'use client'

/**
 * GPU Infrastructure Admin Page
 *
 * vast.ai GPU Management for LLM Processing
 */

import { useEffect, useState, useCallback } from 'react'
import { PagePurpose } from '@/components/common/PagePurpose'

interface VastStatus {
  instance_id: number | null
  status: string
  gpu_name: string | null
  dph_total: number | null
  endpoint_base_url: string | null
  last_activity: string | null
  auto_shutdown_in_minutes: number | null
  total_runtime_hours: number | null
  total_cost_usd: number | null
  account_credit: number | null
  account_total_spend: number | null
  session_runtime_minutes: number | null
  session_cost_usd: number | null
  message: string | null
  error?: string
}

export default function GPUInfrastructurePage() {
  const [status, setStatus] = useState<VastStatus | null>(null)
  const [loading, setLoading] = useState(true)
  const [actionLoading, setActionLoading] = useState<string | null>(null)
  const [error, setError] = useState<string | null>(null)
  const [message, setMessage] = useState<string | null>(null)

  const API_PROXY = '/api/admin/gpu'

  const fetchStatus = useCallback(async () => {
    setLoading(true)
    setError(null)

    try {
      const response = await fetch(API_PROXY)
      const data = await response.json()

      if (!response.ok) {
        throw new Error(data.error || `HTTP ${response.status}`)
      }

      setStatus(data)
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Verbindungsfehler')
      setStatus({
        instance_id: null,
        status: 'error',
        gpu_name: null,
        dph_total: null,
        endpoint_base_url: null,
        last_activity: null,
        auto_shutdown_in_minutes: null,
        total_runtime_hours: null,
        total_cost_usd: null,
        account_credit: null,
        account_total_spend: null,
        session_runtime_minutes: null,
        session_cost_usd: null,
        message: 'Verbindung fehlgeschlagen'
      })
    } finally {
      setLoading(false)
    }
  }, [])

  useEffect(() => {
    fetchStatus()
  }, [fetchStatus])

  useEffect(() => {
    const interval = setInterval(fetchStatus, 30000)
    return () => clearInterval(interval)
  }, [fetchStatus])

  const powerOn = async () => {
    setActionLoading('on')
    setError(null)
    setMessage(null)

    try {
      const response = await fetch(API_PROXY, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ action: 'on' }),
      })

      const data = await response.json()

      if (!response.ok) {
        throw new Error(data.error || data.detail || 'Aktion fehlgeschlagen')
      }

      setMessage('Start angefordert')
      setTimeout(fetchStatus, 3000)
      setTimeout(fetchStatus, 10000)
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Fehler beim Starten')
      fetchStatus()
    } finally {
      setActionLoading(null)
    }
  }

  const powerOff = async () => {
    setActionLoading('off')
    setError(null)
    setMessage(null)

    try {
      const response = await fetch(API_PROXY, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ action: 'off' }),
      })

      const data = await response.json()

      if (!response.ok) {
        throw new Error(data.error || data.detail || 'Aktion fehlgeschlagen')
      }

      setMessage('Stop angefordert')
      setTimeout(fetchStatus, 3000)
      setTimeout(fetchStatus, 10000)
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Fehler beim Stoppen')
      fetchStatus()
    } finally {
      setActionLoading(null)
    }
  }

  const getStatusBadge = (s: string) => {
    const baseClasses = 'px-3 py-1 rounded-full text-sm font-semibold uppercase'
    switch (s) {
      case 'running':
        return `${baseClasses} bg-green-100 text-green-800`
      case 'stopped':
      case 'exited':
        return `${baseClasses} bg-red-100 text-red-800`
      case 'loading':
      case 'scheduling':
      case 'creating':
      case 'starting...':
      case 'stopping...':
        return `${baseClasses} bg-yellow-100 text-yellow-800`
      default:
        return `${baseClasses} bg-slate-100 text-slate-600`
    }
  }

  const getCreditColor = (credit: number | null) => {
    if (credit === null) return 'text-slate-500'
    if (credit < 5) return 'text-red-600'
    if (credit < 15) return 'text-yellow-600'
    return 'text-green-600'
  }

  return (
    <div>
      {/* Page Purpose */}
      <PagePurpose
        title="GPU Infrastruktur"
        purpose="Verwalten Sie die vast.ai GPU-Instanzen fuer LLM-Verarbeitung und OCR. Starten/Stoppen Sie GPUs bei Bedarf und ueberwachen Sie Kosten in Echtzeit."
        audience={['DevOps', 'Entwickler', 'System-Admins']}
        architecture={{
          services: ['vast.ai API', 'Ollama', 'VLLM'],
          databases: ['PostgreSQL (Logs)'],
        }}
        relatedPages={[
          { name: 'Security', href: '/infrastructure/security', description: 'DevSecOps Dashboard' },
          { name: 'Builds', href: '/infrastructure/builds', description: 'CI/CD Pipeline' },
        ]}
        collapsible={true}
        defaultCollapsed={true}
      />

      {/* Status Cards */}
      <div className="bg-white rounded-xl border border-slate-200 p-6 mb-6">
        <div className="grid grid-cols-2 md:grid-cols-3 lg:grid-cols-6 gap-6">
          <div>
            <div className="text-sm text-slate-500 mb-2">Status</div>
            {loading ? (
              <span className="px-3 py-1 rounded-full text-sm font-semibold bg-slate-100 text-slate-600">
                Laden...
              </span>
            ) : (
              <span className={getStatusBadge(
                actionLoading === 'on' ? 'starting...' :
                actionLoading === 'off' ? 'stopping...' :
                status?.status || 'unknown'
              )}>
                {actionLoading === 'on' ? 'starting...' :
                 actionLoading === 'off' ? 'stopping...' :
                 status?.status || 'unbekannt'}
              </span>
            )}
          </div>

          <div>
            <div className="text-sm text-slate-500 mb-2">GPU</div>
            <div className="font-semibold text-slate-900">
              {status?.gpu_name || '-'}
            </div>
          </div>

          <div>
            <div className="text-sm text-slate-500 mb-2">Kosten/h</div>
            <div className="font-semibold text-slate-900">
              {status?.dph_total ? `$${status.dph_total.toFixed(3)}` : '-'}
            </div>
          </div>

          <div>
            <div className="text-sm text-slate-500 mb-2">Auto-Stop</div>
            <div className="font-semibold text-slate-900">
              {status && status.auto_shutdown_in_minutes !== null
                ? `${status.auto_shutdown_in_minutes} min`
                : '-'}
            </div>
          </div>

          <div>
            <div className="text-sm text-slate-500 mb-2">Budget</div>
            <div className={`font-bold text-lg ${getCreditColor(status?.account_credit ?? null)}`}>
              {status && status.account_credit !== null
                ? `$${status.account_credit.toFixed(2)}`
                : '-'}
            </div>
          </div>

          <div>
            <div className="text-sm text-slate-500 mb-2">Session</div>
            <div className="font-semibold text-slate-900">
              {status && status.session_runtime_minutes !== null && status.session_cost_usd !== null
                ? `${Math.round(status.session_runtime_minutes)} min / $${status.session_cost_usd.toFixed(3)}`
                : '-'}
            </div>
          </div>
        </div>

        {/* Buttons */}
        <div className="flex items-center gap-4 mt-6 pt-6 border-t border-slate-200">
          <button
            onClick={powerOn}
            disabled={actionLoading !== null || status?.status === 'running'}
            className="px-6 py-2 bg-orange-600 text-white rounded-lg font-medium hover:bg-orange-700 disabled:opacity-50 disabled:cursor-not-allowed transition-colors"
          >
            Starten
          </button>
          <button
            onClick={powerOff}
            disabled={actionLoading !== null || status?.status !== 'running'}
            className="px-6 py-2 bg-red-600 text-white rounded-lg font-medium hover:bg-red-700 disabled:opacity-50 disabled:cursor-not-allowed transition-colors"
          >
            Stoppen
          </button>
          <button
            onClick={fetchStatus}
            disabled={loading}
            className="px-4 py-2 border border-slate-300 text-slate-700 rounded-lg font-medium hover:bg-slate-50 disabled:opacity-50 transition-colors"
          >
            {loading ? 'Aktualisiere...' : 'Aktualisieren'}
          </button>

          {message && (
            <span className="ml-4 text-sm text-green-600 font-medium">{message}</span>
          )}
          {error && (
            <span className="ml-4 text-sm text-red-600 font-medium">{error}</span>
          )}
        </div>
      </div>

      {/* Extended Stats */}
      <div className="grid grid-cols-1 lg:grid-cols-2 gap-6 mb-6">
        <div className="bg-white rounded-xl border border-slate-200 p-6">
          <h3 className="font-semibold text-slate-900 mb-4">Kosten-Uebersicht</h3>
          <div className="space-y-4">
            <div className="flex justify-between items-center">
              <span className="text-slate-600">Session Laufzeit</span>
              <span className="font-semibold">
                {status && status.session_runtime_minutes !== null
                  ? `${Math.round(status.session_runtime_minutes)} Minuten`
                  : '-'}
              </span>
            </div>
            <div className="flex justify-between items-center">
              <span className="text-slate-600">Session Kosten</span>
              <span className="font-semibold">
                {status && status.session_cost_usd !== null
                  ? `$${status.session_cost_usd.toFixed(4)}`
                  : '-'}
              </span>
            </div>
            <div className="flex justify-between items-center pt-4 border-t border-slate-100">
              <span className="text-slate-600">Gesamtlaufzeit</span>
              <span className="font-semibold">
                {status && status.total_runtime_hours !== null
                  ? `${status.total_runtime_hours.toFixed(1)} Stunden`
                  : '-'}
              </span>
            </div>
            <div className="flex justify-between items-center">
              <span className="text-slate-600">Gesamtkosten</span>
              <span className="font-semibold">
                {status && status.total_cost_usd !== null
                  ? `$${status.total_cost_usd.toFixed(2)}`
                  : '-'}
              </span>
            </div>
            <div className="flex justify-between items-center">
              <span className="text-slate-600">vast.ai Ausgaben</span>
              <span className="font-semibold">
                {status && status.account_total_spend !== null
                  ? `$${status.account_total_spend.toFixed(2)}`
                  : '-'}
              </span>
            </div>
          </div>
        </div>

        <div className="bg-white rounded-xl border border-slate-200 p-6">
          <h3 className="font-semibold text-slate-900 mb-4">Instanz-Details</h3>
          <div className="space-y-4">
            <div className="flex justify-between items-center">
              <span className="text-slate-600">Instanz ID</span>
              <span className="font-mono text-sm">
                {status?.instance_id || '-'}
              </span>
            </div>
            <div className="flex justify-between items-center">
              <span className="text-slate-600">GPU</span>
              <span className="font-semibold">
                {status?.gpu_name || '-'}
              </span>
            </div>
            <div className="flex justify-between items-center">
              <span className="text-slate-600">Stundensatz</span>
              <span className="font-semibold">
                {status?.dph_total ? `$${status.dph_total.toFixed(4)}/h` : '-'}
              </span>
            </div>
            <div className="flex justify-between items-center">
              <span className="text-slate-600">Letzte Aktivitaet</span>
              <span className="text-sm">
                {status?.last_activity
                  ? new Date(status.last_activity).toLocaleString('de-DE')
                  : '-'}
              </span>
            </div>
            {status?.endpoint_base_url && status.status === 'running' && (
              <div className="pt-4 border-t border-slate-100">
                <div className="text-slate-600 text-sm mb-1">Endpoint</div>
                <code className="text-xs bg-slate-100 px-2 py-1 rounded block overflow-x-auto">
                  {status.endpoint_base_url}
                </code>
              </div>
            )}
          </div>
        </div>
      </div>

      {/* Info */}
      <div className="bg-orange-50 border border-orange-200 rounded-xl p-4">
        <div className="flex gap-3">
          <svg className="w-5 h-5 text-orange-600 flex-shrink-0 mt-0.5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M13 16h-1v-4h-1m1-4h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z" />
          </svg>
          <div>
            <h4 className="font-semibold text-orange-900">Auto-Shutdown</h4>
            <p className="text-sm text-orange-800 mt-1">
              Die GPU-Instanz wird automatisch gestoppt, wenn sie laengere Zeit inaktiv ist.
              Der Status wird alle 30 Sekunden automatisch aktualisiert.
            </p>
          </div>
        </div>
      </div>
    </div>
  )
}
