--- a/template.yaml	Thu Sep 16 18:03:26 2021 +0200
+++ b/template.yaml	Fri Sep 17 17:42:30 2021 +0200
@@ -13,6 +13,7 @@
       ApiKeyRequired: true
 
 Resources:
+
   ##
   ### START API GATEWAY CONFIGURATION ###
   ##
@@ -38,7 +39,7 @@
       Description: Deployment of Api version 1
       RestApiId: !Ref ServerlessRestApi
 
-  # Create usage plan
+  # Create PaidUsagePlan usage plan
   PaidUsagePlan:
     Type: AWS::ApiGateway::UsagePlan
     Properties:
@@ -59,7 +60,7 @@
         - Key: "Name"
           Value: "tweet-analysis::rest-api::paid-usage-plan"
 
-  # Create Api key
+  # Create Api key for PaidUsagePlan
   PaidApiKey:
     Type: AWS::ApiGateway::ApiKey
     Properties:
@@ -119,21 +120,22 @@
         - Key: "application-id"
           Value: "tweet-analysis"
         - Key: "Name"
-          Value: "tweet-analysis::certificate::dennistech.io"
+          Value: "tweet-analysis::domain-certificate::dennistech.io"
 
-  # Map domain to the regional domain generated by Api Gateway
+  # Map tweet-analysis.dennistech.io to the regional domain generated by Api Gateway
   DomainMapping:
     Type: AWS::Route53::RecordSet
     Properties:
+      Name: tweet-analysis.dennistech.io
+      Comment: Map domain to the regional domain generated by Api Gateway
       HostedZoneId: Z0937998E3C5GEK4NHO9
-      Name: tweet-analysis.dennistech.io
       Type: A
       AliasTarget:
         DNSName: !GetAtt Domain.RegionalDomainName
         EvaluateTargetHealth: true
         HostedZoneId: !GetAtt Domain.RegionalHostedZoneId
 
-  # Map paths from your domain name to your API stages
+  # Configure mapping in API Gateway custom domain to point to v1 stage
   PathMapping:
     Type: AWS::ApiGateway::BasePathMapping
     Properties:
@@ -153,6 +155,7 @@
   GetTweetSentimentFunction:
     Type: AWS::Serverless::Function
     Properties:
+      FunctionName: GetTweetSentimentFunction
       Description: Fetch tweets and analyse sentiment using AWS Comprehend
       CodeUri: src/
       Handler: handlers/sentiment.get_tweet_sentiment
@@ -161,15 +164,31 @@
         - AWSSecretsManagerGetSecretValuePolicy:
             SecretArn:
               arn:aws:secretsmanager:eu-west-2:339008578167:secret:tweet-analysis-keys-gKo6DQ
+      Layers:
+        - !Ref TweetAnalysisSharedFunctions
       Events:
         CallGetTweetSentiment:
           Type: Api
           Properties:
             Path: /sentiment
             Method: get
+            RequestParameters:
+              - method.request.querystring.twitterUser:
+                  Required: false
+              - method.request.querystring.numberOfTweets:
+                  Required: false
       Tags:
         Name: "tweet-analysis::get-tweet-sentiment-function"
 
+  # Define dependencies
+  TweetAnalysisSharedFunctions:
+    Type: AWS::Serverless::LayerVersion
+    Properties:
+      Description: Shared functions across lambda functions
+      CompatibleRuntimes:
+        - python3.9
+      ContentUri: dependencies/
+
   ##
   ### END FUNCTION CONFIGURATION ###
   ##