'use strict';

// MKH 成品补货预警推送 —— 配置 + 推送状态（本地库 system_config）
//
// ── 配置键 mkh_replenish_alert_config ─────────────────────────────
//   { enabled, recipientAlias, scope }
//   · recipientAlias 为空时回退顺序：环境变量 → 统一通知中心默认收件人
//   · scope: 'warning'（缺货 + 3 天内预警，默认）| 'outOfStock'（仅缺货）
//
// ── 状态键 mkh_replenish_alert_state ──────────────────────────────
//   { version, notified: { [skuId]: { level, firstNotifiedAt, lastNotifiedAt, ... } }, lastRunAt }
//   · 用于实现「只提醒新出现的预警」：已在 notified 里的商品不再重复推送；
//     商品恢复到正常范围后从 notified 移除，下次再预警会重新提醒。

const database = require('../config/database');
const {
  getYydNotificationCenterRuntimeConfig,
  toAdminConfig: toNotificationCenterAdminConfig,
} = require('./yydNotificationCenterSettings');

const CONFIG_KEY = 'mkh_replenish_alert_config';
const STATE_KEY = 'mkh_replenish_alert_state';
const CONFIG_CACHE_TTL_MS = 30 * 1000;

const SCOPES = Object.freeze({ WARNING: 'warning', OUT_OF_STOCK: 'outOfStock' });

const SCOPE_OPTIONS = Object.freeze([
  { value: SCOPES.WARNING, label: '缺货 + 3天内预警' },
  { value: SCOPES.OUT_OF_STOCK, label: '仅缺货' },
]);

let cachedConfig = null;
let cachedAt = 0;

function normalizeText(value, maxLength = 200) {
  return String(value ?? '').trim().slice(0, maxLength);
}

function safeJsonParse(value, fallback = {}) {
  if (value && typeof value === 'object') return value;
  try {
    const parsed = JSON.parse(String(value || ''));
    return parsed && typeof parsed === 'object' ? parsed : fallback;
  } catch (_error) {
    return fallback;
  }
}

function normalizeScope(value) {
  const text = normalizeText(value, 40).toLowerCase();
  if (!text) return SCOPES.WARNING;
  if (text === 'outofstock' || text === 'out_of_stock' || text === '缺货') return SCOPES.OUT_OF_STOCK;
  if (text === 'warning' || text === 'warn' || text === '预警' || text === 'all') return SCOPES.WARNING;
  return SCOPES.WARNING;
}

function normalizeFlag(value, fallback = true) {
  if (value === undefined || value === null || value === '') return fallback;
  if (typeof value === 'boolean') return value;
  const text = String(value).trim().toLowerCase();
  if (['1', 'true', 'yes', 'on'].includes(text)) return true;
  if (['0', 'false', 'no', 'off'].includes(text)) return false;
  return fallback;
}

async function readSystemConfigValue(key) {
  const rows = await database.local.query(
    'SELECT config_value AS configValue FROM system_config WHERE config_key = ? LIMIT 1',
    [key]
  );
  return rows?.[0]?.configValue;
}

async function upsertSystemConfigValue(key, value, configType = 'json') {
  const payload = typeof value === 'string' ? value : JSON.stringify(value);
  const rows = await database.local.query(
    'SELECT id FROM system_config WHERE config_key = ? LIMIT 1',
    [key]
  );
  if (rows?.[0]) {
    await database.local.query(
      'UPDATE system_config SET config_value = ?, config_type = ? WHERE config_key = ?',
      [payload, configType, key]
    );
  } else {
    await database.local.insert('system_config', {
      config_key: key,
      config_value: payload,
      config_type: configType,
    });
  }
  return payload;
}

// ── 配置 ────────────────────────────────────────────────────────
async function getMkhReplenishAlertRuntimeConfig({ forceRefresh = false } = {}) {
  if (!forceRefresh && cachedConfig && Date.now() - cachedAt < CONFIG_CACHE_TTL_MS) {
    return { ...cachedConfig };
  }
  let stored = {};
  try {
    stored = safeJsonParse(await readSystemConfigValue(CONFIG_KEY), {});
  } catch (error) {
    console.warn('读取补货预警推送配置失败，使用默认值:', error.message);
  }
  cachedConfig = {
    enabled: normalizeFlag(stored.enabled, true),
    recipientAlias: normalizeText(stored.recipientAlias || stored.recipient_alias, 50),
    scope: normalizeScope(stored.scope),
    recipientAliasFallback: normalizeText(process.env.MKH_REPLENISH_ALERT_RECIPIENT_ALIAS, 50),
  };
  cachedAt = Date.now();
  return { ...cachedConfig };
}

/**
 * 解析实际收件人 alias：配置填写值 → 环境变量 → 统一通知中心默认收件人。
 */
async function resolveMkhReplenishAlertRecipient(options = {}) {
  const config = options.config || await getMkhReplenishAlertRuntimeConfig();
  if (config.recipientAlias) return { alias: config.recipientAlias, source: 'config' };
  if (config.recipientAliasFallback) return { alias: config.recipientAliasFallback, source: 'environment' };
  let center = {};
  try {
    center = await getYydNotificationCenterRuntimeConfig({ forceRefresh: options.forceRefresh === true });
  } catch (_error) {
    center = {};
  }
  const alias = normalizeText(center?.recipientAlias, 50);
  return { alias, source: alias ? 'notification_center' : 'none' };
}

async function getMkhReplenishAlertAdminConfig() {
  const config = await getMkhReplenishAlertRuntimeConfig({ forceRefresh: true });
  const recipient = await resolveMkhReplenishAlertRecipient({ config });
  let center = {};
  try {
    center = await getYydNotificationCenterRuntimeConfig();
  } catch (_error) {
    center = {};
  }
  const centerAdmin = toNotificationCenterAdminConfig(center);
  const state = await loadMkhReplenishAlertState();
  return {
    enabled: config.enabled,
    scope: config.scope,
    recipientAlias: config.recipientAlias,
    effectiveRecipientAlias: recipient.alias || '',
    recipientSource: recipient.source,
    notificationCenterConfigured: centerAdmin.configured,
    notificationCenterBaseUrl: centerAdmin.baseUrl,
    notificationCenter: {
      configured: centerAdmin.configured,
      baseUrl: centerAdmin.baseUrl,
      projectCode: centerAdmin.projectCode,
      projectSecretConfigured: centerAdmin.projectSecretConfigured,
      projectSecretPreview: centerAdmin.projectSecretPreview,
      recipientAlias: centerAdmin.recipientAlias,
    },
    notifiedCount: Object.keys(state.notified || {}).length,
    lastRunAt: state.lastRunAt || null,
    scopeOptions: SCOPE_OPTIONS.map((item) => ({ ...item })),
  };
}

async function saveMkhReplenishAlertConfig(input = {}) {
  const current = await getMkhReplenishAlertRuntimeConfig({ forceRefresh: true });
  const rawAlias = input.recipientAlias ?? input.recipient_alias;
  const next = {
    enabled: normalizeFlag(input.enabled, current.enabled),
    recipientAlias: normalizeText(rawAlias === undefined ? current.recipientAlias : rawAlias, 50),
    scope: normalizeScope(input.scope || current.scope),
  };
  await upsertSystemConfigValue(CONFIG_KEY, next);
  cachedConfig = { ...next, recipientAliasFallback: current.recipientAliasFallback };
  cachedAt = Date.now();
  return getMkhReplenishAlertAdminConfig();
}

// ── 推送状态 ────────────────────────────────────────────────────
async function loadMkhReplenishAlertState() {
  let parsed = {};
  try {
    parsed = safeJsonParse(await readSystemConfigValue(STATE_KEY), {});
  } catch (error) {
    console.warn('读取补货预警推送状态失败，按空状态处理:', error.message);
  }
  const notified = parsed.notified && typeof parsed.notified === 'object' && !Array.isArray(parsed.notified)
    ? parsed.notified
    : {};
  return {
    version: 1,
    notified,
    lastRunAt: normalizeText(parsed.lastRunAt, 40) || null,
  };
}

async function saveMkhReplenishAlertState(state = {}) {
  const value = {
    version: 1,
    notified: state.notified && typeof state.notified === 'object' ? state.notified : {},
    lastRunAt: normalizeText(state.lastRunAt, 40) || null,
  };
  await upsertSystemConfigValue(STATE_KEY, value);
  return value;
}

/** 清空「已推送」记录，让下一次检查重新按新增口径判断（便于测试）。 */
async function resetMkhReplenishAlertState() {
  return saveMkhReplenishAlertState({ notified: {}, lastRunAt: null });
}

module.exports = {
  CONFIG_KEY,
  STATE_KEY,
  SCOPES,
  SCOPE_OPTIONS,
  getMkhReplenishAlertAdminConfig,
  getMkhReplenishAlertRuntimeConfig,
  loadMkhReplenishAlertState,
  normalizeFlag,
  normalizeScope,
  resetMkhReplenishAlertState,
  resolveMkhReplenishAlertRecipient,
  saveMkhReplenishAlertConfig,
  saveMkhReplenishAlertState,
};