Fix: [AEA-0000] - Redeploy notification table stage 1 (#1657)

## Summary

- ⚠️ Potential issues that might be caused by this change

### Details

Remove references to the table, whilst also reverting the table
definition to the old one so collisions are prevented!

Author: wildjames

SAMtemplates/tables/main.yaml

@@ -426,19 +426,29 @@ Resources:
       PointInTimeRecoverySpecification:
         PointInTimeRecoveryEnabled: true
       AttributeDefinitions:
-        - AttributeName: NHSNumber
+        - AttributeName: PrescriptionID
           AttributeType: S
-        - AttributeName: ODSCode
+        - AttributeName: NHSNumber
           AttributeType: S
       KeySchema:
-        - AttributeName: NHSNumber
-          KeyType: HASH       # Partition key
-        - AttributeName: ODSCode
-          KeyType: RANGE      # Sort key
+        - AttributeName: PrescriptionID
+          KeyType: HASH
       BillingMode: !If
         - EnableDynamoDBAutoScalingCondition
         - PROVISIONED
         - PAY_PER_REQUEST
+      GlobalSecondaryIndexes:
+        - IndexName: NotificationNHSNumberIndex
+          KeySchema:
+            - AttributeName: NHSNumber
+              KeyType: HASH
+          Projection:
+            ProjectionType: ALL
+          ProvisionedThroughput: !If
+            - EnableDynamoDBAutoScalingCondition
+            - ReadCapacityUnits: 1
+              WriteCapacityUnits: !Ref MinWritePrescriptionNotificationStateCapacity
+            - !Ref "AWS::NoValue"
       ProvisionedThroughput: !If
         - EnableDynamoDBAutoScalingCondition
         - ReadCapacityUnits: 1
@@ -514,6 +524,59 @@ Resources:
         PredefinedMetricSpecification:
           PredefinedMetricType: DynamoDBReadCapacityUtilization
 
+  # Scaling for the indexes
+  NotificationNHSNumberIndexScalingWriteTarget:
+    Type: AWS::ApplicationAutoScaling::ScalableTarget
+    DependsOn: PrescriptionNotificationStateTable
+    Condition: EnableDynamoDBAutoScalingCondition
+    Properties:
+      MinCapacity: !Ref MinWritePrescriptionNotificationStateCapacity
+      MaxCapacity: !Ref MaxWritePrescriptionNotificationStateCapacity
+      ResourceId: !Sub table/${PrescriptionNotificationStateTable}/index/NotificationNHSNumberIndex
+      RoleARN: !GetAtt DynamoDbScalingRole.Arn
+      ScalableDimension: "dynamodb:index:WriteCapacityUnits"
+      ServiceNamespace: dynamodb
+
+  NotificationNHSNumberIndexScalingWritePolicy:
+    Type: AWS::ApplicationAutoScaling::ScalingPolicy
+    Condition: EnableDynamoDBAutoScalingCondition
+    Properties:
+      PolicyName: NotificationNHSNumberIndexScalingWritePolicy
+      PolicyType: TargetTrackingScaling
+      ScalingTargetId: !Ref NotificationNHSNumberIndexScalingWriteTarget
+      TargetTrackingScalingPolicyConfiguration:
+        TargetValue: 50
+        ScaleInCooldown: 600
+        ScaleOutCooldown: 0
+        PredefinedMetricSpecification:
+          PredefinedMetricType: DynamoDBWriteCapacityUtilization
+
+  NotificationNHSNumberIndexScalingReadTarget:
+    Type: AWS::ApplicationAutoScaling::ScalableTarget
+    DependsOn: PrescriptionNotificationStateTable
+    Condition: EnableDynamoDBAutoScalingCondition
+    Properties:
+      MinCapacity: 1
+      MaxCapacity: 100
+      ResourceId: !Sub table/${PrescriptionNotificationStateTable}/index/NotificationNHSNumberIndex
+      RoleARN: !GetAtt DynamoDbScalingRole.Arn
+      ScalableDimension: "dynamodb:index:ReadCapacityUnits"
+      ServiceNamespace: dynamodb
+
+  NotificationNHSNumberIndexScalingReadPolicy:
+    Type: AWS::ApplicationAutoScaling::ScalingPolicy
+    Condition: EnableDynamoDBAutoScalingCondition
+    Properties:
+      PolicyName: NotificationNHSNumberIndexReadScalingPolicy
+      PolicyType: TargetTrackingScaling
+      ScalingTargetId: !Ref NotificationNHSNumberIndexScalingReadTarget
+      TargetTrackingScalingPolicyConfiguration:
+        TargetValue: 70
+        ScaleInCooldown: 60
+        ScaleOutCooldown: 60
+        PredefinedMetricSpecification:
+          PredefinedMetricType: DynamoDBReadCapacityUtilization
+
 Outputs:
   PrescriptionStatusUpdatesTableName:
     Description: PrescriptionStatusUpdates table name