# API Documentation Summary - Task 13.2

## Overview
Added comprehensive OpenAPI/Swagger documentation to the Expedia Rapid API Integration endpoints and DTOs.

## Changes Made

### 1. Controller Documentation (ExpediaController.java)

#### Added Class-Level Annotations:
- `@Tag`: "Expedia Accommodation Booking" with detailed description
- `@SecurityRequirement`: Bearer authentication requirement

#### Endpoint: POST /api/v1/expedia/search
- **@Operation**: Detailed summary and description of the search workflow
- **@ApiResponses**: 
  - 200: Success with example room response
  - 400: Invalid search parameters
  - 403: Insufficient permissions
  - 503: Service unavailable
  - 504: Request timeout
- **@RequestBody**: Example search request with location, dates, and occupancy
- **Requirements**: 2.1 - Shop Service Availability Search

#### Endpoint: POST /api/v1/expedia/price-check/{roomId}
- **@Operation**: Detailed summary and description of price validation workflow
- **@ApiResponses**:
  - 200: Price validated successfully
  - 409: Price changed (with old and new prices)
  - 410: Cached link expired
  - 403: Insufficient permissions
  - 503: Service unavailable
- **@Parameter**: roomId with description and example
- **Requirements**: 3.1 - Price Check Service, 7.2 - Price Change Detection

#### Endpoint: POST /api/v1/expedia/book/{roomId}
- **@Operation**: Detailed summary and description of booking workflow with hold & resume pattern
- **@ApiResponses**:
  - 200: Booking completed successfully with confirmation
  - 402: Insufficient wallet balance
  - 410: Cached link expired
  - 403: Insufficient permissions
  - 503: Service unavailable
  - 504: Request timeout
- **@Parameter**: roomId and agencyId with descriptions and examples
- **@RequestBody**: Example booking request with travelers, payment, and contact info
- **Requirements**: 4.1 - Booking Service with Hold & Resume, 5.1-5.7 - Payment Processing

### 2. DTO Documentation

#### ExpediaShopRequest.java
- Added `@Schema` annotations to all fields:
  - location: Location code with example "LAX"
  - checkIn: Check-in date (future date required)
  - checkOut: Check-out date (future date required)
  - adults: Number of adults (minimum 1)
  - children: Number of children (minimum 0)
  - currency: Currency code (ISO 4217)

#### ExpediaShopResponse.java
- Added `@Schema` annotations to ExpediaRoom nested class:
  - roomId: Unique identifier
  - roomType: Room type description
  - description: Detailed room description
  - maxOccupancy: Maximum guests
  - bedCount: Number of beds
  - bedType: Type of bed
  - price: Pricing information
  - cancellationPolicy: Cancellation details
  - refundable: Refundability status
  - links: HATEOAS links (hidden from docs)

#### ExpediaBookingRequest.java
- Added `@Schema` annotations to all fields:
  - travelers: List of guest information
  - payment: Payment card information
  - email: Contact email
  - phone: Contact phone
- Added `@Schema` annotations to ExpediaPaymentInfo nested class:
  - All payment card fields with examples

#### ExpediaTraveler.java
- Added `@Schema` annotations:
  - givenName: First name
  - surname: Last name
  - birthDate: Date of birth (past date required)
  - gender: Gender with allowable values

#### ExpediaPriceCheckResponse.java
- Added `@Schema` annotations:
  - status: Price validation status with allowable values
  - originalPrice: Original price from search
  - currentPrice: Current price
  - roomId: Room identifier
  - message: Additional information
  - links: HATEOAS links (hidden from docs)

#### PriceChangeErrorResponse.java
- Added `@Schema` annotations:
  - originalPrice: Original price
  - newPrice: New/current price
  - currency: Currency code
  - message: Error message

#### ExpediaBookingResponse.java
- Added `@Schema` annotations to main class and all nested classes:
  - ExpediaBookingDetails: Complete booking information
  - PropertyInfo: Hotel/property details
  - RoomInfo: Room details
  - GuestInfo: Guest information
- All fields documented with descriptions and examples

#### ExpediaPrice.java
- Added `@Schema` annotations:
  - total: Total price including taxes and fees
  - base: Base price before taxes
  - taxes: Total taxes
  - fees: Total fees
  - currency: Currency code

## Documentation Features

### Comprehensive Examples
- All request/response examples include realistic data
- Examples demonstrate the complete booking workflow
- Error responses include appropriate HTTP status codes

### Detailed Descriptions
- Each endpoint includes workflow explanation
- Requirements traceability maintained
- HATEOAS pattern explained
- Hold & Resume pattern documented

### HTTP Status Codes
All error responses documented with:
- 200: Success
- 400: Bad Request (invalid parameters)
- 402: Payment Required (insufficient balance)
- 403: Forbidden (insufficient permissions)
- 409: Conflict (price changed)
- 410: Gone (link expired)
- 503: Service Unavailable (circuit breaker open)
- 504: Gateway Timeout (request timeout)

## Accessing the Documentation

The API documentation can be accessed at:
- **Swagger UI**: http://localhost:8080/swagger-ui.html
- **OpenAPI JSON**: http://localhost:8080/v3/api-docs
- **OpenAPI YAML**: http://localhost:8080/v3/api-docs.yaml

## Requirements Validated

This implementation validates the following requirements:
- **Requirement 2.1**: Shop Service - Availability Search
- **Requirement 3.1**: Price Check Service - Validation
- **Requirement 4.1**: Booking Service with Hold & Resume
- **Requirement 7.2**: Error Handling for Price Changes
- **Requirement 7.3**: Price Change Notification

## Testing

All existing tests pass successfully:
- ExpediaBookingServiceTest: 6 tests ✓
- ExpediaClientImplTest: 11 tests ✓
- ExpediaLinkCacheImplTest: 24 tests ✓
- ExpediaSignatureGeneratorTest: 13 tests ✓
- ExpediaConfigTest: 4 tests ✓

**Total: 58 tests passed**

## Notes

- HATEOAS links are marked as `hidden = true` in the schema to avoid cluttering the API documentation with internal implementation details
- All examples use realistic data that matches the validation constraints
- Documentation follows the same pattern as existing FlightController for consistency
- Security requirements are properly documented with Bearer authentication