export default function getNodeSequence(xmlObj) {
  if (!xmlObj.childNodes[0].childNodes[0]) return [];
  let nodeList = Array.from(xmlObj.childNodes[0].childNodes[0].childNodes)
  let res = [];
  let startNode = nodeList.find((item) => item.tagName == 'bpmn:startEvent');
  if (!startNode) {
    console.log('缺少开始节点');
    return;
  }
  let nextNodeId = getNodeId(startNode, true, nodeList);
  res.push({
    nodeId: startNode.id,
    preNodeId: null,
    nextNodeId: nextNodeId,
  })
  while (nextNodeId) {
    if (!nextNodeId) break
    let currentId = nextNodeId;
    let currentNode = nodeList.find(item => item.id == currentId);
    nextNodeId = getNodeId(currentNode, true, nodeList);
    let preNodeId = getNodeId(currentNode, false, nodeList);
    res.push(
      {
        nodeId: currentId,
        preNodeId,
        nextNodeId,
      }
    )
  }
  console.log(res);
  return res

}
/**
 * 
 * @param {节点} node 
 * @param {true:下一个节点的id;false:上一个节点的id} flag 
 * @returns 
 */
const getNodeId = (node, flag, nodeList) => {
  let theTagName = flag ? 'bpmn:outgoing' : 'bpmn:incoming';
  let childNodeList = Array.from(node.childNodes);
  let FlowId = childNodeList.find(item => item.tagName == theTagName)?.firstChild?.data;//找到指入或指出箭头节点
  if (!FlowId) return false;
  let targetId = nodeList.find(item => item.id == FlowId)?.getAttribute(flag ? 'targetRef' : 'sourceRef')
  if (!targetId) return false;
  return targetId;
}