Implement creating a subscription, but no webhooks yet

hushline/premium.py

@@ -1,22 +1,90 @@
-from flask import Blueprint, redirect, render_template, session, url_for
+from flask import (
+    Blueprint,
+    current_app,
+    flash,
+    redirect,
+    render_template,
+    request,
+    session,
+    url_for,
+)
 from werkzeug.wrappers.response import Response
 
 from .db import db
-from .model import User
+from .model import Tier, User
+from .stripe import create_subscription, get_latest_invoice_payment_intent_client_secret
 from .utils import authentication_required
 
+FREE_TIER = 1
+BUSINESS_TIER = 2
+
 
 def create_blueprint() -> Blueprint:
     bp = Blueprint("premium", __file__, url_prefix="/premium")
 
     @bp.route("/", methods=["GET"])
     @authentication_required
-    def premium() -> Response | str:
+    def index() -> Response | str:
         user = db.session.get(User, session.get("user_id"))
         if not user:
             session.clear()
             return redirect(url_for("login"))
 
         return render_template("premium.html", user=user)
 
+    @bp.route("/upgrade", methods=["GET", "POST"])
+    @authentication_required
+    def upgrade() -> Response | str:
+        if request.method == "GET":
+            return redirect(url_for("premium.index"))
+
+        user = db.session.get(User, session.get("user_id"))
+        if not user:
+            session.clear()
+            return redirect(url_for("login"))
+
+        # If the user is already on the business tier
+        if user.tier_id == BUSINESS_TIER:
+            flash("👍 You're already upgraded.")
+            return redirect(url_for("premium.index"))
+
+        # Select the business tier
+        business_tier = db.session.query(Tier).get(BUSINESS_TIER)
+        if not business_tier:
+            flash("⚠️ Something went wrong!")
+            return redirect(url_for("premium.index"))
+
+        # Subscribe the user to the business tier
+        try:
+            stripe_subscription = create_subscription(user, business_tier)
+        except Exception as e:
+            current_app.logger.error(f"Stripe error: {e}")
+            flash("⚠️ Something went wrong!")
+            return redirect(url_for("premium.index"))
+
+        return render_template(
+            "premium_subscribe.html",
+            user=user,
+            tier=business_tier,
+            stripe_subscription_id=stripe_subscription.id,
+            stripe_client_secret=get_latest_invoice_payment_intent_client_secret(
+                stripe_subscription
+            ),
+            stripe_publishable_key=current_app.config.get("STRIPE_PUBLISHABLE_KEY"),
+        )
+
+    @bp.route("/downgrade", methods=["POST"])
+    @authentication_required
+    def downgrade() -> Response:
+        user = db.session.get(User, session.get("user_id"))
+        if not user:
+            session.clear()
+            return redirect(url_for("login"))
+
+        # user.premium = False
+        # db.session.add(user)
+        # db.session.commit()
+
+        return redirect(url_for("premium.index"))
+
     return bp

hushline/static/css/style.css

@@ -2055,3 +2055,9 @@ p.bio + .extra-fields {
 .plan-recommended .plan-status {
   font-weight: bold;
 }
+
+#card-element {
+  margin-bottom: 1rem;
+  padding: 1rem;
+  border: 1px solid #666;
+}

hushline/static/js/premium-subscribe.js

@@ -0,0 +1,37 @@
+document.addEventListener("DOMContentLoaded", async function () {
+  const stripeClientSecret = document.querySelector(
+    "input[name='stripe_client_secret']",
+  ).value;
+  const stripePublishableKey = document.querySelector(
+    "input[name='stripe_publishable_key']",
+  ).value;
+  const pathPrefix = window.location.pathname.split("/").slice(0, -1).join("/");
+
+  stripe = Stripe(stripePublishableKey);
+  const elements = stripe.elements();
+  const cardElement = elements.create("card");
+  cardElement.mount("#card-element");
+
+  const form = document.querySelector("#subscribe-form");
+  form.addEventListener("submit", async (e) => {
+    e.preventDefault();
+    const nameInput = document.getElementById("name");
+
+    // Create payment method and confirm payment intent
+    const result = await stripe.confirmCardPayment(stripeClientSecret, {
+      payment_method: {
+        card: cardElement,
+        billing_details: {
+          name: nameInput.value,
+        },
+      },
+    });
+
+    if (result.error) {
+      alert(`Payment failed: ${result.error.message}`);
+      return;
+    } else {
+      window.location.href = pathPrefix;
+    }
+  });
+});

hushline/stripe.py

@@ -2,7 +2,7 @@
 from flask import current_app
 
 from .db import db
-from .model import Tier
+from .model import Tier, User
 
 
 def init_stripe() -> None:
@@ -86,3 +86,46 @@ def update_price(tier: Tier) -> None:
     db.session.commit()
 
     stripe.Product.modify(tier.stripe_product_id, default_price=price.id)
+
+
+def create_customer(user: User) -> stripe.Customer:
+    email: str = user.email if user.email is not None else ""
+
+    if user.stripe_customer_id is None:
+        stripe_customer = stripe.Customer.create(email=email)
+        user.stripe_customer_id = stripe_customer.id
+        db.session.add(user)
+        db.session.commit()
+        return stripe_customer
+
+    return stripe.Customer.modify(user.stripe_customer_id, email=email)
+
+
+def create_subscription(user: User, tier: Tier) -> stripe.Subscription:
+    stripe_customer = create_customer(user)
+
+    # Create a subscription
+    stripe_subscription = stripe.Subscription.create(
+        customer=stripe_customer.id,
+        items=[{"price": tier.stripe_price_id}],
+        payment_behavior="default_incomplete",
+    )
+    user.stripe_subscription_id = stripe_subscription.id
+    db.session.add(user)
+    db.session.commit()
+
+    return stripe_subscription
+
+
+def get_latest_invoice_payment_intent_client_secret(
+    subscription: stripe.Subscription,
+) -> str | None:
+    if subscription.latest_invoice is None:
+        return None
+
+    stripe_invoice = stripe.Invoice.retrieve(str(subscription.latest_invoice))
+    if stripe_invoice.payment_intent is None:
+        return None
+
+    stripe_payment_intent = stripe.PaymentIntent.retrieve(str(stripe_invoice.payment_intent))
+    return stripe_payment_intent.client_secret

hushline/templates/premium.html

@@ -16,7 +16,9 @@ <h3>Free</h3>
       <p>Tor Onion Service: ✅</p>
       <p>End-to-End Encrypted: ✅</p>
       {% if user.tier_id == 2 %}
-        <button id="subscribe">Downgrade</button>
+        <form action="{{ url_for('premium.downgrade') }}" method="post">
+          <button id="downgrade">Downgrade</button>
+        </form>
       {% endif %}
     </div>
     <div class="plan plan-recommended">
@@ -31,12 +33,13 @@ <h3>Business</h3>
       <p>Monthly Messages: Unlimited</p>
       <p>Forwarding Addresses: 100</p>
       {% if user.tier_id == 1 %}
-        <button id="subscribe">Upgrade for $20/mo</button>
+        <form action="{{ url_for('premium.upgrade') }}" method="post">
+          <button id="upgrade">Upgrade for $20/mo</button>
+        </form>
       {% endif %}
     </div>
   </div>
 {% endblock %}
 
 {% block scripts %}
-  <script src="{{ url_for('static', filename='js/premium.js') }}"></script>
 {% endblock %}

hushline/templates/premium_subscribe.html

@@ -0,0 +1,31 @@
+{% extends "base.html" %}
+{% block title %}Subscribe to {{ tier.name }}{% endblock %}
+{% block content %}
+  <h2>Subscribe to {{ tier.name }}</h2>
+  <form id="subscribe-form">
+    <input
+      type="hidden"
+      name="stripe_client_secret"
+      value="{{ stripe_client_secret }}"
+    />
+    <input
+      type="hidden"
+      name="stripe_publishable_key"
+      value="{{ stripe_publishable_key }}"
+    />
+    <div>
+      <label for="name">Full Name</label>
+      <input type="text" id="name" placeholder="Enter your name" />
+    </div>
+    <div>
+      <label for="card-element">Credit Card Details</label>
+      <div id="card-element"></div>
+    </div>
+    <button id="submit">Subscribe</button>
+  </form>
+{% endblock %}
+
+{% block scripts %}
+  <script src="https://js.stripe.com/v3/"></script>
+  <script src="{{ url_for('static', filename='js/premium-subscribe.js') }}"></script>
+{% endblock %}