import React, { useState, useEffect } from 'react'
import {
  Box,
  Typography,
  Paper,
  IconButton,
  Button,
  Dialog,
  DialogTitle,
  DialogContent,
  DialogActions,
  CircularProgress,
  Alert,
} from '@mui/material'
import {
  PictureAsPdf,
  Download,
  Close,
  ZoomIn,
  ZoomOut,
  NavigateBefore,
  NavigateNext,
} from '@mui/icons-material'
import type { Document } from '../types'

interface FilePreviewProps {
  document: Document
  onClose: () => void
}

export const FilePreview: React.FC<FilePreviewProps> = ({ document, onClose }) => {
  const [loading, setLoading] = useState(true)
  const [error, setError] = useState<string | null>(null)
  const [page, setPage] = useState(1)
  const [scale, setScale] = useState(1.0)
  const [numPages, setNumPages] = useState(0)

  useEffect(() => {
    setLoading(true)
    setError(null)
    setPage(1)
    setScale(1.0)

    // Simuler le chargement du PDF
    const timer = setTimeout(() => {
      setNumPages(3) // Simuler 3 pages
      setLoading(false)
    }, 1000)

    return () => clearTimeout(timer)
  }, [document])

  const handleDownload = () => {
    if (document.previewUrl) {
      const link = window.document.createElement('a')
      link.href = document.previewUrl
      link.download = document.name
      link.click()
    }
  }

  const isPDF = document.type.includes('pdf') || document.name.toLowerCase().endsWith('.pdf')

  if (!isPDF) {
    return (
      <Paper sx={{ p: 3, mt: 2 }}>
        <Box display="flex" justifyContent="space-between" alignItems="center" mb={2}>
          <Typography variant="h6">{document.name}</Typography>
          <IconButton onClick={onClose} title="Fermer">
            <Close />
          </IconButton>
        </Box>
        <Alert severity="info">
          Aperçu non disponible pour ce type de fichier ({document.type})
        </Alert>
      </Paper>
    )
  }

  return (
    <Dialog open onClose={onClose} maxWidth="lg" fullWidth>
      <DialogTitle>
        <Box display="flex" justifyContent="space-between" alignItems="center">
          <Box display="flex" alignItems="center" gap={1}>
            <PictureAsPdf color="error" />
            <Typography variant="h6">{document.name}</Typography>
          </Box>
          <IconButton onClick={onClose} title="Fermer">
            <Close />
          </IconButton>
        </Box>
      </DialogTitle>

      <DialogContent dividers>
        {loading && (
          <Box display="flex" justifyContent="center" alignItems="center" minHeight="400px">
            <CircularProgress />
            <Typography variant="body2" sx={{ ml: 2 }}>
              Chargement du PDF...
            </Typography>
          </Box>
        )}

        {error && (
          <Alert severity="error" sx={{ mb: 2 }}>
            {error}
          </Alert>
        )}

        {!loading && !error && (
          <Box>
            {/* Contrôles de navigation */}
            <Box display="flex" justifyContent="space-between" alignItems="center" mb={2}>
              <Box display="flex" alignItems="center" gap={1}>
                <Button
                  variant="outlined"
                  size="small"
                  startIcon={<NavigateBefore />}
                  onClick={() => setPage(prev => Math.max(prev - 1, 1))}
                  disabled={page <= 1}
                >
                  Précédent
                </Button>
                <Typography variant="body2">
                  Page {page} sur {numPages}
                </Typography>
                <Button
                  variant="outlined"
                  size="small"
                  endIcon={<NavigateNext />}
                  onClick={() => setPage(prev => Math.min(prev + 1, numPages))}
                  disabled={page >= numPages}
                >
                  Suivant
                </Button>
              </Box>

              <Box display="flex" alignItems="center" gap={1}>
                <Button
                  variant="outlined"
                  size="small"
                  startIcon={<ZoomOut />}
                  onClick={() => setScale(prev => Math.max(prev - 0.2, 0.5))}
                >
                  Zoom -
                </Button>
                <Typography variant="body2">
                  {Math.round(scale * 100)}%
                </Typography>
                <Button
                  variant="outlined"
                  size="small"
                  startIcon={<ZoomIn />}
                  onClick={() => setScale(prev => Math.min(prev + 0.2, 2.0))}
                >
                  Zoom +
                </Button>
              </Box>
            </Box>

            {/* Aperçu PDF avec viewer intégré */}
            <Box sx={{
              border: '1px solid',
              borderColor: 'grey.300',
              borderRadius: 1,
              overflow: 'hidden',
              maxHeight: '70vh',
              display: 'flex',
              justifyContent: 'center',
              backgroundColor: 'grey.50'
            }}>
              {document.previewUrl ? (
                <Box sx={{ width: '100%', height: '600px' }}>
                  {/* Utiliser un viewer PDF intégré */}
                  <iframe
                    src={`${document.previewUrl}#toolbar=1&navpanes=1&scrollbar=1&page=1&view=FitH`}
                    width="100%"
                    height="100%"
                    style={{
                      border: 'none',
                      transform: `scale(${scale})`,
                      transformOrigin: 'top left',
                      width: `${100 / scale}%`,
                      height: `${600 / scale}px`
                    }}
                    title={`Aperçu de ${document.name}`}
                    onLoad={() => setLoading(false)}
                    onError={() => {
                      setError('Erreur de chargement du PDF')
                      setLoading(false)
                    }}
                  />
                </Box>
              ) : (
                <Box display="flex" justifyContent="center" alignItems="center" minHeight="400px">
                  <Box textAlign="center">
                    <PictureAsPdf sx={{ fontSize: 64, color: 'error.main', mb: 2 }} />
                    <Typography variant="h6" gutterBottom>
                      Aperçu PDF
                    </Typography>
                    <Typography variant="body2" color="text.secondary">
                      Le fichier PDF "{document.name}" a été uploadé avec succès.
                    </Typography>
                    <Typography variant="body2" color="text.secondary">
                      Taille: {(document.size / 1024 / 1024).toFixed(2)} MB
                    </Typography>
                  </Box>
                </Box>
              )}
            </Box>
          </Box>
        )}
      </DialogContent>

      <DialogActions>
        <Button onClick={onClose}>
          Fermer
        </Button>
        <Button
          variant="contained"
          startIcon={<Download />}
          onClick={handleDownload}
          disabled={!document.previewUrl}
        >
          Télécharger
        </Button>
      </DialogActions>
    </Dialog>
  )
}