import functools
from flask import Blueprint, flash, g, redirect, render_template, request, session, url_for
from werkzeug.security import check_password_hash, generate_password_hash
from .database import get_database

blueprint = Blueprint("auth", __name__, url_prefix="/auth")

@blueprint.route("/register", methods=("GET", "POST"))
def register():
    if request.method == "POST":
        username = request.form["username"]
        password = request.form["password"]
        db = get_database()
        error = None

        if not username:
            error = "username_required"
        elif not password:
            error = "password_required"

        if error is None:
            try:
                db.execute(
                    "INSERT INTO user (username, password) VALUES (?, ?)",
                    (username, generate_password_hash(password)),
                )
                db.commit()
            except db.IntegrityError:
                error = f"User {username} is already registered."
            else:
                return redirect(url_for("auth.login"))

        flash(error)

    return render_template("auth/register.html")

@blueprint.route("/login", methods=("GET", "POST"))
def login():
    if request.method == "POST":
        username = request.form["username"]
        password = request.form["password"]
        db = get_database()
        error = None
        user = db.execute(
            "SELECT * FROM user WHERE username = ?", (username,)
        ).fetchone()

        if user is None:
            error = "incorrect_username"
        elif not check_password_hash(user["password"], password):
            error = "incorrect_password"

        if error is None:
            session.clear()
            session["user_id"] = user["id"]
            return redirect(url_for("index"))

        flash(error)

    return render_template("auth/login.html")

@blueprint.before_app_request
def load_logged_in_user():
    user_id = session.get("user_id")

    if user_id is None:
        g.user = None
    else:
        g.user = get_database().execute(
            "SELECT * FROM user WHERE id = ?", (user_id,)
        ).fetchone()

@blueprint.route("/logout")
def logout():
    session.clear()
    return redirect(url_for("index"))

def login_required(view):
    @functools.wraps(view)
    def wrapped_view(**kwargs):
        if g.user is None:
            return redirect(url_for("auth.login"))

        return view(**kwargs)

    return wrapped_view