import { useEffect, useRef, useState } from 'react'
import { Terminal as XTerm } from '@xterm/xterm'
import { FitAddon } from '@xterm/addon-fit'
import '@xterm/xterm/css/xterm.css'
import {
  Play,
  Square,
  RotateCw,
  Pause,
  PlayCircle,
  Trash2,
  RefreshCw,
  TerminalSquare,
  ScrollText,
  X,
} from 'lucide-react'
import { api, getToken, type Container, type ContainerStats, type Integration } from '../lib/api'

const TEXT_PRIMARY = '#E8E6E0'
const TEXT_SECONDARY = '#7A7D85'
const GOLD = '#C8A434'

const cardBase: React.CSSProperties = {
  backgroundColor: 'rgba(10, 10, 12, 0.92)',
  border: '1px solid rgba(200, 164, 52, 0.08)',
  borderRadius: '12px',
  boxShadow: '0 0 20px rgba(200, 164, 52, 0.03)',
}

function stateColor(state: string): string {
  if (state === 'running') return '#2ECC71'
  if (state === 'paused') return '#E0A82E'
  if (state === 'exited' || state === 'dead') return '#E74C3C'
  return TEXT_SECONDARY
}

function formatBytes(bytes: number): string {
  if (bytes < 1024) return `${bytes} B`
  const units = ['KB', 'MB', 'GB', 'TB']
  let v = bytes
  let i = -1
  do {
    v /= 1024
    i++
  } while (v >= 1024 && i < units.length - 1)
  return `${v.toFixed(1)} ${units[i]}`
}

export default function Containers() {
  const [hosts, setHosts] = useState<Integration[]>([])
  const [integrationId, setIntegrationId] = useState<number | ''>('')
  const [containers, setContainers] = useState<Container[]>([])
  const [error, setError] = useState<string | null>(null)
  const [loading, setLoading] = useState(false)
  const [busyId, setBusyId] = useState<string | null>(null)
  const [statsById, setStatsById] = useState<Record<string, ContainerStats>>({})
  const [logsContainer, setLogsContainer] = useState<Container | null>(null)
  const [execContainer, setExecContainer] = useState<Container | null>(null)

  useEffect(() => {
    api.listIntegrations().then(({ integrations }) => {
      const dockerHosts = integrations.filter((i) => i.type === 'docker')
      setHosts(dockerHosts)
      if (dockerHosts.length > 0) setIntegrationId(dockerHosts[0].id)
    })
  }, [])

  function refresh() {
    if (!integrationId) return
    setLoading(true)
    setError(null)
    api
      .listContainers(integrationId)
      .then(({ containers }) => {
        setContainers(containers)
        containers.forEach((c) => {
          if (c.state !== 'running') return
          api
            .containerStats(integrationId, c.id)
            .then((stats) => setStatsById((prev) => ({ ...prev, [c.id]: stats })))
            .catch(() => {})
        })
      })
      .catch((err) => setError(err instanceof Error ? err.message : 'Failed to list containers'))
      .finally(() => setLoading(false))
  }

  useEffect(() => {
    refresh()
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [integrationId])

  async function runAction(c: Container, action: 'start' | 'stop' | 'restart' | 'pause' | 'unpause') {
    if (!integrationId) return
    setBusyId(c.id)
    setError(null)
    try {
      await api.containerAction(integrationId, c.id, action)
      refresh()
    } catch (err) {
      setError(err instanceof Error ? err.message : `Failed to ${action} container`)
    } finally {
      setBusyId(null)
    }
  }

  async function removeContainer(c: Container) {
    if (!integrationId) return
    if (!confirm(`Remove container "${c.name}"? This cannot be undone.`)) return
    setBusyId(c.id)
    setError(null)
    try {
      await api.removeContainer(integrationId, c.id, c.state === 'running')
      refresh()
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Failed to remove container')
    } finally {
      setBusyId(null)
    }
  }

  return (
    <div className="space-y-4">
      <div className="flex items-center justify-between">
        <div>
          <h1 className="text-xl font-semibold" style={{ color: TEXT_PRIMARY }}>
            Containers
          </h1>
          <p className="text-sm" style={{ color: TEXT_SECONDARY }}>
            Manage Docker containers across your configured hosts.
          </p>
        </div>
        <div className="flex items-center gap-2">
          <select
            value={integrationId}
            onChange={(e) => setIntegrationId(Number(e.target.value))}
            className="rounded-md border border-white/10 bg-transparent px-2 py-1.5 text-sm"
            style={{ color: TEXT_PRIMARY }}
          >
            {hosts.length === 0 && <option value="">No Docker integrations</option>}
            {hosts.map((h) => (
              <option key={h.id} value={h.id}>
                {h.name}
              </option>
            ))}
          </select>
          <button
            onClick={refresh}
            className="flex items-center gap-1 rounded-md px-2.5 py-1.5 text-xs"
            style={{ border: '1px solid rgba(255,255,255,0.1)', color: TEXT_PRIMARY }}
          >
            <RefreshCw size={13} className={loading ? 'animate-spin' : ''} /> Refresh
          </button>
        </div>
      </div>

      {error && (
        <div className="flex items-center justify-between rounded-md px-3 py-2 text-sm" style={{ backgroundColor: 'rgba(231,76,60,0.1)', color: '#E74C3C' }}>
          <span>{error}</span>
          <button onClick={() => setError(null)} style={{ color: TEXT_SECONDARY }}>
            <X size={14} />
          </button>
        </div>
      )}

      <div style={cardBase} className="overflow-hidden">
        <table className="w-full text-sm">
          <thead>
            <tr style={{ color: TEXT_SECONDARY, borderBottom: '1px solid rgba(255,255,255,0.06)' }}>
              <th className="px-3 py-2 text-left font-medium">Name</th>
              <th className="px-3 py-2 text-left font-medium">Image</th>
              <th className="px-3 py-2 text-left font-medium">State</th>
              <th className="px-3 py-2 text-left font-medium">CPU</th>
              <th className="px-3 py-2 text-left font-medium">Memory</th>
              <th className="px-3 py-2 text-left font-medium">Ports</th>
              <th className="px-3 py-2 text-right font-medium">Actions</th>
            </tr>
          </thead>
          <tbody>
            {containers.length === 0 && (
              <tr>
                <td colSpan={7} className="px-3 py-6 text-center" style={{ color: TEXT_SECONDARY }}>
                  {integrationId ? 'No containers found.' : 'Select a Docker integration to view containers.'}
                </td>
              </tr>
            )}
            {containers.map((c) => {
              const stats = statsById[c.id]
              const busy = busyId === c.id
              return (
                <tr key={c.id} style={{ borderBottom: '1px solid rgba(255,255,255,0.04)' }}>
                  <td className="px-3 py-2" style={{ color: TEXT_PRIMARY }}>
                    {c.name}
                  </td>
                  <td className="px-3 py-2" style={{ color: TEXT_SECONDARY }}>
                    {c.image}
                  </td>
                  <td className="px-3 py-2">
                    <span className="flex items-center gap-1.5">
                      <span className="inline-block h-2 w-2 rounded-full" style={{ background: stateColor(c.state) }} />
                      <span style={{ color: TEXT_PRIMARY }}>{c.status}</span>
                    </span>
                  </td>
                  <td className="px-3 py-2" style={{ color: TEXT_SECONDARY }}>
                    {stats ? `${stats.cpuPercent.toFixed(1)}%` : '—'}
                  </td>
                  <td className="px-3 py-2" style={{ color: TEXT_SECONDARY }}>
                    {stats ? `${formatBytes(stats.memUsage)} / ${formatBytes(stats.memLimit)}` : '—'}
                  </td>
                  <td className="px-3 py-2" style={{ color: TEXT_SECONDARY }}>
                    {c.ports.length === 0 ? '—' : c.ports.map((p) => `${p.publicPort ?? ''}${p.publicPort ? ':' : ''}${p.privatePort}/${p.type}`).join(', ')}
                  </td>
                  <td className="px-3 py-2">
                    <div className="flex items-center justify-end gap-1.5">
                      {c.state === 'running' ? (
                        <>
                          <button disabled={busy} onClick={() => runAction(c, 'pause')} title="Pause" style={{ color: TEXT_SECONDARY }}>
                            <Pause size={14} />
                          </button>
                          <button disabled={busy} onClick={() => runAction(c, 'restart')} title="Restart" style={{ color: TEXT_SECONDARY }}>
                            <RotateCw size={14} />
                          </button>
                          <button disabled={busy} onClick={() => runAction(c, 'stop')} title="Stop" style={{ color: TEXT_SECONDARY }}>
                            <Square size={14} />
                          </button>
                          <button disabled={busy} onClick={() => setExecContainer(c)} title="Exec terminal" style={{ color: GOLD }}>
                            <TerminalSquare size={14} />
                          </button>
                        </>
                      ) : c.state === 'paused' ? (
                        <button disabled={busy} onClick={() => runAction(c, 'unpause')} title="Unpause" style={{ color: TEXT_SECONDARY }}>
                          <PlayCircle size={14} />
                        </button>
                      ) : (
                        <button disabled={busy} onClick={() => runAction(c, 'start')} title="Start" style={{ color: TEXT_SECONDARY }}>
                          <Play size={14} />
                        </button>
                      )}
                      <button disabled={busy} onClick={() => setLogsContainer(c)} title="Logs" style={{ color: TEXT_SECONDARY }}>
                        <ScrollText size={14} />
                      </button>
                      <button disabled={busy} onClick={() => removeContainer(c)} title="Remove" style={{ color: '#E74C3C' }}>
                        <Trash2 size={14} />
                      </button>
                    </div>
                  </td>
                </tr>
              )
            })}
          </tbody>
        </table>
      </div>

      {logsContainer && integrationId && (
        <LogsModal integrationId={integrationId} container={logsContainer} onClose={() => setLogsContainer(null)} />
      )}
      {execContainer && integrationId && (
        <ExecModal integrationId={integrationId} container={execContainer} onClose={() => setExecContainer(null)} />
      )}
    </div>
  )
}

function LogsModal({ integrationId, container, onClose }: { integrationId: number; container: Container; onClose: () => void }) {
  const [logs, setLogs] = useState('')
  const [loading, setLoading] = useState(true)
  const [error, setError] = useState<string | null>(null)

  function load() {
    setLoading(true)
    setError(null)
    api
      .containerLogs(integrationId, container.id)
      .then(({ logs }) => setLogs(logs))
      .catch((err) => setError(err instanceof Error ? err.message : 'Failed to fetch logs'))
      .finally(() => setLoading(false))
  }

  useEffect(load, [])

  return (
    <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/60 p-6">
      <div style={cardBase} className="flex h-[70vh] w-full max-w-3xl flex-col p-4">
        <div className="mb-2 flex items-center justify-between">
          <h2 className="text-sm font-medium" style={{ color: TEXT_PRIMARY }}>
            Logs — {container.name}
          </h2>
          <div className="flex items-center gap-2">
            <button onClick={load} style={{ color: TEXT_SECONDARY }} title="Refresh">
              <RefreshCw size={14} className={loading ? 'animate-spin' : ''} />
            </button>
            <button onClick={onClose} style={{ color: TEXT_SECONDARY }}>
              <X size={16} />
            </button>
          </div>
        </div>
        {error && <p className="mb-2 text-xs" style={{ color: '#E74C3C' }}>{error}</p>}
        <pre className="min-h-0 flex-1 overflow-auto whitespace-pre-wrap rounded-md p-3 text-xs" style={{ backgroundColor: '#0A0A0C', color: TEXT_PRIMARY }}>
          {logs || (loading ? 'Loading…' : 'No logs.')}
        </pre>
      </div>
    </div>
  )
}

function ExecModal({ integrationId, container, onClose }: { integrationId: number; container: Container; onClose: () => void }) {
  const containerRef = useRef<HTMLDivElement>(null)
  const wsRef = useRef<WebSocket | null>(null)
  const [connected, setConnected] = useState(false)

  useEffect(() => {
    if (!containerRef.current) return
    const term = new XTerm({
      cursorBlink: true,
      fontSize: 13,
      fontFamily: 'ui-monospace, SFMono-Regular, Menlo, monospace',
      theme: { background: '#15161A', foreground: '#E8E6E0', cursor: GOLD },
    })
    const fit = new FitAddon()
    term.loadAddon(fit)
    term.open(containerRef.current)
    fit.fit()

    const token = getToken()
    const proto = window.location.protocol === 'https:' ? 'wss' : 'ws'
    const ws = new WebSocket(`${proto}://${window.location.host}/api/docker/exec?token=${encodeURIComponent(token ?? '')}`)
    wsRef.current = ws

    ws.onopen = () => {
      ws.send(JSON.stringify({ type: 'connect', integrationId, containerId: container.id, cols: term.cols, rows: term.rows }))
    }
    ws.onmessage = (event) => {
      const msg = JSON.parse(event.data)
      if (msg.type === 'ready') {
        setConnected(true)
      } else if (msg.type === 'data') {
        term.write(Uint8Array.from(atob(msg.data), (c) => c.charCodeAt(0)))
      } else if (msg.type === 'error') {
        term.writeln(`\r\n\x1b[31mError: ${msg.message}\x1b[0m`)
        setConnected(false)
      } else if (msg.type === 'exit') {
        term.writeln('\r\n\x1b[33mSession ended.\x1b[0m')
        setConnected(false)
      }
    }
    ws.onclose = () => setConnected(false)

    term.onData((data) => {
      if (ws.readyState === WebSocket.OPEN) {
        ws.send(JSON.stringify({ type: 'input', data: btoa(data) }))
      }
    })
    term.onResize(({ cols, rows }) => {
      if (ws.readyState === WebSocket.OPEN) ws.send(JSON.stringify({ type: 'resize', cols, rows }))
    })

    const onResize = () => fit.fit()
    window.addEventListener('resize', onResize)
    return () => {
      window.removeEventListener('resize', onResize)
      if (ws.readyState === WebSocket.OPEN) ws.send(JSON.stringify({ type: 'disconnect' }))
      ws.close()
      term.dispose()
    }
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [])

  return (
    <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/60 p-6">
      <div style={cardBase} className="flex h-[70vh] w-full max-w-3xl flex-col p-4">
        <div className="mb-2 flex items-center justify-between">
          <h2 className="flex items-center gap-2 text-sm font-medium" style={{ color: TEXT_PRIMARY }}>
            <span className="inline-block h-2 w-2 rounded-full" style={{ background: connected ? '#2ECC71' : '#7A7D85' }} />
            Exec — {container.name}
          </h2>
          <button onClick={onClose} style={{ color: TEXT_SECONDARY }}>
            <X size={16} />
          </button>
        </div>
        <div ref={containerRef} className="min-h-0 flex-1" />
      </div>
    </div>
  )
}
