feat: implement fare calculation with missed trips discount logic

swift-lift-fare-calculation/swift-lift-fare-calculation.py

@@ -1,22 +1,91 @@
 import boto3
 import json
-
+from math import ceil
 from botocore.exceptions import ClientError
+
 print("Packages have imported successfully")
 
+# Initialize DynamoDB
+dynamodb = boto3.resource('dynamodb')
+
+# DynamoDB table name
+TRIPS_TABLE = "trips"  # Replace with your table name
+
 def lambda_handler(event, context):
+    body = {}
+    statusCode = 200
+    headers = {
+        "Content-Type": "application/json"
+    }
     try:
         print("Processing")
         print(event)
-        print(context)
+
+        # Extract passenger_id and total trips from the event
+        passenger_id = event.get('passenger_id')
+        total_trips = event.get('total_trips')
+        if not passenger_id or not total_trips:
+            raise ValueError("passenger_id and total_trips must be provided")
+
+        # Fetch missed trips for the passenger
+        trips_table = dynamodb.Table(TRIPS_TABLE)
+        response = trips_table.get_item(Key={"passenger_id": passenger_id})
+        if 'Item' not in response:
+            raise ValueError("Passenger data not found")
+
+        missed_trips = response['Item'].get('missed_trips', 0)
+        print(f"Total trips: {total_trips}, Missed trips: {missed_trips}")
+
+        # Calculate the discount threshold
+        discount_threshold = ceil(total_trips * 0.4)
+
+        # Calculate eligible missed trips for discount
+        eligible_missed_trips = max(0, missed_trips - discount_threshold)
+        discount_per_trip = 0.15 * 350  # 15% of R350
+        total_discount = eligible_missed_trips * discount_per_trip
+
+        # Calculate the final fare
+        final_fare = 350 - total_discount
+        final_fare = max(final_fare, 0)  # Ensure fare is not negative
+
+        print(f"Final fare calculated: R{final_fare}")
+
+        body = {
+            "passenger_id": passenger_id,
+            "total_trips": total_trips,
+            "missed_trips": missed_trips,
+            "discount_threshold": discount_threshold,
+            "eligible_missed_trips": eligible_missed_trips,
+            "total_discount": total_discount,
+            "final_fare": final_fare
+        }
+
+        return {
+            'statusCode': statusCode,
+            'body': json.dumps(body),
+            'headers': headers
+        }
+
+    except ValueError as ve:
+        print(f"Value error occurred: {ve}")
         return {
-            'statusCode': 200,
-            'body': json.dumps('Process completed successfully')
+            'statusCode': 400,
+            'body': json.dumps(str(ve)),
+            'headers': headers
+        }
+
+    except ClientError as ce:
+        print(f"Client error occurred: {ce}")
+        return {
+            'statusCode': 500,
+            'body': json.dumps("Error accessing DynamoDB"),
+            'headers': headers
         }
 
     except Exception as e:
         print(f"An error occurred: {e}")
         return {
             'statusCode': 500,
-            'body': json.dumps('Error occurred during processing')
+            'body': json.dumps('Error occurred during processing'),
+            'headers': headers
         }