'use client'

import { useState, useEffect, useCallback } from 'react'
import type { TabId, TrOCRStatus, OCRResult, TrainingExample, MagicSettings } from './types'
import { DEFAULT_SETTINGS } from './types'

export function useMagicHelp() {
  const [activeTab, setActiveTab] = useState<TabId>('overview')
  const [status, setStatus] = useState<TrOCRStatus | null>(null)
  const [loading, setLoading] = useState(true)
  const [ocrResult, setOcrResult] = useState<OCRResult | null>(null)
  const [ocrLoading, setOcrLoading] = useState(false)
  const [examples, setExamples] = useState<TrainingExample[]>([])
  const [trainingImage, setTrainingImage] = useState<File | null>(null)
  const [trainingText, setTrainingText] = useState('')
  const [fineTuning, setFineTuning] = useState(false)
  const [settings, setSettings] = useState<MagicSettings>(DEFAULT_SETTINGS)
  const [settingsSaved, setSettingsSaved] = useState(false)

  const fetchStatus = useCallback(async () => {
    try {
      const res = await fetch('/api/klausur/trocr/status')
      const data = await res.json()
      setStatus(data)
    } catch {
      setStatus({ status: 'error', error: 'Failed to fetch status' })
    } finally {
      setLoading(false)
    }
  }, [])

  const fetchExamples = useCallback(async () => {
    try {
      const res = await fetch('/api/klausur/trocr/training/examples')
      const data = await res.json()
      setExamples(data.examples || [])
    } catch (error) {
      console.error('Failed to fetch examples:', error)
    }
  }, [])

  useEffect(() => {
    fetchStatus()
    fetchExamples()
    // Load settings from localStorage
    const saved = localStorage.getItem('magic-help-settings')
    if (saved) {
      try {
        setSettings(JSON.parse(saved))
      } catch {
        // ignore parse errors
      }
    }
  }, [fetchStatus, fetchExamples])

  const handleFileUpload = async (file: File) => {
    setOcrLoading(true)
    setOcrResult(null)

    const formData = new FormData()
    formData.append('file', file)

    try {
      const res = await fetch(`/api/klausur/trocr/extract?detect_lines=${settings.autoDetectLines}`, {
        method: 'POST',
        body: formData,
      })
      const data = await res.json()
      if (data.text !== undefined) {
        setOcrResult(data)
      } else {
        setOcrResult({ text: `Error: ${data.detail || 'Unknown error'}`, confidence: 0, processing_time_ms: 0, model: '', has_lora_adapter: false })
      }
    } catch (error) {
      setOcrResult({ text: `Error: ${error}`, confidence: 0, processing_time_ms: 0, model: '', has_lora_adapter: false })
    } finally {
      setOcrLoading(false)
    }
  }

  const handleAddTrainingExample = async () => {
    if (!trainingImage || !trainingText.trim()) {
      alert('Please provide both an image and the correct text')
      return
    }

    const formData = new FormData()
    formData.append('file', trainingImage)

    try {
      const res = await fetch(`/api/klausur/trocr/training/add?ground_truth=${encodeURIComponent(trainingText)}`, {
        method: 'POST',
        body: formData,
      })
      const data = await res.json()
      if (data.example_id) {
        alert(`Training example added! Total: ${data.total_examples}`)
        setTrainingImage(null)
        setTrainingText('')
        fetchStatus()
        fetchExamples()
      } else {
        alert(`Error: ${data.detail || 'Unknown error'}`)
      }
    } catch (error) {
      alert(`Error: ${error}`)
    }
  }

  const handleFineTune = async () => {
    if (!confirm('Start fine-tuning? This may take several minutes.')) return

    setFineTuning(true)
    try {
      const res = await fetch('/api/klausur/trocr/training/fine-tune', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          epochs: settings.epochs,
          learning_rate: settings.learningRate,
          lora_rank: settings.loraRank,
          lora_alpha: settings.loraAlpha,
        }),
      })
      const data = await res.json()
      if (data.status === 'success') {
        alert(`Fine-tuning successful!\nExamples used: ${data.examples_used}\nEpochs: ${data.epochs}`)
        fetchStatus()
      } else {
        alert(`Fine-tuning failed: ${data.message}`)
      }
    } catch (error) {
      alert(`Error: ${error}`)
    } finally {
      setFineTuning(false)
    }
  }

  const saveSettings = () => {
    localStorage.setItem('magic-help-settings', JSON.stringify(settings))
    setSettingsSaved(true)
    setTimeout(() => setSettingsSaved(false), 2000)
  }

  const getStatusBadge = () => {
    if (!status) return null
    switch (status.status) {
      case 'available':
        return <span className="px-2 py-1 text-xs font-medium rounded-full bg-green-500/20 text-green-400">Available</span>
      case 'not_installed':
        return <span className="px-2 py-1 text-xs font-medium rounded-full bg-red-500/20 text-red-400">Not Installed</span>
      case 'error':
        return <span className="px-2 py-1 text-xs font-medium rounded-full bg-yellow-500/20 text-yellow-400">Error</span>
    }
  }

  return {
    activeTab,
    setActiveTab,
    status,
    loading,
    ocrResult,
    ocrLoading,
    examples,
    trainingImage,
    setTrainingImage,
    trainingText,
    setTrainingText,
    fineTuning,
    settings,
    setSettings,
    settingsSaved,
    fetchStatus,
    handleFileUpload,
    handleAddTrainingExample,
    handleFineTune,
    saveSettings,
    getStatusBadge,
  }
}