# API Specification

## REST API Specification

```yaml
openapi: 3.0.0
info:
  title: Book Reading Tracker API
  version: 1.0.0
  description: REST API for tracking book reading progress and calculating reading pace to meet deadlines

servers:
  - url: http://localhost:3000/api
    description: Local development server
  - url: https://books.yourdomain.com/api
    description: Production server (Coolify deployment)

paths:
  /health:
    get:
      summary: Health check endpoint
      description: Returns API status and timestamp for monitoring
      responses:
        '200':
          description: API is healthy
          content:
            application/json:
              schema:
                type: object
                properties:
                  status:
                    type: string
                    example: "ok"
                  timestamp:
                    type: string
                    format: date-time

  /books/search:
    get:
      summary: Search for books
      description: Search Open Library API for books by title, author, or ISBN
      parameters:
        - name: q
          in: query
          required: true
          schema:
            type: string
            maxLength: 200
          description: Search query (title, author, or ISBN)
      responses:
        '200':
          description: Search results
          content:
            application/json:
              schema:
                type: object
                properties:
                  results:
                    type: array
                    items:
                      type: object
                      properties:
                        olid:
                          type: string
                        title:
                          type: string
                        author:
                          type: string
                        publishYear:
                          type: integer
                        coverUrl:
                          type: string
                        totalPages:
                          type: integer
        '400':
          $ref: '#/components/responses/BadRequest'
        '500':
          $ref: '#/components/responses/ServerError'

  /books:
    get:
      summary: Get all active books
      description: Retrieve all books with status='reading' including progress calculations
      responses:
        '200':
          description: List of active books with progress
          content:
            application/json:
              schema:
                type: object
                properties:
                  books:
                    type: array
                    items:
                      allOf:
                        - $ref: '#/components/schemas/Book'
                        - type: object
                          properties:
                            currentPage:
                              type: integer
                            pagesRemaining:
                              type: integer
                            daysRemaining:
                              type: integer
                            requiredPace:
                              type: number
                            actualPace:
                              type: number
                              nullable: true
                            status:
                              type: string
                              enum: [on-track, slightly-behind, behind]
        '500':
          $ref: '#/components/responses/ServerError'

    post:
      summary: Add a new book
      description: Add a book to the user's reading list with a deadline
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
                - title
                - totalPages
                - deadlineDate
              properties:
                title:
                  type: string
                  maxLength: 500
                author:
                  type: string
                  maxLength: 500
                  nullable: true
                totalPages:
                  type: integer
                  minimum: 1
                coverUrl:
                  type: string
                  maxLength: 1000
                  nullable: true
                deadlineDate:
                  type: string
                  format: date
      responses:
        '201':
          description: Book created successfully
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Book'
        '400':
          $ref: '#/components/responses/BadRequest'
        '500':
          $ref: '#/components/responses/ServerError'

  /books/{bookId}:
    get:
      summary: Get book by ID
      description: Retrieve a specific book with full details
      parameters:
        - $ref: '#/components/parameters/BookId'
      responses:
        '200':
          description: Book details
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Book'
        '404':
          $ref: '#/components/responses/NotFound'
        '500':
          $ref: '#/components/responses/ServerError'

    delete:
      summary: Delete a book
      description: Remove a book and all associated reading logs
      parameters:
        - $ref: '#/components/parameters/BookId'
      responses:
        '204':
          description: Book deleted successfully
        '404':
          $ref: '#/components/responses/NotFound'
        '500':
          $ref: '#/components/responses/ServerError'

  /books/{bookId}/progress:
    get:
      summary: Get book progress
      description: Calculate and return reading progress with pace metrics
      parameters:
        - $ref: '#/components/parameters/BookId'
      responses:
        '200':
          description: Progress calculations
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ProgressCalculation'
        '404':
          $ref: '#/components/responses/NotFound'
        '500':
          $ref: '#/components/responses/ServerError'

  /books/{bookId}/logs:
    get:
      summary: Get reading logs for a book
      description: Retrieve all reading logs for a specific book
      parameters:
        - $ref: '#/components/parameters/BookId'
      responses:
        '200':
          description: Reading logs
          content:
            application/json:
              schema:
                type: object
                properties:
                  logs:
                    type: array
                    items:
                      $ref: '#/components/schemas/ReadingLog'
        '404':
          $ref: '#/components/responses/NotFound'
        '500':
          $ref: '#/components/responses/ServerError'

    post:
      summary: Log reading progress
      description: Create or update a reading log entry for a specific date
      parameters:
        - $ref: '#/components/parameters/BookId'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
                - currentPage
              properties:
                currentPage:
                  type: integer
                  minimum: 1
                logDate:
                  type: string
                  format: date
                  description: Date of the log (defaults to today if not provided)
      responses:
        '201':
          description: Log created successfully
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ReadingLog'
        '200':
          description: Log updated successfully (if log already existed for this date)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ReadingLog'
        '400':
          $ref: '#/components/responses/BadRequest'
        '404':
          $ref: '#/components/responses/NotFound'
        '500':
          $ref: '#/components/responses/ServerError'

components:
  schemas:
    Book:
      type: object
      properties:
        id:
          type: integer
        title:
          type: string
        author:
          type: string
          nullable: true
        totalPages:
          type: integer
        coverUrl:
          type: string
          nullable: true
        deadlineDate:
          type: string
          format: date
        isPrimary:
          type: boolean
        status:
          type: string
          enum: [reading, finished, paused]
        createdAt:
          type: string
          format: date-time
        updatedAt:
          type: string
          format: date-time

    ReadingLog:
      type: object
      properties:
        id:
          type: integer
        bookId:
          type: integer
        logDate:
          type: string
          format: date
        currentPage:
          type: integer
        createdAt:
          type: string
          format: date-time
        updatedAt:
          type: string
          format: date-time

    ProgressCalculation:
      type: object
      properties:
        bookId:
          type: integer
        currentPage:
          type: integer
        totalPages:
          type: integer
        pagesRemaining:
          type: integer
        deadlineDate:
          type: string
          format: date
        daysRemaining:
          type: integer
        requiredPace:
          type: number
          format: float
        actualPace:
          type: number
          format: float
          nullable: true
        status:
          type: string
          enum: [on-track, slightly-behind, behind]
        lastLoggedDate:
          type: string
          format: date
          nullable: true

    Error:
      type: object
      properties:
        error:
          type: string
          description: Error message
        details:
          type: object
          description: Additional error details
          nullable: true

  parameters:
    BookId:
      name: bookId
      in: path
      required: true
      schema:
        type: integer
      description: Unique book identifier

  responses:
    BadRequest:
      description: Invalid request
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            error: "Validation failed"
            details:
              field: "deadlineDate"
              message: "Deadline must be in the future"

    NotFound:
      description: Resource not found
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            error: "Book not found"

    ServerError:
      description: Internal server error
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            error: "Internal server error"
            details: null
```

---