/**
 * 连锁 / 门店两级选择的公用逻辑。
 *
 * 抽出来的原因：驻店填报（packageUser/self-report/create.vue）与跑店填报
 * （packageUser/self-report/visit.vue）都要「先选连锁、再选门店」，
 * 且门店全量可达 8000+ 条 —— 明细必须挂在实例上而不是页面 data，
 * 否则页面 data 树膨胀到 1MB+，每次 setData 的 diff/序列化都会从 ~490ms 涨到 ~1000ms。
 *
 * 用法：在页面 methods 里混入本文件的 methods（页面 data 仍需自己声明
 * merchantChainList / merchantLoading / merchantStoreSearchKeyword / 各 picker 的开关与 value）。
 */

export function pickFirstText(source, keys = []) {
  if (!source || typeof source !== 'object') return ''
  for (let i = 0; i < keys.length; i += 1) {
    const value = source[keys[i]]
    if (value !== undefined && value !== null && String(value).trim()) {
      return String(value).trim()
    }
  }
  return ''
}

export function unwrapList(data) {
  if (Array.isArray(data)) return data
  if (!data || typeof data !== 'object') return []
  const keys = ['list', 'records', 'rows', 'items', 'data', 'result', 'chainList']
  for (let i = 0; i < keys.length; i += 1) {
    const value = data[keys[i]]
    if (Array.isArray(value)) return value
    if (value && typeof value === 'object') {
      const nested = unwrapList(value)
      if (nested.length) return nested
    }
  }
  return [data]
}

export function normalizeMerchant(item) {
  const id = item.id ?? item.merchantId ?? item.merchant_id
  const text = item.name || item.merchantName || item.merchant_name || item.title || '未命名门店'
  const lat = Number(item.lat ?? item.latitude ?? item.merchantLat ?? item.merchant_lat)
  const lng = Number(item.lng ?? item.longitude ?? item.merchantLng ?? item.merchant_lng)
  const address = [item.province, item.city, item.region, item.area, item.address].filter(Boolean).join('')
  return {
    id,
    text,
    chainId: item.chainId ?? item.chain_id ?? '',
    chainName: item.chainName || item.chain || item.chainAbb || '',
    lat: Number.isFinite(lat) ? lat : null,
    lng: Number.isFinite(lng) ? lng : null,
    province: item.province || item.province_str || '',
    city: item.city || item.city_str || '',
    address
  }
}

export function normalizeMerchantChain(item, index) {
  const chainName = pickFirstText(item, ['chainName', 'chain', 'chainAbb', 'name', 'title']) || `连锁${index + 1}`
  const rawChainId = item.chainId ?? item.chain_id ?? item.id ?? item.chainCode ?? item.chain_code ?? chainName
  const chainId = rawChainId === undefined || rawChainId === null || String(rawChainId).trim() === ''
    ? `chain_${index}`
    : rawChainId
  const childCandidates = ['children', 'merchantList', 'merchants', 'shopList', 'list', 'records']
  let rawChildren = []
  for (let i = 0; i < childCandidates.length; i += 1) {
    const list = item[childCandidates[i]]
    if (Array.isArray(list) && list.length) {
      rawChildren = list
      break
    }
  }
  let merchants = rawChildren
    .map(child => normalizeMerchant(child))
    .filter(merchant => merchant.id !== undefined && merchant.id !== null && String(merchant.id).trim() !== '')
    .map(merchant => Object.assign({}, merchant, {chainId, chainName}))
  if (!merchants.length) {
    const selfMerchant = normalizeMerchant(item)
    if (selfMerchant.id !== undefined && selfMerchant.id !== null && String(selfMerchant.id).trim() !== '') {
      merchants = [Object.assign({}, selfMerchant, {chainId, chainName})]
    }
  }
  return {
    id: chainId,
    text: chainName,
    merchants
  }
}

// 接口可能返回「扁平门店列表（带 chainName）」，也可能返回「连锁嵌套门店」，两种都兼容
export function groupMerchantListByChain(list) {
  const chainMap = {}
  ;(Array.isArray(list) ? list : []).forEach((item, index) => {
    const merchant = normalizeMerchant(item)
    if (merchant.id === undefined || merchant.id === null || String(merchant.id).trim() === '') return
    const chainName = pickFirstText(item, ['chainName', 'chain', 'chainAbb', 'chain_name'])
    if (!chainName) return
    const rawChainId = item.chainId ?? item.chain_id ?? item.chainCode ?? item.chain_code ?? chainName
    const chainId = rawChainId === undefined || rawChainId === null || String(rawChainId).trim() === ''
      ? `chain_${index}`
      : rawChainId
    const key = String(chainId)
    if (!chainMap[key]) {
      chainMap[key] = {id: chainId, text: chainName, merchants: []}
    }
    chainMap[key].merchants.push(Object.assign({}, merchant, {chainId, chainName}))
  })
  return Object.keys(chainMap).map(key => chainMap[key])
}

export function flattenMerchantsFromChains(chainList) {
  const list = []
  ;(Array.isArray(chainList) ? chainList : []).forEach(chain => {
    const merchants = Array.isArray(chain.merchants) ? chain.merchants : []
    merchants.forEach(merchant => {
      if (!merchant || merchant.id === '' || merchant.id === null || merchant.id === undefined) return
      list.push(Object.assign({}, merchant, {
        chainId: merchant.chainId || chain.id || '',
        chainName: merchant.chainName || chain.text || ''
      }))
    })
  })
  return list
}

// 门店关键词过滤：连锁名命中由调用方另判，这里只按门店名匹配
export function filterMerchantStores(merchants, keyword) {
  const list = Array.isArray(merchants) ? merchants : []
  const text = String(keyword || '').trim()
  if (!text) return list
  return list.filter(merchant => (merchant.text || '').includes(text))
}

export default {
  pickFirstText,
  unwrapList,
  normalizeMerchant,
  normalizeMerchantChain,
  groupMerchantListByChain,
  flattenMerchantsFromChains,
  filterMerchantStores
}