<template>
  <a-select
    :style="{ width: width }"
    :value="modelValue"
    @change="handleChange"
    placeholder="请选择鱼名称"
    mode="multiple"
    show-search
    :filter-option="filterOption"
    class="custom-fish-select"
    :dropdownMatchSelectWidth="false"
    :getPopupContainer="(triggerNode: HTMLElement) => triggerNode.parentNode"
    @dropdownVisibleChange="handleDropdownVisibleChange"
  >
    <!-- 自定义 Tag 显示名称 -->
    <template #tagRender="{ value: tagId, onClose }">
      <a-tag 
        closable 
        @close="onClose" 
        style="margin-right: 3px; max-width: 120px"
      >
        {{ getFishNameById(tagId) }}
      </a-tag>
    </template>

    <template #dropdownRender>
      <div class="custom-dropdown-container">
        <!-- 左侧：可滚动的选项列表 -->
        <div class="dropdown-left-list">
          <div
            v-for="opt in filteredOptions"
            :key="opt.id"
            class="dropdown-item"
            :class="{
              'is-active': Array.isArray(modelValue) && modelValue.includes(opt.id),
              'is-hovered': opt.id === hoveredId,
            }"
            @click.stop="handleSelectOption(opt)"
            @mouseenter="hoveredId = opt.id"
          >
            <span class="item-name">{{ opt.name }}</span>
            <!-- 选中对勾 -->
            <span v-if="Array.isArray(modelValue) && modelValue.includes(opt.id)" class="check-icon">✓</span>
          </div>
          <div v-if="filteredOptions.length === 0" class="empty-tip">
            无匹配数据
          </div>
        </div>

        <!-- 中间分割线 -->
        <div class="dropdown-divider"></div>

        <!-- 右侧：固定显示的别名/详情 -->
        <div class="dropdown-right-detail">
          <div v-if="currentDetailData" class="detail-content">
            <div class="detail-title">{{ currentDetailData.name }}</div>
            <div class="detail-alias" :title="currentDetailData.alias">
              {{ currentDetailData.alias || "暂无别名" }}
            </div>
          </div>
          <div v-else class="detail-placeholder">请选择或悬停查看</div>
        </div>
      </div>
    </template>
  </a-select>
</template>

<script lang="ts" setup>
import { ref, computed } from "vue";

// --- Props & Emits ---
interface Props {
  modelValue: string[]; // 接收选中的 ID 数组
  options: any[];
  width: string;
}

const props = defineProps<Props>();

const emit = defineEmits<{
  (e: "update:modelValue", value: string[]): void;
}>();

// --- State ---
// 这里可以改为从 API 获取，目前先保留静态数据作为示例
const options = ref<any>(props.options || []);

const hoveredId = ref<string | null>(null);

// --- Computed ---
const filteredOptions = computed(() => {
  return options.value;
});

const currentDetailData = computed(() => {
  if (hoveredId.value) {
    return options.value.find((item: any) => item.id === hoveredId.value);
  }
  return null;
});

// --- Methods ---
const handleDropdownVisibleChange = (open: boolean) => {
  if (!open) {
    hoveredId.value = null;
  }
};

const filterOption = (input: string, option: any) => {
  if (!input) return true;
  const targetOpt = options.value.find((item: any) => item.id === option.value);
  if (!targetOpt) return false;

  const lowerInput = input.toLowerCase();
  const nameMatch = targetOpt.name?.toLowerCase().includes(lowerInput);
  const aliasMatch = targetOpt.alias?.toLowerCase().includes(lowerInput);
  return nameMatch || aliasMatch;
};

const handleSelectOption = (opt: any) => {
  let newValues: string[] = Array.isArray(props.modelValue) ? [...props.modelValue] : [];
  const index = newValues.indexOf(opt.id);

  if (index > -1) {
    newValues.splice(index, 1);
  } else {
    newValues.push(opt.id);
  }
  
  // 触发更新
  emit("update:modelValue", newValues);
};

const handleChange = (val: any) => {
  // 处理直接通过 a-select 内部机制触发的变化（如删除 tag）
  emit("update:modelValue", val);
};

const getFishNameById = (id: string) => {
  if (!id) return "";
  const fish = options.value.find((item: any) => item.id === id);
  return fish ? fish.name : id;
};
</script>

<style lang="scss" scoped>
.custom-fish-select {
  :deep(.ant-select-dropdown) {
    padding: 0 !important;
    min-width: 400px !important;
    width: auto !important;
  }
}

.custom-dropdown-container {
  display: flex;
  background: #fff;
  border-radius: 4px;
  overflow: hidden;
  height: 300px; /* 固定高度 */
}

.dropdown-left-list {
  width: 150px;
  height: 100%;
  overflow-y: auto;
  border-right: 1px solid #f0f0f0;
  
  &::-webkit-scrollbar {
    width: 6px;
  }
  &::-webkit-scrollbar-thumb {
    background: #ccc;
    border-radius: 3px;
  }
}

.dropdown-item {
  padding: 8px 12px;
  cursor: pointer;
  font-size: 14px;
  color: #333;
  transition: background-color 0.3s;
  display: flex;
  justify-content: space-between;
  align-items: center;

  &:hover {
    background-color: #f5f5f5;
  }

  &.is-active {
    background-color: #e6f7ff;
    color: #1890ff;
    font-weight: 500;
  }

  &.is-hovered {
    background-color: #fafafa;
  }

  .item-name {
    display: block;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    flex: 1;
  }
  
  .check-icon {
    color: #1890ff;
    font-weight: bold;
    margin-left: 8px;
  }
}

.dropdown-divider {
  width: 1px;
  background-color: #e8e8e8;
  height: 100%;
}

.dropdown-right-detail {
  width: 250px;
  height: 100%;
  padding: 16px;
  box-sizing: border-box;
  background-color: #fff;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  position: relative;
}

.detail-content {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.detail-title {
  font-size: 16px;
  font-weight: bold;
  color: #333;
  margin-bottom: 4px;
}

.detail-alias {
  font-size: 14px;
  color: #666;
  line-height: 1.5;
  word-break: break-all;
}

.detail-placeholder {
  color: #999;
  font-size: 14px;
  text-align: center;
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
}

.empty-tip {
  padding: 10px;
  color: #999;
  text-align: center;
  font-size: 12px;
}
</style>