pq(self, client, p, q):
        p, q = map(int, (p, q))
        if abs(p) > 1000 or abs(q) > 1000:
            return
        client.position = (p * CHUNK_SIZE, 0, q * CHUNK_SIZE, 0, 0)
        client.send(YOU, client.client_id, *client.position)
        self.send_position(client)

    def on_help(self, client, topic=None):
        if topic is None:
            client.send(TALK, 'Type "t" to chat. Type "/" to type commands:')
            client.send(
                TALK, '/goto [NAME], /help [TOPIC], /list, /login NAME, /logout, /nick')
            client.send(
                TALK, '/offline [FILE], /online HOST [PORT], /pq P Q, /spawn, /view N')
            return
        topic = topic.lower().strip()
        if topic == 'goto':
            client.send(TALK, 'Help: /goto [NAME]')
            client.send(TALK, 'Teleport to another user.')
            client.send(
                TALK, 'If NAME is unspecified, a random user is chosen.')
        elif topic == 'list':
            client.send(TALK, 'Help: /list')
            client.send(TALK, 'Display a list of connected users.')
        elif topic == 'login':
            client.send(TALK, 'Help: /login NAME')
            client.send(TALK, 'Switch to another registered username.')
            client.send(
                TALK, 'The login server will be re-contacted. The username is case-sensitive.')
        elif topic == 'logout':
            client.send(TALK, 'Help: /logout')
            client.send(TALK, 'Unauthenticate and become a guest user.')
            client.send(
                TALK, 'Automatic logins will not occur again until the /login command is re-issued.')
        elif topic == 'offline':
            client.send(TALK, 'Help: /offline [FILE]')
            client.send(TALK, 'Switch to offline mode.')
            client.send(
                TALK, 'FILE specifies the save file to use and defaults to "craft".')
        elif topic == 'online':
            client.send(TALK, 'Help: /online HOST [PORT]')
            client.send(TALK, 'Connect to the specified server.')
        elif topic == 'nick':
            client.send(TALK, 'Help: /nick [NICK]')
            client.send(TALK, 'Get or set your nickname.')
        elif topic == 'pq':
            client.send(TALK, 'Help: /pq P Q')
            client.send(TALK, 'Teleport to the specified chunk.')
        elif topic == 'spawn':
            client.send(TALK, 'Help: /spawn')
            client.send(TALK, 'Teleport back to the spawn point.')
        elif topic == 'view':
            client.send(TALK, 'Help: /view N')
            client.send(TALK, 'Set viewing distance, 1 - 24.')

    def on_list(self, client):
        client.send(TALK,
                    'Players: %s' % ', '.join(x.nick for x in self.clients))

    def send_positions(self, client):
        for other in self.clients:
            if other == client:
                continue
            client.send(POSITION, other.client_id, *other.position)

    def send_position(self, client):
        for other in self.clients:
            if other == client:
                continue
            other.send(POSITION, client.client_id, *client.position)

    def send_nicks(self, client):
        for other in self.clients:
            if other == client:
                continue
            client.send(NICK, other.client_id, other.nick)

    def send_nick(self, client):
        for other in self.clients:
            other.send(NICK, client.client_id, client.nick)

    def send_disconnect(self, client):
        for other in self.clients:
            if other == client:
                continue
            other.send(DISCONNECT, client.client_id)

    def send_block(self, client, p, q, x, y, z, w):
        for other in self.clients:
            if other == client:
                continue
            other.send(BLOCK, p, q, x, y, z, w)
            other.send(REDRAW, p, q)

    def send_light(self, client, p, q, x, y, z, w):
        for other in self.clients:
            if other == client:
                continue
            other.send(LIGHT, p, q, x, y, z, w)
            other.send(REDRAW, p, q)

    def send_sign(self, client, p, q, x, y, z, face, text):
        for other in self.clients:
            if other == client:
                continue
            other.send(SIGN, p, q, x, y, z, face, text)

    def send_talk(self, text):
        log(text)
        for client in self.clients:
            client.send(TALK, text)


def cleanup():
    world = World(None)
    conn = sqlite3.connect(DB_PATH)
    query = 'select x, y, z from block order by rowid desc limit 1;'
    last = list(conn.execute(query))[0]
    query = 'select distinct p, q from block;'
    chunks = list(conn.execute(query))
    count = 0
    total = 0
    delete_query = 'delete from block where x = %d and y = %d and z = %d;'
    print('begin;')
    for p, q in chunks:
        chunk = world.create_chunk(p, q)
        query = 'select x, y, z, w from block where p = :p and q = :q;'
        rows = conn.execute(query, {'p': p, 'q': q})
        for x, y, z, w in rows:
            if chunked(x) != p or chunked(z) != q:
                continue
            total += 1
            if (x, y, z) == last:
                continue
            original = chunk.get((x, y, z), 0)
            if w == original or original in INDESTRUCTIBLE_ITEMS:
                count += 1
                print(delete_query % (x, y, z))
    conn.close()
    print('commit;')
    print >> sys.stderr, '%d of %d blocks will be cleaned up' % (count, total)


def main():
    if len(sys.argv) == 2 and sys.argv[1] == 'cleanup':
        cleanup()
        return
    host, port = DEFAULT_HOST, DEFAULT_PORT
    if len(sys.argv) > 1:
        host = sys.argv[1]
    if len(sys.argv) > 2:
        port = int(sys.argv[2])
    log('SERV', host, port)
    model = Model(None)
    model.start()
    server = Server((host, port), Handler)
    server.model = model
    server.serve_forever()


if __name__ == '__main__':
    main()