/**
 * Data Transfer Objects for the REST API.
 * Wire format for request/response bodies — independent of domain entities.
 * Mirrors `apps/interfaces/api/src/dto/*.rs`.
 */

/* -------------------------------------------------------------------------- */
/*  Auth DTOs                                                                 */
/* -------------------------------------------------------------------------- */

export interface LoginRequest {
  username: string;
  password: string;
}

export interface RegisterRequest {
  username: string;
  password: string;
  /** Optional display name. */
  display_name?: string;
}

export interface RefreshRequest {
  refresh_token: string;
}

export interface AuthResponse {
  access_token: string;
  refresh_token: string;
  token_type: string;
  expires_in: number;
}

/* -------------------------------------------------------------------------- */
/*  Session DTOs                                                              */
/* -------------------------------------------------------------------------- */

export interface CreateSessionRequest {
  title: string;
}

export interface SessionResponse {
  id: string;
  created_at: number;
  updated_at: number;
  title: string;
  model: string;
  message_count: number;
  archived: boolean;
  summary?: string;
}

export interface SessionListResponse {
  sessions: SessionResponse[];
  total: number;
}

/* -------------------------------------------------------------------------- */
/*  Conversation DTOs                                                         */
/* -------------------------------------------------------------------------- */

export interface AddMessageRequest {
  role: string;
  content: string;
}

export interface ToolFunctionResponse {
  name: string;
  arguments: string;
}

export interface ToolCallResponse {
  id: string;
  function: ToolFunctionResponse;
}

export interface MessageResponse {
  role: string;
  content?: string;
  tool_calls?: ToolCallResponse[];
  tool_call_id?: string;
}

export interface ConversationResponse {
  session_id: string;
  messages: MessageResponse[];
  message_count: number;
  model: string;
  system_prompt: string;
  max_tokens?: number;
  temperature?: number;
}

export interface ChatCompletionRequest {
  session_id: string;
  message: string;
  model?: string;
  max_tokens?: number;
  temperature?: number;
}

export interface ChatCompletionResponse {
  reply: string;
  prompt_tokens: number;
  completion_tokens: number;
}

/* -------------------------------------------------------------------------- */
/*  Error DTO                                                                 */
/* -------------------------------------------------------------------------- */

export interface ErrorResponse {
  message: string;
  code: number;
}

/** Build a standardised error response body. */
export function errorBody(message: string, code: number): ErrorResponse {
  return { message, code };
}