import { useEffect, useMemo, useState } from 'react'
import api from '@/services/api'

interface ServerRow {
  server_id: number
  identifier: string
  display_name: string
  online: boolean
  openclaw_version?: string | null
  cpu_pct?: number | null
  mem_pct?: number | null
  disk_pct?: number | null
  swap_pct?: number | null
  agents: Array<{ id?: string; name?: string; status?: string }>
  last_seen_at?: string | null
}

interface OverviewData {
  issues: {
    total_issues: number
    new_issues_24h: number
    processed_issues_24h: number
    computed_at: string
  }
  servers: ServerRow[]
  generated_at: string
}

interface AdminUser {
  id: number
  is_admin: boolean
}

interface ServerItem {
  server_id: number
  identifier: string
  display_name: string
  online: boolean
}

export default function MonitorPage() {
  const [data, setData] = useState<OverviewData | null>(null)
  const [loading, setLoading] = useState(true)
  const [isAdmin, setIsAdmin] = useState(false)
  const [servers, setServers] = useState<ServerItem[]>([])

  const [serverForm, setServerForm] = useState({ identifier: '', display_name: '' })

  const canAdmin = useMemo(() => !!localStorage.getItem('token') && isAdmin, [isAdmin])

  const load = async () => {
    try {
      const res = await api.get<OverviewData>('/monitor/public/overview')
      setData(res.data)
      const token = localStorage.getItem('token')
      if (token) {
        try {
          const me = await api.get<AdminUser>('/auth/me')
          setIsAdmin(!!me.data.is_admin)
        } catch {
          setIsAdmin(false)
        }
      } else {
        setIsAdmin(false)
      }
    } finally {
      setLoading(false)
    }
  }

  const loadAdminData = async () => {
    if (!canAdmin) return
    const s = await api.get<ServerItem[]>('/monitor/admin/servers')
    setServers(s.data)
  }

  useEffect(() => {
    load()
    const t = setInterval(load, 30000)
    return () => clearInterval(t)
  }, [])

  useEffect(() => {
    loadAdminData()
  }, [canAdmin])

  const addServer = async () => {
    await api.post('/monitor/admin/servers', serverForm)
    setServerForm({ identifier: '', display_name: '' })
    await loadAdminData()
  }

  const deleteServer = async (id: number) => {
    await api.delete('/monitor/admin/servers/' + id)
    await loadAdminData()
  }

  const createChallenge = async (id: number) => {
    const r = await api.post<{ identifier: string; challenge_uuid: string; expires_at: string }>('/monitor/admin/servers/' + id + '/challenge')
    alert('identifier=' + r.data.identifier + ' | challenge_uuid=' + r.data.challenge_uuid + ' | expires_at=' + r.data.expires_at)
  }

  if (loading) return <div className="loading">Monitor loading...</div>
  if (!data) return <div className="loading">Monitor load failed</div>

  return (
    <div className="dashboard monitor-page">
      <h2>📡 Monitor</h2>

      <div className="stats-grid">
        <div className="stat-card total">
          <span className="stat-number">{data.issues.total_issues}</span>
          <span className="stat-label">Total Tasks</span>
        </div>
        <div className="stat-card" style={{ borderLeftColor: 'var(--accent)' }}>
          <span className="stat-number">{data.issues.new_issues_24h}</span>
          <span className="stat-label">New (24h)</span>
        </div>
        <div className="stat-card" style={{ borderLeftColor: 'var(--success)' }}>
          <span className="stat-number">{data.issues.processed_issues_24h}</span>
          <span className="stat-label">Processed (24h)</span>
        </div>
      </div>

      <div className="section">
        <h3>Server Monitoring</h3>
        {data.servers.length === 0 ? <p className="empty">No monitored servers</p> : (
          <div className="monitor-grid">
            {data.servers.map((s) => (
              <div key={s.server_id} className="monitor-card">
                <div className="monitor-card-header">
                  <div>
                    <strong>{s.display_name}</strong>
                    <div className="text-dim">{s.identifier}</div>
                  </div>
                  <span className={'badge ' + (s.online ? 'status-online' : 'status-offline')}>{s.online ? 'online' : 'offline'}</span>
                </div>
                <div className="monitor-metrics">
                  CPU {s.cpu_pct ?? '-'}% · MEM {s.mem_pct ?? '-'}% · DISK {s.disk_pct ?? '-'}% · SWAP {s.swap_pct ?? '-'}%
                </div>
                <div className="text-dim">OpenClaw: {s.openclaw_version || '-'}</div>
                <div className="text-dim">Agents: {s.agents?.length || 0}</div>
              </div>
            ))}
          </div>
        )}
      </div>

      {canAdmin && (
        <div className="section">
          <h3>Admin</h3>

          <div className="monitor-admin">
            <div className="monitor-card">
              <h4>Servers</h4>
              <div className="inline-form">
                <input placeholder='identifier' value={serverForm.identifier} onChange={(e) => setServerForm({ ...serverForm, identifier: e.target.value })} />
                <input placeholder='display_name' value={serverForm.display_name} onChange={(e) => setServerForm({ ...serverForm, display_name: e.target.value })} />
                <button className="btn-primary" onClick={addServer}>Add Server</button>
              </div>
              <ul>
                {servers.map((s) => (
                  <li key={s.server_id}>
                    {s.display_name} ({s.identifier})
                    <button className="btn-secondary" onClick={() => createChallenge(s.server_id)} style={{ marginLeft: 8 }}>Generate Challenge</button>
                    <button className="btn-danger" onClick={() => deleteServer(s.server_id)} style={{ marginLeft: 8 }}>Delete</button>
                  </li>
                ))}
              </ul>
            </div>
          </div>
        </div>
      )}
    </div>
  )
}