package com.ruoyi.flowable.utils;

import org.flowable.bpmn.converter.BpmnXMLConverter;
import org.flowable.bpmn.model.BpmnModel;
import org.flowable.bpmn.model.FlowElement;
import org.flowable.bpmn.model.Process;
import org.flowable.bpmn.model.StartEvent;
import org.flowable.common.engine.impl.util.io.StringStreamSource;

import java.util.Collection;

/**
 * @author KonBAI
 * @createTime 2022/3/26 19:04
 */
public class ModelUtils {

    private static final BpmnXMLConverter bpmnXMLConverter = new BpmnXMLConverter();

    /**
     * xml转bpmnModel对象
     *
     * @param xml xml
     * @return bpmnModel对象
     */
    public static BpmnModel getBpmnModel(String xml) {
        return bpmnXMLConverter.convertToBpmnModel(new StringStreamSource(xml), false, false);
    }

    /**
     * bpmnModel转xml对象
     *
     * @param bpmnModel bpmnModel对象
     * @return xml
     */
    public static byte[] getBpmnXml(BpmnModel bpmnModel) {
        return bpmnXMLConverter.convertToXML(bpmnModel);
    }

    /**
     * 获取开始节点
     *
     * @param model bpmnModel对象
     * @return 开始节点（未找到开始节点，返回null）
     */
    public static StartEvent getStartEvent(BpmnModel model) {
        Process process = model.getMainProcess();
        Collection<FlowElement> elements = process.getFlowElements();
        return (StartEvent) elements.stream()
            .filter(flowElement -> flowElement instanceof StartEvent)
            .findFirst().orElse(null);
    }
}