/**
 * LLM(AI 검증) 앱 설정 (gc_app_settings.llm_settings_json)
 */

export interface LlmAppSettings {
  /** LLM AI 검증 사용 여부 */
  enabled: boolean;
  /** LLM 서버 호스트 (IP 또는 도메인) */
  host: string;
  /** LLM 서버 포트 */
  port: number;
  /** HTTPS 사용 여부 */
  useHttps: boolean;
  /** OpenAI 호환 chat completions 경로 */
  chatPath: string;
  /** 모델 ID */
  model: string;
  /** 최대 생성 토큰 */
  maxTokens: number;
  /** temperature (0~2) */
  temperature: number;
  /** 요청 타임아웃 (ms) */
  timeoutMs: number;
}

export const DEFAULT_LLM_APP_SETTINGS: LlmAppSettings = {
  enabled: true,
  host: '127.0.0.1',
  port: 16000,
  useHttps: false,
  chatPath: '/v1/chat/completions',
  model: 'mlx-community/Qwen2.5-7B-Instruct-4bit',
  maxTokens: 1024,
  temperature: 0.1,
  timeoutMs: 120_000,
};

function clampInt(v: unknown, min: number, max: number, fallback: number): number {
  const n = Number(v);
  if (!Number.isFinite(n)) return fallback;
  return Math.max(min, Math.min(max, Math.round(n)));
}

function clampFloat(v: unknown, min: number, max: number, fallback: number): number {
  const n = Number(v);
  if (!Number.isFinite(n)) return fallback;
  return Math.max(min, Math.min(max, n));
}

export function resolveLlmAppSettings(
  raw?: Partial<LlmAppSettings> | null,
): LlmAppSettings {
  const d = DEFAULT_LLM_APP_SETTINGS;
  if (!raw || typeof raw !== 'object') return { ...d };
  const host = typeof raw.host === 'string' && raw.host.trim() ? raw.host.trim() : d.host;
  const chatPath = typeof raw.chatPath === 'string' && raw.chatPath.trim()
    ? (raw.chatPath.startsWith('/') ? raw.chatPath.trim() : `/${raw.chatPath.trim()}`)
    : d.chatPath;
  const model = typeof raw.model === 'string' && raw.model.trim() ? raw.model.trim() : d.model;
  return {
    enabled: raw.enabled === undefined ? d.enabled : Boolean(raw.enabled),
    host,
    port: clampInt(raw.port, 1, 65535, d.port),
    useHttps: raw.useHttps === undefined ? d.useHttps : Boolean(raw.useHttps),
    chatPath,
    model,
    maxTokens: clampInt(raw.maxTokens, 64, 8192, d.maxTokens),
    temperature: clampFloat(raw.temperature, 0, 2, d.temperature),
    timeoutMs: clampInt(raw.timeoutMs, 5_000, 600_000, d.timeoutMs),
  };
}

/** 설정 UI용 — host·port·프로토콜로 base URL 미리보기 */
export function buildLlmBaseUrl(settings: LlmAppSettings): string {
  const scheme = settings.useHttps ? 'https' : 'http';
  const omitPort = (settings.useHttps && settings.port === 443)
    || (!settings.useHttps && settings.port === 80);
  if (omitPort) return `${scheme}://${settings.host}`;
  return `${scheme}://${settings.host}:${settings.port}`;
}

export function buildLlmEndpointUrl(settings: LlmAppSettings): string {
  return `${buildLlmBaseUrl(settings)}${settings.chatPath}`;
}