User can use lifetime coupon

app/dashboard/templates/dashboard/pricing.html

@@ -52,6 +52,26 @@
         Yearly <br>
         $29.99/year
       </button>
+
+      <hr class="my-6">
+
+      <form method="post">
+        {{ coupon_form.csrf_token }}
+        <input type="hidden" name="form-name" value="create">
+
+        <div class="font-weight-bold mb-2">Coupon</div>
+        <div class="small-text">
+          If you have a lifetime coupon, please paste it here. <br>
+          For information, we offer free premium account for education (student, professor or technical staff working at
+          an educational institute). <br>
+          Drop us an email at hi@simplelogin.io with your student ID or certificate to get the coupon.
+        </div>
+
+
+        {{ coupon_form.code(class="form-control", placeholder="Coupon") }}
+        {{ render_field_errors(coupon_form.code) }}
+        <button class="btn btn-lg btn-success mt-2">Apply</button>
+      </form>
     </div>
   </div>
 

app/dashboard/views/pricing.py

@@ -1,13 +1,23 @@
 from flask import render_template, flash, redirect, url_for
 from flask_login import login_required, current_user
+from flask_wtf import FlaskForm
+from wtforms import StringField, validators
 
 from app.config import (
     PADDLE_VENDOR_ID,
     PADDLE_MONTHLY_PRODUCT_ID,
     PADDLE_YEARLY_PRODUCT_ID,
     URL,
+    ADMIN_EMAIL,
 )
 from app.dashboard.base import dashboard_bp
+from app.email_utils import send_email
+from app.extensions import db
+from app.models import LifetimeCoupon
+
+
+class CouponForm(FlaskForm):
+    code = StringField("Coupon Code", validators=[validators.DataRequired()])
 
 
 @dashboard_bp.route("/pricing", methods=["GET", "POST"])
@@ -18,12 +28,39 @@ def pricing():
         flash("You are already a premium user", "warning")
         return redirect(url_for("dashboard.index"))
 
+    coupon_form = CouponForm()
+
+    if coupon_form.validate_on_submit():
+        code = coupon_form.code.data
+
+        coupon = LifetimeCoupon.get_by(code=code)
+
+        if coupon and coupon.nb_used > 0:
+            coupon.nb_used -= 1
+            current_user.lifetime = True
+            db.session.commit()
+
+            # notify admin
+            send_email(
+                ADMIN_EMAIL,
+                subject=f"User {current_user.id} used lifetime coupon. Coupon nb_used: {coupon.nb_used}",
+                plaintext="",
+                html="",
+            )
+
+            flash("You are upgraded to lifetime premium!", "success")
+            return redirect(url_for("dashboard.index"))
+
+        else:
+            flash(f"Coupon *{code}* expired or invalid", "warning")
+
     return render_template(
         "dashboard/pricing.html",
         PADDLE_VENDOR_ID=PADDLE_VENDOR_ID,
         PADDLE_MONTHLY_PRODUCT_ID=PADDLE_MONTHLY_PRODUCT_ID,
         PADDLE_YEARLY_PRODUCT_ID=PADDLE_YEARLY_PRODUCT_ID,
         success_url=URL + "/dashboard/subscription_success",
+        coupon_form=coupon_form,
     )