function firstNonEmpty(values) {
  return values.find(value => typeof value === 'string' && value.trim())?.trim() || '';
}

function positiveNumber(values, fallback) {
  const value = Number(firstNonEmpty(values.map(item => item == null ? '' : String(item))));
  return Number.isFinite(value) && value > 0 ? value : fallback;
}

export function readNewApiConfig(options = {}) {
  return {
    // API key may be injected by trusted application code/tests, but MCP tool schemas
    // never expose it. End users should configure one of the environment variables.
    apiKey: firstNonEmpty([options.apiKey, process.env.FMODE_LLM_API_KEY, process.env.LLM_API_KEY]),
    // Never accept a caller-controlled endpoint field from an MCP invocation. The
    // `trustedBaseUrl` option exists only for direct dependency injection in tests.
    baseUrl: firstNonEmpty([options.trustedBaseUrl, process.env.FMODE_LLM_BASE_URL, process.env.LLM_BASE_URL]),
    allowInsecureHttp: options.allowInsecureHttp === true || /^true$/i.test(process.env.FMODE_ALLOW_INSECURE_HTTP || ''),
    timeoutMs: positiveNumber([options.timeoutMs, process.env.FMODE_LLM_TIMEOUT_MS], 180000),
    usdToCnyRate: positiveNumber([process.env.FMODE_USD_TO_CNY_RATE], 6.8),
    geminiGenerationReserveUsd: positiveNumber([
      process.env.FMODE_GEMINI_GENERATION_RESERVE_USD,
      process.env.FMODE_GEMINI_GENERATION_RESERVE
    ], 0.10),
    geminiVisionReserveUsd: positiveNumber([
      process.env.FMODE_GEMINI_VISION_RESERVE_USD,
      process.env.FMODE_GEMINI_VISION_RESERVE
    ], 0.01),
    seedreamImagePriceUsd: positiveNumber([
      process.env.FMODE_SEEDREAM_IMAGE_PRICE_USD,
      process.env.FMODE_SEEDREAM_IMAGE_PRICE
    ], 0.03)
  };
}

export function asBearerToken(token) {
  const value = String(token || '').trim();
  if (!value) return '';
  return /^Bearer\s+/i.test(value) ? value : `Bearer ${value}`;
}