import { memo, useCallback, useEffect, useRef, useState } from 'react'
import { Server, Plus } from 'lucide-react'
import { Button } from '@/components/ui/button'
import { clusterApi, deploymentApi, collectorApi } from '@/api'
import { PageContainer } from '@/components/PageContainer'
import { LoadingSpinner } from '@/components/LoadingSpinner'
import { EmptyState } from '@/components/EmptyState'
import { ErrorState } from '@/components/ErrorState'
import { PaginationBar } from '@/components/PaginationBar'
import { ConfirmDialog } from '@/components/ConfirmDialog'
import { toast } from 'sonner'
import { useListQuery } from '@/hooks/useListQuery'
import type { Cluster } from '@/types'
import { ClusterCard } from './components/ClusterCard'
import { ClusterFormDialog } from './components/ClusterFormDialog'
import { ClusterDetailDialog } from './components/ClusterDetailDialog'

/**
 * 集群管理页 — 只做编排：数据走 useListQuery（取消+版本号），
 * 卡片/表单/详情/删除确认均为域内子组件。成功操作静默（列表刷新即反馈）。
 */
const ClustersPage = memo(function ClustersPage() {
  const query = useListQuery<Cluster>((params, signal) =>
    clusterApi.list(params, { signal })
  )

  const [formOpen, setFormOpen] = useState(false)
  const [detailCluster, setDetailCluster] = useState<Cluster | null>(null)
  const [deleteTarget, setDeleteTarget] = useState<Cluster | null>(null)
  const [deleting, setDeleting] = useState(false)
  const [validating, setValidating] = useState<number | null>(null)

  // 验证后延时刷新列表的定时器（卸载清理）
  const timeoutsRef = useRef<ReturnType<typeof setTimeout>[]>([])
  useEffect(() => {
    const timers = timeoutsRef.current
    return () => {
      timers.forEach((id) => clearTimeout(id))
    }
  }, [])

  // 删除保护:引用检查(部署/采集器仍指向该集群时警告)
  const [refCount, setRefCount] = useState<{ dep: number; col: number }>({ dep: 0, col: 0 })
  useEffect(() => {
    if (!deleteTarget) return
    Promise.all([
      deploymentApi.list({ page: 1, pageSize: 100 }),
      collectorApi.list({ page: 1, pageSize: 100 }),
    ]).then(([d, c]) => {
      setRefCount({
        dep: d.list.filter((x) => x.clusterID === deleteTarget.id).length,
        col: c.list.filter((x) => x.clusterID === deleteTarget.id).length,
      })
    }).catch(() => setRefCount({ dep: 0, col: 0 }))
  }, [deleteTarget])

  const handleDelete = useCallback(async () => {
    const id = deleteTarget?.id
    if (!id) return
    setDeleting(true)
    try {
      await clusterApi.remove(id)
      setDeleteTarget(null)
      query.refresh()
    } catch (err) {
      toast.error(err instanceof Error ? err.message : '删除集群失败')
    } finally {
      setDeleting(false)
    }
  }, [deleteTarget, query])

  const handleValidate = useCallback(
    async (id: number) => {
      setValidating(id)
      try {
        await clusterApi.validate(id)
        timeoutsRef.current.push(setTimeout(() => query.refresh(), 3000))
      } catch (err) {
        toast.error(err instanceof Error ? err.message : '验证失败')
      } finally {
        timeoutsRef.current.push(setTimeout(() => setValidating(null), 3000))
      }
    },
    [query]
  )

  return (
    <PageContainer
      title="集群管理"
      description="管理用于 Loki 部署的 Kubernetes 集群"
      action={
        <Button
          className="bg-primary hover:bg-primary/90"
          onClick={() => setFormOpen(true)}
        >
          <Plus className="w-4 h-4 mr-1" />
          添加集群
        </Button>
      }
    >
      {query.loading ? (
        <LoadingSpinner className="h-64" />
      ) : query.error ? (
        <ErrorState message={query.error} onRetry={query.refresh} />
      ) : query.list.length === 0 ? (
        <EmptyState
          icon={Server}
          title="暂无集群"
          description="添加第一个 Kubernetes 集群开始使用"
        />
      ) : (
        <>
          <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
            {query.list.map((cluster) => (
              <ClusterCard
                key={cluster.id}
                cluster={cluster}
                validating={validating}
                onViewInfo={setDetailCluster}
                onValidate={handleValidate}
                onDelete={setDeleteTarget}
              />
            ))}
          </div>
          <PaginationBar
            page={query.page}
            pageSize={query.pageSize}
            total={query.total}
            onPageChange={query.setPage}
          />
        </>
      )}

      <ClusterFormDialog
        open={formOpen}
        onOpenChange={setFormOpen}
        onCreated={query.reload}
      />

      <ClusterDetailDialog
        key={detailCluster?.id ?? 'none'}
        cluster={detailCluster}
        onClose={() => setDetailCluster(null)}
      />

      <ConfirmDialog
        open={deleteTarget !== null}
        onOpenChange={(open) => {
          if (!open) setDeleteTarget(null)
        }}
        name={deleteTarget?.name}
        loading={deleting}
        description={
          refCount.dep + refCount.col > 0
            ? `确定要删除「${deleteTarget?.name}」吗?警告:仍有 ${refCount.dep} 个部署、${refCount.col} 个采集策略引用该集群,删除后它们将无法工作。`
            : undefined
        }
        onConfirm={handleDelete}
      />
    </PageContainer>
  )
})

export default ClustersPage