from flask import Blueprint, redirect, url_for
from redis import Redis

bp = Blueprint('counter', __name__)
r = Redis()
KEY = 'counter'

@bp.route('/')
def show_counter():
    rv = '''<h1>{}</h1><a href="up">Up</a>
            <br><a href="down">Down</a>'''
    return rv.format(r.get(KEY))

@bp.route('/up')
def counter_up():
    r.incr(KEY)
    return redirect(url_for('.show_counter'))

@bp.route('/down')
def counter_down():
    r.incr(KEY, -1)
    return redirect(url_for('.show_counter'))