openapi: 3.0.3
info:
  title: "Simple Social Media Application API"
  description: "Backend API for the Simple Social Media Application"
  version: "1.0.0"
  contact:
    name: "API Support"
    email: "api.support@contoso.com"

servers:
  - url: http://localhost:8000/api

tags:
  - name: "Posts"
  - name: "Comments"
  - name: "Likes"

paths:
  /posts:
    get:
      tags: ["Posts"]
      summary: List all posts
      description: "Retrieve a list of all posts in the social media application."
      operationId: getPosts
      responses:
        "200":
          description: "Successfully retrieved the list of posts."
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: "#/components/schemas/Post"
        "500":
          description: "Internal server error"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
    post:
      tags: ["Posts"]
      summary: Create a new post
      description: "Create a new post in the social media application."
      operationId: createPost
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: "#/components/schemas/CreatePostRequest"
      responses:
        "201":
          description: "Successfully created a new post."
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Post"
        "400":
          description: "Bad request"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
        "500":
          description: "Internal server error"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"

  /posts/{postId}:
    get:
      tags: ["Posts"]
      summary: Retrieve a specific post by ID
      description: "Retrieve a specific post by its ID."
      operationId: getPost
      parameters:
        - name: postId
          in: path
          required: true
          schema:
            type: integer
          description: "ID of the post to retrieve"
      responses:
        "200":
          description: "Successfully retrieved the post."
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Post"
        "404":
          description: "Post not found"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
        "500":
          description: "Internal server error"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
    patch:
      tags: ["Posts"]
      summary: Update a specific post by ID
      description: "Update a specific post."
      operationId: updatePost
      parameters:
        - name: postId
          in: path
          required: true
          schema:
            type: integer
          description: "ID of the post to update"
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: "#/components/schemas/UpdatePostRequest"
      responses:
        "200":
          description: "Successfully updated the post."
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Post"
        "400":
          description: "Bad request"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
        "404":
          description: "Post not found"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
        "500":
          description: "Internal server error"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
    delete:
      tags: ["Posts"]
      summary: Delete a specific post by ID
      description: "Delete a specific post."
      operationId: deletePost
      parameters:
        - name: postId
          in: path
          required: true
          schema:
            type: integer
          description: "ID of the post to delete"
      responses:
        "204":
          description: "Successfully deleted the post."
        "404":
          description: "Post not found"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
        "500":
          description: "Internal server error"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"

  /posts/{postId}/comments:
    get:
      tags: ["Comments"]
      summary: Retrieve a list of comments for a specific post
      description: "Retrieve a list of comments for a specific post."
      operationId: getComments
      parameters:
        - name: postId
          in: path
          required: true
          schema:
            type: integer
          description: "ID of the post to retrieve comments for"
      responses:
        "200":
          description: "Successfully retrieved the list of comments."
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: "#/components/schemas/Comment"
        "404":
          description: "Post not found"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
        "500":
          description: "Internal server error"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
    post:
      tags: ["Comments"]
      summary: Create a comment on a specific post
      description: "Create a comment on a specific post."
      operationId: createComment
      parameters:
        - name: postId
          in: path
          required: true
          schema:
            type: integer
          description: "ID of the post to create a comment on"
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: "#/components/schemas/CreateCommentRequest"
      responses:
        "201":
          description: "Successfully created a comment."
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Comment"
        "400":
          description: 잘못된 요청
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
        "404":
          description: 포스트를 찾을 수 없음
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
        "500":
          description: "Internal server error"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"

  /posts/{postId}/comments/{commentId}:
    get:
      tags: ["Comments"]
      summary: Retrieve a specific comment by ID
      description: "Retrieve a specific comment by its ID."
      operationId: getComment
      parameters:
        - name: postId
          in: path
          required: true
          schema:
            type: integer
          description: "ID of the post the comment belongs to"
        - name: commentId
          in: path
          required: true
          schema:
            type: integer
          description: "ID of the comment to retrieve"
      responses:
        "200":
          description: "Successfully retrieved the comment."
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Comment"
        "404":
          description: 댓글 또는 포스트를 찾을 수 없음
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
        "500":
          description: "Internal server error"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
    patch:
      tags: ["Comments"]
      summary: Update a specific comment by ID
      description: "Update a specific comment."
      operationId: updateComment
      parameters:
        - name: postId
          in: path
          required: true
          schema:
            type: integer
          description: ID of the post the comment belongs to
        - name: commentId
          in: path
          required: true
          schema:
            type: integer
          description: ID of the comment to update
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: "#/components/schemas/UpdateCommentRequest"
      responses:
        "200":
          description: 댓글 수정 성공
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Comment"
        "400":
          description: "Bad request"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
        "404":
          description: "Comment or post not found"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
        "500":
          description: "Internal server error"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
    delete:
      tags: ["Comments"]
      summary: Delete a specific comment by ID
      description: "Delete a specific comment."
      operationId: deleteComment
      parameters:
        - name: postId
          in: path
          required: true
          schema:
            type: integer
          description: "ID of the post the comment belongs to"
        - name: commentId
          in: path
          required: true
          schema:
            type: integer
          description: "ID of the comment to delete"
      responses:
        "204":
          description: "Successfully deleted the comment."
        "404":
          description: "Comment or post not found"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
        "500":
          description: "Internal server error"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"

  /posts/{postId}/likes:
    post:
      tags: ["Likes"]
      summary: Like a specific post
      description: "Like a specific post."
      operationId: likePost
      parameters:
        - name: postId
          in: path
          required: true
          schema:
            type: integer
          description: "ID of the post to like"
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: "#/components/schemas/LikeRequest"
      responses:
        "201":
          description: "Successfully liked the post."
        "400":
          description: "Bad request"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
        "404":
          description: "Post not found"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
        "500":
          description: "Internal server error"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
    delete:
      tags: ["Likes"]
      summary: Unlike a specific post
      description: "Unlike a specific post."
      operationId: unlikePost
      parameters:
        - name: postId
          in: path
          required: true
          schema:
            type: integer
          description: "ID of the post to unlike"
      responses:
        "204":
          description: "Successfully unliked the post."
        "400":
          description: "Bad request"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
        "404":
          description: "Post not found"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"
        "500":
          description: "Internal server error"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ErrorResponse"

components:
  schemas:
    Post:
      type: object
      properties:
        id:
          type: integer
          example: 1
        username:
          type: string
          example: "alice"
        content:
          type: string
          example: "Hello, this is my first post!"
        createdAt:
          type: string
          format: date-time
          example: "2025-01-01T12:34:56Z"
        updatedAt:
          type: string
          format: date-time
          example: "2025-01-01T12:40:00Z"
        likeCount:
          type: integer
          example: 3
        commentCount:
          type: integer
          example: 10
      required:
        - id
        - username
        - content
        - createdAt
        - updatedAt
        - likeCount
        - commentCount

    CreatePostRequest:
      type: object
      required:
        - username
        - content
      properties:
        username:
          type: string
          example: "alice"
        content:
          type: string
          example: "Hello, this is my first post!"

    UpdatePostRequest:
      type: object
      properties:
        content:
          type: string
          example: "Updated content of the post"
      required:
        - content

    Comment:
      type: object
      properties:
        id:
          type: integer
          example: 100
        postId:
          type: integer
          example: 1
        username:
          type: string
          example: "bob"
        content:
          type: string
          example: "Nice post!"
        createdAt:
          type: string
          format: date-time
          example: "2025-01-01T13:00:00Z"
        updatedAt:
          type: string
          format: date-time
          example: "2025-01-01T13:10:00Z"
      required:
        - id
        - postId
        - username
        - content
        - createdAt
        - updatedAt

    CreateCommentRequest:
      type: object
      required:
        - username
        - content
      properties:
        username:
          type: string
          example: "bob"
        content:
          type: string
          example: "Nice post!"

    UpdateCommentRequest:
      type: object
      properties:
        content:
          type: string
          example: "Updated comment."
      required:
        - content

    LikeRequest:
      type: object
      required:
        - username
      properties:
        username:
          type: string
          example: "charlie"

    ErrorResponse:
      type: object
      properties:
        message:
          type: string
          example: "Bad Request, Not Found or Internal Server Error"
      required:
        - message