import { useState } from 'react'
import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query'
import { toast } from 'sonner'
import { cardsApi, isCardsApiError } from '@/api/cards'
import { formatApiError, getDetailedErrorMessage } from '@/lib/error-utils'
import type { GameCardDto, PaginatedResponse } from '@/types/models'
import { Button } from '@/components/ui/button'
import { Input } from '@/components/ui/input'
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card'
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from '@/components/ui/table'
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from '@/components/ui/dialog'
import {
  AlertDialog,
  AlertDialogAction,
  AlertDialogCancel,
  AlertDialogContent,
  AlertDialogDescription,
  AlertDialogFooter,
  AlertDialogHeader,
  AlertDialogTitle,
} from '@/components/ui/alert-dialog'
import { Label } from '@/components/ui/label'
import { Textarea } from '@/components/ui/textarea'
import { ImageUpload } from '@/components/ui/image-upload'
import { CardVoicesManager } from '@/components/CardVoicesManager'
import { BulkCardUpload } from '@/components/BulkCardUpload'
import { BulkCardEditor } from '@/components/BulkCardEditor'
import { packsApi } from '@/api/packs'
import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select'
import { Plus, Search, Edit, Trash2, ChevronLeft, ChevronRight, Upload, List, Grid } from 'lucide-react'

type ViewMode = 'list' | 'grid'

export default function CardsPage() {
  const queryClient = useQueryClient()
  const [page, setPage] = useState(1)
  const [search, setSearch] = useState('')
  const [viewMode, setViewMode] = useState<ViewMode>('list')
  const [selectedCard, setSelectedCard] = useState<GameCardDto | null>(null)
  const [isDialogOpen, setIsDialogOpen] = useState(false)
  const [isDeleteDialogOpen, setIsDeleteDialogOpen] = useState(false)
  const [cardToDelete, setCardToDelete] = useState<GameCardDto | null>(null)
  const [isBulkUploadOpen, setIsBulkUploadOpen] = useState(false)
  const [isBulkEditorOpen, setIsBulkEditorOpen] = useState(false)
  const [uploadedImages, setUploadedImages] = useState<Array<{
    id: string
    file: File
    preview: string
    base64: string
  }>>([])
  const [bulkUploadPackId, setBulkUploadPackId] = useState<string | undefined>(undefined)

  // Form state
  const [formData, setFormData] = useState({
    packId: '',
    original: '',
    translation: '',
    mnemo: '',
    transcription: '',
    transcriptionMnemo: '',
    back: '',
    image: undefined as string | undefined,
    imageBack: undefined as string | undefined,
  })

  const limit = 20

  // Fetch cards
  const { data, isLoading, error } = useQuery<PaginatedResponse<GameCardDto>>({
    queryKey: ['cards', page, search],
    queryFn: () => cardsApi.getCards({ page, limit, search }),
    retry: (failureCount, error) => {
      // Don't retry on client errors (4xx)
      if (isCardsApiError(error) && error.statusCode && error.statusCode >= 400 && error.statusCode < 500) {
        return false
      }
      return failureCount < 2
    },
  })

  // Mutations
  const createMutation = useMutation({
    mutationFn: (card: GameCardDto) => cardsApi.upsertCard(card),
    onSuccess: (response) => {
      queryClient.invalidateQueries({ queryKey: ['cards'] })
      toast.success('Card created successfully')
      closeDialog()
      // Update selectedCard with the new ID from response
      if (response?.card?.id) {
        setSelectedCard(response.card)
      }
    },
    onError: (error: unknown) => {
      const errorMessage = isCardsApiError(error) 
        ? error.message 
        : getDetailedErrorMessage(error, 'create', 'card')
      toast.error(errorMessage)
      console.error('Error creating card:', error)
    },
  })

  const updateMutation = useMutation({
    mutationFn: (card: GameCardDto) => cardsApi.upsertCard(card),
    onSuccess: (response) => {
      queryClient.invalidateQueries({ queryKey: ['cards'] })
      toast.success('Card updated successfully')
      closeDialog()
      // Update selectedCard with the updated card from response
      if (response?.card) {
        setSelectedCard(response.card)
      }
    },
    onError: (error: unknown) => {
      const errorMessage = isCardsApiError(error) 
        ? error.message 
        : getDetailedErrorMessage(error, 'update', 'card')
      toast.error(errorMessage)
      console.error('Error updating card:', error)
    },
  })

  const deleteMutation = useMutation({
    mutationFn: (cardId: string) => cardsApi.deleteCard(cardId),
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['cards'] })
      toast.success('Card deleted successfully')
      setIsDeleteDialogOpen(false)
      setCardToDelete(null)
    },
    onError: (error: unknown) => {
      const errorMessage = isCardsApiError(error) 
        ? error.message 
        : getDetailedErrorMessage(error, 'delete', 'card')
      toast.error(errorMessage)
      console.error('Error deleting card:', error)
    },
  })

  // Fetch packs for packId selection
  const { data: packsData } = useQuery({
    queryKey: ['packs', 1, 100, ''],
    queryFn: () => packsApi.getPacks({ page: 1, limit: 100, search: '' }),
  })

  const openCreateDialog = () => {
    setSelectedCard(null)
    setFormData({
      packId: '',
      original: '',
      translation: '',
      mnemo: '',
      transcription: '',
      transcriptionMnemo: '',
      back: '',
      image: undefined,
      imageBack: undefined,
    })
    setIsDialogOpen(true)
  }

  const openEditDialog = (card: GameCardDto) => {
    setSelectedCard(card)
    setFormData({
      packId: (card as any).packId || '',
      original: card.original || '',
      translation: card.translation || '',
      mnemo: card.mnemo || '',
      transcription: card.transcription || '',
      transcriptionMnemo: card.transcriptionMnemo || '',
      back: card.back || '',
      image: card.image,
      imageBack: card.imageBack,
    })
    setIsDialogOpen(true)
  }

  const closeDialog = () => {
    setIsDialogOpen(false)
    setSelectedCard(null)
  }

  const handleSubmit = (e: React.FormEvent) => {
    e.preventDefault()

    if (!formData.original.trim() || !formData.translation.trim() || !formData.mnemo.trim()) {
      toast.error('Original, translation and mnemo are required')
      return
    }

    // Determine if this is an update or create
    const isUpdate = selectedCard !== null && selectedCard.id !== undefined && selectedCard.id !== null && selectedCard.id !== ''

    const cardData: GameCardDto = {
      id: isUpdate ? selectedCard.id : null,
      packId: formData.packId.trim() || undefined,
      original: formData.original.trim(),
      translation: formData.translation.trim(),
      mnemo: formData.mnemo.trim(),
      transcription: formData.transcription.trim() || undefined,
      transcriptionMnemo: formData.transcriptionMnemo.trim() || undefined,
      back: formData.back.trim() || undefined,
      image: formData.image || undefined,
      imageBack: formData.imageBack || undefined,
    }

    if (isUpdate) {
      updateMutation.mutate(cardData)
    } else {
      createMutation.mutate(cardData)
    }
  }

  const handleDelete = (card: GameCardDto) => {
    setCardToDelete(card)
    setIsDeleteDialogOpen(true)
  }

  const confirmDelete = () => {
    if (cardToDelete) {
      deleteMutation.mutate(cardToDelete.id)
    }
  }

  const handleSearch = (value: string) => {
    setSearch(value)
    setPage(1) // Reset to first page when searching
  }

  // Group cards by pack
  const groupedCards = data?.items.reduce((acc, card) => {
    const packId = card.packId || '__no_pack__'
    if (!acc[packId]) {
      acc[packId] = []
    }
    acc[packId].push(card)
    return acc
  }, {} as Record<string, GameCardDto[]>) || {}

  // Get pack name by ID
  const getPackName = (packId: string): string => {
    if (packId === '__no_pack__') {
      return 'No Pack'
    }
    const pack = packsData?.items.find(p => p.id === packId)
    return pack?.title || packId
  }

  // Get image source - handles both base64 and URLs
  const getImageSrc = (image?: string): string | undefined => {
    if (!image) return undefined
    
    // If it's already a data URL or http/https URL, return as is
    if (image.startsWith('data:') || image.startsWith('http://') || image.startsWith('https://')) {
      return image
    }
    
    // Otherwise, assume it's base64 and add the data URL prefix
    // Try to detect image type from base64 or default to png
    return `data:image/png;base64,${image}`
  }

  if (error) {
    const errorMessage = isCardsApiError(error)
      ? error.message 
      : formatApiError(error)
    return (
      <div className="space-y-6">
        <div>
          <h1 className="text-3xl font-bold tracking-tight">Cards Management</h1>
          <p className="text-muted-foreground">Error loading cards</p>
        </div>
        <Card>
          <CardContent className="pt-6">
            <div className="space-y-2">
              <p className="text-red-500 font-medium">Failed to load cards</p>
              <p className="text-sm text-muted-foreground">{errorMessage}</p>
              <Button 
                variant="outline" 
                size="sm" 
                onClick={() => queryClient.invalidateQueries({ queryKey: ['cards'] })}
                className="mt-2"
              >
                Retry
              </Button>
            </div>
          </CardContent>
        </Card>
      </div>
    )
  }

  return (
    <div className="space-y-6">
      <div className="flex items-center justify-between">
        <div>
          <h1 className="text-3xl font-bold tracking-tight">Cards Management</h1>
          <p className="text-muted-foreground">
            View, create, edit and delete game cards
          </p>
        </div>
        <div className="flex items-center space-x-2">
          <Button variant="outline" onClick={() => setIsBulkUploadOpen(true)}>
            <Upload className="mr-2 h-4 w-4" />
            Bulk Upload
          </Button>
          <Button onClick={openCreateDialog}>
            <Plus className="mr-2 h-4 w-4" />
            Add Card
          </Button>
        </div>
      </div>

      {/* Search */}
      <Card>
        <CardContent className="pt-6">
          <div className="flex items-center space-x-2">
            <Search className="h-4 w-4 text-muted-foreground" />
            <Input
              placeholder="Search cards..."
              value={search}
              onChange={(e) => handleSearch(e.target.value)}
              className="max-w-sm"
            />
          </div>
        </CardContent>
      </Card>

      {/* Cards Table */}
      <Card>
        <CardHeader>
          <div className="flex items-center justify-between">
            <div>
              <CardTitle>All Cards ({data?.total || 0})</CardTitle>
              <CardDescription>
                Manage game cards in the system
              </CardDescription>
            </div>
            <div className="flex items-center space-x-2">
              <Button
                variant={viewMode === 'list' ? 'default' : 'outline'}
                size="sm"
                onClick={() => setViewMode('list')}
              >
                <List className="h-4 w-4" />
              </Button>
              <Button
                variant={viewMode === 'grid' ? 'default' : 'outline'}
                size="sm"
                onClick={() => setViewMode('grid')}
              >
                <Grid className="h-4 w-4" />
              </Button>
            </div>
          </div>
        </CardHeader>
        <CardContent>
          {isLoading ? (
            <div className="text-center py-8">Loading cards...</div>
          ) : (
            <>
              {viewMode === 'list' ? (
                <>
                  {Object.entries(groupedCards).map(([packId, cards]) => (
                    <div key={packId} className="mb-8">
                      <div className="bg-muted/50 px-4 py-3 rounded-t-lg border-b-2 border-primary/20 mb-0">
                        <h3 className="text-xl font-bold">
                          {getPackName(packId)}
                        </h3>
                        <p className="text-sm text-muted-foreground mt-1">
                          {cards.length} {cards.length === 1 ? 'card' : 'cards'}
                        </p>
                      </div>
                      <Table>
                        <TableHeader>
                          <TableRow>
                            <TableHead>ID</TableHead>
                            <TableHead>Original</TableHead>
                            <TableHead>Translation</TableHead>
                            <TableHead>Mnemo</TableHead>
                            <TableHead>Actions</TableHead>
                          </TableRow>
                        </TableHeader>
                        <TableBody>
                          {cards.map((card) => (
                            <TableRow key={card.id || `temp-${card.original}`}>
                              <TableCell>{card.id || '-'}</TableCell>
                              <TableCell className="font-medium">{card.original}</TableCell>
                              <TableCell>{card.translation}</TableCell>
                              <TableCell className="max-w-xs truncate">{card.mnemo}</TableCell>
                              <TableCell>
                                <div className="flex items-center space-x-2">
                                  <Button
                                    variant="ghost"
                                    size="sm"
                                    onClick={() => openEditDialog(card)}
                                  >
                                    <Edit className="h-4 w-4" />
                                  </Button>
                                  <Button
                                    variant="ghost"
                                    size="sm"
                                    onClick={() => handleDelete(card)}
                                  >
                                    <Trash2 className="h-4 w-4" />
                                  </Button>
                                </div>
                              </TableCell>
                            </TableRow>
                          ))}
                        </TableBody>
                      </Table>
                    </div>
                  ))}
                </>
              ) : (
                <>
                  {Object.entries(groupedCards).map(([packId, cards]) => (
                    <div key={packId} className="mb-8">
                      <div className="bg-muted/50 px-4 py-3 rounded-lg border-b-2 border-primary/20 mb-4">
                        <h3 className="text-xl font-bold">
                          {getPackName(packId)}
                        </h3>
                        <p className="text-sm text-muted-foreground mt-1">
                          {cards.length} {cards.length === 1 ? 'card' : 'cards'}
                        </p>
                      </div>
                      <div className="grid grid-cols-2 sm:grid-cols-3 md:grid-cols-4 lg:grid-cols-5 xl:grid-cols-6 gap-4">
                        {cards.map((card) => (
                          <div
                            key={card.id || `temp-${card.original}`}
                            className="border rounded-lg overflow-hidden hover:shadow-md transition-shadow cursor-pointer group"
                            onClick={() => openEditDialog(card)}
                          >
                            <div className="aspect-square bg-muted relative">
                              {getImageSrc(card.image) ? (
                                <img
                                  src={getImageSrc(card.image)}
                                  alt={card.original}
                                  className="w-full h-full object-cover"
                                  onError={(e) => {
                                    const target = e.target as HTMLImageElement
                                    target.style.display = 'none'
                                  }}
                                />
                              ) : (
                                <div className="w-full h-full flex items-center justify-center text-muted-foreground">
                                  No Image
                                </div>
                              )}
                              <div className="absolute top-2 right-2 opacity-0 group-hover:opacity-100 transition-opacity">
                                <div className="flex space-x-1">
                                  <Button
                                    variant="secondary"
                                    size="icon"
                                    className="h-7 w-7"
                                    onClick={(e) => {
                                      e.stopPropagation()
                                      openEditDialog(card)
                                    }}
                                  >
                                    <Edit className="h-3 w-3" />
                                  </Button>
                                  <Button
                                    variant="destructive"
                                    size="icon"
                                    className="h-7 w-7"
                                    onClick={(e) => {
                                      e.stopPropagation()
                                      handleDelete(card)
                                    }}
                                  >
                                    <Trash2 className="h-3 w-3" />
                                  </Button>
                                </div>
                              </div>
                            </div>
                            <div className="p-2">
                              <p className="font-medium text-sm truncate" title={card.original}>
                                {card.original}
                              </p>
                              {card.translation && (
                                <p className="text-xs text-muted-foreground truncate" title={card.translation}>
                                  {card.translation}
                                </p>
                              )}
                            </div>
                          </div>
                        ))}
                      </div>
                    </div>
                  ))}
                </>
              )}

              {/* Pagination */}
              {data && data.totalPages > 1 && (
                <div className="flex items-center justify-between mt-4">
                  <div className="text-sm text-muted-foreground">
                    Showing {((page - 1) * limit) + 1} to {Math.min(page * limit, data.total)} of {data.total} cards
                  </div>
                  <div className="flex items-center space-x-2">
                    <Button
                      variant="outline"
                      size="sm"
                      onClick={() => setPage(page - 1)}
                      disabled={page <= 1}
                    >
                      <ChevronLeft className="h-4 w-4" />
                      Previous
                    </Button>
                    <span className="text-sm">
                      Page {page} of {data.totalPages}
                    </span>
                    <Button
                      variant="outline"
                      size="sm"
                      onClick={() => setPage(page + 1)}
                      disabled={page >= data.totalPages}
                    >
                      Next
                      <ChevronRight className="h-4 w-4" />
                    </Button>
                  </div>
                </div>
              )}
            </>
          )}
        </CardContent>
      </Card>

      {/* Create/Edit Dialog */}
      <Dialog open={isDialogOpen} onOpenChange={setIsDialogOpen}>
        <DialogContent className="sm:max-w-[700px] max-h-[90vh] overflow-y-auto">
          <DialogHeader>
            <DialogTitle>
              {selectedCard ? 'Edit Card' : 'Create New Card'}
            </DialogTitle>
            <DialogDescription>
              {selectedCard ? 'Update the card information' : 'Add a new card to the system'}
            </DialogDescription>
          </DialogHeader>
          <form onSubmit={handleSubmit}>
            <div className="grid gap-4 py-4">
              <div className="space-y-2">
                <Label htmlFor="packId">Pack ID (optional)</Label>
                <Select
                  value={formData.packId || undefined}
                  onValueChange={(value: string) => {
                    // If "none" is selected, clear the packId
                    const packId = value === '__none__' ? '' : value
                    setFormData(prev => ({ ...prev, packId }))
                  }}
                >
                  <SelectTrigger>
                    <SelectValue placeholder="Select a pack (optional)" />
                  </SelectTrigger>
                  <SelectContent>
                    <SelectItem value="__none__">None</SelectItem>
                    {packsData?.items && packsData.items.length > 0 ? (
                      packsData.items.map((pack) => (
                        <SelectItem key={pack.id} value={pack.id}>
                          {pack.title || pack.id}
                        </SelectItem>
                      ))
                    ) : null}
                  </SelectContent>
                </Select>
              </div>

              <div className="grid grid-cols-2 gap-4">
                <div className="space-y-2">
                  <Label htmlFor="original">Original *</Label>
                  <Input
                    id="original"
                    value={formData.original}
                    onChange={(e) => setFormData(prev => ({ ...prev, original: e.target.value }))}
                    placeholder="e.g. cerdo"
                    required
                  />
                </div>
                <div className="space-y-2">
                  <Label htmlFor="translation">Translation *</Label>
                  <Input
                    id="translation"
                    value={formData.translation}
                    onChange={(e) => setFormData(prev => ({ ...prev, translation: e.target.value }))}
                    placeholder="e.g. pig"
                    required
                  />
                </div>
              </div>

              <div className="space-y-2">
                <Label htmlFor="mnemo">Mnemo *</Label>
                <Input
                  id="mnemo"
                  value={formData.mnemo}
                  onChange={(e) => setFormData(prev => ({ ...prev, mnemo: e.target.value }))}
                  placeholder="e.g. [pig] with heart"
                  required
                />
              </div>

              <div className="grid grid-cols-2 gap-4">
                <div className="space-y-2">
                  <Label htmlFor="transcription">Transcription</Label>
                  <Input
                    id="transcription"
                    value={formData.transcription}
                    onChange={(e) => setFormData(prev => ({ ...prev, transcription: e.target.value }))}
                    placeholder="e.g. sɛrdo"
                  />
                </div>
                <div className="space-y-2">
                  <Label htmlFor="transcriptionMnemo">Transcription Mnemo</Label>
                  <Input
                    id="transcriptionMnemo"
                    value={formData.transcriptionMnemo}
                    onChange={(e) => setFormData(prev => ({ ...prev, transcriptionMnemo: e.target.value }))}
                    placeholder="e.g. pig with heart"
                  />
                </div>
              </div>

              <div className="space-y-2">
                <Label htmlFor="back">Back Side</Label>
                <Textarea
                  id="back"
                  value={formData.back}
                  onChange={(e: React.ChangeEvent<HTMLTextAreaElement>) => setFormData(prev => ({ ...prev, back: e.target.value }))}
                  placeholder="Additional information on the back of the card"
                  rows={3}
                />
              </div>

              <div className="grid grid-cols-2 gap-4">
                <div className="space-y-2">
                  <ImageUpload
                    label="Front Image"
                    value={formData.image}
                    onChange={(value) => setFormData(prev => ({ ...prev, image: value }))}
                    disabled={createMutation.isPending || updateMutation.isPending}
                  />
                </div>
                <div className="space-y-2">
                  <ImageUpload
                    label="Back Image"
                    value={formData.imageBack}
                    onChange={(value) => setFormData(prev => ({ ...prev, imageBack: value }))}
                    disabled={createMutation.isPending || updateMutation.isPending}
                  />
                </div>
              </div>

              {selectedCard && selectedCard.id && (
                <div className="space-y-2">
                  <CardVoicesManager
                    cardId={selectedCard.id}
                    disabled={createMutation.isPending || updateMutation.isPending}
                  />
                </div>
              )}
            </div>
            <DialogFooter>
              <Button type="button" variant="outline" onClick={closeDialog}>
                Cancel
              </Button>
              <Button type="submit" disabled={createMutation.isPending || updateMutation.isPending}>
                {createMutation.isPending || updateMutation.isPending ? 'Saving...' : (selectedCard ? 'Update' : 'Create')}
              </Button>
            </DialogFooter>
          </form>
        </DialogContent>
      </Dialog>

      {/* Delete Confirmation Dialog */}
      <AlertDialog open={isDeleteDialogOpen} onOpenChange={setIsDeleteDialogOpen}>
        <AlertDialogContent>
          <AlertDialogHeader>
            <AlertDialogTitle>Delete Card</AlertDialogTitle>
            <AlertDialogDescription>
              Are you sure you want to delete the card "{cardToDelete?.original}"? This action cannot be undone.
            </AlertDialogDescription>
          </AlertDialogHeader>
          <AlertDialogFooter>
            <AlertDialogCancel>Cancel</AlertDialogCancel>
            <AlertDialogAction
              onClick={confirmDelete}
              className="bg-red-600 hover:bg-red-700"
              disabled={deleteMutation.isPending}
            >
              {deleteMutation.isPending ? 'Deleting...' : 'Delete'}
            </AlertDialogAction>
          </AlertDialogFooter>
        </AlertDialogContent>
      </AlertDialog>

      {/* Bulk Upload Dialog */}
      {isBulkUploadOpen && !isBulkEditorOpen && (
        <Dialog open={isBulkUploadOpen} onOpenChange={setIsBulkUploadOpen}>
          <DialogContent className="sm:max-w-[900px] max-h-[90vh] overflow-y-auto">
            <BulkCardUpload
              onImagesUploaded={(images, packId) => {
                setUploadedImages(images)
                setBulkUploadPackId(packId)
                setIsBulkUploadOpen(false)
                setIsBulkEditorOpen(true)
              }}
              onClose={() => {
                setIsBulkUploadOpen(false)
                setUploadedImages([])
                setBulkUploadPackId(undefined)
              }}
            />
          </DialogContent>
        </Dialog>
      )}

      {/* Bulk Editor Dialog */}
      {isBulkEditorOpen && (
        <Dialog open={isBulkEditorOpen} onOpenChange={setIsBulkEditorOpen}>
          <DialogContent className="sm:max-w-[1200px] max-h-[90vh] overflow-y-auto">
            <BulkCardEditor
              images={uploadedImages}
              defaultPackId={bulkUploadPackId}
              onComplete={() => {
                setIsBulkEditorOpen(false)
                setUploadedImages([])
                setBulkUploadPackId(undefined)
                queryClient.invalidateQueries({ queryKey: ['cards'] })
                toast.success('All cards saved successfully!')
              }}
              onCancel={() => {
                setIsBulkEditorOpen(false)
                setUploadedImages([])
                setBulkUploadPackId(undefined)
              }}
            />
          </DialogContent>
        </Dialog>
      )}
    </div>
  )
}