<template>
  <view class="uni-data-pickerview">
    <scroll-view class="selected-area" scroll-x="true" scroll-y="false" :show-scrollbar="false">
      <view class="selected-list">
        <view class="selected-item" :class="{'selected-item-active':index==selectedIndex}" v-for="(item,index) in selected"
          :key="index" v-if="item.text" @click="handleSelect(index)">
          <text class="">{{item.text}}</text>
        </view>
      </view>
    </scroll-view>
    <view class="tab-c">
      <scroll-view class="list" v-for="(child, i) in dataList" :key="i" v-if="i==selectedIndex" :scroll-y="true">
        <view class="item" :class="{'is-disabled': !!item.disable}" v-for="(item, j) in child" :key="j" @click="handleNodeClick(item, i, j)">
          <text class="item-text">{{item.text}}</text>
          <view class="check" v-if="selected.length > i && item.value == selected[i].value"></view>
        </view>
      </scroll-view>
      <view class="loading-cover" v-if="loading">
        <uni-load-more class="load-more" :contentText="loadMore" status="loading"></uni-load-more>
      </view>
      <view class="error-message" v-if="errorMessage">
        <text class="error-text">{{errorMessage}}</text>
      </view>
    </view>
  </view>
</template>

<script>
  import dataPicker from "./uni-data-picker.js"

  /**
   * uni-data-pickerview
   * @description uni-data-pickerview
   * @tutorial https://uniapp.dcloud.net.cn/uniCloud/uni-data-picker
   * @property {Array} localdata 本地数据，参考
   * @property {Boolean} step-searh = [true|false] 是否分布查询
   * @value true 启用分布查询，仅查询当前选中节点
   * @value false 关闭分布查询，一次查询出所有数据
   * @property {String|DBFieldString} self-field 分布查询当前字段名称
   * @property {String|DBFieldString} parent-field 分布查询父字段名称
   * @property {String|DBCollectionString} collection 表名
   * @property {String|DBFieldString} field 查询字段，多个字段用 `,` 分割
   * @property {String} orderby 排序字段及正序倒叙设置
   * @property {String|JQLString} where 查询条件
   */
  export default {
    name: 'UniDataPickerView',
    mixins: [dataPicker],
    props: {
      managedMode: {
        type: Boolean,
        default: false
      }
    },
    data() {
      return {}
    },
    created() {
      if (this.managedMode) {
        return
      }

      this.$nextTick(() => {
        this.load()
      })
    },
    methods: {
      onPropsChange() {
        this._treeData = []
        this.selectedIndex = 0
        this.load()
      },
      load() {
        if (this.isLocaldata) {
          this.loadData()
        } else if (this.value.length) {
          this.getTreePath((res) => {
            this.loadData()
          })
        }
      },
      handleSelect(index) {
        this.selectedIndex = index
      },
      handleNodeClick(item, i, j) {
        if (item.disable) {
          return
        }

        const node = this.dataList[i][j]
        const {
          value,
          text
        } = node

        if (i < this.selected.length - 1) {
          this.selected.splice(i, this.selected.length - i)
          this.selected.push(node)
        } else if (i === this.selected.length - 1) {
          this.selected[i] = node
        }

        if (node.isleaf) {
          this.onSelectedChange(node, node.isleaf)
          return
        }

        const {
          isleaf,
          hasNodes
        } = this._updateBindData()

        if (this.isLocaldata && (!hasNodes || isleaf)) {
          this.onSelectedChange(node, true)
          return
        }

        if (!isleaf && !hasNodes) {
          this._loadNodeData((data) => {
            if (!data.length) {
              node.isleaf = true
            } else {
              this._treeData.push(...data)
              this._updateBindData(node)
            }
            this.onSelectedChange(node, node.isleaf)
          }, this._nodeWhere())
          return
        }

        this.onSelectedChange(node, false)
      },
      updateData(data) {
        this._treeData = data.treeData
        this.selected = data.selected
        if (!this._treeData.length) {
          this.loadData()
        } else {
          //this.selected = data.selected
          this._updateBindData()
        }
      },
      onDataChange() {
        this.$emit('datachange')
      },
      onSelectedChange(node, isleaf) {
        if (isleaf) {
          this._dispatchEvent()
        }

				if (node) {
					this.$emit('nodeclick', node)
				}
      },
      _dispatchEvent() {
        this.$emit('change', this.selected.slice(0))
      }
    }
  }
</script>

<style scoped>
  .uni-data-pickerview {
    flex: 1;
    /* #ifndef APP-NVUE */
    display: flex;
    /* #endif */
    flex-direction: column;
    overflow: hidden;
    height: 100%;
  }

  .error-text {
    color: #DD524D;
  }

  .loading-cover {
    position: absolute;
    left: 0;
    top: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(255, 255, 255, .5);
    /* #ifndef APP-NVUE */
    display: flex;
    /* #endif */
    flex-direction: column;
    align-items: center;
    z-index: 1001;
  }

  .load-more {
		/* #ifndef APP-NVUE */
    margin: auto;
		/* #endif */
  }

  .error-message {
    background-color: #fff;
    position: absolute;
    left: 0;
    top: 0;
    right: 0;
    bottom: 0;
    padding: 15px;
    opacity: .9;
    z-index: 102;
  }

  /* #ifdef APP-NVUE */
  .selected-area {
    width: 750rpx;
  }

  /* #endif */

  .selected-list {
    /* #ifndef APP-NVUE */
    display: flex;
    /* #endif */
    flex-direction: row;
    flex-wrap: nowrap;
    padding: 0 5px;
    border-bottom: 1px solid #f8f8f8;
  }

  .selected-item {
    margin-left: 10px;
    margin-right: 10px;
    padding: 12px 0;
		/* #ifndef APP-NVUE */
		white-space: nowrap;
		/* #endif */
  }

  .selected-item-active {
    border-bottom: 2px solid #007aff;
  }

  .selected-item-text {
    color: #007aff;
  }

  .tab-c {
    position: relative;
    flex: 1;
    /* #ifndef APP-NVUE */
    display: flex;
    /* #endif */
    flex-direction: row;
    overflow: hidden;
  }

  .list {
    flex: 1;
  }

  .item {
    padding: 12px 15px;
    border-bottom: 1px solid #f0f0f0;
    /* #ifndef APP-NVUE */
    display: flex;
    /* #endif */
    flex-direction: row;
  }

  .is-disabled {
    opacity: .5;
  }

  .item-text {
    flex: 1;
    color: #333333;
  }

  .check {
    margin-right: 5px;
    border: 2px solid #007aff;
    border-left: 0;
    border-top: 0;
    height: 12px;
    width: 6px;
    transform-origin: center;
    /* #ifndef APP-NVUE */
    transition: all 0.3s;
    /* #endif */
    transform: rotate(45deg);
  }
</style>
