server.py

"""Network Game Server."""
import argparse
import asyncio
import json
import logging
import os.path
import random
from collections import namedtuple
from functools import reduce
from operator import add

import requests
from requests import RequestException
import websockets

from consts import MAX_HIGHSCORES, GameStatus
from game import Game, reduce_score, TIMEOUT

logging.basicConfig(
    level=logging.DEBUG, format="%(asctime)s - %(name)s - %(levelname)s - %(message)s"
)
wslogger = logging.getLogger("websockets")
wslogger.setLevel(logging.WARN)

logger = logging.getLogger("Server")
logger.setLevel(logging.INFO)

Player = namedtuple("Player", ["name", "ws"])

HIGHSCORE_FILE = "highscores.json"


class GameServer:
    """Network Game Server."""

    def __init__(self, level, timeout, grading=None):
        self.game = Game(level, timeout)
        self.players = asyncio.Queue()
        self.viewers = set()
        self.current_player = None
        self.grading = grading
        self._level = level
        self._timeout = timeout

        self._highscores = []
        if os.path.isfile(HIGHSCORE_FILE):
            with open(HIGHSCORE_FILE, "r") as infile:
                self._highscores = json.load(infile)

    def save_highscores(self, score):
        """Update highscores, storing to file."""
        logger.debug("Save highscores")
        logger.info(
            "FINAL SCORE <%s>: %s puzzles with %s moves and %s pushes in %s steps, currently %s boxes on goal",
            self.current_player.name,
            *score,
        )

        self._highscores.append((self.current_player.name, reduce_score(*score),))
        self._highscores = sorted(self._highscores, key=lambda s: s[1])[:MAX_HIGHSCORES]

        with open(HIGHSCORE_FILE, "w") as outfile:
            json.dump(self._highscores, outfile)

    async def send_info(self, game_info, highscores=False):
        """Send game info to viewer and player."""
        if highscores:
            game_info["highscores"] = self._highscores
            game_info["player"] = self.current_player.name

        if self.viewers:
            await asyncio.wait(
                [client.send(json.dumps(game_info)) for client in self.viewers]
            )
        await self.current_player.ws.send(json.dumps(game_info))

    async def incomming_handler(self, websocket, path):
        """Process new clients arriving at the server."""
        try:
            async for message in websocket:
                data = json.loads(message)
                if data["cmd"] == "join":
                    if path == "/player":
                        logger.info("<%s> has joined", data["name"])
                        await self.players.put(Player(data["name"], websocket))

                    if path == "/viewer":
                        logger.info("Viewer connected")
                        self.viewers.add(websocket)
                        game_info = self.game.info()
                        await websocket.send(json.dumps(game_info))

                if data["cmd"] == "key" and self.current_player.ws == websocket:
                    logger.debug((self.current_player.name, data))
                    if len(data["key"]) > 0:
                        self.game.keypress(data["key"][0])
                    else:
                        self.game.keypress("")

        except websockets.exceptions.ConnectionClosed as closed_reason:
            logger.info("Client disconnected: %s", closed_reason)
            if websocket in self.viewers:
                self.viewers.remove(websocket)

    async def mainloop(self):
        """Main loop, runing the Game."""
        while True:
            logger.info("Waiting for player")
            self.current_player = await self.players.get()

            if self.current_player.ws.closed:
                logger.error("<%s> disconnect while waiting", self.current_player.name)
                continue

            try:
                logger.info("Starting game for <%s>", self.current_player.name)
                self.game = Game(self._level, self._timeout, self.current_player.name)

                game_info = self.game.info()
                await self.send_info(game_info)

                if self.grading:
                    game_record = dict()
                    game_record["player"] = self.current_player.name
                    game_record["papertrail"] = self.game.papertrail

                while self.game.running:
                    game_status = await self.game.next_frame()

                    if game_status == GameStatus.NEW_MAP:
                        game_info = self.game.info()
                        await self.send_info(game_info)

                    state = self.game.state
                    await self.current_player.ws.send(state)
                    if self.viewers:
                        await asyncio.wait(
                            [client.send(state) for client in self.viewers]
                        )
                self.save_highscores(self.game.score)

                game_info = self.game.info()
                game_info["score"] = self.game.score
                await self.send_info(game_info, highscores=True)

                logger.info("Disconnecting <%s>", self.current_player.name)
            except websockets.exceptions.ConnectionClosed:
                self.current_player = None
            finally:
                try:
                    if self.grading:
                        game_record["puzzles"], game_record["total_moves"], game_record["total_pushes"], game_record["total_steps"], game_record["box_on_goal"] = self.game.score
                        game_record["papertrail"] = self.game.papertrail
                        game_record["level"] = self.game.level
                        requests.post(self.grading, json=game_record)
                except RequestException as err:
                    logger.error(err)
                    logger.warning("Could not save score to server")

                if self.current_player:
                    await self.current_player.ws.close()


if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument("--bind", help="IP address to bind to", default="")
    parser.add_argument("--port", help="TCP port", type=int, default=8000)
    parser.add_argument("--level", help="start on level", type=int, default=1)
    parser.add_argument("--seed", help="Seed number", type=int, default=0)
    parser.add_argument(
        "--timeout", help="Timeout after this amount of steps", type=int, default=TIMEOUT
    )
    parser.add_argument(
        "--grading-server",
        help="url of grading server",
        default="http://bomberman-aulas.ws.atnog.av.it.pt/game",
    )
    args = parser.parse_args()

    if args.seed > 0:
        random.seed(args.seed)

    g = GameServer(args.level, args.timeout, args.grading_server)

    game_loop_task = asyncio.ensure_future(g.mainloop())

    logger.info("Listenning @ %s:%s", args.bind, args.port)
    websocket_server = websockets.serve(g.incomming_handler, args.bind, args.port)

    loop = asyncio.get_event_loop()
    loop.run_until_complete(asyncio.gather(websocket_server, game_loop_task))
    loop.close()