(() => {
    // 注入样式
    const style = document.createElement('style');
    style.textContent = `
.tree-select-menu {
  max-height: 500px;
  overflow-y: auto;
  min-width: 250px;
  font-family: Arial, sans-serif;
  font-size: 12px;
  user-select: none;
  border: 1px solid #dee2e6;
  padding-left: 4px;
}
.tree-node {
  cursor: default;
  padding: 4px 8px;
  display: block;
  white-space: nowrap;
  position: relative;
  text-align: left;
}
.tree-node::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0px;
  bottom: 0;
  width: 1px;
  border-left: 1px dashed #ccc;
}
.tree-node:not(.leaf) [data-level="0"] >.tree-label {
  font-weight: bold;
}
.tree-node[data-level="0"]::before,
.tree-node[data-level="0"]::after {
  display: none !important;
}
.tree-node::after {
  content: '';
  position: absolute;
  top: 14px;
  left: 0px;
  width: 10px;
  height: 1px;
  background-color: #ccc;
}
.tree-node:last-child::before {
  height: 14px;
}
.tree-node.leaf {
  cursor: pointer;
  color: #007bff;
  background-color: #fff;
}
.tree-node.leaf:hover {
  background-color: #e9ecef;
}
.tree-label {
  display: inline-block;
  vertical-align: middle;
}
.tree-toggle {
  display: inline-block;
  width: 14px;
  text-align: center;
  margin-right: 6px;
  user-select: none;
  font-size: 12px;
  vertical-align: middle;
}
.tree-children {
  display: none;
  margin-left: 18px;
  padding-left: 8px;
}
.tree-expanded > .tree-children {
  display: block;
}
.tree-select button {
  color: #495057;
  border: 1px solid #ced4da;
  padding: .25rem .5rem;
}
.tree-select button:active {
  color: #6c757d !important;
  border: 1px solid #ced4da;
  background-color: #fff !important;
}
#tree-container .show>.btn-outline-secondary.dropdown-toggle {
  color: #6c757d !important;
  border: 1px solid #80bdff;
  background-color: #fff !important;
  box-shadow: 0 0 0 .2rem rgba(0, 123, 255, .25);
}
#tree-container .show>.btn-outline-secondary.dropdown-toggle:focus {
  border-color: #80bdff;
  box-shadow: 0 0 0 .2rem rgba(0, 123, 255, .25);
}
.tree-select .btn-outline-secondary:hover {
  color: #6c757d;
  border: 1px solid #ced4da;
  background-color: #fff;
}
.tree-select .btn-outline-secondary:focus {
  border-color: #80bdff;
  box-shadow: 0 0 0 .2rem rgba(0, 123, 255, .25);
}
`;
    document.head.appendChild(style);

    class TreeSelect {
        constructor({ element, data, selected, onSelect }) {
            this.container = typeof element === 'string' ? document.querySelector(element) : element;
            this.onSelect = onSelect;
            this.selectedId = selected;
            this.data = this.buildTree(data);
            this.selectedNode = this.findNodeById(this.data, this.selectedId);
            this.render();
        }

        // ✅ flat → tree 转换函数
        buildTree(data, parentId = '-1') {
            // 找出所有属于 parentId 的节点
            const children = data
                .filter(item => item.tree_pid === parentId)
                .sort((a, b) => a.tree_order - b.tree_order); // ✅ 按 tree_order 升序排序

            return children.map(item => {
                const nodeChildren = this.buildTree(data, item.id);
                return {
                    id: item.id,
                    label: item.name,
                    selected: item.id === this.selectedId,
                    children: nodeChildren.length ? nodeChildren : undefined
                };
            });
        }

        findNodeById(nodes, id) {
            for (const node of nodes) {
                if (node.id === id) return node;
                if (node.children) {
                    const found = this.findNodeById(node.children, id);
                    if (found) return found;
                }
            }
            return null;
        }

        render() {
            this.container.innerHTML = `
        <div class="dropdown tree-select">
          <button class="btn btn-sm btn-outline-secondary w-100 dropdown-toggle text-left" type="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
            ${this.selectedNode ? this.selectedNode.label : '请选择分类'}
          </button>
          <div class="dropdown-menu tree-select-menu"></div>
        </div>
      `;
            this.button = this.container.querySelector('button');
            this.menu = this.container.querySelector('.dropdown-menu');
            this.button.dataset.selectedId = this.selectedNode?.id || '';
            this.renderTree(this.data, this.menu, 0);
        }

        renderTree(nodes, parentEl, level = 0) {
            nodes.forEach(node => {
                const wrapper = document.createElement('div');
                wrapper.className = 'tree-node tree-expanded'; // 默认展开
                wrapper.dataset.level = level;

                const isLeaf = !node.children || node.children.length === 0;
                if (isLeaf) wrapper.classList.add('leaf');
                const toggle = document.createElement('span');
                toggle.className = 'tree-toggle';
                toggle.innerHTML = isLeaf ? '' : '<i class="fa fa-minus-square-o"></i>';

                if (!isLeaf) {
                    wrapper.appendChild(toggle);
                    const toggle2 = document.createElement('span');
                    toggle2.className = 'tree-folder';
                    toggle2.innerHTML = '<i class="fa fa-folder-o"></i> ';
                    wrapper.appendChild(toggle2);
                }

                const label = document.createElement('span');
                label.className = 'tree-label';
                label.innerHTML = isLeaf ? '&nbsp; ' + node.label : node.label;
                wrapper.appendChild(label);

                if (!isLeaf) {
                    const childrenContainer = document.createElement('div');
                    childrenContainer.className = 'tree-children';
                    wrapper.appendChild(childrenContainer);
                    this.renderTree(node.children, childrenContainer, level + 1);

                    if (this.isNodeOrChildSelected(node)) {
                        wrapper.classList.add('tree-expanded');
                        toggle.innerHTML = '<i class="fa fa-minus-square-o"></i>';
                    }

                    // 👇 点击整行展开/收起
                    wrapper.addEventListener('click', e => {
                        e.stopPropagation();
                        const expanded = wrapper.classList.toggle('tree-expanded');
                        toggle.innerHTML = expanded ? '<i class="fa fa-minus-square-o"></i>' : '<i class="fa fa-plus-square-o"></i>';
                    });
                } else {
                    // 👇 叶子节点可选中
                    wrapper.addEventListener('click', e => {
                        e.stopPropagation();
                        this.selectNode(node);
                    });
                }

                parentEl.appendChild(wrapper);
            });
        }

        isNodeOrChildSelected(node) {
            if (node.selected) return true;
            if (!node.children) return false;
            return node.children.some(child => this.isNodeOrChildSelected(child));
        }

        selectNode(node) {
            this.selectedNode = node;
            this.button.textContent = node.label;
            this.button.dataset.selectedId = node.id;
            $('.tree-select button').dropdown('toggle');
            if (typeof this.onSelect === 'function') {
                this.onSelect(node.id, node.label);
            }
        }

        getValue() {
            return this.button.dataset.selectedId || null;
        }
    }

    window.TreeSelect = TreeSelect;
})();