import { ref, readonly, computed } from 'vue'
import { nextTick } from 'vue'
import type { CheckInStatus } from '~/types/checkin'

export interface UseQRGeneratorOptions {
  showSnackbar: (title: string, message: string, color: string, icon: string) => void
  generateRandomPatientId: () => string
}

export const useQRGenerator = (options: UseQRGeneratorOptions) => {
  const { showSnackbar, generateRandomPatientId } = options

  // State
  const generatePatientId = ref(generateRandomPatientId())
  const generateStatus = ref<CheckInStatus>('ALLOWED')
  const generatedQRData = ref('')

  // Generate random patient ID
  const generateRandomId = () => {
    generatePatientId.value = generateRandomPatientId()
  }

  // Quick generate QR for testing
  const generateQuickQR = (patientId: string, status: string) => {
    generatePatientId.value = patientId
    generateStatus.value = status as CheckInStatus
    generateQRCode()
  }

  // Generate QR Code function
  const generateQRCode = async () => {
    if (!generatePatientId.value) {
      showSnackbar('Error', 'Mohon isi ID Pasien', 'error', 'mdi-alert')
      return
    }

    generatedQRData.value = `${generatePatientId.value}|${generateStatus.value}`
    
    await nextTick()
    
    // Clear previous QR code
    const qrContainer = document.getElementById('qrcode')
    if (qrContainer) {
      qrContainer.innerHTML = ''
      
      try {
        // Use qrcode package that's already installed
        const QRCode = (await import('qrcode')).default
        
        // Create QR code as data URL
        const qrDataUrl = await QRCode.toDataURL(generatedQRData.value, {
          errorCorrectionLevel: 'M',
          type: 'image/png',
          quality: 0.92,
          margin: 1,
          color: {
            dark: '#000000',
            light: '#FFFFFF'
          },
          width: 300
        })
        
        // Create img element and append to container
        const img = document.createElement('img')
        img.src = qrDataUrl
        img.alt = 'QR Code'
        img.style.width = '100%'
        img.style.maxWidth = '300px'
        img.style.height = 'auto'
        img.style.display = 'block'
        img.style.margin = '0 auto'
        qrContainer.appendChild(img)
        
        console.log('QR Code created successfully:', generatedQRData.value)
        showSnackbar('Berhasil!', 'QR Code berhasil di-generate. Silakan scan untuk testing', 'success', 'mdi-check-circle')
      } catch (error) {
        console.error('Error creating QR code:', error)
        showSnackbar('Error', 'Gagal membuat QR Code. Silakan coba lagi', 'error', 'mdi-alert')
      }
    } else {
      showSnackbar('Error', 'Container QR Code tidak ditemukan', 'error', 'mdi-alert')
    }
  }

  // Download QR Code
  const downloadQR = async () => {
    const img = document.querySelector('#qrcode img') as HTMLImageElement
    if (img && img.src) {
      try {
        // Convert img src (data URL) to blob
        const response = await fetch(img.src)
        const blob = await response.blob()
        const url = URL.createObjectURL(blob)
        const link = document.createElement('a')
        const fileName = `QR-Test-${generatePatientId.value}-${generateStatus.value}-${Date.now()}.png`
        link.download = fileName
        link.href = url
        link.style.display = 'none'
        document.body.appendChild(link)
        link.click()
        document.body.removeChild(link)
        URL.revokeObjectURL(url)
        showSnackbar('Berhasil!', `QR Code berhasil didownload: ${fileName}`, 'success', 'mdi-download')
      } catch (error) {
        console.error('Download error:', error)
        // Fallback: use img src directly
        const link = document.createElement('a')
        link.download = `QR-Test-${generatePatientId.value}-${generateStatus.value}.png`
        link.href = img.src
        link.click()
        showSnackbar('Berhasil!', 'QR Code berhasil didownload', 'success', 'mdi-download')
      }
    } else {
      showSnackbar('Error', 'QR Code belum di-generate. Silakan generate terlebih dahulu', 'error', 'mdi-alert')
    }
  }

  // Copy QR Code to Clipboard
  const copyQRToClipboard = async () => {
    const img = document.querySelector('#qrcode img') as HTMLImageElement
    if (img && img.src) {
      try {
        // Convert img src to blob
        const response = await fetch(img.src)
        const blob = await response.blob()
        
        try {
          await navigator.clipboard.write([
            new ClipboardItem({
              'image/png': blob
            })
          ])
          showSnackbar('Berhasil!', 'QR Code berhasil disalin ke clipboard', 'success', 'mdi-content-copy')
        } catch (err: any) {
          console.error('Clipboard error:', err)
          // Fallback: download instead
          showSnackbar('Info', 'Copy ke clipboard tidak didukung. Gunakan tombol Download.', 'info', 'mdi-information')
        }
      } catch (error) {
        console.error('Copy error:', error)
        showSnackbar('Error', 'Gagal menyalin QR Code', 'error', 'mdi-alert')
      }
    } else {
      showSnackbar('Error', 'QR Code belum di-generate. Silakan generate terlebih dahulu', 'error', 'mdi-alert')
    }
  }

  // Share QR Code
  const shareQR = async () => {
    const img = document.querySelector('#qrcode img') as HTMLImageElement
    if (img && img.src) {
      try {
        // Convert img src to blob
        const response = await fetch(img.src)
        const blob = await response.blob()
        const file = new File([blob], `QR-Test-${generatePatientId.value}-${generateStatus.value}.png`, { type: 'image/png' })
        
        if (navigator.share && navigator.canShare({ files: [file] })) {
          try {
            await navigator.share({
              files: [file],
              title: 'QR Code Check-in Test',
              text: `QR Code untuk testing: ${generatedQRData.value}`
            })
            showSnackbar('Berhasil!', 'QR Code berhasil dibagikan', 'success', 'mdi-share')
          } catch (err: any) {
            if (err.name !== 'AbortError') {
              // Fallback to copy or download
              copyQRToClipboard()
            }
          }
        } else {
          // Fallback: try copy to clipboard
          copyQRToClipboard()
        }
      } catch (error) {
        console.error('Share error:', error)
        showSnackbar('Error', 'Gagal membagikan QR Code', 'error', 'mdi-alert')
      }
    } else {
      showSnackbar('Error', 'QR Code belum di-generate. Silakan generate terlebih dahulu', 'error', 'mdi-alert')
    }
  }

  // Computed untuk v-model
  const generatePatientIdModel = computed({
    get: () => generatePatientId.value,
    set: (value: string) => {
      generatePatientId.value = value
    }
  })

  const generateStatusModel = computed({
    get: () => generateStatus.value,
    set: (value: CheckInStatus) => {
      generateStatus.value = value
    }
  })

  return {
    generatePatientId: generatePatientIdModel,
    generateStatus: generateStatusModel,
    generatedQRData: readonly(generatedQRData),
    generateRandomId,
    generateQuickQR,
    generateQRCode,
    downloadQR,
    copyQRToClipboard,
    shareQR,
  }
}