package com.flow.flowable.cmd;

import org.flowable.bpmn.model.MultiInstanceLoopCharacteristics;
import org.flowable.common.engine.api.FlowableException;
import org.flowable.common.engine.impl.interceptor.Command;
import org.flowable.common.engine.impl.interceptor.CommandContext;
import org.flowable.engine.ManagementService;
import org.flowable.engine.RuntimeService;
import org.flowable.engine.TaskService;
import org.flowable.engine.impl.cfg.ProcessEngineConfigurationImpl;
import org.flowable.engine.impl.util.CommandContextUtil;
import org.flowable.engine.runtime.Execution;
import org.flowable.task.api.Task;

import java.util.List;
import java.util.Objects;

public class DeleteTaskExecutionCmd implements Command<Void> {
    protected String processInstanceId;
    protected String activityId;
    protected String assignee;

    public DeleteTaskExecutionCmd(String processInstanceId, String activityId, String assignee) {
        this.processInstanceId = processInstanceId;
        this.activityId = activityId;
        this.assignee = assignee;
    }

    @Override
    public Void execute(CommandContext commandContext) {
        ProcessEngineConfigurationImpl processEngineConfiguration = CommandContextUtil.getProcessEngineConfiguration();
        ManagementService managementService = processEngineConfiguration.getManagementService();
        MultiInstanceLoopCharacteristics loopCharacteristics = managementService.executeCommand(new GetLoopCharacteristicsCmd(this.processInstanceId, this.activityId));
        if (Objects.nonNull(loopCharacteristics)) {
            RuntimeService runtimeService = processEngineConfiguration.getRuntimeService();
            String collectionName = loopCharacteristics.getInputDataItem();
            collectionName = collectionName.substring(2, collectionName.length() - 1);
            List<String> assigneeList = runtimeService.getVariable(
                    this.processInstanceId,
                    collectionName,
                    List.class
            );
            if (!assigneeList.contains(this.assignee)) {
                throw new FlowableException(String.format("会签办理者中没有用户：%s", this.assignee));
            }
            if (assigneeList.size() == 1) {
                throw new FlowableException("会签必须保留一个用户");
            }
            Execution miExecution = managementService.executeCommand(new GetMultiInstanceRootExecutionCmd(this.processInstanceId, this.activityId));
            if (loopCharacteristics.isSequential()) {
                Integer loopCounter = runtimeService.getVariableLocal(miExecution.getId(), "loopCounter", Integer.class);
                if (!assigneeList.subList(loopCounter, assigneeList.size() - 1).contains(this.assignee)) {
                    throw new FlowableException(String.format("会签后续办理者中没有用户：%s", this.assignee));
                }
            } else {
                TaskService taskService = processEngineConfiguration.getTaskService();
                List<Task> tasks = taskService.createTaskQuery()
                        .processInstanceId(this.processInstanceId)
                        .taskDefinitionKey(this.activityId)
                        .active()
                        .list();
                if (tasks.stream().noneMatch(task -> task.getAssignee().equals(this.assignee))) {
                    throw new FlowableException(String.format("没有用户：%s的会签任务", this.assignee));
                }
                Integer nrOfActiveInstances = runtimeService.getVariableLocal(miExecution.getId(), "nrOfActiveInstances", Integer.class);
                runtimeService.setVariableLocal(miExecution.getId(), "nrOfActiveInstances", nrOfActiveInstances - 1);
                List<Task> deleteTasks = taskService.createTaskQuery()
                        .processInstanceId(this.processInstanceId)
                        .taskDefinitionKey(this.activityId)
                        .taskAssignee(this.assignee)
                        .list();
                for (Task deleteTask : deleteTasks) {
                    runtimeService.deleteMultiInstanceExecution(deleteTask.getExecutionId(), false);
                }
            }
            assigneeList.remove(this.assignee);
            runtimeService.setVariable(this.processInstanceId, collectionName, assigneeList);
        } else {
            throw new FlowableException("当前节点不支持减签");
        }
        return null;
    }
}