import { useQuery } from '@tanstack/react-query'
import { useState, useMemo, useEffect } from 'react'
import apiClient from '@/api/client'
import { monitoringApi } from '@/api/monitoring'
import { storageApi } from '@/api/storage'
import { formatBytes } from '@/lib/format'
import { 
  Cpu, 
  MemoryStick, 
  Clock, 
  Activity, 
  RefreshCw,
  TrendingDown,
  CheckCircle2,
  AlertTriangle
} from 'lucide-react'
import {
  LineChart,
  Line,
  XAxis,
  YAxis,
  CartesianGrid,
  Tooltip,
  Legend,
  ResponsiveContainer,
} from 'recharts'

export default function Dashboard() {
  const [activeTab, setActiveTab] = useState<'jobs' | 'logs' | 'alerts'>('jobs')
  const [networkDataPoints, setNetworkDataPoints] = useState<Array<{ time: string; inbound: number; outbound: number }>>([])
  const refreshInterval = 5

  const { data: health } = useQuery({
    queryKey: ['health'],
    queryFn: async () => {
      const response = await apiClient.get('/health')
      return response.data
    },
    refetchInterval: refreshInterval * 1000,
  })

  const { data: metrics } = useQuery({
    queryKey: ['metrics'],
    queryFn: monitoringApi.getMetrics,
    refetchInterval: refreshInterval * 1000,
  })

  const { data: alerts } = useQuery({
    queryKey: ['alerts', 'dashboard'],
    queryFn: () => monitoringApi.listAlerts({ is_acknowledged: false, limit: 10 }),
    refetchInterval: refreshInterval * 1000,
  })

  const { data: repositories = [] } = useQuery({
    queryKey: ['storage', 'repositories'],
    queryFn: storageApi.listRepositories,
  })

  // Calculate uptime (mock for now, would come from metrics)
  const uptime = metrics?.system?.uptime_seconds || 0
  const days = Math.floor(uptime / 86400)
  const hours = Math.floor((uptime % 86400) / 3600)
  const minutes = Math.floor((uptime % 3600) / 60)

  // Mock active jobs (would come from tasks API)
  const activeJobs = [
    {
      id: '1',
      name: 'Daily Backup: VM-Cluster-01',
      type: 'Replication',
      progress: 45,
      speed: '145 MB/s',
      status: 'running',
      eta: '1h 12m',
    },
    {
      id: '2',
      name: 'ZFS Scrub: Pool-01',
      type: 'Maintenance',
      progress: 78,
      speed: '1.2 GB/s',
      status: 'running',
    },
  ]

  // Mock system logs
  const systemLogs = [
    { time: '10:45:22', level: 'INFO', source: 'systemd', message: 'Started User Manager for UID 1000.' },
    { time: '10:45:15', level: 'WARN', source: 'smartd', message: 'Device: /dev/ada5, SMART Usage Attribute: 194 Temperature_Celsius changed from 38 to 41' },
    { time: '10:44:58', level: 'INFO', source: 'kernel', message: 'ix0: link state changed to UP' },
    { time: '10:42:10', level: 'INFO', source: 'zfs', message: 'zfs_arc_reclaim_thread: reclaiming 157286400 bytes ...' },
  ]

  const totalStorage = Array.isArray(repositories) ? repositories.reduce((sum, repo) => sum + (repo?.size_bytes || 0), 0) : 0
  const usedStorage = Array.isArray(repositories) ? repositories.reduce((sum, repo) => sum + (repo?.used_bytes || 0), 0) : 0
  const storagePercent = totalStorage > 0 ? (usedStorage / totalStorage) * 100 : 0

  // Initialize network data
  useEffect(() => {
    // Generate initial 30 data points
    const initialData = []
    const now = Date.now()
    for (let i = 29; i >= 0; i--) {
      const time = new Date(now - i * 5000)
      const minutes = time.getMinutes().toString().padStart(2, '0')
      const seconds = time.getSeconds().toString().padStart(2, '0')
      
      const baseInbound = 800 + Math.random() * 400
      const baseOutbound = 400 + Math.random() * 200
      
      initialData.push({
        time: `${minutes}:${seconds}`,
        inbound: Math.round(baseInbound),
        outbound: Math.round(baseOutbound),
      })
    }
    setNetworkDataPoints(initialData)

    // Update data every 5 seconds
    const interval = setInterval(() => {
      setNetworkDataPoints((prev) => {
        const now = new Date()
        const minutes = now.getMinutes().toString().padStart(2, '0')
        const seconds = now.getSeconds().toString().padStart(2, '0')
        
        const baseInbound = 800 + Math.random() * 400
        const baseOutbound = 400 + Math.random() * 200
        
        const newPoint = {
          time: `${minutes}:${seconds}`,
          inbound: Math.round(baseInbound),
          outbound: Math.round(baseOutbound),
        }
        
        // Keep only last 30 points
        const updated = [...prev.slice(1), newPoint]
        return updated
      })
    }, 5000)

    return () => clearInterval(interval)
  }, [])

  // Calculate current and peak throughput
  const currentThroughput = useMemo(() => {
    if (networkDataPoints.length === 0) return { inbound: 0, outbound: 0, total: 0 }
    const last = networkDataPoints[networkDataPoints.length - 1]
    return {
      inbound: last.inbound,
      outbound: last.outbound,
      total: last.inbound + last.outbound,
    }
  }, [networkDataPoints])

  const peakThroughput = useMemo(() => {
    if (networkDataPoints.length === 0) return 0
    return Math.max(...networkDataPoints.map((d) => d.inbound + d.outbound))
  }, [networkDataPoints])

  const systemStatus = health?.status === 'healthy' ? 'System Healthy' : 'System Degraded'
  const isHealthy = health?.status === 'healthy'

  return (
    <div className="min-h-screen bg-background-dark text-white overflow-hidden">
      {/* Header */}
      <header className="flex-none px-6 py-5 border-b border-border-dark bg-background-dark/95 backdrop-blur z-10">
        <div className="flex flex-wrap justify-between items-end gap-3 max-w-[1600px] mx-auto">
          <div className="flex flex-col gap-1">
            <h2 className="text-white text-3xl font-black tracking-tight">System Monitor</h2>
            <p className="text-text-secondary text-sm">Real-time telemetry, storage health, and system event logs</p>
          </div>
          <div className="flex items-center gap-3">
            <div className="flex items-center gap-2 px-3 py-2 bg-card-dark rounded-lg border border-border-dark">
              <span className="relative flex h-2 w-2">
                {isHealthy && (
                  <>
                    <span className="animate-ping absolute inline-flex h-full w-full rounded-full bg-emerald-400 opacity-75"></span>
                    <span className="relative inline-flex rounded-full h-2 w-2 bg-emerald-500"></span>
                  </>
                )}
                {!isHealthy && (
                  <span className="relative inline-flex rounded-full h-2 w-2 bg-yellow-500"></span>
                )}
              </span>
              <span className={`text-xs font-medium ${isHealthy ? 'text-emerald-400' : 'text-yellow-400'}`}>
                {systemStatus}
              </span>
            </div>
            <button className="flex items-center gap-2 h-10 px-4 bg-card-dark hover:bg-[#233648] border border-border-dark text-white text-sm font-bold rounded-lg transition-colors">
              <RefreshCw className="h-4 w-4" />
              <span>Refresh: {refreshInterval}s</span>
            </button>
          </div>
        </div>
      </header>

      {/* Scrollable Content */}
      <div className="flex-1 overflow-y-auto custom-scrollbar p-6">
        <div className="flex flex-col gap-6 max-w-[1600px] mx-auto pb-10">
          {/* Top Stats Row */}
          <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-4 gap-4">
            {/* CPU */}
            <div className="flex flex-col gap-2 rounded-xl p-5 border border-border-dark bg-card-dark">
              <div className="flex justify-between items-start">
                <p className="text-text-secondary text-sm font-medium">CPU Load</p>
                <Cpu className="text-text-secondary w-5 h-5" />
              </div>
              <div className="flex items-end gap-3 mt-1">
                <p className="text-white text-3xl font-bold">
                  {metrics?.system?.cpu_usage_percent?.toFixed(0) || 0}%
                </p>
                <span className="text-emerald-500 text-sm font-medium mb-1 flex items-center">
                  <TrendingDown className="w-4 h-4 mr-1" />
                  2%
                </span>
              </div>
              <div className="h-1.5 w-full bg-[#233648] rounded-full mt-3 overflow-hidden">
                <div 
                  className="h-full bg-primary rounded-full transition-all"
                  style={{ width: `${metrics?.system?.cpu_usage_percent || 0}%` }}
                ></div>
              </div>
            </div>

            {/* RAM */}
            <div className="flex flex-col gap-2 rounded-xl p-5 border border-border-dark bg-card-dark">
              <div className="flex justify-between items-start">
                <p className="text-text-secondary text-sm font-medium">RAM Usage</p>
                <MemoryStick className="text-text-secondary w-5 h-5" />
              </div>
              <div className="flex items-end gap-3 mt-1">
                <p className="text-white text-3xl font-bold">
                  {formatBytes(metrics?.system?.memory_used_bytes || 0, 1)}
                </p>
                <span className="text-text-secondary text-xs mb-2">
                  / {formatBytes(metrics?.system?.memory_total_bytes || 0, 1)}
                </span>
              </div>
              <div className="h-1.5 w-full bg-[#233648] rounded-full mt-3 overflow-hidden">
                <div 
                  className="h-full bg-emerald-500 rounded-full transition-all"
                  style={{ width: `${metrics?.system?.memory_usage_percent || 0}%` }}
                ></div>
              </div>
            </div>

            {/* Storage Health */}
            <div className="flex flex-col gap-2 rounded-xl p-5 border border-border-dark bg-card-dark">
              <div className="flex justify-between items-start">
                <p className="text-text-secondary text-sm font-medium">Storage Status</p>
                <CheckCircle2 className="text-emerald-500 w-5 h-5" />
              </div>
              <div className="flex items-end gap-3 mt-1">
                <p className="text-white text-3xl font-bold">Online</p>
                <span className="text-text-secondary text-sm font-medium mb-1">No Errors</span>
              </div>
              <div className="flex gap-1 mt-3">
                <div className="h-1.5 flex-1 bg-emerald-500 rounded-l-full"></div>
                <div className="h-1.5 flex-1 bg-emerald-500"></div>
                <div className="h-1.5 flex-1 bg-emerald-500"></div>
                <div className="h-1.5 flex-1 bg-emerald-500 rounded-r-full"></div>
              </div>
            </div>

            {/* Uptime */}
            <div className="flex flex-col gap-2 rounded-xl p-5 border border-border-dark bg-card-dark">
              <div className="flex justify-between items-start">
                <p className="text-text-secondary text-sm font-medium">System Uptime</p>
                <Clock className="text-text-secondary w-5 h-5" />
              </div>
              <div className="mt-1">
                <p className="text-white text-3xl font-bold">
                  {days}d {hours}h {minutes}m
                </p>
              </div>
              <p className="text-text-secondary text-xs mt-3">Last reboot: Manual Patching</p>
            </div>
          </div>

          {/* Middle Section: Charts & Storage */}
          <div className="grid grid-cols-1 xl:grid-cols-3 gap-6">
            {/* Charts Column (2/3) */}
            <div className="xl:col-span-2 flex flex-col gap-6">
              {/* Network Chart */}
              <div className="bg-card-dark border border-border-dark rounded-xl p-6 shadow-sm">
                <div className="flex justify-between items-center mb-6">
                  <div>
                    <h3 className="text-white text-lg font-bold">Network Throughput</h3>
                    <p className="text-text-secondary text-sm">Inbound vs Outbound (eth0)</p>
                  </div>
                  <div className="text-right">
                    <p className="text-white text-2xl font-bold leading-tight">
                      {(currentThroughput.total / 1000).toFixed(1)} Gbps
                    </p>
                    <p className="text-emerald-500 text-sm">Peak: {(peakThroughput / 1000).toFixed(1)} Gbps</p>
                  </div>
                </div>
                <div className="h-[200px] w-full">
                  <ResponsiveContainer width="100%" height="100%">
                    <LineChart data={networkDataPoints} margin={{ top: 5, right: 10, left: 0, bottom: 0 }}>
                      <CartesianGrid strokeDasharray="3 3" stroke="#324d67" opacity={0.3} />
                      <XAxis
                        dataKey="time"
                        stroke="#92adc9"
                        style={{ fontSize: '11px' }}
                        tick={{ fill: '#92adc9' }}
                      />
                      <YAxis
                        stroke="#92adc9"
                        style={{ fontSize: '11px' }}
                        tick={{ fill: '#92adc9' }}
                        label={{ value: 'Mbps', angle: -90, position: 'insideLeft', fill: '#92adc9', style: { fontSize: '11px' } }}
                      />
                      <Tooltip
                        contentStyle={{
                          backgroundColor: '#1a2632',
                          border: '1px solid #324d67',
                          borderRadius: '8px',
                          color: '#fff',
                        }}
                        labelStyle={{ color: '#92adc9', fontSize: '12px' }}
                        itemStyle={{ color: '#fff', fontSize: '12px' }}
                        formatter={(value: number) => [`${value} Mbps`, '']}
                      />
                      <Legend
                        wrapperStyle={{ fontSize: '12px', color: '#92adc9' }}
                        iconType="line"
                      />
                      <Line
                        type="monotone"
                        dataKey="inbound"
                        stroke="#137fec"
                        strokeWidth={2}
                        dot={false}
                        name="Inbound"
                        activeDot={{ r: 4 }}
                      />
                      <Line
                        type="monotone"
                        dataKey="outbound"
                        stroke="#10b981"
                        strokeWidth={2}
                        dot={false}
                        name="Outbound"
                        activeDot={{ r: 4 }}
                      />
                    </LineChart>
                  </ResponsiveContainer>
                </div>
              </div>

              {/* Storage Chart */}
              <div className="bg-card-dark border border-border-dark rounded-xl p-6 shadow-sm">
                <div className="flex justify-between items-center mb-6">
                  <div>
                    <h3 className="text-white text-lg font-bold">Storage Capacity</h3>
                    <p className="text-text-secondary text-sm">Repository usage</p>
                  </div>
                  <div className="text-right">
                    <p className="text-white text-2xl font-bold leading-tight">
                      {storagePercent.toFixed(1)}%
                    </p>
                    <p className="text-text-secondary text-sm">Target: &lt;90%</p>
                  </div>
                </div>
                <div className="h-[150px] w-full relative">
                  <div className="w-full h-full bg-[#111a22] rounded flex items-center justify-center">
                    <div className="w-full px-4">
                      <div className="w-full bg-[#233648] h-2 rounded-full overflow-hidden">
                        <div 
                          className="bg-primary h-full rounded-full transition-all"
                          style={{ width: `${storagePercent}%` }}
                        ></div>
                      </div>
                    </div>
                  </div>
                </div>
              </div>
            </div>

            {/* Storage Info Column (1/3) */}
            <div className="flex flex-col gap-6">
              <div className="bg-card-dark border border-border-dark rounded-xl p-6 h-full shadow-sm flex flex-col">
                <div className="flex justify-between items-center mb-4">
                  <h3 className="text-white text-lg font-bold">Storage Overview</h3>
                  <span className="bg-[#233648] text-white text-xs px-2 py-1 rounded border border-border-dark">
                    {repositories?.length || 0} Repos
                  </span>
                </div>
                <div className="mt-4 pt-4 border-t border-border-dark">
                  <div className="flex justify-between text-sm text-text-secondary">
                    <span>Total Capacity</span>
                    <span className="text-white font-bold">{formatBytes(totalStorage)}</span>
                  </div>
                  <div className="w-full bg-[#233648] h-2 rounded-full mt-2 overflow-hidden">
                    <div 
                      className="bg-primary h-full transition-all"
                      style={{ width: `${storagePercent}%` }}
                    ></div>
                  </div>
                  <div className="flex justify-between text-xs text-text-secondary mt-1">
                    <span>Used: {formatBytes(usedStorage)}</span>
                    <span>Free: {formatBytes(totalStorage - usedStorage)}</span>
                  </div>
                </div>
              </div>
            </div>
          </div>

          {/* Bottom Section: Tabs & Logs */}
          <div className="bg-card-dark border border-border-dark rounded-xl shadow-sm overflow-hidden flex flex-col h-[400px]">
            {/* Tabs Header */}
            <div className="flex border-b border-border-dark bg-[#161f29]">
              <button
                onClick={() => setActiveTab('jobs')}
                className={`px-6 py-4 text-sm font-bold transition-colors ${
                  activeTab === 'jobs'
                    ? 'text-primary border-b-2 border-primary bg-card-dark'
                    : 'text-text-secondary hover:text-white'
                }`}
              >
                Active Jobs{' '}
                {activeJobs.length > 0 && (
                  <span className="ml-2 bg-primary/20 text-primary px-1.5 py-0.5 rounded text-xs">
                    {activeJobs.length}
                  </span>
                )}
              </button>
              <button
                onClick={() => setActiveTab('logs')}
                className={`px-6 py-4 text-sm font-medium transition-colors ${
                  activeTab === 'logs'
                    ? 'text-primary border-b-2 border-primary bg-card-dark'
                    : 'text-text-secondary hover:text-white'
                }`}
              >
                System Logs
              </button>
              <button
                onClick={() => setActiveTab('alerts')}
                className={`px-6 py-4 text-sm font-medium transition-colors ${
                  activeTab === 'alerts'
                    ? 'text-primary border-b-2 border-primary bg-card-dark'
                    : 'text-text-secondary hover:text-white'
                }`}
              >
                Alerts History
              </button>
              <div className="flex-1 flex justify-end items-center px-4">
                <div className="relative">
                  <Activity className="absolute left-2 top-1.5 text-text-secondary w-4 h-4" />
                  <input
                    className="bg-[#111a22] border border-border-dark rounded-md py-1 pl-8 pr-3 text-sm text-white focus:outline-none focus:border-primary w-48 transition-all"
                    placeholder="Search logs..."
                    type="text"
                  />
                </div>
              </div>
            </div>

            {/* Tab Content */}
            <div className="flex-1 overflow-hidden flex flex-col">
              {activeTab === 'jobs' && (
                <div className="p-0">
                  <table className="w-full text-left border-collapse">
                    <thead className="bg-[#1a2632] text-xs uppercase text-text-secondary font-medium sticky top-0 z-10">
                      <tr>
                        <th className="px-6 py-3 border-b border-border-dark">Job Name</th>
                        <th className="px-6 py-3 border-b border-border-dark">Type</th>
                        <th className="px-6 py-3 border-b border-border-dark w-1/3">Progress</th>
                        <th className="px-6 py-3 border-b border-border-dark">Speed</th>
                        <th className="px-6 py-3 border-b border-border-dark">Status</th>
                      </tr>
                    </thead>
                    <tbody className="text-sm divide-y divide-border-dark">
                      {activeJobs.map((job) => (
                        <tr key={job.id} className="group hover:bg-[#233648] transition-colors">
                          <td className="px-6 py-4 font-medium text-white">{job.name}</td>
                          <td className="px-6 py-4 text-text-secondary">{job.type}</td>
                          <td className="px-6 py-4">
                            <div className="flex items-center gap-3">
                              <div className="w-full bg-[#111a22] rounded-full h-2 overflow-hidden">
                                <div
                                  className="bg-primary h-full rounded-full relative overflow-hidden"
                                  style={{ width: `${job.progress}%` }}
                                >
                                  <div className="absolute inset-0 bg-white/20 animate-pulse"></div>
                                </div>
                              </div>
                              <span className="text-xs font-mono text-white">{job.progress}%</span>
                            </div>
                            {job.eta && (
                              <p className="text-[10px] text-text-secondary mt-1">ETA: {job.eta}</p>
                            )}
                          </td>
                          <td className="px-6 py-4 text-text-secondary font-mono">{job.speed}</td>
                          <td className="px-6 py-4">
                            <span className="inline-flex items-center px-2 py-1 rounded text-xs font-medium bg-primary/20 text-primary">
                              Running
                            </span>
                          </td>
                        </tr>
                      ))}
                    </tbody>
                  </table>
                </div>
              )}

              {activeTab === 'logs' && (
                <>
                  <div className="px-6 py-2 bg-[#161f29] border-y border-border-dark flex items-center justify-between">
                    <h4 className="text-xs uppercase text-text-secondary font-bold tracking-wider">
                      Recent System Events
                    </h4>
                    <button className="text-xs text-primary hover:text-white transition-colors">
                      View All Logs
                    </button>
                  </div>
                  <div className="flex-1 overflow-y-auto custom-scrollbar bg-[#111a22]">
                    <table className="w-full text-left border-collapse">
                      <tbody className="text-sm font-mono divide-y divide-border-dark/50">
                        {systemLogs.map((log, idx) => (
                          <tr key={idx} className="group hover:bg-[#233648] transition-colors">
                            <td className="px-6 py-2 text-text-secondary w-32 whitespace-nowrap">
                              {log.time}
                            </td>
                            <td className="px-6 py-2 w-24">
                              <span
                                className={
                                  log.level === 'INFO'
                                    ? 'text-emerald-500'
                                    : log.level === 'WARN'
                                    ? 'text-yellow-500'
                                    : 'text-red-500'
                                }
                              >
                                {log.level}
                              </span>
                            </td>
                            <td className="px-6 py-2 w-32 text-white">{log.source}</td>
                            <td className="px-6 py-2 text-text-secondary truncate max-w-lg">
                              {log.message}
                            </td>
                          </tr>
                        ))}
                      </tbody>
                    </table>
                  </div>
                </>
              )}

              {activeTab === 'alerts' && (
                <div className="flex-1 overflow-y-auto custom-scrollbar bg-[#111a22] p-6">
                  {alerts?.alerts && alerts.alerts.length > 0 ? (
                    <div className="space-y-3">
                      {alerts.alerts.map((alert) => (
                        <div
                          key={alert.id}
                          className="bg-[#1a2632] border border-border-dark rounded-lg p-4 hover:bg-[#233648] transition-colors"
                        >
                          <div className="flex items-start justify-between">
                            <div className="flex-1">
                              <div className="flex items-center gap-2 mb-1">
                                <AlertTriangle
                                  className={`w-4 h-4 ${
                                    alert.severity === 'critical'
                                      ? 'text-red-500'
                                      : alert.severity === 'warning'
                                      ? 'text-yellow-500'
                                      : 'text-blue-500'
                                  }`}
                                />
                                <h4 className="text-white font-medium">{alert.title}</h4>
                                <span
                                  className={`px-2 py-0.5 rounded text-xs font-medium ${
                                    alert.severity === 'critical'
                                      ? 'bg-red-500/20 text-red-400'
                                      : alert.severity === 'warning'
                                      ? 'bg-yellow-500/20 text-yellow-400'
                                      : 'bg-blue-500/20 text-blue-400'
                                  }`}
                                >
                                  {alert.severity}
                                </span>
                              </div>
                              <p className="text-text-secondary text-sm">{alert.message}</p>
                              <p className="text-text-secondary text-xs mt-2 font-mono">
                                {new Date(alert.created_at).toLocaleString()}
                              </p>
                            </div>
                          </div>
                        </div>
                      ))}
                    </div>
                  ) : (
                    <div className="text-center py-12">
                      <CheckCircle2 className="w-12 h-12 text-emerald-500 mx-auto mb-4" />
                      <p className="text-text-secondary">No alerts</p>
                    </div>
                  )}
                </div>
              )}
            </div>
          </div>
        </div>
      </div>
    </div>
  )
}