/**
 * Cloud function: authCreditManager
 *
 * This file is the account and credit gateway for the current video-workflow
 * project. It intentionally uses the existing Parse user session and APIGAuth
 * balance instead of creating a second AppUser/UserCreditAccount system.
 *
 * Data source of truth:
 * - Login/session: Parse _User + X-Parse-Session-Token
 * - Balance: APIGAuth.count for VIDEO_WORKFLOW_APIG_ID
 * - Consumption marker: APIGAuth.used + APIGAuth.lastBilling
 * - Recharge: existing APIGOrder/saveRecharge platform endpoints
 */

const PARSE_API_HOST = env('PARSE_API_HOST', 'https://server.fmode.cn');
const PARSE_APP_ID = env('PARSE_APP_ID', 'ncloudmaster');
const VIDEO_WORKFLOW_APIG_ID = env('VIDEO_WORKFLOW_APIG_ID', '6pFf6EAdKT');
const DEFAULT_APIG_TITLE = env('VIDEO_WORKFLOW_APIG_TITLE', '短视频AI工作流');
const DEFAULT_UNIT_PRICE_CNY = Number(env('VIDEO_WORKFLOW_APIG_UNIT_PRICE_CNY', '0.1')) || 0.1;

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

    if (action === 'me') return me(request, response);
    if (action === 'balance') return balance(request, response);
    if (action === 'ledger') return ledger(request, response);
    if (action === 'rechargeContext') return rechargeContext(request, response);
    if (action === 'reserve') return reserve(request, response);
    if (action === 'commitReservation') return commitReservation(request, response);
    if (action === 'refundReservation') return refundReservation(request, response);
    if (action === 'createRechargeOrder') return createRechargeOrder(request, response);
    if (action === 'saveRecharge') return saveRecharge(request, response);
    if (action === 'adminListUsers') return unsupported(response, '账号列表请继续使用 Parse 用户体系或后续单独建设管理后台。');
    if (action === 'adminCreateUser') return unsupported(response, '账号创建请继续使用 Parse 用户体系，不再由 authCreditManager 自建账号。');
    if (action === 'adminAdjustCredit') return unsupported(response, '调额请直接调整 APIGAuth 或后续建设受控管理员云函数。');
    if (action === 'register' || action === 'login' || action === 'changePassword') {
      return unsupported(response, '当前项目使用 Parse 手机验证码登录，不再使用 authCreditManager 自建密码账号。');
    }

    return response.json({ code: 400, success: false, error: `未知 action: ${action || '(empty)'}` });
  } catch (error) {
    const status = Number(error && (error.status || error.statusCode)) || 500;
    console.error('authCreditManager failed:', error && error.message, error && error.stack);
    return response.json({
      code: status,
      success: false,
      error: error && error.message ? error.message : '账号积分服务调用失败',
      detail: error && error.detail ? error.detail : undefined,
    });
  }
}

async function me(request, response) {
  const { user } = await requireParseUser(request);
  return response.json({ code: 200, success: true, data: parseUserToAppUser(user) });
}

async function balance(request, response) {
  const context = await loadCreditContext(request);
  return response.json({ code: 200, success: true, data: toCreditBalance(context) });
}

async function ledger(request, response) {
  const context = await loadCreditContext(request);
  const limit = clampNumber(pickParam(request, 'limit'), 1, 200, 50);
  const items = [];
  const lastBilling = context.auth && context.auth.lastBilling && typeof context.auth.lastBilling === 'object'
    ? context.auth.lastBilling
    : null;

  if (lastBilling) {
    items.push({
      objectId: lastBilling.reservationId || lastBilling.idempotencyKey || `lastBilling-${context.auth.objectId}`,
      userId: context.user.objectId,
      type: lastBilling.status === 'refunded' ? 'refund' : 'consume',
      amount: -Math.abs(Number(lastBilling.costCredits || 0)),
      balanceAfter: Number(lastBilling.balanceAfter || context.balance),
      title: lastBilling.title || lastBilling.operation || '生成扣费记录',
      detail: lastBilling,
      createdAt: lastBilling.updatedAt || context.auth.updatedAt || context.auth.createdAt || new Date().toISOString(),
    });
  }

  return response.json({ code: 200, success: true, data: items.slice(0, limit) });
}

async function rechargeContext(request, response) {
  const context = await loadCreditContext(request);
  return response.json({
    code: 200,
    success: true,
    data: {
      authId: context.auth.objectId,
      userId: context.user.objectId,
      payUserId: readCompanyId(context.user) || context.auth.objectId,
      apig: {
        objectId: context.apig.objectId,
        title: context.apig.title,
        count: context.balance,
        priceStep: normalizePriceSteps(context.apig.priceStep),
      },
    },
  });
}

async function reserve(request, response) {
  const context = await loadCreditContext(request);
  const operation = clean(pickParam(request, 'operation')) || 'unknown';
  const title = clean(pickParam(request, 'title')) || operation;
  const detail = normalizeObject(pickParam(request, 'detail'));
  const cost = Math.max(0, Number(pickParam(request, 'cost') || 0));
  const idempotencyKey = clean(pickParam(request, 'idempotencyKey'))
    || `${operation}:${context.user.objectId}:${stableJson({ cost, title, detail })}`;

  if (cost <= 0) {
    return response.json({
      code: 200,
      success: true,
      data: { reservationId: `free-${Date.now()}`, balance: context.balance, cost: 0 },
    });
  }

  const lastBilling = context.auth.lastBilling && typeof context.auth.lastBilling === 'object'
    ? context.auth.lastBilling
    : null;
  if (lastBilling && lastBilling.idempotencyKey === idempotencyKey) {
    if (lastBilling.status === 'reserved' || lastBilling.status === 'submitted' || lastBilling.status === 'committed') {
      return response.json({
        code: 200,
        success: true,
        data: {
          reservationId: lastBilling.reservationId,
          balance: Number(lastBilling.balanceAfter || context.balance),
          cost: Number(lastBilling.costCredits || cost),
          reused: true,
        },
      });
    }
  }

  if (context.balance < cost) {
    return response.json({
      code: 402,
      success: false,
      error: `余额不足：当前 ${context.balance}，本次需要 ${cost}`,
    });
  }

  const reservationId = generateId(16);
  const oldUsed = Number(context.auth.used || 0);
  const nextBalance = context.balance - cost;
  const nextUsed = oldUsed + cost;
  const now = new Date().toISOString();
  const lastBillingPatch = {
    kind: 'video_workflow_consume',
    status: 'reserved',
    reservationId,
    idempotencyKey,
    operation,
    title,
    costCredits: cost,
    unitPriceCny: DEFAULT_UNIT_PRICE_CNY,
    balanceBefore: context.balance,
    balanceAfter: nextBalance,
    usedBefore: oldUsed,
    usedAfter: nextUsed,
    detail,
    updatedAt: now,
  };

  await updateApigAuth(context.auth.objectId, {
    count: nextBalance,
    used: nextUsed,
    lastBilling: lastBillingPatch,
  }, context.sessionToken);

  return response.json({
    code: 200,
    success: true,
    data: { reservationId, balance: nextBalance, cost },
  });
}

async function commitReservation(request, response) {
  const context = await loadCreditContext(request);
  const reservationId = clean(pickParam(request, 'reservationId'));
  const detail = normalizeObject(pickParam(request, 'detail'));
  const lastBilling = context.auth.lastBilling && typeof context.auth.lastBilling === 'object'
    ? context.auth.lastBilling
    : null;

  if (!lastBilling || lastBilling.reservationId !== reservationId) {
    return response.json({ code: 200, success: true, data: true, ignored: true });
  }

  await updateApigAuth(context.auth.objectId, {
    lastBilling: {
      ...lastBilling,
      status: 'committed',
      commitDetail: detail,
      updatedAt: new Date().toISOString(),
    },
  }, context.sessionToken);

  return response.json({ code: 200, success: true, data: true });
}

async function refundReservation(request, response) {
  const context = await loadCreditContext(request);
  const reservationId = clean(pickParam(request, 'reservationId'));
  const reason = clean(pickParam(request, 'reason')) || '任务失败退回积分';
  const lastBilling = context.auth.lastBilling && typeof context.auth.lastBilling === 'object'
    ? context.auth.lastBilling
    : null;

  if (!lastBilling || lastBilling.reservationId !== reservationId || lastBilling.status === 'refunded') {
    return response.json({ code: 200, success: true, data: true, ignored: true });
  }

  const refundCredits = Math.abs(Number(lastBilling.costCredits || 0));
  const currentUsed = Number(context.auth.used || 0);
  const nextBalance = context.balance + refundCredits;
  const nextUsed = Math.max(0, currentUsed - refundCredits);

  await updateApigAuth(context.auth.objectId, {
    count: nextBalance,
    used: nextUsed,
    lastBilling: {
      ...lastBilling,
      status: 'refunded',
      refundReason: reason,
      balanceAfter: nextBalance,
      usedAfter: nextUsed,
      updatedAt: new Date().toISOString(),
    },
  }, context.sessionToken);

  return response.json({ code: 200, success: true, data: true });
}

async function createRechargeOrder(request, response) {
  const context = await loadCreditContext(request);
  const count = Math.max(0, Number(pickParam(request, 'count') || 0));
  const amountCny = Math.max(0, Number(pickParam(request, 'amountCny') || pickParam(request, 'price') || 0));
  const params = normalizeObject(pickParam(request, 'params'));

  if (count <= 0 || amountCny <= 0) {
    return response.json({ code: 400, success: false, error: '缺少有效的充值积分或充值金额' });
  }

  const payUserId = readCompanyId(context.user) || context.auth.objectId;
  const order = await requestJson(`${apiBase()}/api/apig/created-apigorder`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      user: payUserId,
      fcompany: payUserId,
      type: clean(pickParam(request, 'type')) || 'wxpay',
      authid: context.auth.objectId,
      params,
      apigid: context.apig.objectId,
      oldCount: context.balance,
      count,
      amountCny,
    }),
  }, 20000);

  if (order && Number(order.code) === 200 && order.data) {
    return response.json({ code: 200, success: true, data: order.data });
  }

  return response.json({
    code: 500,
    success: false,
    error: order && (order.message || order.error) || '创建 APIGOrder 失败',
    raw: order,
  });
}

async function saveRecharge(request, response) {
  const context = await loadCreditContext(request);
  const payUserId = clean(pickParam(request, 'payUserId')) || readCompanyId(context.user) || context.auth.objectId;
  const authId = clean(pickParam(request, 'authId')) || context.auth.objectId;
  const apigId = clean(pickParam(request, 'apigId')) || context.apig.objectId;
  const oldCount = Math.max(0, Number(pickParam(request, 'oldCount') || context.balance || 0));
  const count = Math.max(0, Number(pickParam(request, 'count') || 0));
  const orderId = clean(pickParam(request, 'orderId'));

  if (!authId || !apigId || count <= 0) {
    return response.json({ code: 400, success: false, error: '缺少有效的充值到账参数' });
  }

  const saved = await requestJson(`${apiBase()}/api/apig/saveRecharge`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      user: payUserId,
      authComp: payUserId,
      authid: authId,
      apigid: apigId,
      oldCount,
      count,
      orderid: orderId,
    }),
  }, 20000);

  if (saved && saved.code && Number(saved.code) >= 400) {
    return response.json({
      code: Number(saved.code),
      success: false,
      error: saved.message || saved.error || '充值到账失败',
      raw: saved,
    });
  }

  return response.json({ code: 200, success: true, data: true, raw: saved });
}

async function loadCreditContext(request) {
  const { sessionToken, user } = await requireParseUser(request);
  const auth = await ensureVideoWorkflowAuth(user.objectId, sessionToken);
  const apigInfo = auth && auth.objectId ? await fetchApigPayInfo(auth.objectId).catch(() => null) : null;
  const apig = normalizeApig(auth, apigInfo);
  const balance = Number(apigInfo && apigInfo.count !== undefined ? apigInfo.count : auth.count || 0);
  const used = Number(apigInfo && apigInfo.used !== undefined ? apigInfo.used : auth.used || 0);
  return { sessionToken, user, auth: { ...auth, count: balance, used }, apig, balance, used };
}

async function requireParseUser(request) {
  const sessionToken = clean(pickParam(request, 'sessionToken') || headerValue(request, 'x-parse-session-token'));
  if (!sessionToken) {
    const error = new Error('请先登录');
    error.status = 401;
    throw error;
  }

  const user = await parseRequest('GET', '/users/me?include=company', undefined, sessionToken);
  if (!user || !user.objectId) {
    const error = new Error('登录已失效，请重新登录');
    error.status = 401;
    throw error;
  }

  return { sessionToken, user };
}

async function findVideoWorkflowAuth(userId, sessionToken) {
  const where = encodeURIComponent(JSON.stringify({
    api: { __type: 'Pointer', className: 'APIG', objectId: VIDEO_WORKFLOW_APIG_ID },
    user: { __type: 'Pointer', className: '_User', objectId: userId },
  }));
  const data = await parseRequest('GET', `/classes/APIGAuth?where=${where}&include=api&limit=1`, undefined, sessionToken);
  return Array.isArray(data.results) ? data.results[0] || null : null;
}

async function ensureVideoWorkflowAuth(userId, sessionToken) {
  const existing = await findVideoWorkflowAuth(userId, sessionToken);
  if (existing) return existing;

  const body = {
    api: { __type: 'Pointer', className: 'APIG', objectId: VIDEO_WORKFLOW_APIG_ID },
    user: { __type: 'Pointer', className: '_User', objectId: userId },
    count: 0,
    used: 0,
  };
  const created = await parseRequest('POST', '/classes/APIGAuth', body, sessionToken);
  return { ...body, ...created };
}

async function updateApigAuth(authId, patch, sessionToken) {
  return parseRequest('PUT', `/classes/APIGAuth/${encodeURIComponent(authId)}`, patch, sessionToken);
}

async function fetchApigPayInfo(authId) {
  const resp = await requestJson(`${apiBase()}/api/apig/getApig`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ authid: authId }),
  }, 15000);
  if (resp && Number(resp.code) === 200 && resp.data) return resp.data;
  return null;
}

async function parseRequest(method, path, body, sessionToken) {
  const url = `${apiBase()}/parse${path}`;
  const headers = {
    'Content-Type': 'application/json',
    'Accept': 'application/json',
    'X-Parse-Application-Id': PARSE_APP_ID,
  };
  if (sessionToken) headers['X-Parse-Session-Token'] = sessionToken;
  const init = { method, headers };
  if (body !== undefined) init.body = JSON.stringify(body);
  const { status, ok, rawText, data } = await requestJsonWithMeta(url, init, 15000);
  if (!ok) {
    const error = new Error(readErrorMessage(data, rawText) || `Parse ${method} ${path} failed`);
    error.status = status || 500;
    error.detail = data || rawText || '';
    throw error;
  }
  return data;
}

async function requestJson(url, init, timeoutMs) {
  const result = await requestJsonWithMeta(url, init, timeoutMs);
  if (!result.ok) {
    const error = new Error(readErrorMessage(result.data, result.rawText) || `HTTP ${result.status}`);
    error.status = result.status || 500;
    error.detail = result.data || result.rawText || '';
    throw error;
  }
  return result.data;
}

async function requestJsonWithMeta(url, init, timeoutMs) {
  const controller = typeof AbortController !== 'undefined' ? new AbortController() : null;
  const timer = controller ? setTimeout(() => controller.abort(), timeoutMs || 15000) : null;
  try {
    const resp = await fetch(url, { ...init, signal: controller ? controller.signal : undefined });
    const rawText = await resp.text();
    const data = safeJson(rawText);
    return { status: resp.status, ok: resp.ok, rawText, data };
  } catch (error) {
    if (error && error.name === 'AbortError') {
      const timeoutError = new Error('请求超时，请稍后重试');
      timeoutError.status = 504;
      throw timeoutError;
    }
    throw error;
  } finally {
    if (timer) clearTimeout(timer);
  }
}

function parseUserToAppUser(user) {
  const mobile = user.mobilePhoneNumber || user.mobile || '';
  return {
    objectId: user.objectId,
    username: user.username || mobile || user.objectId,
    email: user.email || '',
    phone: mobile,
    displayName: user.nickname || user.name || user.displayName || maskMobile(mobile) || user.username || user.objectId,
    companyId: readCompanyId(user),
    role: user.role === 'admin' || user.isAdmin === true ? 'admin' : 'user',
    createdAt: user.createdAt,
  };
}

function toCreditBalance(context) {
  return {
    balance: Number(context.balance || 0),
    gifted: 0,
    totalRecharged: Number(context.balance || 0) + Number(context.used || 0),
    totalConsumed: Number(context.used || 0),
    authId: context.auth.objectId,
    apigId: context.apig.objectId,
  };
}

function normalizeApig(auth, apigInfo) {
  const source = apigInfo || auth.api || {};
  const objectId = source.objectId || source.api && source.api.objectId || auth.api && auth.api.objectId || VIDEO_WORKFLOW_APIG_ID;
  return {
    objectId,
    title: source.title || source.api && source.api.title || auth.api && auth.api.title || DEFAULT_APIG_TITLE,
    count: Number(source.count !== undefined ? source.count : auth.count || 0),
    used: Number(source.used !== undefined ? source.used : auth.used || 0),
    price: Number(source.price || auth.api && auth.api.price || DEFAULT_UNIT_PRICE_CNY),
    priceStep: source.priceStep || source.api && source.api.priceStep || [],
  };
}

function normalizePriceSteps(raw) {
  const rows = Array.isArray(raw) ? raw : [];
  return rows
    .map((item) => {
      const row = item && typeof item === 'object' ? item : {};
      return { count: Number(row.count || 0), price: Number(row.price || 0) };
    })
    .filter((item) => item.count > 0 && item.price > 0);
}

function readCompanyId(user) {
  const company = user && user.company;
  return company && typeof company === 'object' ? clean(company.objectId) : '';
}

function unsupported(response, message) {
  return response.json({ code: 501, success: false, error: message });
}

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

function headerValue(request, name) {
  const headers = request && request.headers || {};
  const target = String(name || '').toLowerCase();
  for (const key of Object.keys(headers)) {
    if (key.toLowerCase() === target) return headers[key];
  }
  return '';
}

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

function apiBase() {
  return String(PARSE_API_HOST || '').replace(/\/+$/, '').replace(/\/parse$/i, '');
}

function clean(value) {
  return String(value || '').trim();
}

function clampNumber(value, min, max, fallback) {
  const n = Number(value);
  if (!Number.isFinite(n)) return fallback;
  return Math.max(min, Math.min(max, Math.floor(n)));
}

function normalizeObject(value) {
  if (!value) return {};
  if (typeof value === 'object') return value;
  if (typeof value === 'string') {
    const parsed = safeJson(value);
    return parsed && typeof parsed === 'object' ? parsed : { value };
  }
  return { value };
}

function stableJson(value) {
  if (Array.isArray(value)) return `[${value.map(stableJson).join(',')}]`;
  if (value && typeof value === 'object') {
    return `{${Object.keys(value).sort().map((key) => `${JSON.stringify(key)}:${stableJson(value[key])}`).join(',')}}`;
  }
  return JSON.stringify(value);
}

function safeJson(text) {
  try {
    return text ? JSON.parse(text) : null;
  } catch {
    return null;
  }
}

function readErrorMessage(data, fallback) {
  if (typeof data === 'string') return data;
  if (!data || typeof data !== 'object') return fallback || '';
  return data.error || data.message || data.msg || data.data && (data.data.error || data.data.message) || fallback || '';
}

function maskMobile(mobile) {
  const value = String(mobile || '');
  return /^1[3-9]\d{9}$/.test(value) ? value.replace(/(\d{3})\d{4}(\d{4})/, '$1****$2') : value;
}

function generateId(length) {
  const chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
  let id = '';
  for (let i = 0; i < (length || 10); i += 1) {
    id += chars.charAt(Math.floor(Math.random() * chars.length));
  }
  return id;
}