import hmac

from flask import (
    Blueprint,
    current_app,
    flash,
    redirect,
    render_template,
    request,
    session,
    url_for,
)

from web.auth import validate_csrf
bp = Blueprint('access', __name__, url_prefix='/access')


@bp.route('/', methods=['GET', 'POST'])
def login():
    if current_app.config['SITE_VISIBILITY'] != 'private':
        return redirect(url_for('main.index'))
    if request.method == 'POST':
        validate_csrf()
        token = request.form.get('token') or ''
        viewer_token = current_app.config['VIEWER_TOKEN']
        if viewer_token and hmac.compare_digest(
            token,
            viewer_token,
        ):
            session['viewer_access'] = True
            target = request.args.get('next')
            if not target or not target.startswith('/') or target.startswith('//'):
                target = url_for('main.index')
            return redirect(target)
        flash('访问密码错误', 'error')
    return render_template('access/login.html')


@bp.route('/logout')
def logout():
    session.pop('viewer_access', None)
    return redirect(url_for('access.login'))