feat: API to fetch total order amount by passing tickets and discount code

Author: shreyanshdwivedi

app/api/auth.py

@@ -39,7 +39,10 @@
 from app.models.mail import PASSWORD_RESET, PASSWORD_CHANGE, \
     PASSWORD_RESET_AND_VERIFY
 from app.models.notification import PASSWORD_CHANGE as PASSWORD_CHANGE_NOTIF
+from app.models.discount_code import DiscountCode
+from app.models.event import Event
 from app.models.order import Order
+from app.models.ticket import Ticket
 from app.models.user import User
 from app.models.event_invoice import EventInvoice
 
@@ -503,3 +506,49 @@ def resend_emails():
                                             "Only placed and completed orders have confirmation").respond()
     else:
         return ForbiddenError({'source': ''}, "Co-Organizer Access Required").respond()
+
+
+@ticket_blueprint.route('/orders/calculate-amount', methods=['POST'])
+@jwt_required
+def calculate_amount():
+    data = request.json['data']
+    tickets = data['tickets']
+    discount_code = None
+    tax = None
+    taxType = True
+    event = None
+    if 'event' in data:
+        event_identifier = data['event']
+        event = safe_query(db, Event, 'identifier', event_identifier, 'identifier')
+    else:
+        return UnprocessableEntityError({'source': 'data/event'},
+                                        "Event info missing").respond()
+
+    if 'discount-code' in data:
+        discount_code_id = data['discount-code']
+        discount_code = safe_query(db, DiscountCode, 'id', discount_code_id, 'id')
+    if event.tax:
+        tax = event.tax
+        taxType = tax.is_tax_included_in_price
+
+    amount = 0.0
+    for ticket_info in tickets:
+        ticket_identifier = ticket_info['id']
+        quantity = ticket_info['quantity']
+        ticket = safe_query(db, Ticket, 'id', ticket_identifier, 'id')
+        if ticket.event.id != event.id:
+            return UnprocessableEntityError({'source': 'data/tickets'},
+                                            "Invalid Ticket").respond()
+        price = ticket.price
+
+        if tax and not taxType:
+            price = price * (100 + tax.rate)/100
+        if discount_code:
+            for code in ticket.discount_codes:
+                if discount_code.id == code.id:
+                    if code.type == 'amount':
+                        price = price - code.value
+                    else:
+                        price = price * (100 - code.value)/100
+        amount = amount + price * quantity
+    return jsonify(amount=amount)