Features Follow and Timeline

[espenia]

Social Interaction Features

Overview

This pull request introduces essential social interaction features to the Twitter Challenge application, including follow/unfollow functionality, timeline generation.

Key Changes

New Follow Management Features

• Implemented complete follow/unfollow functionality between users
• Created endpoints for managing follow relationships
• Added follower and following list retrieval endpoints
• Implemented validation to prevent self-follows and handle edge cases

Timeline Infrastructure

• Built timeline generation system that combines user's own tweets with tweets from followed users
• Implemented caching mechanism for timelines to improve performance
• Created configurable timeline parameters (freshness timeout, tweet limits)
• Added automatic cache invalidation and regeneration when needed

New Endpoints

Follow a User

Description: Create a new follow relationship between users

Endpoint: POST /api/follows/{followerId}

Request:

curl -X POST http://localhost:8090/api/follows/user123 \
  -H "Content-Type: application/json" \
  -d '{
    "followedId": "user456"
  }'

Request Schema:

{
  "followedId": "string"
}

Response Schema:

{
  "id": "string",
  "followerId": "string",
  "followedId": "string",
  "createdAt": "date-time"
}

Status Codes:

• 201 Created - Follow relationship successfully created
• 400 Bad Request - Invalid request (e.g., attempting to follow yourself)
• 404 Not Found - User ID not found

Unfollow a User

Description: Remove an existing follow relationship between users

Endpoint: DELETE /api/follows/{followerId}/{followedId}

Request:

curl -X DELETE http://localhost:8090/api/follows/user123/user456

Response: No content

Status Codes:

• 204 No Content - Successfully unfollowed
• 404 Not Found - Follow relationship or user not found

Get User Timeline

Description: Retrieve a user's timeline containing tweets from the user and users they follow

Endpoint: GET /api/timeline/{userId}

Request:

curl -X GET http://localhost:8090/api/timeline/user123

Response Schema:

{
  "id": "string",
  "userId": "string",
  "tweetIds": [
    "string"
  ],
  "lastUpdated": "date-time",
  "tweets": [
    {
      "id": "string",
      "userId": "string",
      "content": "string",
      "createdAt": "date-time",
      "likeCount": 0
    }
  ]
}

Status Codes:

• 200 OK - Timeline successfully retrieved
• 404 Not Found - User ID not found

Get User Followers

Description: Retrieve a list of users who follow a specific user

Endpoint: GET /api/follows/followers/{userId}

Request:

curl -X GET http://localhost:8090/api/follows/followers/user123

Response Schema:

[
  {
    "id": "string",
    "followerId": "string",
    "followedId": "string",
    "createdAt": "date-time"
  }
]

Status Codes:

• 200 OK - Followers list successfully retrieved
• 404 Not Found - User ID not found

Get User Following

Description: Retrieve a list of users that a specific user is following

Endpoint: GET /api/follows/following/{userId}

Request:

curl -X GET http://localhost:8090/api/follows/following/user123

Response Schema:

[
  {
    "id": "string",
    "followerId": "string",
    "followedId": "string",
    "createdAt": "date-time"
  }
]

Status Codes:

• 200 OK - Following list successfully retrieved
• 404 Not Found - User ID not found

Related Issues

• Closes Features Follow and Timeline #3: Implement follow/unfollow functionality
• Closes #4: Create timeline endpoint
• Closes #5: Add follower listing endpoints