'use client'

import Link from 'next/link'
import { SkeletonDots } from '@/components/common/SkeletonText'
import { TrainingMetrics } from '@/components/ai/TrainingMetrics'
import type { TrOCRStatus, TrainingExample, MagicSettings } from '../types'
import { API_BASE } from '../types'

interface TabTrainingProps {
  status: TrOCRStatus | null
  examples: TrainingExample[]
  trainingImage: File | null
  trainingText: string
  fineTuning: boolean
  settings: MagicSettings
  showTrainingDashboard: boolean
  onSetTrainingImage: (file: File | null) => void
  onSetTrainingText: (text: string) => void
  onAddExample: () => void
  onFineTune: () => void
  onToggleDashboard: () => void
}

export function TabTraining({
  status,
  examples,
  trainingImage,
  trainingText,
  fineTuning,
  settings,
  showTrainingDashboard,
  onSetTrainingImage,
  onSetTrainingText,
  onAddExample,
  onFineTune,
  onToggleDashboard,
}: TabTrainingProps) {
  const exampleCount = status?.training_examples_count || 0
  const progressPct = Math.min(100, (exampleCount / 10) * 100)

  return (
    <div className="space-y-6">
      {/* Training Overview */}
      <TrainingOverviewCard
        status={status}
        settings={settings}
        exampleCount={exampleCount}
        progressPct={progressPct}
      />

      <div className="grid grid-cols-1 md:grid-cols-2 gap-6">
        {/* Add Training Example */}
        <AddExampleCard
          trainingImage={trainingImage}
          trainingText={trainingText}
          onSetTrainingImage={onSetTrainingImage}
          onSetTrainingText={onSetTrainingText}
          onAddExample={onAddExample}
        />

        {/* Fine-Tuning */}
        <FineTuningCard
          settings={settings}
          fineTuning={fineTuning}
          exampleCount={exampleCount}
          hasLoraAdapter={status?.has_lora_adapter || false}
          onFineTune={onFineTune}
        />
      </div>

      {/* Training Examples List */}
      {examples.length > 0 && (
        <ExamplesListCard examples={examples} />
      )}

      {/* Training Dashboard Demo */}
      <TrainingDashboardCard
        showDashboard={showTrainingDashboard}
        onToggle={onToggleDashboard}
      />
    </div>
  )
}

/* ------------------------------------------------------------------ */

function TrainingOverviewCard({
  status,
  settings,
  exampleCount,
  progressPct,
}: {
  status: TrOCRStatus | null
  settings: MagicSettings
  exampleCount: number
  progressPct: number
}) {
  return (
    <div className="bg-white rounded-xl shadow-sm border p-6">
      <h2 className="text-lg font-semibold text-slate-900 mb-4">Training mit LoRA</h2>
      <p className="text-sm text-slate-500 mb-4">
        LoRA (Low-Rank Adaptation) ermoeglicht effizientes Fine-Tuning ohne das Basismodell zu veraendern.
        Das Training erfolgt lokal auf Ihrem System.
      </p>

      <div className="grid grid-cols-2 md:grid-cols-4 gap-4 mb-6">
        <div className="bg-slate-50 rounded-lg p-4 text-center">
          <div className="text-3xl font-bold text-slate-900">{exampleCount}</div>
          <div className="text-xs text-slate-500">Trainingsbeispiele</div>
        </div>
        <div className="bg-slate-50 rounded-lg p-4 text-center">
          <div className="text-3xl font-bold text-slate-900">10</div>
          <div className="text-xs text-slate-500">Minimum benoetigt</div>
        </div>
        <div className="bg-slate-50 rounded-lg p-4 text-center">
          <div className="text-3xl font-bold text-slate-900">{settings.loraRank}</div>
          <div className="text-xs text-slate-500">LoRA Rank</div>
        </div>
        <div className="bg-slate-50 rounded-lg p-4 text-center">
          <div className="text-3xl font-bold text-slate-900">{status?.has_lora_adapter ? '\u2713' : '\u2717'}</div>
          <div className="text-xs text-slate-500">Adapter aktiv</div>
        </div>
      </div>

      <div className="mb-6">
        <div className="flex justify-between text-sm mb-1">
          <span className="text-slate-500">Fortschritt zum Fine-Tuning</span>
          <span className="text-slate-500">{progressPct.toFixed(0)}%</span>
        </div>
        <div className="h-2 bg-slate-200 rounded-full overflow-hidden">
          <div
            className="h-full bg-gradient-to-r from-purple-500 to-blue-500 transition-all duration-500"
            style={{ width: `${progressPct}%` }}
          />
        </div>
      </div>
    </div>
  )
}

function AddExampleCard({
  trainingImage,
  trainingText,
  onSetTrainingImage,
  onSetTrainingText,
  onAddExample,
}: {
  trainingImage: File | null
  trainingText: string
  onSetTrainingImage: (file: File | null) => void
  onSetTrainingText: (text: string) => void
  onAddExample: () => void
}) {
  return (
    <div className="bg-white rounded-xl shadow-sm border p-6">
      <h2 className="text-lg font-semibold text-slate-900 mb-4">Trainingsbeispiel hinzufuegen</h2>
      <p className="text-sm text-slate-500 mb-4">
        Lade ein Bild mit handgeschriebenem Text hoch und gib die korrekte Transkription ein.
      </p>

      <div className="space-y-4">
        <div>
          <label className="block text-sm text-slate-700 mb-1">Bild</label>
          <input
            type="file"
            accept="image/*"
            className="w-full bg-slate-50 border border-slate-300 rounded-lg px-3 py-2 text-sm"
            onChange={(e) => onSetTrainingImage(e.target.files?.[0] || null)}
          />
          {trainingImage && (
            <div className="mt-2 text-xs text-green-600">
              Bild ausgewaehlt: {trainingImage.name}
            </div>
          )}
        </div>
        <div>
          <label className="block text-sm text-slate-700 mb-1">Korrekter Text (Ground Truth)</label>
          <textarea
            className="w-full bg-slate-50 border border-slate-300 rounded-lg px-3 py-2 text-sm text-slate-900 resize-none"
            rows={3}
            placeholder="Gib hier den korrekten Text ein..."
            value={trainingText}
            onChange={(e) => onSetTrainingText(e.target.value)}
          />
        </div>
        <button
          onClick={onAddExample}
          className="w-full px-4 py-2 bg-purple-600 hover:bg-purple-700 text-white rounded-lg text-sm font-medium transition-colors"
        >
          + Trainingsbeispiel hinzufuegen
        </button>
      </div>
    </div>
  )
}

function FineTuningCard({
  settings,
  fineTuning,
  exampleCount,
  hasLoraAdapter,
  onFineTune,
}: {
  settings: MagicSettings
  fineTuning: boolean
  exampleCount: number
  hasLoraAdapter: boolean
  onFineTune: () => void
}) {
  return (
    <div className="bg-white rounded-xl shadow-sm border p-6">
      <h2 className="text-lg font-semibold text-slate-900 mb-4">Fine-Tuning starten</h2>
      <p className="text-sm text-slate-500 mb-4">
        Trainiere das Modell mit den gesammelten Beispielen. Der Prozess dauert
        je nach Anzahl der Beispiele einige Minuten.
      </p>

      <div className="bg-slate-50 rounded-lg p-4 mb-4">
        <div className="grid grid-cols-2 gap-4 text-sm">
          <div>
            <span className="text-slate-500">Epochen:</span>
            <span className="text-slate-900 ml-2">{settings.epochs}</span>
          </div>
          <div>
            <span className="text-slate-500">Learning Rate:</span>
            <span className="text-slate-900 ml-2">{settings.learningRate}</span>
          </div>
          <div>
            <span className="text-slate-500">LoRA Rank:</span>
            <span className="text-slate-900 ml-2">{settings.loraRank}</span>
          </div>
          <div>
            <span className="text-slate-500">Batch Size:</span>
            <span className="text-slate-900 ml-2">{settings.batchSize}</span>
          </div>
        </div>
      </div>

      <button
        onClick={onFineTune}
        disabled={fineTuning || exampleCount < 10}
        className="w-full px-4 py-2 bg-green-600 hover:bg-green-700 disabled:bg-slate-300 disabled:cursor-not-allowed text-white rounded-lg text-sm font-medium transition-colors"
      >
        {fineTuning ? (
          <span className="flex items-center justify-center gap-2">
            <SkeletonDots />
            Fine-Tuning laeuft...
          </span>
        ) : (
          'Fine-Tuning starten'
        )}
      </button>

      {exampleCount < 10 && (
        <p className="text-xs text-yellow-600 mt-2 text-center">
          Noch {10 - exampleCount} Beispiele benoetigt
        </p>
      )}

      <Link
        href="/ai/ocr-labeling?model=trocr-lora"
        className="w-full mt-4 px-4 py-2 bg-teal-100 text-teal-700 border border-teal-300 rounded-lg hover:bg-teal-200 flex items-center justify-center gap-2 transition-colors"
      >
        <span>🏷️</span>
        Ground Truth in OCR-Labeling sammeln
      </Link>
    </div>
  )
}

function ExamplesListCard({ examples }: { examples: TrainingExample[] }) {
  return (
    <div className="bg-white rounded-xl shadow-sm border p-6">
      <h2 className="text-lg font-semibold text-slate-900 mb-4">Trainingsbeispiele ({examples.length})</h2>
      <div className="space-y-2 max-h-64 overflow-y-auto">
        {examples.map((ex, i) => (
          <div key={i} className="flex items-center gap-4 bg-slate-50 rounded-lg p-3">
            <span className="text-slate-400 font-mono text-sm w-8">{i + 1}.</span>
            <span className="text-slate-900 text-sm flex-1 truncate">{ex.ground_truth}</span>
            <span className="text-slate-400 text-xs">{new Date(ex.created_at).toLocaleDateString('de-DE')}</span>
          </div>
        ))}
      </div>
    </div>
  )
}

function TrainingDashboardCard({
  showDashboard,
  onToggle,
}: {
  showDashboard: boolean
  onToggle: () => void
}) {
  return (
    <div className="bg-white rounded-xl shadow-sm border p-6">
      <div className="flex items-center justify-between mb-4">
        <div>
          <h2 className="text-lg font-semibold text-slate-900">Training Dashboard</h2>
          <p className="text-sm text-slate-500">Live-Metriken waehrend des Trainings</p>
        </div>
        <button
          onClick={onToggle}
          className={`px-4 py-2 rounded-lg text-sm font-medium transition-colors ${
            showDashboard
              ? 'bg-red-600 hover:bg-red-700 text-white'
              : 'bg-purple-600 hover:bg-purple-700 text-white'
          }`}
        >
          {showDashboard ? 'Demo stoppen' : 'Demo starten'}
        </button>
      </div>

      {showDashboard ? (
        <TrainingMetrics
          apiBase={API_BASE}
          simulateMode={true}
          onComplete={onToggle}
        />
      ) : (
        <div className="bg-slate-50 rounded-lg p-8 text-center">
          <div className="text-4xl mb-3">📈</div>
          <div className="text-slate-600 mb-2">
            Das Training Dashboard zeigt Echtzeit-Metriken waehrend des Fine-Tunings
          </div>
          <div className="text-sm text-slate-400">
            Klicke &quot;Demo starten&quot; um eine simulierte Training-Session zu sehen
          </div>
        </div>
      )}
    </div>
  )
}