'use client'

import { useState, useCallback } from 'react'
import { motion, useMotionValue, useTransform, AnimatePresence, type PanInfo } from 'framer-motion'
import { Card, CardContent, CardHeader } from '@/components/ui/card'
import { Button } from '@/components/ui/button'
import { Badge } from '@/components/ui/badge'
import { formatCurrency, formatDate } from '@/lib/utils'
import { checkExpenseWarnings } from '@/lib/tax/expense-warnings'
import { X, ArrowLeft, ArrowRight, Building, AlertTriangle, Check, FileText, Link2, Receipt as ReceiptIcon, SkipForward } from 'lucide-react'
import type { Transaction, TransactionCategory, Invoice, Customer } from '@/types'
import type { SuggestedCategory } from '@/lib/transactions/category-suggestions'

interface TransactionWithInvoice extends Transaction {
  potential_invoice?: Invoice & { customer?: Customer }
}

interface SwipeCategorizationViewProps {
  transactions: TransactionWithInvoice[]
  suggestions?: Record<string, SuggestedCategory[]>
  onCategorize: (id: string, isBusiness: boolean, category?: TransactionCategory) => Promise<boolean>
  onMatchInvoice?: (transactionId: string, invoiceId: string) => Promise<boolean>
  onClose: () => void
}

const expenseCategories: { value: TransactionCategory; label: string }[] = [
  { value: 'expense_equipment', label: 'Utrustning' },
  { value: 'expense_software', label: 'Programvara' },
  { value: 'expense_travel', label: 'Resor' },
  { value: 'expense_office', label: 'Kontor' },
  { value: 'expense_marketing', label: 'Marknadsföring' },
  { value: 'expense_professional_services', label: 'Konsulter' },
  { value: 'expense_education', label: 'Utbildning' },
  { value: 'expense_bank_fees', label: 'Bankavgift' },
  { value: 'expense_card_fees', label: 'Kortavgift' },
  { value: 'expense_currency_exchange', label: 'Valutaväxling' },
  { value: 'expense_other', label: 'Övrigt' },
]

const incomeCategories: { value: TransactionCategory; label: string }[] = [
  { value: 'income_services', label: 'Tjänster' },
  { value: 'income_products', label: 'Produkter' },
  { value: 'income_other', label: 'Övrigt' },
]

export default function SwipeCategorizationView({
  transactions,
  suggestions,
  onCategorize,
  onMatchInvoice,
  onClose,
}: SwipeCategorizationViewProps) {
  const [showAllCategories, setShowAllCategories] = useState(false)
  const [currentIndex, setCurrentIndex] = useState(0)
  const [showCategorySelect, setShowCategorySelect] = useState(false)
  const [isProcessing, setIsProcessing] = useState(false)
  const [error, setError] = useState<string | null>(null)

  const currentTransaction = transactions[currentIndex]
  const warnings = currentTransaction
    ? checkExpenseWarnings(currentTransaction.description)
    : []

  const x = useMotionValue(0)
  const rotate = useTransform(x, [-200, 0, 200], [-15, 0, 15])
  const opacity = useTransform(x, [-200, -100, 0, 100, 200], [0.5, 1, 1, 1, 0.5])

  const businessIndicatorOpacity = useTransform(x, [0, 100, 200], [0, 0.5, 1])
  const skipIndicatorOpacity = useTransform(x, [-200, -100, 0], [1, 0.5, 0])

  const moveToNext = useCallback(() => {
    x.set(0)
    if (currentIndex < transactions.length - 1) {
      setCurrentIndex(currentIndex + 1)
    } else {
      onClose()
    }
  }, [x, currentIndex, transactions.length, onClose])

  const handleDrag = useCallback(
    (_event: MouseEvent | TouchEvent | PointerEvent, info: PanInfo) => {
      if (isProcessing) return
      x.set(info.offset.x)
    },
    [isProcessing, x]
  )

  const handleDragEnd = useCallback(
    async (_event: MouseEvent | TouchEvent | PointerEvent, info: PanInfo) => {
      if (isProcessing || !currentTransaction) return

      const mx = info.offset.x
      const vx = Math.abs(info.velocity.x)
      const shouldSwipe = Math.abs(mx) > 100 || vx > 500

      if (shouldSwipe) {
        if (mx > 0) {
          // Swipe right = categorize as business
          if (currentTransaction.amount < 0) {
            // Show category selector for business expenses
            setShowCategorySelect(true)
            x.set(0)
          } else {
            setIsProcessing(true)
            setError(null)
            try {
              const success = await onCategorize(
                currentTransaction.id,
                true,
                'income_other'
              )
              if (success) {
                moveToNext()
              } else {
                setError('Kunde inte kategorisera. Tryck "Hoppa över" för att gå vidare.')
              }
            } catch {
              setError('Ett fel uppstod. Tryck "Hoppa över" för att gå vidare.')
            } finally {
              setIsProcessing(false)
            }
          }
        } else {
          // Swipe left = skip
          moveToNext()
        }
      } else {
        x.set(0)
      }
    },
    [isProcessing, currentTransaction, onCategorize, x, moveToNext]
  )

  const handleCategorySelect = async (category: TransactionCategory) => {
    setIsProcessing(true)
    setError(null)
    try {
      const success = await onCategorize(currentTransaction.id, true, category)
      if (success) {
        setShowCategorySelect(false)
        moveToNext()
      } else {
        setError('Kunde inte kategorisera. Tryck "Hoppa över" för att gå vidare.')
      }
    } catch {
      setError('Ett fel uppstod. Tryck "Hoppa över" för att gå vidare.')
    } finally {
      setIsProcessing(false)
    }
  }

  const handleMatchInvoice = async () => {
    if (!currentTransaction.potential_invoice || !onMatchInvoice) return

    setIsProcessing(true)
    setError(null)
    try {
      const success = await onMatchInvoice(
        currentTransaction.id,
        currentTransaction.potential_invoice.id
      )
      if (success) {
        moveToNext()
      } else {
        setError('Kunde inte matcha faktura. Tryck "Hoppa över" för att gå vidare.')
      }
    } catch {
      setError('Ett fel uppstod. Tryck "Hoppa över" för att gå vidare.')
    } finally {
      setIsProcessing(false)
    }
  }

  const handleSkip = useCallback(() => {
    setError(null)
    setShowCategorySelect(false)
    moveToNext()
  }, [moveToNext])

  if (!currentTransaction) {
    return (
      <div className="fixed inset-0 bg-background z-50 flex flex-col items-center justify-center">
        <div className="text-center">
          <div className="h-16 w-16 rounded-full bg-success/10 flex items-center justify-center mx-auto mb-4">
            <Check className="h-8 w-8 text-success" />
          </div>
          <h2 className="text-2xl font-bold">Klart!</h2>
          <p className="text-muted-foreground mt-2">
            Alla transaktioner är nu kategoriserade
          </p>
          <Button onClick={onClose} className="mt-6">
            Tillbaka till transaktioner
          </Button>
        </div>
      </div>
    )
  }

  if (showCategorySelect) {
    const categories =
      currentTransaction.amount > 0 ? incomeCategories : expenseCategories

    return (
      <div className="fixed inset-0 bg-background z-50 flex flex-col">
        <div className="flex items-center justify-between p-4 border-b">
          <Button variant="ghost" size="icon" onClick={() => setShowCategorySelect(false)}>
            <ArrowLeft className="h-5 w-5" />
          </Button>
          <h1 className="font-semibold">Välj kategori</h1>
          <div className="w-10" />
        </div>

        <div className="flex-1 overflow-auto p-4">
          <Card className="mb-4">
            <CardContent className="pt-4">
              <p className="font-medium">{currentTransaction.description}</p>
              <p className="text-2xl font-bold mt-2">
                {formatCurrency(Math.abs(currentTransaction.amount), currentTransaction.currency)}
              </p>
            </CardContent>
          </Card>

          {error && (
            <div className="p-3 rounded-lg bg-destructive/10 text-destructive text-sm mb-4">
              {error}
            </div>
          )}

          <div className="space-y-2">
            {categories.map((cat) => (
              <Button
                key={cat.value}
                variant="outline"
                className="w-full justify-start h-auto py-3"
                onClick={() => handleCategorySelect(cat.value)}
                disabled={isProcessing}
              >
                {cat.label}
              </Button>
            ))}
          </div>

          <Button
            variant="ghost"
            className="w-full mt-4 text-muted-foreground"
            onClick={handleSkip}
          >
            <SkipForward className="mr-2 h-4 w-4" />
            Hoppa över
          </Button>
        </div>
      </div>
    )
  }

  return (
    <div className="fixed inset-0 bg-background z-50 flex flex-col">
      {/* Header */}
      <div className="flex items-center justify-between p-4 border-b">
        <Button variant="ghost" size="icon" onClick={onClose}>
          <X className="h-5 w-5" />
        </Button>
        <div className="text-center">
          <p className="text-sm text-muted-foreground">
            {currentIndex + 1} av {transactions.length}
          </p>
        </div>
        <div className="w-10" />
      </div>

      {/* Instructions */}
      <div className="flex justify-between px-8 py-4 text-sm">
        <div className="flex items-center gap-2 text-muted-foreground">
          <ArrowLeft className="h-4 w-4" />
          <SkipForward className="h-4 w-4" />
          <span>Hoppa över</span>
        </div>
        <div className="flex items-center gap-2 text-muted-foreground">
          <span>Kategorisera</span>
          <Building className="h-4 w-4" />
          <ArrowRight className="h-4 w-4" />
        </div>
      </div>

      {/* Card stack */}
      <div className="flex-1 flex items-center justify-center px-4 relative">
        {/* Swipe indicators */}
        <motion.div
          className="absolute left-8 flex items-center gap-2 text-muted-foreground"
          style={{ opacity: skipIndicatorOpacity }}
        >
          <SkipForward className="h-8 w-8" />
          <span className="font-semibold">Hoppa över</span>
        </motion.div>

        <motion.div
          className="absolute right-8 flex items-center gap-2 text-success"
          style={{ opacity: businessIndicatorOpacity }}
        >
          <span className="font-semibold">Företag</span>
          <Building className="h-8 w-8" />
        </motion.div>

        <AnimatePresence>
          <motion.div
            key={currentTransaction.id}
            drag="x"
            dragConstraints={{ left: 0, right: 0 }}
            dragElastic={1}
            onDrag={handleDrag}
            onDragEnd={handleDragEnd}
            style={{ x, rotate, opacity }}
            className="w-full max-w-sm touch-none cursor-grab active:cursor-grabbing"
          >
            <Card className="shadow-lg">
              <CardHeader>
                <div className="flex items-center justify-between">
                  <Badge variant="outline">{formatDate(currentTransaction.date)}</Badge>
                  <div className="flex items-center gap-2">
                    {currentTransaction.receipt_id && (
                      <Badge variant="secondary" className="gap-1">
                        <ReceiptIcon className="h-3 w-3" />
                        Kvitto
                      </Badge>
                    )}
                    <Badge>{currentTransaction.currency}</Badge>
                  </div>
                </div>
              </CardHeader>
              <CardContent className="space-y-4">
                <p className="text-lg font-medium">{currentTransaction.description}</p>

                <p
                  className={`text-3xl font-bold ${
                    currentTransaction.amount > 0 ? 'text-success' : ''
                  }`}
                >
                  {currentTransaction.amount > 0 ? '+' : ''}
                  {formatCurrency(currentTransaction.amount, currentTransaction.currency)}
                </p>

                {/* Potential Invoice Match */}
                {currentTransaction.potential_invoice && (
                  <div className="p-4 rounded-lg border-2 border-success/40 bg-success/5 space-y-2">
                    <div className="flex items-center justify-between">
                      <div className="flex items-center gap-2 text-success">
                        <FileText className="h-5 w-5" />
                        <span className="font-semibold text-sm">Fakturamatchning hittad</span>
                      </div>
                      <Badge variant="outline" className="text-success border-success">
                        Match
                      </Badge>
                    </div>
                    <div className="text-sm">
                      <p className="font-medium">
                        Faktura {currentTransaction.potential_invoice.invoice_number}
                      </p>
                      <p className="text-muted-foreground">
                        {currentTransaction.potential_invoice.customer?.name || 'Okänd kund'}
                      </p>
                      <p className="font-medium text-success">
                        {formatCurrency(
                          currentTransaction.potential_invoice.total,
                          currentTransaction.potential_invoice.currency
                        )}
                      </p>
                    </div>
                  </div>
                )}

                {/* Warnings */}
                {warnings.length > 0 && (
                  <div className="space-y-2 pt-4 border-t">
                    {warnings.map((warning, idx) => (
                      <div
                        key={idx}
                        className={`flex items-start gap-2 p-2 rounded text-sm ${
                          warning.warningLevel === 'danger'
                            ? 'bg-destructive/10 text-destructive'
                            : warning.warningLevel === 'warning'
                            ? 'bg-warning/10 text-warning-foreground'
                            : 'bg-muted'
                        }`}
                      >
                        <AlertTriangle className="h-4 w-4 flex-shrink-0 mt-0.5" />
                        <div>
                          <p className="font-medium">{warning.category}</p>
                          <p className="text-xs opacity-90">{warning.message}</p>
                        </div>
                      </div>
                    ))}
                  </div>
                )}
              </CardContent>
            </Card>
          </motion.div>
        </AnimatePresence>
      </div>

      {/* Action buttons */}
      <div className="p-4 border-t">
        <div className="flex flex-col gap-3 max-w-sm mx-auto">
          {/* Error message */}
          {error && (
            <div className="p-3 rounded-lg bg-destructive/10 text-destructive text-sm">
              {error}
            </div>
          )}

          {/* Invoice match button - primary action when there's a match */}
          {currentTransaction.potential_invoice && onMatchInvoice && (
            <Button
              className="w-full bg-success hover:bg-success/90 text-success-foreground"
              onClick={handleMatchInvoice}
              disabled={isProcessing}
            >
              <Link2 className="mr-2 h-4 w-4" />
              Matcha med Faktura {currentTransaction.potential_invoice.invoice_number}
            </Button>
          )}

          {/* Suggested categories - shown as quick-select buttons */}
          {suggestions && suggestions[currentTransaction.id] && suggestions[currentTransaction.id].length > 0 && (
            <div className="space-y-2">
              <p className="text-xs text-muted-foreground text-center">Föreslagna kategorier</p>
              <div className="grid grid-cols-2 gap-2">
                {suggestions[currentTransaction.id].map((suggestion) => (
                  <Button
                    key={suggestion.category}
                    variant="outline"
                    className="h-auto py-2.5 px-3 text-left justify-start border-primary/30 hover:border-primary hover:bg-primary/5"
                    onClick={() => handleCategorySelect(suggestion.category)}
                    disabled={isProcessing}
                  >
                    <div className="flex flex-col">
                      <span className="text-sm font-medium">{suggestion.label}</span>
                      {suggestion.account && (
                        <span className="text-xs text-muted-foreground">{suggestion.account}</span>
                      )}
                    </div>
                  </Button>
                ))}
              </div>
            </div>
          )}

          {/* Categorization button */}
          <Button
            className="w-full"
            onClick={() => {
              if (currentTransaction.amount < 0) {
                setShowCategorySelect(true)
              } else {
                handleCategorySelect('income_other')
              }
            }}
            disabled={isProcessing}
          >
            <Building className="mr-2 h-4 w-4" />
            Kategorisera
          </Button>

          {/* Skip button - always visible */}
          <Button
            variant="ghost"
            className="w-full text-muted-foreground"
            onClick={handleSkip}
            disabled={isProcessing}
          >
            <SkipForward className="mr-2 h-4 w-4" />
            Hoppa över
          </Button>
        </div>
      </div>
    </div>
  )
}