openapi: 3.0.0
info:
  title: User CRUD API
  version: 1.0.0
servers:
  - url: https://api.example.com/v1
paths:
  /users:
    get:
      summary: Get all users
      responses:
        '200':
          description: A list of users
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/User'
    post:
      summary: Create a new user
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/UserCreate'
      responses:
        '201':
          description: User created
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/User'
  /users/{userId}:
    get:
      summary: Get a user by ID
      parameters:
        - name: userId
          in: path
          required: true
          schema:
            type: string
      responses:
        '200':
          description: User details
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/User'
        '404':
          description: User not found
    put:
      summary: Update a user by ID
      parameters:
        - name: userId
          in: path
          required: true
          schema:
            type: string
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/UserUpdate'
      responses:
        '200':
          description: User updated
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/User'
        '404':
          description: User not found
    delete:
      summary: Delete a user by ID
      parameters:
        - name: userId
          in: path
          required: true
          schema:
            type: string
      responses:
        '204':
          description: User deleted successfully
        '404':
          description: User not found

components:
  schemas:
    User:
      type: object
      properties:
        id:
          type: string
          example: "123"
        username:
          type: string
          example: "johndoe"
        email:
          type: string
          format: email
          example: "johndoe@example.com"
      required:
        - id
        - username
        - email
    UserCreate:
      type: object
      properties:
        username:
          type: string
          example: "johndoe"
        email:
          type: string
          format: email
          example: "johndoe@example.com"
        password:
          type: string
          format: password
      required:
        - username
        - email
        - password
    UserUpdate:
      type: object
      properties:
        username:
          type: string
          example: "john_doe_updated"
        email:
          type: string
          format: email
          example: "johnupdated@example.com"
      required:
        - username
        - email