'use client'

import { useState } from 'react'
import AdminLayout from '@/components/admin/AdminLayout'
import {
  WizardStepper,
  WizardNavigation,
  EducationCard,
  ArchitectureContext,
  TestRunner,
  TestSummary,
  type WizardStep,
  type TestCategoryResult,
  type FullTestResults,
  type EducationContent,
  type ArchitectureContextType,
} from '@/components/wizard'

// ==============================================
// Constants
// ==============================================

const BACKEND_URL = process.env.NEXT_PUBLIC_BACKEND_URL || 'http://localhost:8000'

const STEPS: WizardStep[] = [
  { id: 'welcome', name: 'Willkommen', icon: '👋', status: 'pending' },
  { id: 'api-health', name: 'API Status', icon: '💚', status: 'pending', category: 'api-health' },
  { id: 'detection', name: 'GPU Erkennung', icon: '🔍', status: 'pending', category: 'detection' },
  { id: 'cloud', name: 'Cloud GPU', icon: '☁️', status: 'pending', category: 'cloud' },
  { id: 'summary', name: 'Zusammenfassung', icon: '📊', status: 'pending' },
]

const EDUCATION_CONTENT: Record<string, EducationContent> = {
  'welcome': {
    title: 'Willkommen zum GPU Wizard',
    content: [
      'GPUs beschleunigen KI-Workloads um das 10-100fache.',
      '',
      'BreakPilot unterstuetzt:',
      '• NVIDIA GPUs (CUDA) - GeForce, Tesla, A100',
      '• AMD GPUs (ROCm) - Radeon, Instinct',
      '• Cloud GPUs (vast.ai) - On-Demand Miete',
      '',
      'Anwendungsfaelle:',
      '• LLM Inference (lokale Modelle)',
      '• Embedding-Generierung',
      '• Fine-Tuning von Modellen',
      '• OCR und Bildverarbeitung',
    ],
  },
  'api-health': {
    title: 'GPU Admin API - Verwaltungsschnittstelle',
    content: [
      'Die GPU API verwaltet lokale und Cloud-GPUs.',
      '',
      'Endpunkte:',
      '• /api/gpu/status - Aktueller GPU-Status',
      '• /api/gpu/jobs - Laufende GPU-Jobs',
      '• /api/gpu/metrics - Auslastung und Temperatur',
      '',
      'vast.ai Integration:',
      '• /vast/instances - Gemietete Instanzen',
      '• /vast/offers - Verfuegbare Angebote',
      '• /vast/start - Instanz starten',
    ],
  },
  'detection': {
    title: 'GPU Hardware-Erkennung',
    content: [
      'Automatische Erkennung verfuegbarer GPUs.',
      '',
      'NVIDIA (nvidia-smi):',
      '• GPU-Modell und VRAM',
      '• Treiber-Version',
      '• Aktuelle Auslastung',
      '• Temperatur und Stromverbrauch',
      '',
      'AMD (rocm-smi):',
      '• ROCm-Version',
      '• GPU-Modell',
      '• Memory-Statistiken',
      '',
      'PyTorch CUDA Check:',
      '• torch.cuda.is_available()',
      '• torch.cuda.device_count()',
    ],
  },
  'cloud': {
    title: 'Cloud GPUs mit vast.ai',
    content: [
      'vast.ai bietet guenstige Cloud-GPUs auf Abruf.',
      '',
      'Vorteile:',
      '• 3-10x guenstiger als AWS/GCP',
      '• Peer-to-Peer Marktplatz',
      '• Minutengenaue Abrechnung',
      '• Zugriff auf A100, H100, etc.',
      '',
      'Typische Preise:',
      '• RTX 3090: ~$0.20/Stunde',
      '• A100 40GB: ~$1.00/Stunde',
      '• H100: ~$2.50/Stunde',
      '',
      'Konfiguration: VAST_API_KEY Umgebungsvariable',
    ],
  },
  'summary': {
    title: 'Test-Zusammenfassung',
    content: [
      'Hier sehen Sie eine Uebersicht aller durchgefuehrten Tests:',
      '• Lokale GPU-Erkennung',
      '• Cloud-GPU Verfuegbarkeit',
      '• API-Status',
    ],
  },
}

const ARCHITECTURE_CONTEXTS: Record<string, ArchitectureContextType> = {
  'api-health': {
    layer: 'api',
    services: ['backend'],
    dependencies: ['PostgreSQL', 'vast.ai API'],
    dataFlow: ['Browser', 'FastAPI', 'GPU Manager', 'PostgreSQL'],
  },
  'detection': {
    layer: 'service',
    services: ['backend'],
    dependencies: ['nvidia-smi', 'rocm-smi', 'PyTorch'],
    dataFlow: ['FastAPI', 'Subprocess', 'GPU Driver', 'Hardware'],
  },
  'cloud': {
    layer: 'service',
    services: ['backend'],
    dependencies: ['vast.ai API', 'SSH', 'Docker'],
    dataFlow: ['FastAPI', 'vast.ai API', 'Cloud Instance', 'GPU'],
  },
}

// ==============================================
// Main Component
// ==============================================

export default function GPUWizardPage() {
  const [currentStep, setCurrentStep] = useState(0)
  const [steps, setSteps] = useState<WizardStep[]>(STEPS)
  const [categoryResults, setCategoryResults] = useState<Record<string, TestCategoryResult>>({})
  const [fullResults, setFullResults] = useState<FullTestResults | null>(null)
  const [isLoading, setIsLoading] = useState(false)
  const [error, setError] = useState<string | null>(null)

  const currentStepData = steps[currentStep]
  const isTestStep = currentStepData?.category !== undefined
  const isWelcome = currentStepData?.id === 'welcome'
  const isSummary = currentStepData?.id === 'summary'

  const runCategoryTest = async (category: string) => {
    setIsLoading(true)
    setError(null)

    try {
      const response = await fetch(`${BACKEND_URL}/api/admin/gpu-tests/${category}`, {
        method: 'POST',
      })

      if (!response.ok) {
        throw new Error(`HTTP ${response.status}: ${response.statusText}`)
      }

      const result: TestCategoryResult = await response.json()
      setCategoryResults((prev) => ({ ...prev, [category]: result }))

      setSteps((prev) =>
        prev.map((step) =>
          step.category === category
            ? { ...step, status: result.failed === 0 ? 'completed' : 'failed' }
            : step
        )
      )
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Unbekannter Fehler')
    } finally {
      setIsLoading(false)
    }
  }

  const runAllTests = async () => {
    setIsLoading(true)
    setError(null)

    try {
      const response = await fetch(`${BACKEND_URL}/api/admin/gpu-tests/run-all`, {
        method: 'POST',
      })

      if (!response.ok) {
        throw new Error(`HTTP ${response.status}: ${response.statusText}`)
      }

      const results: FullTestResults = await response.json()
      setFullResults(results)

      setSteps((prev) =>
        prev.map((step) => {
          if (step.category) {
            const catResult = results.categories.find((c) => c.category === step.category)
            if (catResult) {
              return { ...step, status: catResult.failed === 0 ? 'completed' : 'failed' }
            }
          }
          return step
        })
      )

      const newCategoryResults: Record<string, TestCategoryResult> = {}
      results.categories.forEach((cat) => {
        newCategoryResults[cat.category] = cat
      })
      setCategoryResults(newCategoryResults)
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Unbekannter Fehler')
    } finally {
      setIsLoading(false)
    }
  }

  const goToNext = () => {
    if (currentStep < steps.length - 1) {
      setSteps((prev) =>
        prev.map((step, idx) =>
          idx === currentStep && step.status === 'pending'
            ? { ...step, status: 'completed' }
            : step
        )
      )
      setCurrentStep((prev) => prev + 1)
    }
  }

  const goToPrev = () => {
    if (currentStep > 0) {
      setCurrentStep((prev) => prev - 1)
    }
  }

  const handleStepClick = (index: number) => {
    if (index <= currentStep || steps[index - 1]?.status !== 'pending') {
      setCurrentStep(index)
    }
  }

  return (
    <AdminLayout
      title="GPU Wizard"
      description="Interaktives Lernen und Testen der GPU-Infrastruktur"
    >
      {/* Header */}
      <div className="bg-white rounded-lg shadow p-4 mb-6 flex items-center justify-between">
        <div className="flex items-center">
          <span className="text-3xl mr-3">🎮</span>
          <div>
            <h2 className="text-lg font-bold text-gray-800">GPU Infrastructure Wizard</h2>
            <p className="text-sm text-gray-600">CUDA, ROCm & vast.ai</p>
          </div>
        </div>
        <a href="/admin/gpu" className="text-blue-600 hover:text-blue-800 text-sm">
          &larr; Zurueck zu GPU Management
        </a>
      </div>

      {/* Stepper */}
      <div className="bg-white rounded-lg shadow p-6 mb-6">
        <WizardStepper steps={steps} currentStep={currentStep} onStepClick={handleStepClick} />
      </div>

      {/* Content */}
      <div className="bg-white rounded-lg shadow p-6">
        <div className="flex items-center mb-6">
          <span className="text-3xl mr-3">{currentStepData?.icon}</span>
          <div>
            <h2 className="text-xl font-bold text-gray-800">
              Schritt {currentStep + 1}: {currentStepData?.name}
            </h2>
            <p className="text-gray-500 text-sm">
              {currentStep + 1} von {steps.length}
            </p>
          </div>
        </div>

        <EducationCard content={EDUCATION_CONTENT[currentStepData?.id || '']} />

        {isTestStep && currentStepData?.category && ARCHITECTURE_CONTEXTS[currentStepData.category] && (
          <ArchitectureContext
            context={ARCHITECTURE_CONTEXTS[currentStepData.category]}
            currentStep={currentStepData.name}
          />
        )}

        {error && (
          <div className="bg-red-50 border border-red-200 text-red-700 rounded-lg p-4 mb-6">
            <strong>Fehler:</strong> {error}
          </div>
        )}

        {isWelcome && (
          <div className="text-center py-8">
            <button
              onClick={goToNext}
              className="bg-blue-600 text-white px-8 py-3 rounded-lg font-medium hover:bg-blue-700 transition-colors"
            >
              Wizard starten
            </button>
          </div>
        )}

        {isTestStep && currentStepData?.category && (
          <TestRunner
            category={currentStepData.category}
            categoryResult={categoryResults[currentStepData.category]}
            isLoading={isLoading}
            onRunTests={() => runCategoryTest(currentStepData.category!)}
          />
        )}

        {isSummary && (
          <div>
            {!fullResults ? (
              <div className="text-center py-8">
                <p className="text-gray-600 mb-4">
                  Fuehren Sie alle Tests aus um eine Zusammenfassung zu sehen.
                </p>
                <button
                  onClick={runAllTests}
                  disabled={isLoading}
                  className={`px-6 py-3 rounded-lg font-medium transition-colors ${
                    isLoading
                      ? 'bg-gray-400 cursor-not-allowed'
                      : 'bg-blue-600 text-white hover:bg-blue-700'
                  }`}
                >
                  {isLoading ? 'Alle Tests laufen...' : 'Alle Tests ausfuehren'}
                </button>
              </div>
            ) : (
              <TestSummary results={fullResults} />
            )}
          </div>
        )}

        <WizardNavigation
          currentStep={currentStep}
          totalSteps={steps.length}
          onPrev={goToPrev}
          onNext={goToNext}
          showNext={!isSummary}
          isLoading={isLoading}
        />
      </div>

      <div className="text-center text-gray-500 text-sm mt-6">
        Diese Tests pruefen die GPU-Infrastruktur.
        Bei Fragen wenden Sie sich an das DevOps-Team.
      </div>
    </AdminLayout>
  )
}
