/**
 * Service contract
 * 
 * Orchestration boundary for server-side operations.
 * Returns API DTOs or Page DTOs only.
 * Must be stateless.
 * 
 * Based on WEBSITE_CONTRACT.md:
 * - Services orchestrate IO and composition
 * - They do not prepare UI
 * - They return ApiDto or PageDto only
 */

/**
 * Base service interface for orchestration operations
 */
export interface Service<TApiDto = unknown, TPageDto = unknown> {
  /**
   * Execute a service operation
   * Returns either API Transport DTO or Page DTO
   */
  execute(...args: unknown[]): Promise<TApiDto | TPageDto>;
}

/**
 * Service that returns API Transport DTOs
 */
export interface ApiService<TApiDto = unknown> extends Service<TApiDto, never> {
  execute(...args: unknown[]): Promise<TApiDto>;
}

/**
 * Service that returns Page DTOs
 */
export interface PageService<TPageDto = unknown> extends Service<never, TPageDto> {
  execute(...args: unknown[]): Promise<TPageDto>;
}