import { Wifi, WifiOff, AlertCircle, Loader2, HardDrive, Clock, ChevronUp } from 'lucide-react'
import { useEffect, useState, useMemo } from 'react'
import { useTabStore, type ConnectionStatus } from '../../stores/tabStore'
import { usePoolStore } from '../../stores/connection/poolStore'
import type { ConnectionState } from '../../stores/connection'
import { useConnectionPanelStore } from '../../stores/connectionPanelStore'
import { useSessionStore } from '../../stores'
import packageJson from '../../../package.json'

// ============== Status Display Config ==============

interface StatusDisplay {
  icon: React.ReactNode
  label: string
  colorClass: string
  animateClass: string
}

const STATUS_CONFIG: Record<string, StatusDisplay> = {
  connected: {
    icon: <Wifi className="w-3 h-3" />,
    label: '已连接',
    colorClass: 'text-green-400',
    animateClass: '',
  },
  connecting: {
    icon: <Loader2 className="w-3 h-3 animate-spin" />,
    label: '连接中',
    colorClass: 'text-yellow-400',
    animateClass: 'animate-pulse',
  },
  background: {
    icon: <Wifi className="w-3 h-3" />,
    label: '后台',
    colorClass: 'text-green-400',
    animateClass: '',
  },
  suspended: {
    icon: <WifiOff className="w-3 h-3" />,
    label: '已挂起',
    colorClass: 'text-yellow-400',
    animateClass: '',
  },
  reconnecting: {
    icon: <Loader2 className="w-3 h-3 animate-spin" />,
    label: '重连中',
    colorClass: 'text-yellow-400',
    animateClass: 'animate-pulse',
  },
  error: {
    icon: <AlertCircle className="w-3 h-3" />,
    label: '连接错误',
    colorClass: 'text-red-400',
    animateClass: '',
  },
  disconnected: {
    icon: <WifiOff className="w-3 h-3" />,
    label: '未连接',
    colorClass: 'text-txt-muted',
    animateClass: '',
  },
}

// ============== Helper: format bytes ==============

function formatBytes(bytes: number): string {
  if (bytes === 0) return '0 B'
  const units = ['B', 'KB', 'MB', 'GB']
  const k = 1024
  const i = Math.floor(Math.log(bytes) / Math.log(k))
  const value = bytes / Math.pow(k, i)
  return `${value.toFixed(i === 0 ? 0 : 1)} ${units[i]}`
}

// ============== Helper: map tab connectionStatus to ConnectionState ==============

function mapTabStatusToConnectionState(status?: ConnectionStatus): ConnectionState | undefined {
  if (!status) return undefined
  // tabStore's ConnectionStatus: 'disconnected' | 'connecting' | 'connected' | 'error'
  // maps directly to ConnectionState values
  return status as ConnectionState
}

// ============== Component ==============

export default function StatusBar() {
  const togglePanel = useConnectionPanelStore((s) => s.toggle)
  const [version, setVersion] = useState(packageJson.version)
  const [currentTime, setCurrentTime] = useState(new Date())

  // Tab store
  const activeTabId = useTabStore((s) => s.activeTabId)
  const tabs = useTabStore((s) => s.tabs)

  // Connection store (pool) — subscribe to connections to reactively update
  const connections = usePoolStore((s) => s.connections)
  const sessions = useSessionStore((s) => s.sessions)

  // Total connection count for the panel badge
  const totalConnections = connections.size

  // Derive the active tab
  const activeTab = useMemo(
    () => tabs.find((t) => t.id === activeTabId),
    [tabs, activeTabId]
  )

  // Determine the connection state and info for the active tab
  const { connectionState, hostLabel, stats, tabKind } = useMemo(() => {
    if (!activeTab || activeTab.type === 'welcome' || activeTab.type === 'settings') {
      return {
        connectionState: undefined,
        hostLabel: undefined,
        stats: undefined,
        tabKind: activeTab?.type as string | undefined,
      }
    }

    if (activeTab.type === 'serial') {
      return {
        connectionState: mapTabStatusToConnectionState(activeTab.connectionStatus),
        hostLabel: activeTab.serialConfig
          ? `${activeTab.serialConfig.path} · ${activeTab.serialConfig.baudRate}`
          : activeTab.title,
        stats: undefined,
        tabKind: activeTab.type,
      }
    }

    // 1. Try to get connection from pool via connectionInstance
    const instance = activeTab.connectionInstance
    if (instance?.connectionId) {
      const conn = connections.get(instance.connectionId)
      if (conn) {
        return {
          connectionState: conn.state,
          hostLabel: `${conn.config.username}@${conn.config.host}:${conn.config.port || 22}`,
          stats: conn.stats,
          tabKind: activeTab.type,
        }
      }
    }

    // 2. Session id → session store
    if (activeTab.sessionId) {
      const session = sessions.find((s) => s.id === activeTab.sessionId)
      if (session) {
        return {
          connectionState: mapTabStatusToConnectionState(activeTab.connectionStatus),
          hostLabel: `${session.username}@${session.host}:${session.port || 22}`,
          stats: undefined,
          tabKind: activeTab.type,
        }
      }
    }

    // 3. Fall back to tab's own connectionConfig
    const state = mapTabStatusToConnectionState(activeTab.connectionStatus)
    const config = activeTab.connectionConfig
    const label = config
      ? `${config.username}@${config.host}:${config.port || 22}`
      : activeTab.isLocal
        ? '本地终端'
        : undefined

    return { connectionState: state, hostLabel: label, stats: undefined, tabKind: activeTab.type }
  }, [activeTab, connections, sessions])

  // Clock timer + version
  useEffect(() => {
    if (window.opsxApi) {
      window.opsxApi.getVersion().then((v: string) => {
        setVersion(v)
      }).catch(() => undefined)
    }

    const timer = setInterval(() => {
      setCurrentTime(new Date())
    }, 1000)

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

  const formatTime = (date: Date) => {
    return date.toLocaleTimeString('zh-CN', {
      hour: '2-digit',
      minute: '2-digit',
      second: '2-digit',
    })
  }

  // Resolve status display
  const statusKey = connectionState ?? 'disconnected'
  const statusCfg = STATUS_CONFIG[statusKey] ?? STATUS_CONFIG.disconnected

  // Format transfer info if available
  const transferLabel = stats && stats.bytesTransferred > 0
    ? `↑↓ ${formatBytes(stats.bytesTransferred)}`
    : null

  return (
    <div className="h-7 bg-dark-800/95 border-t border-dark-700/40 flex items-center px-3 text-[11px] text-content-primary select-none">
      {/* Left: Connection status area — clickable to toggle ConnectionPanel */}
      <button
        type="button"
        onClick={togglePanel}
        className={`flex items-center gap-1.5 rounded-md px-1.5 py-0.5 -ml-1
                     hover:bg-dark-700/70 transition-colors cursor-pointer group
                     ${statusCfg.colorClass} ${statusCfg.animateClass}`}
        title="点击打开连接管理面板"
      >
        {statusCfg.icon && (
          <span className="transition-colors duration-300">{statusCfg.icon}</span>
        )}
        <span className="transition-colors duration-300 font-medium">{statusCfg.label}</span>
        {hostLabel && (
          <>
            <span className="text-txt-faint mx-0.5">·</span>
            <span className="text-content-secondary font-mono truncate max-w-[280px]" title={hostLabel}>
              {hostLabel}
            </span>
          </>
        )}
        {tabKind && tabKind !== 'welcome' && tabKind !== 'settings' && (
          <span className="ml-1.5 px-1.5 py-px rounded text-[10px] text-txt-faint bg-dark-700/80 capitalize">
            {tabKind === 'terminal' ? '终端' : tabKind === 'sftp' ? 'SFTP' : tabKind === 'portforward' ? '转发' : tabKind}
          </span>
        )}
        {totalConnections > 0 && (
          <span className="ml-1 px-1.5 py-px rounded-full bg-accent-blue/20 text-accent-blue text-[10px] font-medium tabular-nums">
            {totalConnections}
          </span>
        )}
        <ChevronUp className="w-3 h-3 text-txt-faint transition-transform duration-200 group-hover:rotate-180" />
      </button>

      {/* Center: Transfer stats */}
      {transferLabel && (
        <div className="flex items-center gap-1 ml-3 text-txt-muted tabular-nums">
          <HardDrive className="w-3 h-3" />
          <span>{transferLabel}</span>
        </div>
      )}

      <div className="flex-1" />

      <div className="flex items-center gap-3 text-txt-faint">
        <div className="flex items-center gap-1 tabular-nums">
          <Clock className="w-3 h-3" />
          <span>{formatTime(currentTime)}</span>
        </div>
        <span className="hidden sm:inline opacity-80">OpsXShell v{version}</span>
      </div>
    </div>
  )
}