#!/usr/bin/env python3
"""
Simple file host using Flask.
"""
import os
import time
import string
import urllib
import functools

from flask import Flask, session, request, abort, redirect, url_for, g, \
	render_template
from flask_socketio import SocketIO, emit, join_room
from flask_paranoid import Paranoid
import MySQLdb
import bleach
from passlib.hash import argon2

class ReverseProxied(object):
	"""
	Wrap the application in this middleware and configure the 
	front-end server to add these headers, to let you quietly bind 
	this to a URL other than / and to an HTTP scheme that is 
	different than what is used locally.

	In nginx:
	location /myprefix {
		proxy_pass http://192.168.0.1:5001;
		proxy_set_header Host $host;
		proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
		proxy_set_header X-Scheme $scheme;
		proxy_set_header X-Script-Name /myprefix;
		}

	:param app: the WSGI application
	"""
	def __init__(self, app):
		self.app = app

	def __call__(self, environ, start_response):
		script_name = environ.get('HTTP_X_SCRIPT_NAME', '')
		if script_name:
			environ['SCRIPT_NAME'] = script_name
			path_info = environ['PATH_INFO']
			if path_info.startswith(script_name):
				environ['PATH_INFO'] = path_info[len(script_name):]

		scheme = environ.get('HTTP_X_SCHEME', '')
		if scheme:
			environ['wsgi.url_scheme'] = scheme
		return self.app(environ, start_response)


app = Flask(__name__)
app.wsgi_app = ReverseProxied(app.wsgi_app)
app.config['MAX_CONTENT_LENGTH'] = 16 * 1024 * 1024
socketio = SocketIO(app)
paranoid = Paranoid(app)
paranoid.redirect_view = 'index'


def db_execute(*args, **kwargs):
	"""
	Opens a connection to the app's database and executes the SQL statements
	passed to this function.
	"""
	passwd = app.config.get("DB_KEY")
	with MySQLdb.connect(user="anonkun", passwd=passwd, db="anonkun") as cur:
		cur.execute(*args, **kwargs)
		return cur


def init():
	"""
	Initializes the application.
	"""
	# init secret key
	if os.path.exists("secret_key"):
		with open("secret_key", "rb") as file:
			secret_key = file.read()
	else:
		secret_key = os.urandom(64)
		with open("secret_key", "wb") as file:
			file.write(secret_key)
	app.secret_key = secret_key

	# init db
	with open("db_key", "r") as file:
		passwd = file.read().strip() # TODO: encrypt this
	app.config["DB_KEY"] = passwd
	try:
		db_execute("SELECT * FROM `users`").fetchone()
	except MySQLdb.ProgrammingError: # database not initialized
		with open("anonkun.sql", "r") as file:
			commands = file.read().split(";")
		for cmd in commands:
			cmd = cmd.strip()
			if not cmd:
				continue
			db_execute(cmd)


def login_required(url=None):
	"""
	A decorator function to protect certain endpoints by requiring the user
	to either pass a valid session cookie, or pass thier username and
	password along with the request to login.
	"""
	def actual_decorator(func):
		@functools.wraps(func)
		def _nop(*args, **kwargs):
			username = session.get("username")
			if verify_username(username):
				return func(*args, **kwargs)

			username = request.form.get("user")
			password = request.form.get("pass")
			if verify_password(username, password):
				return func(*args, **kwargs)

			if url:
				return redirect(url_for(url))
			else:
				abort(401)
		return _nop 
	return actual_decorator


def add_user(username, password):
	"""
	Adds a user to the database.
	"""
	if verify_username(username): # username taken
		return "username_taken"
	elif len(username) > 20:
		return "username_too_long"

	pw_hash = argon2.hash(password)
	db_execute(
		"INSERT INTO `users` (`username`, `password_hash`) VALUES (%s, %s)",
		(username, pw_hash))
	return "success"


def verify_password(username, password):
	"""
	Verifies a user's password.
	"""
	user = verify_username(username)
	if not user:
		return False

	user_id, _, pw_hash = user

	if argon2.verify(password, pw_hash):
		session["user_id"] = user_id
		return True
	else:
		return False


def verify_username(username):
	"""
	Checks to see if the given username is in the database.
	"""
	user = db_execute("SELECT * FROM `users` WHERE `username` = %s",
		(username,)).fetchone()
	if user:
		return user
	else:
		return False


@socketio.on('joined', namespace="/chat")
def joined(data):
	"""
	Sent by clients when they enter a room.
	"""
	room = data["room"]
	join_room(room)


@socketio.on('message', namespace="/chat")
def text(data):
	"""
	Sent by a client when the user entered a new message.
	"""
	room = data["room"]
	
	message = data["message"]
	name = data["name"]
	date = int(time.time())
	data["date"] = date
	
	emit('message', data, room=room)


@app.template_filter("strftime")
def unix2string(unix):
	"""
	Converts a unix timestamp into a string.
	"""
	form = "%Y-%m-%d %H:%M:%S"
	t = time.localtime(unix)
	return time.strftime(form, t)


messages = [{"name":"Anonymous", "date":1528998539, "message":"lol"}, {"name":"Namefag", "date":1528998521, "message":"kek"}]
@app.route("/quest/<path:quest_title>")
def quest(quest_title):
	"""
	An arbituary quest page.
	"""
	quest_title, _, extra = quest_title.partition("/")
	res = db_execute("SELECT * FROM `quests` WHERE `ident_title` = %s",
		(quest_title,))
	data = res.fetchone()
	if not data:
		abort(404)
	quest_id, quest_title, _, owner_id, quest_data = data

	res = db_execute("SELECT * FROM `chat_messages` WHERE `room_id` = '%s'",
		(quest_id,))
	messages = res.fetchall()
	return render_template('quest.html',
		quest_title=quest_title,
		quest_body=quest_data,
		room_id=quest_id,
		messages=messages)


@app.route("/create_quest", methods=["GET", "POST"])
@login_required("login")
def create_quest():
	"""
	Starts a new quest.
	"""
	if request.method == "GET":
		return render_template("create_quest.html")
	canon_title = request.form.get("quest_title")
	quest_body = request.form.get("quest_body")

	ident_title = sanitize_title(canon_title)
	quest_body = bleach.clean(quest_body.strip())
	quest_body = quest_body.replace("\n", "<br />")

	db_execute(
		"INSERT INTO `quests` (`canon_title`, `ident_title`, `quest_data`) " \
		"VALUES (%s, %s, %s)", (canon_title, ident_title, quest_body))
	return redirect(url_for('quest', quest_title=ident_title))


@app.route("/login", methods=["GET", "POST"])
def login():
	"""
	Logs the user in.
	"""
	if request.method == "GET":
		return render_template("login.html")

	username = request.form.get("user")
	password = request.form.get("pass")

	if verify_password(username, password):
		session["username"] = username
		return redirect(url_for("index"))
	else:
		abort(401)


@app.route("/signup", methods=["GET", "POST"])
def signup():
	"""
	Create a new account.
	"""
	if request.method == "GET":
		return render_template("signup.html")

	username = request.form.get("user")
	password = request.form.get("pass")
	verify_password = request.form.get("verify_pass")

	if len(username) > 20:
		"username_too_long"
	elif len(username) < 3:
		"username_too_short"
	chrs = [c not in string.ascii_letters + string.digits for c in username]
	if any(chrs):
		"username_bad_chars"
	if verify_username(username):
		"username_taken"
	
	if len(password) > 1024:
		"password_too_long"
	elif len(password) < 8:
		"password_too_short"
	
	if password != verify_password:
		"passwords_dont_match"

	res = add_user(username, password)
	return redirect(url_for("index"))


@app.route("/")
def index():
	"""
	The index page.
	"""
	return render_template("index.html")


def sanitize_title(canon_title):
	"""
	Sanitizes the given canonical title for a quest and returns a
	url-friendly version.
	"""
	ident_title = canon_title.lower().replace(" ", "-")
	ident_title = urllib.parse.quote(ident_title)
	return ident_title


init()
if __name__ == "__main__":
	app.run(host='0.0.0.0', port=5050)