/**
 * 云函数：jimengManager
 * 代理即梦图片、视频、数字人、动作迁移等任务接口，避免前端暴露上游地址和 token。
 *
 * 部署后把函数 objectId 填入 src/app/services/cloud-functions.ts 的 jimeng。
 */
const JIMENG_TOKEN = readEnv('JIMENG_TOKEN') || 'Bearer r:f0333969e312a40e4703e8fe4ed1c600';
const JIMENG_BASE_URL = readEnv('JIMENG_BASE_URL') || 'https://server.fmode.cn/api/volcengine/jimeng';
const PARSE_BASE_URL = readEnv('PARSE_BASE_URL') || 'https://server.fmode.cn/parse';
const PARSE_APP_ID = readEnv('PARSE_APP_ID') || 'ncloudmaster';
const REQUEST_TIMEOUT_MS = Number(readEnv('JIMENG_REQUEST_TIMEOUT_MS') || 60000);
const MAX_ATTEMPTS = Math.max(1, Number(readEnv('JIMENG_MAX_ATTEMPTS') || 3));

const ALLOWED_ENDPOINTS = new Set([
  'getVideoV3_720p',
  'getVideoV3_1080p',
  'getVideoV3_Pro',
  'getText2ImgV31',
  'getImgV4',
  'getDataByTask02',
  'getOhIdentifyMain',
  'getOhDateByTask',
  'getOmniHuman',
  'getActorV2',
]);

async function handler(request, response) {
  try {
    const action = pickParam(request, 'action') || 'call';

    if (action === 'call') {
      const endpoint = String(pickParam(request, 'endpoint') || '').trim();
      const payload = pickParam(request, 'payload', 'data') || {};
      if (!ALLOWED_ENDPOINTS.has(endpoint)) {
        return response.json({ code: 400, success: false, error: '不支持的生成接口' });
      }

      const upstreamPayload = stripEmpty({ ...payload, token: JIMENG_TOKEN });
      const data = await postJson(`${JIMENG_BASE_URL}/${endpoint}`, upstreamPayload);
      response.json(data);
      return;
    }

    if (action === 'getWorkResult') {
      const workId = String(pickParam(request, 'workId', 'objectId') || '').trim();
      if (!workId) {
        return response.json({ code: 400, success: false, error: '缺少作品 ID' });
      }
      const data = await getJson(`${PARSE_BASE_URL}/classes/ImagineWork/${encodeURIComponent(workId)}`, {
        'X-Parse-Application-Id': PARSE_APP_ID,
      });
      response.json({ code: 200, success: true, data });
      return;
    }

    response.json({ code: 400, success: false, error: `未知 action: ${action}` });
  } catch (error) {
    console.error('jimengManager failed:', error && error.message ? error.message : error);
    response.json({ code: 500, success: false, error: error && error.message ? error.message : '生成服务调用失败' });
  }
}

function pickParam(request, ...names) {
  const sources = [request.params, request.body, request];
  for (const src of sources) {
    if (!src || typeof src !== 'object') continue;
    for (const n of names) {
      const v = src[n];
      if (v !== undefined && v !== null && v !== '') return v;
    }
  }
  return null;
}

function stripEmpty(value) {
  if (!value || typeof value !== 'object') return value;
  const out = Array.isArray(value) ? [] : {};
  for (const [key, val] of Object.entries(value)) {
    if (val === undefined || val === null || val === '') continue;
    if (val && typeof val === 'object' && !Array.isArray(val)) {
      const nested = stripEmpty(val);
      if (Object.keys(nested).length) out[key] = nested;
    } else {
      out[key] = val;
    }
  }
  return out;
}

async function postJson(url, body) {
  return requestJson(url, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(body),
  });
}

async function getJson(url, headers) {
  const data = await requestJson(url, { method: 'GET', headers });
  if (data && data.success === false) throw new Error(data.error || '查询结果失败');
  return data;
}

async function requestJson(url, options) {
  let lastError = null;
  for (let attempt = 1; attempt <= MAX_ATTEMPTS; attempt++) {
    try {
      const r = await fetchWithTimeout(url, options, REQUEST_TIMEOUT_MS);
      const data = await readResponse(r, url, attempt);
      if (data && data.success === false && isRetryableStatus(data.code) && attempt < MAX_ATTEMPTS) {
        await sleep(backoffMs(attempt));
        continue;
      }
      return data;
    } catch (error) {
      lastError = error;
      if (!isRetryableNetworkError(error) || attempt >= MAX_ATTEMPTS) break;
      await sleep(backoffMs(attempt));
    }
  }

  const message = lastError && lastError.message ? lastError.message : 'fetch failed';
  throw new Error(`即梦上游网络请求失败：${message}；url=${maskUrl(url)}；attempts=${MAX_ATTEMPTS}`);
}

async function fetchWithTimeout(url, options, timeoutMs) {
  if (typeof AbortController === 'undefined') {
    return fetch(url, options);
  }
  const controller = new AbortController();
  const timer = setTimeout(() => controller.abort(), timeoutMs);
  try {
    return await fetch(url, { ...options, signal: controller.signal });
  } finally {
    clearTimeout(timer);
  }
}

async function readResponse(r, url, attempt) {
  const text = await r.text();
  let data = null;
  try { data = text ? JSON.parse(text) : null; } catch {}
  if (!r.ok) {
    return {
      code: r.status,
      success: false,
      error: readError(data, text) || `HTTP ${r.status}`,
      upstream: {
        status: r.status,
        url: maskUrl(url),
        attempt,
        maxAttempts: MAX_ATTEMPTS,
      },
    };
  }
  return data || { code: 500, success: false, error: '服务返回异常' };
}

function isRetryableStatus(status) {
  const code = Number(status || 0);
  return code === 408 || code === 429 || code >= 500;
}

function isRetryableNetworkError(error) {
  const message = error && error.message ? error.message : String(error || '');
  return /fetch failed|ECONNRESET|ETIMEDOUT|ENOTFOUND|EAI_AGAIN|network|abort|timeout/i.test(message);
}

function backoffMs(attempt) {
  return Math.min(12000, 1200 * attempt * attempt);
}

function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

function maskUrl(url) {
  try {
    const u = new URL(url);
    return `${u.origin}${u.pathname}`;
  } catch {
    return String(url || '').split('?')[0];
  }
}

function readError(data, fallback) {
  return data?.error?.message || data?.error || data?.message || data?.msg || fallback || '';
}

function readEnv(name) {
  if (typeof process !== 'undefined' && process.env && process.env[name]) {
    return process.env[name];
  }
  return '';
}