openapi: 3.0.0

info:
  version: '1.0.0'
  title: 'Event Tracker Lambda'
  description: 'Track event attendees'

paths:
  /register:
    post:
      summary: Register
      operationId: register
      tags:
        - Attendance
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/Register'
      responses:
        201:
          description: Attendance registered
        400:
          description: Bad request
          content:
            application/json:
              schema:
                oneOf:
                  - $ref: '#/components/schemas/FailedToParse'
                  - $ref: '#/components/schemas/SchemaValidationFailure'
        404:
          description: No event to register attendance
        500:
          description: An unexpected error occurred
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/UnexepectedFailure'

components:
  schemas:
    Register:
      required:
        - identifier
      properties:
        identifier:
          type: string
          pattern: "^[a-zA-Z0-9]{8}$"
      additionalProperties: false
    FailedToParse:
      required:
        - reason
      properties:
        reason:
          type: string
          default: 'Failed to parse request body'
      additionalProperties: false
    SchemaValidationFailure:
      required:
        - reason
        - failures
      properties:
        reason:
          type: string
          default: 'Request body failed schema validation'
        failures:
          type: array
          items:
            type: object
            required:
              - type
              - message
            properties:
              property:
                type: string
              message:
                type: string
            additionalProperties: false
      additionalProperties: false
    UnexepectedFailure:
      required:
        - reason
      properties:
        reason:
          type: string
          default: 'An unexpected error occurred'
      additionalProperties: false