import os

from flask import Flask, session, flash, redirect, render_template, request, url_for
from flask_session import Session
from sqlalchemy import create_engine
from sqlalchemy.orm import scoped_session, sessionmaker
from werkzeug.exceptions import default_exceptions
from werkzeug.security import check_password_hash, generate_password_hash

app = Flask(__name__)

# Check for environment variable
if not os.getenv("DATABASE_URL"):
    raise RuntimeError("DATABASE_URL is not set")

# Configure session to use filesystem
app.config["SESSION_PERMANENT"] = False
app.config["SESSION_TYPE"] = "filesystem"
Session(app)

# Set up database
engine = create_engine(os.getenv("DATABASE_URL"))
db = scoped_session(sessionmaker(bind=engine))

#Configure goodreads api


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

@app.route("/register", methods==["GET", "POST"])
def register():
    """Register User"""

    if request.method=="POST":

        #hygiene check
        if not request.form.get("username"):
            flash("Please provide username")
        elif not request.form.get("password"):
            flash("Please provide password")
        elif not request.form.get("password")==request.form.get("confirmation"):
            flash("Passwords don't match")

        #hash password and create user in db
        hash = generate_password_hash(request.form.get("password"))
        new_user_id = db.execute("INSERT INTO users (username,hash) VALUES(:username, :hash)",
        username=request.form.get("username"), hash=hash)

        #must be unique username
        if not new_user_id:
            flash("Username not available")

        # Remember which user has logged in
        session["user_id"] = new_user_id

        # Display a flash message
        flash("Registered!")

        # Redirect user to home page
        return redirect(url_for("index"))

    else:
        return render_template("register.html")