API Design

Subscription API

resourse: subscription/
- get # fetches current subscription details
- post # creates new Subscription if doesn't exists
- update # udpates existing subscription
- delete # deletes the subscription
resource: subscription/payment

Course API

resource: course/
resource: module/
resource: content/
resource: content/quiz/question/
resource: content/quiz/submit/{proxy+}
resource: content/quiz/start/{proxy+}
resource: content/quiz/evaluate/{proxy+}
resource: content/video/
resource: content/reading/

Student API

resource: student/
resource: student/favourites/
resource: student/progress/

resource: student/certificate/

--> Mark as complete

Tables:

Users:

Course:

{ id: title: description: additionalDescription: instructor: duration category modules:[ { order: module_id: } ] rating: }

Module: { id: name: contents:{ order: content_id: } }

Content: { name: description: source_path: type: }

//TODO Quiz: { id: name: questions:[ id: question: options: [] correctAnswer: ]

} }

Progress: () { student id courses:[{ courseid: enrolled date: completed_modules:[] completed_content:[] Percentage_completed: }] }

Student: { id: student name: enrolled_courses:[

]
favorite_courses:[

]
subscription_id:

}

Subscription: { id trial_used: payments:[ ] end_date: }

Payments: { date: amount: method: status: }

AWS Guide

Amplify

**CLI Tool**  -> Full Stack Application backend (Resource Provisioning)
**Console** -> deploy website on s3 and cloud front
**SDK** -> merge frontend and backend

Categories (3 of our use)

**API will call function**
		GraphQL
		**REST API** (we are using)
			it uses API Gateway
				it has resources (everything comes after / in URL)
				Every resource is a path but not vice versa
					as path can be proxy path
				Resource is mapped to LAMBDA FUNCTION
				|RESOURCES| = |LAMBDA FUNCTION|

**Function will call Storage**
		**Lambda Function** is a serverless version of a EC2 instance that runs Nodejs
		Path in project directory -> "/amplify/backend/function/function_name/src/index.js"
			(export.handler will run first)
			API Gateway will forward request to Lambda Function in specific format which will be processed in that function (in event variable)
				We have PATH and RESOURCE and METHOD and QUERY STRING PARAMETER and BODY (in case of POST request)
				POSTMAN Configuration
					Authorization Type: AWS Signature
					Configure Access Key with CLI Access Keys
					Region: us-east-1
					Service: execute-api

PERMISSIONS ALREADY SET

**AMPLIFY PUSH** (for deploying code on AWS)
				check everything (dynamoDB, Authentication)
			**AMPLIFY PUSH FUNCTION**
				check only function (better to use in our case)

Storage

Learn from documentation / LinkedIn Learning / ChatGPT
	2 Type**DynamoDB**
		**s3 Bucket** (assets -> images, videos)
			will call s3 bucket directly in order because API gateway has size limit of response, we will fetch the path of asset from DynamoDB and we will make API call to s3 from frontend to fetch the asset (get code from AMPLIFY SDK for js)
				https://docs.amplify.aws/lib/q/platform/react-native/

Console.log() in the Lambda Function are recorded in a cloud watch To Debug -> Open latest cloud watch stream (Log will be sorted as per time) open latest LOG STREAM and check LATEST TIME It might take some time for log to appear (wait for 30-40 seconds)

Cognito -> authentication, authorization https://docs.amplify.aws/lib/auth/overview/q/platform/react-native/#social-provider-federation

DynamoDB -> No-SQL Database s3 -> Blob Storage

API Gateway -> REST API

Lambda -> Serverless EC2 Container that runs nodejs runtime

API Calls from React Native https://docs.amplify.aws/lib/restapi/fetch/q/platform/react-native/

AnuragQ / BrainBuddy