import { useEffect, useState } from 'react'
import { RefreshCw, Maximize2, Minimize2, Users, Signal, TriangleAlert, Cpu, MemoryStick, HardDrive, Download, Upload } from 'lucide-react'
import { toast } from 'sonner'
import { Button } from '@/components/ui/button'
import { Badge } from '@/components/ui/badge'
import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card'
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from '@/components/ui/select'
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from '@/components/ui/table'
import api from '@/api/client'
import { getSystemMetrics, type SystemMetrics } from '@/api/system'
import {
  createRemoteSession,
  fetchStreams,
  fetchViewerSessions,
  sendRemoteCommand,
  type StreamInfo,
  type ViewerSessionInfo,
} from '@/api/streams'
import { formatBytes } from '@/lib/status'
import { PageHeader } from '@/components/page-header'
import { StatCard } from '@/components/stat-card'

interface NodeMetric {
  id: string
  name: string
  online: boolean
  metrics?: {
    cpu_percent?: number | null
    memory_percent?: number | null
    network_in_mbps?: number | null
    network_out_mbps?: number | null
    viewer_count?: number | null
  } | null
}

const QUALITIES = ['1080p', '720p', '480p', '360p']

export default function LiveBoard() {
  const [streams, setStreams] = useState<StreamInfo[]>([])
  const [streamId, setStreamId] = useState<number>()
  const [sessions, setSessions] = useState<ViewerSessionInfo[]>([])
  const [selected, setSelected] = useState<Set<string>>(new Set())
  const [loading, setLoading] = useState(true)
  const [systemMetrics, setSystemMetrics] = useState<SystemMetrics | null>(null)
  const [nodes, setNodes] = useState<NodeMetric[]>([])
  const [quality, setQuality] = useState('auto')
  const [nodeId, setNodeId] = useState('auto')
  const [wallMode, setWallMode] = useState(false)

  async function load() {
    try {
      const programs = await fetchStreams(true)
      setStreams(programs)
      const nextId = streamId || programs.find((p) => p.status === 'live')?.id
      if (nextId) {
        setStreamId(nextId)
        setSessions(await fetchViewerSessions(nextId))
      } else {
        setSessions([])
      }
    } catch {
      toast.error('看板数据加载失败')
    } finally {
      try {
        setSystemMetrics(await getSystemMetrics())
      } catch {
        setSystemMetrics(null)
      }
      try {
        const nodeResponse = await api.get<NodeMetric[]>('/nodes')
        setNodes(nodeResponse.data)
      } catch {
        setNodes([])
      }
      setLoading(false)
    }
  }

  useEffect(() => {
    void load()
    const timer = window.setInterval(load, 5000)
    return () => window.clearInterval(timer)
  }, [streamId])

  async function controlViewers() {
    if (!streamId || selected.size === 0) return
    try {
      const session = await createRemoteSession(streamId)
      const targets = Array.from(selected)
      if (nodeId !== 'auto') await sendRemoteCommand(streamId, session.token, 'switch_node', targets, nodeId)
      if (quality !== 'auto') await sendRemoteCommand(streamId, session.token, 'switch_quality', targets, quality)
      if (nodeId === 'auto' && quality === 'auto') await sendRemoteCommand(streamId, session.token, 'restore_auto', targets)
      toast.success(`已向 ${selected.size} 个观众下发节点与清晰度策略`)
    } catch {
      toast.error('控制命令下发失败，请确认节目已启用审计式播放控制')
    }
  }

  const activeSessions = sessions.filter((s) => Date.now() - new Date(s.last_heartbeat).getTime() < 30000)
  const buffering = activeSessions.filter(
    (s) => s.playback_state === 'buffering' || Number(s.buffered_seconds || 0) < 1,
  )

  const toggleSelect = (id: string) => {
    setSelected((prev) => {
      const next = new Set(prev)
      if (next.has(id)) next.delete(id)
      else next.add(id)
      return next
    })
  }

  return (
    <div className={wallMode ? 'fixed inset-0 z-50 overflow-auto bg-background p-6' : 'space-y-6'}>
      <PageHeader title="直播看板" kicker="Live Board" description="实时检查节目、观众会话、线路与播放健康度">
        <Select value={streamId ? String(streamId) : undefined} onValueChange={(v) => { setStreamId(Number(v)); setSelected(new Set()) }}>
          <SelectTrigger className="w-56">
            <SelectValue placeholder="选择直播节目" />
          </SelectTrigger>
          <SelectContent>
            {streams.map((p) => (
              <SelectItem key={p.id} value={String(p.id)}>
                {p.title} · {p.status}
              </SelectItem>
            ))}
          </SelectContent>
        </Select>
        <Button variant="outline" onClick={() => setWallMode((v) => !v)}>
          {wallMode ? <Minimize2 className="h-4 w-4" /> : <Maximize2 className="h-4 w-4" />}
          {wallMode ? '退出大屏' : '大屏模式'}
        </Button>
        <Button variant="outline" onClick={load}>
          <RefreshCw className="h-4 w-4" />
          刷新
        </Button>
      </PageHeader>

      <div className="grid gap-4 sm:grid-cols-3">
        <StatCard label="活跃观众" value={activeSessions.length} icon={Users} />
        <StatCard label="播放正常" value={Math.max(0, activeSessions.length - buffering.length)} icon={Signal} tone="success" />
        <StatCard label="疑似卡顿" value={buffering.length} icon={TriangleAlert} tone={buffering.length ? 'warning' : 'default'} />
      </div>

      <div className="grid gap-4 sm:grid-cols-2 lg:grid-cols-5">
        <StatCard label="CPU 使用率" value={`${systemMetrics?.cpu_percent.toFixed(1) ?? '—'}%`} icon={Cpu} />
        <StatCard label="内存使用率" value={`${systemMetrics?.memory_percent.toFixed(1) ?? '—'}%`} icon={MemoryStick} />
        <StatCard label="存储使用率" value={`${systemMetrics?.disk_percent.toFixed(1) ?? '—'}%`} icon={HardDrive} />
        <StatCard label="下载总量" value={formatBytes(systemMetrics?.network_received_bytes)} icon={Download} />
        <StatCard label="上传总量" value={formatBytes(systemMetrics?.network_sent_bytes)} icon={Upload} />
      </div>

      <Card>
        <CardHeader>
          <CardTitle className="text-base">节点实时指标</CardTitle>
        </CardHeader>
        <CardContent>
          <div className="grid gap-3 sm:grid-cols-2 lg:grid-cols-3">
            {nodes.map((node) => (
              <div key={node.id} className="rounded-md border border-border p-3">
                <div className="mb-2 flex items-center gap-2">
                  <span className="font-medium">{node.name}</span>
                  <Badge variant={node.online ? 'default' : 'secondary'}>{node.online ? '在线' : '离线'}</Badge>
                </div>
                <div className="space-y-1 text-xs text-muted-foreground">
                  <div>CPU：{node.metrics?.cpu_percent?.toFixed(1) ?? '-'}%</div>
                  <div>内存：{node.metrics?.memory_percent?.toFixed(1) ?? '-'}%</div>
                  <div>NET IN：{node.metrics?.network_in_mbps?.toFixed(2) ?? '-'} Mbps</div>
                  <div>NET OUT：{node.metrics?.network_out_mbps?.toFixed(2) ?? '-'} Mbps</div>
                  <div>观众：{node.metrics?.viewer_count ?? 0}</div>
                </div>
              </div>
            ))}
          </div>
        </CardContent>
      </Card>

      {streamId && (
        <Card>
          <CardHeader className="flex-row items-center justify-between space-y-0">
            <CardTitle className="text-base">审计式观众会话</CardTitle>
            <div className="flex flex-wrap items-center gap-2">
              <Select value={nodeId} onValueChange={setNodeId}>
                <SelectTrigger className="w-44">
                  <SelectValue />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value="auto">节点：保持自动</SelectItem>
                  {nodes.filter((n) => n.online).map((n) => (
                    <SelectItem key={n.id} value={n.id}>
                      节点：{n.name}
                    </SelectItem>
                  ))}
                </SelectContent>
              </Select>
              <Select value={quality} onValueChange={setQuality}>
                <SelectTrigger className="w-32">
                  <SelectValue />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value="auto">恢复自动</SelectItem>
                  {QUALITIES.map((q) => (
                    <SelectItem key={q} value={q}>
                      {q}
                    </SelectItem>
                  ))}
                </SelectContent>
              </Select>
              <Button disabled={selected.size === 0} onClick={controlViewers}>
                批量切换
              </Button>
            </div>
          </CardHeader>
          <CardContent>
            <div className="overflow-x-auto">
              <Table>
                <TableHeader>
                  <TableRow>
                    <TableHead className="w-10">
                      <input
                        type="checkbox"
                        checked={sessions.length > 0 && selected.size === sessions.length}
                        onChange={(e) => setSelected(e.target.checked ? new Set(sessions.map((s) => s.session_id)) : new Set())}
                        className="h-4 w-4 accent-primary"
                      />
                    </TableHead>
                    <TableHead>会话</TableHead>
                    <TableHead>节点</TableHead>
                    <TableHead>清晰度</TableHead>
                    <TableHead>状态</TableHead>
                    <TableHead>缓冲</TableHead>
                    <TableHead>远程调整</TableHead>
                    <TableHead>最后心跳</TableHead>
                    <TableHead>错误</TableHead>
                  </TableRow>
                </TableHeader>
                <TableBody>
                  {loading && sessions.length === 0 ? (
                    <TableRow>
                      <TableCell colSpan={9} className="h-24 text-center text-muted-foreground">
                        加载中…
                      </TableCell>
                    </TableRow>
                  ) : sessions.length === 0 ? (
                    <TableRow>
                      <TableCell colSpan={9} className="h-24 text-center text-muted-foreground">
                        暂无观众会话
                      </TableCell>
                    </TableRow>
                  ) : (
                    sessions.map((s) => (
                      <TableRow key={s.session_id}>
                        <TableCell>
                          <input
                            type="checkbox"
                            checked={selected.has(s.session_id)}
                            onChange={() => toggleSelect(s.session_id)}
                            className="h-4 w-4 accent-primary"
                          />
                        </TableCell>
                        <TableCell>
                          <code className="rounded bg-muted px-1.5 py-0.5 text-xs">{s.session_id.slice(0, 12)}…</code>
                        </TableCell>
                        <TableCell>{s.node_name || '未知'}</TableCell>
                        <TableCell>{s.quality || '自动'}</TableCell>
                        <TableCell>
                          <Badge variant={s.playback_state === 'playing' ? 'default' : s.playback_state === 'buffering' ? 'secondary' : 'outline'}>
                            {s.playback_state}
                          </Badge>
                        </TableCell>
                        <TableCell>{(Number(s.buffered_seconds || 0)).toFixed(1)}s</TableCell>
                        <TableCell>{s.remote_adjusted ? <Badge className="bg-amber-600">已调整</Badge> : '否'}</TableCell>
                        <TableCell className="text-muted-foreground">{new Date(s.last_heartbeat).toLocaleTimeString()}</TableCell>
                        <TableCell className="max-w-0 truncate text-muted-foreground">{s.error || '-'}</TableCell>
                      </TableRow>
                    ))
                  )}
                </TableBody>
              </Table>
            </div>
          </CardContent>
        </Card>
      )}
    </div>
  )
}