from flask import flash, redirect, render_template, request, url_for
from flask_login import current_user, login_required, login_user, logout_user
from . import auth
from .. import db
from .forms import ChangePasswordForm, LoginForm, PasswordResetForm, PasswordResetRequestForm, RegistrationForm
from ..email import send_email
from ..models import User


@auth.route('/login', methods=['GET', 'POST'])
def login():
    form = LoginForm()
    if form.validate_on_submit():
        user = User.query.filter_by(email=form.login.data).first()
        if user is None:
            user = User.query.filter_by(username=form.login.data).first()
        if user is not None and user.verify_password(form.password.data):
            login_user(user, form.remember_me.data)
            next = request.args.get('next')
            if next is None or not next.startswith('/'):
                next = url_for('main.index')
            return redirect(next)
        flash('Invalid username or password.')
    return render_template('auth/login.html.j2', form=form, title='Log in')


@auth.route('/logout')
@login_required
def logout():
    logout_user()
    flash('You have been logged out.')
    return redirect(url_for('main.index'))


@auth.route('/register', methods=['GET', 'POST'])
def register():
    if not current_user.is_anonymous:
        return redirect(url_for('main.index'))
    form = RegistrationForm()
    if form.validate_on_submit():
        user = User(email=form.email.data.lower(),
                    username=form.username.data,
                    password=form.password.data)
        db.session.add(user)
        db.session.commit()
        token = user.generate_confirmation_token()
        send_email(user.email, 'Confirm Your Account',
                   'auth/email/confirm', user=user, token=token)
        flash('A confirmation email has been sent to you by email.')
        return redirect(url_for('auth.login'))
    return render_template('auth/register.html.j2', form=form, title='Register')


@auth.route('/confirm/<token>')
@login_required
def confirm(token):
    if current_user.confirmed:
        return redirect(url_for('main.index'))
    if current_user.confirm(token):
        db.session.commit()
        flash('You have confirmed your account. Thanks!')
    else:
        flash('The confirmation link is invalid or has expired.')
    return redirect(url_for('main.index'))


@auth.before_app_request
def before_request():
    """
    Checks if a user is unconfirmed when visiting specific sites. Redirects to
    unconfirmed view if user is unconfirmed.
    """
    if current_user.is_authenticated \
            and not current_user.confirmed \
            and request.blueprint != 'auth' \
            and request.endpoint != 'static':
        return redirect(url_for('auth.unconfirmed'))


@auth.route('/unconfirmed')
def unconfirmed():
    if current_user.is_anonymous or current_user.confirmed:
        return redirect(url_for('main.index'))
    return render_template('auth/unconfirmed.html.j2', title='Unconfirmed')


@auth.route('/confirm')
@login_required
def resend_confirmation():
    token = current_user.generate_confirmation_token()
    send_email(current_user.email, 'Confirm Your Account', 'auth/email/confirm',
               user=current_user, token=token)
    flash('A new confirmation email has benn sent to you by email.')
    return redirect(url_for('main.index'))


@auth.route('/reset', methods=['GET', 'POST'])
def password_reset_request():
    if not current_user.is_anonymous:
        return redirect(url_for('main.index'))
    form = PasswordResetRequestForm()
    if form.validate_on_submit():
        user = User.query.filter_by(email=form.email.data.lower()).first()
        if user:
            token = user.generate_reset_token()
            send_email(user.email, 'Reset Your Password',
                       'auth/email/reset_password',
                       user=user, token=token)
        flash('An email with instructions to reset your password has been '
              'sent to you.')
        return redirect(url_for('auth.login'))
    return render_template('auth/reset_password_request.html.j2', form=form,
                           title='Password Reset')


@auth.route('/reset/<token>', methods=['GET', 'POST'])
def password_reset(token):
    if not current_user.is_anonymous:
        return redirect(url_for('main.index'))
    form = PasswordResetForm()
    if form.validate_on_submit():
        if User.reset_password(token, form.password.data):
            db.session.commit()
            flash('Your password has been updated.')
            return redirect(url_for('auth.login'))
        else:
            return redirect(url_for('main.index'))
    return render_template('auth/reset_password.html.j2', form=form,
                           title='Password Reset')


@auth.route('/settings', methods=['GET', 'POST'])
@login_required
def settings():
    """
    View where loged in User can change own User information like Password etc.
    """
    change_password_form = ChangePasswordForm()
    if change_password_form.validate_on_submit():
        if current_user.verify_password(change_password_form.old_password.data):
            current_user.password = change_password_form.new_password.data
            db.session.add(current_user)
            db.session.commit()
            flash('Your password has been updated.')
            return redirect(url_for('auth.settings'))
        else:
            flash('Invalid password.')
    return render_template(
        'auth/settings.html.j2',
        form=change_password_form,
        title='Settings'
    )