capsul-flask/capsulflask/payment_stripe.py

import stripe
import json
import decimal


from flask import Blueprint
from flask import request
from flask import current_app
from flask import session
from flask import redirect
from flask import url_for
from flask import jsonify
from flask import flash
from flask import render_template
from werkzeug.exceptions import abort

from capsulflask.auth import account_required

from capsulflask.db import get_model

bp = Blueprint("stripe", __name__, url_prefix="/stripe")

@bp.route("/", methods=("GET", "POST"))
@account_required
def index():

  stripe_checkout_session_id=None
  errors = list()

  if request.method == "POST":
    if "dollars" not in request.form:
      errors.append("dollars is required")
    dollars = None
    try:
      dollars = decimal.Decimal(request.form["dollars"])
    except:
      errors.append("dollars must be a number")

    if dollars and dollars < decimal.Decimal(1):
      errors.append("dollars must be >= 1")

    if len(errors) == 0:

      print(f"creating stripe checkout session for {session['account']}, ${request.form['dollars']}")

      checkout_session = stripe.checkout.Session.create(
        success_url=current_app.config['BASE_URL'] + "/stripe/success?session_id={CHECKOUT_SESSION_ID}",
        cancel_url=current_app.config['BASE_URL'] + "/stripe",
        payment_method_types=["card"],
        customer_email=session["account"],
        line_items=[
          {
            "name": "Capsul Cloud Compute",
            "images": [current_app.config['BASE_URL']+"/static/capsul-product-image.png"],
            "quantity": 1,
            "currency": "usd",
            "amount": int(dollars*100)
          }
        ]
      )
      stripe_checkout_session_id = checkout_session['id']

      print(f"stripe_checkout_session_id={stripe_checkout_session_id} ( {session['account']}, ${request.form['dollars']} )")

      get_model().create_stripe_checkout_session(stripe_checkout_session_id, session["account"], request.form["dollars"])

  for error in errors:
    flash(error)

  return render_template(
    "stripe.html", 
    stripe_checkout_session_id=stripe_checkout_session_id,
    stripe_public_key=current_app.config["STRIPE_PUBLISHABLE_KEY"]
  )

@bp.route("/success", methods=("GET",))
def success():
  stripe_checkout_session_id = request.args.get('session_id')
  if not stripe_checkout_session_id:
    print("/stripe/success returned 400: missing required URL parameter session_id")
    abort(400, "missing required URL parameter session_id")
  else:
    checkout_session = stripe.checkout.Session.retrieve(stripe_checkout_session_id)
    if checkout_session and 'display_items' in checkout_session:
      cents = checkout_session['display_items'][0]['amount']
      dollars = decimal.Decimal(cents)/100

      #consume_stripe_checkout_session deletes the checkout session row and inserts a payment row
      # its ok to call consume_stripe_checkout_session more than once because it only takes an action if the session exists
      success_account = get_model().consume_stripe_checkout_session(stripe_checkout_session_id, dollars)
      if success_account:
        print(f"{success_account} paid ${dollars} successfully (stripe_checkout_session_id={stripe_checkout_session_id})")

    return redirect(url_for("console.account_balance"))

# I don't think the webhook is needed
# @bp.route("/webhook", methods=("POST",))
# def webhook():

#   request_data = json.loads(request.data)
#   signature = request.headers.get('stripe-signature')
#   try:
#     event = stripe.Webhook.construct_event(
#       payload=request_data, 
#       sig_header=signature, 
#       secret=current_app.config['STRIPE_WEBHOOK_SECRET']
#     )
#     if event['type'] == 'checkout.session.completed':
#       dollars = event['data']['object']['display_items'][0]['amount']
#       stripe_checkout_session_id = event['data']['object']['id']

#       #consume_stripe_checkout_session deletes the checkout session row and inserts a payment row
#       # its ok to call consume_stripe_checkout_session more than once because it only takes an action if the session exists
#       get_model().consume_stripe_checkout_session(stripe_checkout_session_id, dollars)
      
#     return jsonify({'status': 'success'})
#   except ValueError as e:
#     print("/stripe/webhook returned 400: bad request", e)
#     abort(400, "bad request")
#   except stripe.error.SignatureVerificationError:
#     print("/stripe/webhook returned 400: invalid signature")
#     abort(400, "invalid signature")