from urllib.parse import urljoin, urlsplit

from flask import flash, redirect, render_template, request, url_for
from flask_login import current_user, login_required, login_user, logout_user

from . import bp
from .forms import LoginForm, LogoutForm, RegistrationForm
from .services import DuplicateUserError, authenticate_user, create_user


def _is_safe_redirect(target: str) -> bool:
    host_url = urlsplit(request.host_url)
    redirect_url = urlsplit(urljoin(request.host_url, target))
    return redirect_url.scheme in {"http", "https"} and (
        host_url.netloc == redirect_url.netloc
    )


@bp.route("/login", methods=["GET", "POST"])
def login():
    if current_user.is_authenticated:
        return redirect(url_for("core.index"))

    form = LoginForm()
    if form.validate_on_submit():
        user = authenticate_user(form.email.data, form.password.data)
        if user is None:
            flash("Email or password is incorrect.", "error")
        else:
            login_user(user, remember=form.remember.data)
            next_page = request.args.get("next", "")
            if next_page and _is_safe_redirect(next_page):
                return redirect(next_page)
            return redirect(url_for("core.index"))

    return render_template("auth/login.html", form=form)


@bp.route("/register", methods=["GET", "POST"])
def register():
    if current_user.is_authenticated:
        return redirect(url_for("core.index"))

    return redirect(url_for("core.login"))
    

@bp.post("/logout")
@login_required
def logout():
    form = LogoutForm()
    if form.validate_on_submit():
        logout_user()
        flash("You have been signed out.", "info")
    return redirect(url_for("core.index"))