<template>
  <div 
    class="column"
    @dragover.prevent="handleDragOver"
    @dragenter.prevent="handleDragEnter"
    @dragleave="handleDragLeave"
    @drop="handleDrop"
    :class="{ 'drag-over': isDragOver }"
    ref="columnRef"
  >
    <div class="column-header">
      <div class="column-title-row">
        <span class="column-dot" :style="{ background: column.color }"></span>
        <h2 class="column-title">{{ column.title }}</h2>
        <span class="column-count">{{ column.cards.length }}</span>
      </div>
      <button class="column-add" @click="emit('create-task')">
        <i data-lucide="plus"></i>
      </button>
    </div>

    <div class="cards" ref="cardsRef">
      <template v-for="(card, index) in column.cards" :key="card.id">
        <!-- Индикатор перед карточкой -->
        <div v-if="isDragOver && dropIndex === index" class="drop-indicator"></div>
        <Card
          :card="card"
          :column-id="column.id"
          :index="index"
          :departments="departments"
          :labels="labels"
          @click="emit('open-task', card)"
          @archive="emit('archive-task', $event)"
        />
      </template>
      
      <!-- Индикатор в конце списка -->
      <div v-if="isDragOver && dropIndex === column.cards.length" class="drop-indicator"></div>
    </div>

  </div>
</template>

<script setup>
import { ref, onMounted, onUpdated } from 'vue'
import Card from './Card.vue'

const props = defineProps({
  column: Object,
  departments: {
    type: Array,
    default: () => []
  },
  labels: {
    type: Array,
    default: () => []
  }
})

const emit = defineEmits(['drop-card', 'open-task', 'create-task', 'archive-task'])

const refreshIcons = () => {
  if (window.lucide) {
    window.lucide.createIcons()
  }
}

onMounted(refreshIcons)
onUpdated(refreshIcons)

const columnRef = ref(null)
const cardsRef = ref(null)
const isDragOver = ref(false)
const dropIndex = ref(-1)
let dragEnterCounter = 0

const handleDragEnter = (e) => {
  dragEnterCounter++
  isDragOver.value = true
}

const calculateDropIndex = (clientY) => {
  if (!cardsRef.value) return props.column.cards.length
  
  const cardElements = cardsRef.value.querySelectorAll('.card')
  let index = props.column.cards.length
  
  for (let i = 0; i < cardElements.length; i++) {
    const rect = cardElements[i].getBoundingClientRect()
    const cardMiddle = rect.top + rect.height / 2
    
    if (clientY < cardMiddle) {
      index = i
      break
    }
  }
  
  return index
}

const handleDragOver = (e) => {
  isDragOver.value = true
  dropIndex.value = calculateDropIndex(e.clientY)
}

const handleDragLeave = (e) => {
  dragEnterCounter--
  if (dragEnterCounter === 0) {
    isDragOver.value = false
    dropIndex.value = -1
  }
}

const handleDrop = (e) => {
  const cardId = parseInt(e.dataTransfer.getData('cardId'))
  const fromColumnId = e.dataTransfer.getData('columnId')
  const toIndex = calculateDropIndex(e.clientY)
  
  dragEnterCounter = 0
  isDragOver.value = false
  dropIndex.value = -1
  
  emit('drop-card', {
    cardId,
    fromColumnId,
    toColumnId: props.column.id,
    toIndex
  })
}

</script>

<style scoped>
.column {
  width: 300px;
  min-width: 300px;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  max-height: calc(100vh - 140px);
}

.column.drag-over .cards {
  background: var(--accent-soft);
  border-radius: 12px;
}

.column-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
  padding: 0 4px;
}

.column-title-row {
  display: flex;
  align-items: center;
  gap: 10px;
}

.column-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
}

.column-title {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
}

.column-count {
  color: var(--text-muted);
  font-size: 13px;
  font-weight: 400;
}

.column-add {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 6px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s;
}

.column-add i {
  width: 16px;
  height: 16px;
}

.column-add:hover {
  background: var(--bg-card);
  color: var(--text-primary);
}

.cards {
  flex: 1;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 4px;
  margin: -4px;
  min-height: 150px;
}

.cards::-webkit-scrollbar {
  width: 4px;
}

.cards::-webkit-scrollbar-track {
  background: transparent;
}

.cards::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.15);
  border-radius: 2px;
}

.cards::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.25);
}

.drop-indicator {
  height: 4px;
  background: var(--accent);
  border-radius: 2px;
  margin: 4px 0;
  animation: pulse 1s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 0.5; }
  50% { opacity: 1; }
}

</style>
