"""
 handler.py

 a flask "blueprint" that handles the form, showing the results.
"""
from flask import Blueprint, render_template, request, g, session
from formy.db import open_db
from random import random

bp = Blueprint("handler", __name__)

def process_form():
    """ Do whatever processing of the data needs to be done.
        Return a dictionary of stuff that the template can display.
    """
    # read database into g['db']
    open_db()  

    # session dictionary encoded automatically in cookie
    # automatically using app.config['SECRET_KEY']
    if 'id' not in session:
        # create a new user_id & store in session.
        session['id'] = str(random())[2:] # 0.123... => '123..'

    # Put this user_id into the database if it isn't there already.
    id = session['id']
    if id not in g.db:
        g.db[id] = { 'username': '?', 'visits': 0 }

    # store stuff that we want to use on the webpage.
    # (Later pass this to the template for it to display.)
    stuff = { 'username'  : g.db[id]['username'],
              'visits'    : g.db[id]['visits'],
              'formname' : request.form.get('name', '')
            }
        
    # update name in database
    g.db[id]['username'] = request.form.get('name', '')
    
    # update visit count
    g.db[id]['visits'] = int(g.db[id]['visits']) + 1

    # The database will be written out when the request terminates
    # because we've registered the db_close() function.
    # Flask automatically puts the session stuff into a cookie.
    
    return stuff

@bp.route('/handler', methods=('POST',))
def handler():
    stuff = process_form()
    # See https://flask.palletsprojects.com/en/1.1.x/templating/
    # and https://jinja.palletsprojects.com/en/2.11.x/templates/
    return render_template('handler.html',    # in templates/
                           stuff=stuff        # accessible in template
                          )