如何将省市区三级树状结构数据扁平化处理并根据选中状态精简结果？

[
  {
    "code": "110000",
    "value": "北京市",
    "checked": "1",
    "children": [
      {
        "code": "110100",
        "value": "北京市",
        "checked": "1",
        "children": [
          { "code": "110101", "value": "东城区", "checked": "1" },
          { "code": "110102", "value": "西城区", "checked": "1" }
        ]
      }
    ]
  },
  {
    "code": "120000",
    "value": "天津市",
    "checked": "1",
    "children": [
      {
        "code": "120100",
        "value": "天津市",
        "checked": "1",
        "children": [
          { "code": "120101", "value": "和平区", "checked": "0" },
          { "code": "120102", "value": "河东区", "checked": "1" }
        ]
      }
    ]
  }
]

[
  {
    "provinceAreald": "110000",
    "cityAreald": null,
    "countryAreald": null,
    "actualAreaLevel": "1"
  },
  {
    "provinceAreald": "120000",
    "cityAreald": "120100",
    "countryAreald": "120102",
    "actualAreaLevel": "3"
  }
]

function flattenData(data) {
  const result = [];

  function processNode(node, parent) {
    if (node.checked === "1") {
      const item = {
        provinceAreald: parent ? parent.code : node.code,
        cityAreald: null,
        countryAreald: null,
        actualAreaLevel: '1'
      };

      if (node.children) {
        const allChildrenChecked = node.children.every(child => child.checked === "1");
        if (allChildrenChecked) {
          item.actualAreaLevel = node.children[0].children ? '2' : '1';
          if(node.children[0].children){
            item.cityAreald = node.children[0].code;
          }
        } else {
          item.actualAreaLevel = '2';
          item.cityAreald = node.code;
          for (const child of node.children) {
            processNode(child, item);
          }
          return;
        }
      }

      result.push(item);
    } else if (node.children) {
      for (const child of node.children) {
        processNode(child, node);
      }
    }
  }

  for (const node of data) {
    processNode(node);
  }

  return result;
}

// 示例用法
const data = [/* ...原始数据 ... */];
const flattenedData = flattenData(data);
console.log(flattenedData);