import { getNodeKey } from '../model/util';

export default {
  methods: {
    creator(parent, nodeTag) {
      const node = this[nodeTag];

      if (parent.isTree) {
        this.tree = parent;
      } else {
        this.tree = parent.tree;
      }

      const tree = this.tree;
      if (!tree) {
        console.warn('Can not find node\'s tree.');
      }

      const props = tree.props || {};
      const childrenKey = props['children'] || 'children';

      this.$watch(`${nodeTag}.data.${childrenKey}`, () => {
        node.updateChildren();
      });

      if (node.expanded) {
        this.expanded = true;
        this.childNodeRendered = true;
      }

      if (this.tree.accordion) {
        this.$on('tree-node-expand', currentNode => {
          if (node !== currentNode) {
            node.collapse();
          }
        });
      }
    },

    getNodeKey(node) {
      return getNodeKey(this.tree.nodeKey, node.data);
    },

    handleSelectChange(checked, indeterminate) {
      const node = this.node || this.source;

      if (this.oldChecked !== checked && this.oldIndeterminate !== indeterminate) {
        this.tree.$emit('check-change', node.data, checked, indeterminate);
      }
      this.oldChecked = checked;
      this.indeterminate = indeterminate;
    },

    handleClick() {
      const node = this.node || this.source;
      const store = this.tree.store;

      store.setCurrentNode(node);
      this.tree.$emit('current-change', store.currentNode ? store.currentNode.data : null, store.currentNode);
      this.tree.currentNode = this;
      if (this.tree.expandOnClickNode) {
        this.handleExpandIconClick();
      }
      if (this.tree.checkOnClickNode && !node.disabled) {
        this.handleCheckChange(null, {
          target: { checked: !node.checked }
        });
      }

      this.tree.$emit('node-click', node.data, node, this);
    },

    handleContextMenu(event) {
      const node = this.node || this.source;

      if (this.tree._events['node-contextmenu'] && this.tree._events['node-contextmenu'].length > 0) {
        event.stopPropagation();
        event.preventDefault();
      }
      this.tree.$emit('node-contextmenu', event, node.data, node, this);
    },

    handleExpandIconClick() {
      const node = this.node || this.source;

      if (node.isLeaf) return;
      if (this.expanded) {
        this.tree.$emit('node-collapse', node.data, node, this);
        node.collapse();
      } else {
        node.expand();
        this.$emit('node-expand', node.data, node, this);
      }
    },

    handleCheckChange(_, ev) {
      const node = this.node || this.source;

      node.setChecked(ev.target.checked, !this.tree.checkStrictly);
      this.$nextTick(() => {
        const store = this.tree.store;
        this.tree.$emit('check', node.data, {
          checkedNodes: store.getCheckedNodes(),
          checkedKeys: store.getCheckedKeys(),
          halfCheckedNodes: store.getHalfCheckedNodes(),
          halfCheckedKeys: store.getHalfCheckedKeys()
        });
      });
    },

    handleChildNodeExpand(nodeData, node, instance) {
      this.broadcast('ElTreeNode', 'tree-node-expand', node);
      this.tree.$emit('node-expand', nodeData, node, instance);
    }
  }
};