import json
import config
import logging
import database as db
from functools import wraps
from flask import Flask, request, session, redirect, g


app = Flask(__name__,
            static_url_path=config.flask.static_url_path,
            static_folder=config.flask.static_folder)
app.secret_key = config.flask.secret_key


class ErrorToClient(Exception):
    pass


@app.errorhandler(ErrorToClient)
def error_to_client(error):
    return json.dumps({'message': error.args[0], 'args': error.args[1:]}), 400


@app.before_request
def before_request():
    g.db_session = db.Session()
    g.user_id = session.get('user_id', None)


@app.teardown_request
def teardown_request(exception):
    db_session = getattr(g, 'db_session', None)
    if db_session is not None:
        db_session.close()


def return_json(f):
    @wraps(f)
    def inner(*a, **k):
        r = f(*a, **k)
        return json.dumps(r)
    return inner