/**
 * 通知渠道 Composable
 * 封装列表/统计/详情/CRUD/批量操作，遵循 VNC §5 标准结构。
 */
import { ref, computed } from 'vue'
import {
  getNotificationChannelListApi,
  getNotificationChannelStatsApi,
  getNotificationChannelDetailApi,
  createNotificationChannelApi,
  updateNotificationChannelApi,
  deleteNotificationChannelApi
} from '@/apis/external-systems/notification_channel_api'
import { unwrap } from './utils'

export function useNotificationChannel() {
  // ===== 响应式状态 =====
  const list = ref([])
  const stats = ref(null)
  const detail = ref(null)
  const total = ref(0)
  const loading = ref(false)
  const detailLoading = ref(false)
  const submitting = ref(false)
  const error = ref(null)

  // ===== 计算属性 =====
  const isEmpty = computed(() => !loading.value && list.value.length === 0)

  // ===== 列表与统计 =====
  async function fetchList(params) {
    loading.value = true
    error.value = null
    try {
      const data = unwrap(await getNotificationChannelListApi(params))
      list.value = data?.items ?? []
      total.value = data?.total ?? list.value.length
    } catch (e) {
      error.value = e
      list.value = []
      total.value = 0
    } finally {
      loading.value = false
    }
  }

  async function fetchStats() {
    error.value = null
    try {
      stats.value = unwrap(await getNotificationChannelStatsApi()) ?? null
    } catch (e) {
      error.value = e
    }
  }

  // ===== 详情 =====
  async function fetchDetail(id) {
    detailLoading.value = true
    error.value = null
    try {
      detail.value = unwrap(await getNotificationChannelDetailApi(id)) ?? null
      return detail.value
    } catch (e) {
      error.value = e
      throw e
    } finally {
      detailLoading.value = false
    }
  }

  // ===== CRUD =====
  async function create(data) {
    submitting.value = true
    error.value = null
    try {
      return unwrap(await createNotificationChannelApi(data))
    } catch (e) {
      error.value = e
      throw e
    } finally {
      submitting.value = false
    }
  }

  async function update(id, data) {
    submitting.value = true
    error.value = null
    try {
      return unwrap(await updateNotificationChannelApi(id, data))
    } catch (e) {
      error.value = e
      throw e
    } finally {
      submitting.value = false
    }
  }

  async function remove(id) {
    error.value = null
    try {
      await deleteNotificationChannelApi(id)
    } catch (e) {
      error.value = e
      throw e
    }
  }

  // ===== 批量操作（逐条调用，返回成功/失败明细） =====
  async function batchUpdateEnabled(items, enabled) {
    const results = { success: 0, failed: [] }
    for (const item of items) {
      try {
        await updateNotificationChannelApi(item.id, { enabled })
        results.success += 1
      } catch (e) {
        results.failed.push({ id: item.id, name: item.name, reason: e.message || '更新失败' })
      }
    }
    return results
  }

  async function batchDelete(items) {
    const results = { success: 0, failed: [] }
    for (const item of items) {
      try {
        await deleteNotificationChannelApi(item.id)
        results.success += 1
      } catch (e) {
        results.failed.push({ id: item.id, name: item.name, reason: e.message || '删除失败' })
      }
    }
    return results
  }

  function resetDetail() {
    detail.value = null
  }

  return {
    // 状态
    list,
    stats,
    detail,
    total,
    loading,
    detailLoading,
    submitting,
    error,
    isEmpty,
    // 列表与统计
    fetchList,
    fetchStats,
    // 详情
    fetchDetail,
    resetDetail,
    // CRUD
    create,
    update,
    remove,
    // 批量操作
    batchUpdateEnabled,
    batchDelete
  }
}