from flask import Blueprint, request, session, render_template, redirect, url_for, abort
from werkzeug.security import generate_password_hash, check_password_hash
from .users import Users
from .exceptions import UsernameTakenError
from .config import config

bp = Blueprint("auth", __name__, url_prefix="/")
users = Users(config.get("general", "db_path"))


def show_error(action, message):
    return render_template(
        "auth.html",
        action=action,
        error=message,
    )


@bp.route("/<action>", methods=["GET", "POST"])
def auth(action):
    if action not in ["login", "register"]:
        abort(404)

    if request.method == "GET":
        # display login/register page
        return render_template("auth.html", action=action)

    # validate login information
    username = request.form.get("username")
    password = request.form.get("password")
    if not all([username, password]):
        return show_error(action, "Please fill in both the username and password.")

    if action == "login":
        user = users.find(username)
        if user is None:
            return show_error("login", f"User {username} does not exist.")

        if not check_password_hash(user["password"], password):
            return show_error("login", "Incorrect password. Sorry.")
    elif action == "register":
        if not config.getboolean("general", "accept_new_users"):
            return show_error("register", "Sorry, but user registrations are closed.")
        try:
            users.register(username, generate_password_hash(password), "en-US")
        except UsernameTakenError as e:
            return show_error("register", e.message)
    else:
        abort(400)

    # give access
    session.clear()
    session["username"] = username
    return redirect(url_for("admin.index"))


@bp.route("/logout")
def logout():
    session.pop("username", None)
    return redirect(url_for("auth.auth", action="login"))