Archipelago/WebHost/__init__.py

"""Friendly reminder that if you want to host this somewhere on the internet, that it's licensed under MIT Berserker66
So unless you're Berserker you need to include license information."""

import json
import os
import logging
import typing
import multiprocessing
import threading
import zlib

from pony.flask import Pony
from flask import Flask, request, redirect, url_for, render_template, Response, session, abort, flash
from flask_caching import Cache

from .models import *

UPLOAD_FOLDER = os.path.relpath('uploads')
LOGS_FOLDER = os.path.relpath('logs')
os.makedirs(LOGS_FOLDER, exist_ok=True)


def allowed_file(filename):
    return filename.endswith('multidata')

app = Flask(__name__)
Pony(app)

app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER
app.config['MAX_CONTENT_LENGTH'] = 1 * 1024 * 1024  # 1 megabyte limit
# if you want persistent sessions on your server, make sure you make this a constant in your config.yaml
app.config["SECRET_KEY"] = os.urandom(32)
app.config['SESSION_PERMANENT'] = True
app.config[
    "WAITRESS_THREADS"] = 10  # waitress uses one thread for I/O, these are for processing of views that then get sent
app.config["PONY"] = {
    'provider': 'sqlite',
    'filename': os.path.abspath('db.db3'),
    'create_db': True
}
app.config["CACHE_TYPE"] = "simple"

cache = Cache(app)

# this local cache is risky business if app hosting is done with subprocesses as it will not sync. Waitress is fine though
multiworlds = {}


@app.before_request
def register_session():
    session.permanent = True  # technically 31 days after the last visit
    if not session.get("_id", None):
        session["_id"] = uuid4()  # uniquely identify each session without needing a login


class MultiworldInstance():
    def __init__(self, room: Room):
        self.room_id = room.id
        self.process: typing.Optional[multiprocessing.Process] = None
        multiworlds[self.room_id] = self

    def start(self):
        if self.process and self.process.is_alive():
            return False

        logging.info(f"Spinning up {self.room_id}")
        with db_session:
            self.process = multiprocessing.Process(group=None, target=run_server_process,
                                                   args=(self.room_id, app.config["PONY"]),
                                                   name="MultiHost")
        self.process.start()

    def stop(self):
        if self.process:
            self.process.terminate()
            self.process = None


@app.route('/seed/<int:seed>')
def view_seed(seed: int):
    seed = Seed.get(id=seed)
    if seed:
        return render_template("view_seed.html", seed=seed)
    else:
        abort(404)


@app.route('/new_room/<int:seed>')
def new_room(seed: int):
    seed = Seed.get(id=seed)
    room = Room(seed=seed, owner=session["_id"])
    commit()
    return redirect(url_for("host_room", room=room.id))


def _read_log(path: str):
    if os.path.exists(path):
        with open(path, encoding="utf-8-sig") as log:
            yield from log
    else:
        yield f"Logfile {path} does not exist. " \
              f"Likely a crash during spinup of multiworld instance or it is still spinning up."


@app.route('/log/<int:room>')
def display_log(room: int):
    # noinspection PyTypeChecker
    return Response(_read_log(os.path.join("logs", str(room) + ".txt")), mimetype="text/plain;charset=UTF-8")


processstartlock = threading.Lock()


@app.route('/hosted/<int:room>', methods=['GET', 'POST'])
def host_room(room: int):
    room = Room.get(id=room)
    if room is None:
        return abort(404)
    if request.method == "POST":
        if room.owner == session["_id"]:
            cmd = request.form["cmd"]
            Command(room=room, commandtext=cmd)
            commit()
    with db_session:
        multiworld = multiworlds.get(room.id, None)
        if not multiworld:
            multiworld = MultiworldInstance(room)

    with processstartlock:
        multiworld.start()

    return render_template("host_room.html", room=room)


from WebHost.customserver import run_server_process
from . import tracker  # to trigger app routing picking up on it

@app.route('/', methods=['GET', 'POST'])
def upload_multidata():
    if request.method == 'POST':
        # check if the post request has the file part
        if 'file' not in request.files:
            flash('No file part')
        else:
            file = request.files['file']
            # if user does not select file, browser also
            # submit an empty part without filename
            if file.filename == '':
                flash('No selected file')
            elif file and allowed_file(file.filename):
                try:
                    multidata = json.loads(zlib.decompress(file.read()).decode("utf-8-sig"))
                except:
                    flash("Could not load multidata. File may be corrupted or incompatible.")
                else:
                    seed = Seed(multidata=multidata)
                    commit()  # place into DB and generate ids
                    return redirect(url_for("view_seed", seed=seed.id))
            else:
                flash("Not recognized file format. Awaiting a .multidata file.")
    rooms = select(room for room in Room if room.owner == session["_id"])
    return render_template("upload_multidata.html", rooms=rooms)