<script setup lang="ts">
import { ref, computed, onMounted } from 'vue'
import { injectService, SERVICE_TOKENS } from '@/core/di-container'
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card'
import { Button } from '@/components/ui/button'
import { Badge } from '@/components/ui/badge'
import { ScrollArea } from '@/components/ui/scroll-area'
import { Dialog, DialogContent, DialogDescription, DialogHeader, DialogTitle } from '@/components/ui/dialog'
import { RefreshCw, Send, QrCode, ArrowUpRight, ArrowDownLeft, Clock, Wallet, ScanLine, Copy, Check } from 'lucide-vue-next'
import ReceiveDialog from '../components/ReceiveDialog.vue'
import SendDialog from '../components/SendDialog.vue'
import QRScanner from '@/components/ui/qr-scanner.vue'
import { format } from 'date-fns'
import { nip19 } from 'nostr-tools'

// Services
const walletService = injectService(SERVICE_TOKENS.WALLET_SERVICE) as any
const paymentService = injectService(SERVICE_TOKENS.PAYMENT_SERVICE) as any
const authService = injectService(SERVICE_TOKENS.AUTH_SERVICE) as any
const toastService = injectService(SERVICE_TOKENS.TOAST_SERVICE) as any

// State
const showReceiveDialog = ref(false)
const showSendDialog = ref(false)
const showQRScanner = ref(false)
const scannedDestination = ref<string>('')
const defaultQrCode = ref<string | null>(null)
const isGeneratingQR = ref(false)
const copiedField = ref<string | null>(null)

// Computed
const transactions = computed(() => walletService?.transactions?.value || [])
const isLoading = computed(() => walletService?.isLoading?.value || false)
const error = computed(() => walletService?.error?.value)
// Use PaymentService for centralized balance calculation
const totalBalance = computed(() => paymentService?.totalBalance || 0)

// TODO: clean up; assuming we only ever give the user one auto-generated paylink
const payLinks = computed(() => walletService?.payLinks?.value || [])
const firstPayLink = computed(() => payLinks.value[0] || null)

// Get transactions grouped by date
const groupedTransactions = computed(() => {
  const groups: Record<string, typeof transactions.value> = {}

  transactions.value.forEach((tx: any) => {
    // Ensure timestamp is valid before formatting
    const timestamp = tx.timestamp instanceof Date && !isNaN(tx.timestamp.getTime())
      ? tx.timestamp
      : new Date()

    const dateKey = format(timestamp, 'MMMM d, yyyy')
    if (!groups[dateKey]) {
      groups[dateKey] = []
    }
    groups[dateKey].push(tx)
  })

  return groups
})

// Methods
async function refresh() {
  await walletService?.refresh()
  // Also refresh auth data to update balance
  await authService?.refresh()
  // Regenerate QR if pay link is available
  if (firstPayLink.value) {
    await generateDefaultQR()
  }
}

function getTransactionIcon(type: string, status: string) {
  if (status === 'pending') {
    return Clock
  }
  return type === 'received' ? ArrowDownLeft : ArrowUpRight
}

function getTransactionColor(type: string, status: string) {
  if (status === 'pending') {
    return 'text-amber-500'
  }
  return type === 'received' ? 'text-green-600' : 'text-red-600'
}


// QR Code generation
function encodeLNURL(url: string): string {
  try {
    // Convert URL to bytes
    const bytes = new TextEncoder().encode(url)
    // Encode as bech32 with 'lnurl' prefix
    const bech32 = nip19.encodeBytes('lnurl', bytes)
    // Return with lightning: prefix in uppercase
    return `lightning:${bech32.toUpperCase()}`
  } catch (error) {
    console.error('Failed to encode LNURL:', error)
    return url // Fallback to original URL
  }
}

async function generateDefaultQR() {
  if (!firstPayLink.value?.lnurl) return

  isGeneratingQR.value = true
  try {
    // Encode LNURL with proper bech32 format and lightning: prefix
    const encodedLNURL = encodeLNURL(firstPayLink.value.lnurl)
    // Use the existing PaymentService QR code generation
    defaultQrCode.value = await paymentService?.generateQRCode(encodedLNURL)
  } catch (error) {
    console.error('Failed to generate default QR code:', error)
  } finally {
    isGeneratingQR.value = false
  }
}

// Copy functionality
async function copyToClipboard(text: string, field: string) {
  try {
    await navigator.clipboard.writeText(text)
    copiedField.value = field
    toastService?.success('Copied to clipboard!')

    setTimeout(() => {
      copiedField.value = null
    }, 2000)
  } catch (error) {
    console.error('Failed to copy:', error)
    toastService?.error('Failed to copy to clipboard')
  }
}

// Click handler for QR code to copy LNURL
function handleQRClick() {
  if (firstPayLink.value?.lnurl) {
    // Encode LNURL with proper bech32 format and lightning: prefix (same as QR code)
    const encodedLNURL = encodeLNURL(firstPayLink.value.lnurl)
    copyToClipboard(encodedLNURL, 'qr-lnurl')
  }
}

// QR Scanner functions
function closeQRScanner() {
  showQRScanner.value = false
}

function handleQRScanResult(result: string) {
  // Clean up the scanned result by removing lightning: prefix if present
  let cleanedResult = result
  if (result.toLowerCase().startsWith('lightning:')) {
    cleanedResult = result.substring(10) // Remove "lightning:" prefix
  }

  // Store the scanned result and close QR scanner
  scannedDestination.value = cleanedResult
  closeQRScanner()

  // Open send dialog with the scanned result
  showSendDialog.value = true
  toastService?.success('QR code scanned successfully!')
}

// Initialize on mount
onMounted(async () => {
  await refresh()
  // Generate QR for first pay link if available
  if (firstPayLink.value) {
    await generateDefaultQR()
  }
})
</script>

<template>
  <div class="container mx-auto py-4 sm:py-8 px-3 sm:px-4 max-w-6xl">
    <!-- Header -->
    <div class="mb-4 sm:mb-6">
      <div class="flex items-center justify-between">
        <h1 class="text-2xl sm:text-3xl font-bold flex items-center gap-2">
          <Wallet class="h-6 w-6 sm:h-8 sm:w-8" />
          Wallet
        </h1>
        <Button variant="ghost" size="sm" @click="refresh" :disabled="isLoading">
          <RefreshCw class="h-4 w-4" :class="{ 'animate-spin': isLoading }" />
        </Button>
      </div>
      <p class="text-sm sm:text-base text-muted-foreground mt-1">Manage your Bitcoin transactions</p>
    </div>

    <!-- Balance Card -->
    <Card class="mb-3 sm:mb-6">
      <CardHeader class="pb-3 sm:pb-6">
        <CardTitle class="text-lg sm:text-xl">Total Balance</CardTitle>
        <CardDescription class="text-sm">Available across all your wallets</CardDescription>
      </CardHeader>
      <CardContent class="pt-0">
        <div class="flex flex-col gap-4 sm:gap-6">
          <!-- Balance Section -->
          <div class="text-center sm:text-left">
            <div class="text-3xl sm:text-4xl font-bold">
              {{ Math.floor(totalBalance / 1000).toLocaleString() }} <span
                class="text-xl sm:text-2xl text-muted-foreground font-normal">sats</span>
            </div>
          </div>

          <!-- Action Buttons -->
          <div class="flex gap-2 sm:gap-3 w-full sm:w-auto">
            <Button variant="default" @click="showReceiveDialog = true"
              class="gap-2 flex-1 sm:flex-none h-10 sm:h-12 text-sm sm:text-base">
              <QrCode class="h-4 w-4 sm:h-5 sm:w-5" />
              Receive
            </Button>
            <Button variant="outline" @click="showSendDialog = true"
              class="gap-2 flex-1 sm:flex-none h-10 sm:h-12 text-sm sm:text-base">
              <Send class="h-4 w-4 sm:h-5 sm:w-5" />
              Send
            </Button>
            <Button variant="outline" @click="showQRScanner = true" class="h-10 w-10 sm:h-12 sm:w-12 p-0"
              title="Scan QR Code">
              <ScanLine class="h-4 w-4 sm:h-5 sm:w-5" />
            </Button>
          </div>
        </div>
      </CardContent>
    </Card>

    <!-- Quick Receive QR Code -->
    <Card v-if="firstPayLink" class="mb-3 sm:mb-6">
      <CardHeader class="pb-3 sm:pb-6">
        <CardTitle class="flex items-center gap-2 text-lg sm:text-xl">
          <QrCode class="h-4 w-4 sm:h-5 sm:w-5" />
          Quick Receive
        </CardTitle>
        <CardDescription class="text-sm">{{ firstPayLink.description }}</CardDescription>
      </CardHeader>
      <CardContent class="pt-0">
        <div class="flex flex-col sm:flex-row items-center gap-4 sm:gap-6">
          <!-- QR Code -->
          <div class="flex-shrink-0">
            <div v-if="isGeneratingQR"
              class="w-48 h-48 sm:w-56 sm:h-56 flex items-center justify-center bg-muted rounded-lg">
              <RefreshCw class="h-6 w-6 sm:h-8 sm:w-8 animate-spin text-muted-foreground" />
            </div>
            <div v-else-if="defaultQrCode" class="text-center">
              <div class="bg-white p-2 sm:p-4 rounded-lg cursor-pointer hover:bg-gray-50 transition-colors"
                @click="handleQRClick" title="Click to copy LNURL">
                <img :src="defaultQrCode" alt="LNURL QR Code" class="w-48 h-48 sm:w-56 sm:h-56" />
              </div>
            </div>
            <div v-else class="w-48 h-48 sm:w-56 sm:h-56 flex items-center justify-center bg-muted rounded-lg">
              <QrCode class="h-8 w-8 sm:h-12 sm:w-12 text-muted-foreground opacity-50" />
            </div>
          </div>

          <!-- Address Info -->
          <div class="flex-1 space-y-3 sm:space-y-4 w-full">
            <div>
              <h4 class="font-medium mb-1 sm:mb-2 text-sm sm:text-base">Payment Range</h4>
              <div class="text-xl sm:text-2xl font-bold text-green-600">
                {{ firstPayLink.min?.toLocaleString() }} - {{ firstPayLink.max?.toLocaleString() }} sats
              </div>
            </div>

            <div v-if="firstPayLink.lnaddress">
              <h4 class="font-medium mb-1 sm:mb-2 text-sm sm:text-base">Lightning Address</h4>
              <div class="flex gap-2">
                <div class="font-mono text-xs sm:text-sm bg-muted px-2 sm:px-3 py-1.5 sm:py-2 rounded flex-1 break-all">
                  {{ firstPayLink.lnaddress }}
                </div>
                <Button variant="outline" size="sm"
                  @click="copyToClipboard(firstPayLink.lnaddress || '', 'lightning-address')"
                  class="h-auto px-2 shrink-0" title="Copy Lightning Address">
                  <Check v-if="copiedField === 'lightning-address'" class="h-3 w-3 sm:h-4 sm:w-4 text-green-600" />
                  <Copy v-else class="h-3 w-3 sm:h-4 sm:w-4" />
                </Button>
              </div>
            </div>

          </div>
        </div>
      </CardContent>
    </Card>

    <!-- Transaction History -->
    <Card>
      <CardHeader class="pb-3 sm:pb-6">
        <CardTitle class="text-lg sm:text-xl">Recent Transactions</CardTitle>
        <CardDescription class="text-sm">Your payment history</CardDescription>
      </CardHeader>
      <CardContent class="pt-0">
        <div v-if="error" class="text-center py-6 sm:py-8 text-destructive">
          {{ error }}
        </div>

        <div v-else-if="transactions.length === 0" class="text-center py-8 sm:py-12 text-muted-foreground">
          <Clock class="h-8 w-8 sm:h-12 sm:w-12 mx-auto mb-3 sm:mb-4 opacity-50" />
          <p class="text-sm sm:text-base">No transactions yet</p>
          <p class="text-xs sm:text-sm mt-1 sm:mt-2">Your transaction history will appear here</p>
        </div>

        <ScrollArea v-else class="h-[400px] sm:h-[500px] pr-2 sm:pr-4">
          <div v-for="(txs, date) in groupedTransactions" :key="date" class="mb-4 sm:mb-6">
            <div class="text-xs sm:text-sm font-medium text-muted-foreground mb-2 sm:mb-3">{{ date }}</div>

            <div class="space-y-3 sm:space-y-4">
              <div v-for="tx in txs" :key="tx.id"
                class="relative p-2.5 sm:p-3 rounded-lg border hover:bg-accent/50 transition-colors">
                <!-- Tag badge in top-left corner -->
                <Badge v-if="tx.tag" variant="secondary"
                  class="absolute -top-2.75 left-8 sm:left-11 text-xs font-medium z-10 bg-blue-100 text-blue-800 border-blue-200 pointer-events-none">
                  {{ tx.tag }}
                </Badge>
                <!-- Mobile Layout: Stack vertically -->
                <div class="block sm:hidden">
                  <!-- Header Row: Icon, Amount, Type -->
                  <div class="flex items-center justify-between mb-1.5">
                    <div class="flex items-center gap-2">
                      <div class="p-1 rounded-full bg-background border"
                        :class="getTransactionColor(tx.type, tx.status)">
                        <component :is="getTransactionIcon(tx.type, tx.status)" class="h-3.5 w-3.5" />
                      </div>
                      <span class="text-xs text-muted-foreground">{{
                        (() => {
                          try {
                            if (tx.timestamp instanceof Date && !isNaN(tx.timestamp.getTime())) {
                              return format(tx.timestamp, 'HH:mm')
                            } else if (tx.timestamp) {
                              // Try to parse as string or number
                              const date = new Date(tx.timestamp)
                              if (!isNaN(date.getTime())) {
                                return format(date, 'HH:mm')
                              }
                            }
                            return '--:--'
                          } catch (error) {
                            console.warn('Failed to format timestamp:', tx.timestamp, error)
                            return '--:--'
                          }
                        })()
                      }}</span>
                    </div>

                    <div class="text-right">
                      <p class="font-semibold text-sm" :class="getTransactionColor(tx.type, tx.status)">
                        {{ tx.type === 'received' ? '+' : '-' }}{{ tx.amount.toLocaleString() }}
                      </p>
                      <p class="text-xs text-muted-foreground">sats</p>
                    </div>
                  </div>

                  <!-- Description Row -->
                  <div class="mb-1">
                    <p class="font-medium text-xs leading-tight break-words pr-1">{{ tx.description }}</p>
                  </div>

                  <!-- Badges Row -->
                  <div class="flex items-center gap-1.5 flex-wrap">
                    <span v-if="tx.fee" class="text-xs text-muted-foreground">
                      Fee: {{ tx.fee }} sats
                    </span>
                  </div>
                </div>

                <!-- Desktop Layout: Better space management -->
                <div class="hidden sm:flex items-start gap-4">
                  <div class="flex items-center gap-3 flex-shrink-0">
                    <div class="p-2 rounded-full bg-background border" :class="getTransactionColor(tx.type, tx.status)">
                      <component :is="getTransactionIcon(tx.type, tx.status)" class="h-4 w-4" />
                    </div>
                    <span class="text-sm text-muted-foreground">{{
                      (() => {
                        try {
                          if (tx.timestamp instanceof Date && !isNaN(tx.timestamp.getTime())) {
                            return format(tx.timestamp, 'HH:mm')
                          } else if (tx.timestamp) {
                            // Try to parse as string or number
                            const date = new Date(tx.timestamp)
                            if (!isNaN(date.getTime())) {
                              return format(date, 'HH:mm')
                            }
                          }
                          return '--:--'
                        } catch (error) {
                          console.warn('Failed to format timestamp:', tx.timestamp, error)
                          return '--:--'
                        }
                      })()
                    }}</span>
                  </div>

                  <!-- Description with flexible width -->
                  <div class="min-w-0 flex-1">
                    <p class="font-medium break-words leading-tight pr-2">{{ tx.description }}</p>
                    <div v-if="tx.fee" class="text-xs text-muted-foreground mt-1">
                      Fee: {{ tx.fee }} sats
                    </div>
                  </div>

                  <!-- Amount - fixed width, always visible -->
                  <div class="text-right flex-shrink-0 min-w-[100px]">
                    <p class="font-semibold whitespace-nowrap" :class="getTransactionColor(tx.type, tx.status)">
                      {{ tx.type === 'received' ? '+' : '-' }}{{ tx.amount.toLocaleString() }} sats
                    </p>
                  </div>
                </div>
              </div>
            </div>
          </div>
        </ScrollArea>
      </CardContent>
    </Card>

    <!-- Dialogs -->
    <ReceiveDialog 
      :open="showReceiveDialog" 
      @update:open="showReceiveDialog = $event"
    />
    
    <SendDialog
      v-if="showSendDialog"
      :open="showSendDialog"
      :initial-destination="scannedDestination"
      @update:open="(open) => {
        showSendDialog = open
        if (!open) scannedDestination = ''
      }"
    />

    <!-- QR Scanner Dialog -->
    <Dialog :open="showQRScanner" @update:open="showQRScanner = $event">
      <DialogContent class="sm:max-w-lg">
        <DialogHeader>
          <DialogTitle class="flex items-center gap-2">
            <ScanLine class="h-5 w-5" />
            Scan QR Code
          </DialogTitle>
          <DialogDescription>
            Point your camera at a Lightning invoice or payment QR code
          </DialogDescription>
        </DialogHeader>

        <QRScanner
          @result="handleQRScanResult"
          @close="closeQRScanner"
        />
      </DialogContent>
    </Dialog>
  </div>
</template>
