/src/main/java/com/stygian/jira/plugins/listeners/DueDateUpdatedEventListener.java

package com.stygian.jira.plugins.listeners;

import com.atlassian.jira.bc.issue.IssueService;
import com.atlassian.jira.component.ComponentAccessor;
import com.atlassian.jira.datetime.DateTimeFormatterFactory;
import com.atlassian.jira.event.issue.IssueEvent;
import com.atlassian.jira.event.type.EventType;
import com.atlassian.jira.issue.CustomFieldManager;
import com.atlassian.jira.issue.Issue;
import com.atlassian.jira.issue.IssueInputParameters;
import com.atlassian.jira.issue.changehistory.ChangeHistory;
import com.atlassian.jira.issue.changehistory.ChangeHistoryManager;
import com.atlassian.jira.issue.fields.CustomField;
import com.atlassian.jira.issue.history.ChangeItemBean;
import com.atlassian.jira.issue.util.DefaultIssueChangeHolder;
import com.atlassian.jira.user.ApplicationUser;
import com.atlassian.plugin.spring.scanner.annotation.imports.JiraImport;
import org.joda.time.DateTime;
import org.joda.time.Days;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import com.atlassian.event.api.EventListener;
import com.atlassian.event.api.EventPublisher;

import java.time.Instant;
import java.time.temporal.ChronoUnit;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.sql.Timestamp;

@Component
public class DueDateUpdatedEventListener implements InitializingBean, DisposableBean {

    private static final Logger log = LoggerFactory.getLogger(DueDateUpdatedEventListener.class);
    @JiraImport
    private final EventPublisher eventPublisher;
    IssueService issueService = ComponentAccessor.getIssueService();
    IssueInputParameters issueInputParameters = issueService.newIssueInputParameters();
    DateTimeFormatterFactory dateTimeFormatterFactory = ComponentAccessor.getComponent(DateTimeFormatterFactory.class);
    DefaultIssueChangeHolder issueChangeHolder = new DefaultIssueChangeHolder();
    IssueService.UpdateValidationResult updateValidationResult = null;
    CustomFieldManager customFieldManager = ComponentAccessor.getCustomFieldManager();

    @Autowired
    public DueDateUpdatedEventListener(EventPublisher eventPublisher) {
        super();
        this.eventPublisher = eventPublisher;
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        log.info("Enabling Due Date Indicator Plugin");
        eventPublisher.register(this);
    }

    @Override
    public void destroy() throws Exception {
        log.info("Disabling Due Date Indicator plugin");
        eventPublisher.unregister(this);
    }


    @EventListener
    public void onIssueEvent(IssueEvent issueEvent) {
        ChangeHistoryManager changeHistoryManager = ComponentAccessor.getChangeHistoryManager();
        Long eventTypeId = issueEvent.getEventTypeId();
        Issue issue = issueEvent.getIssue();
        Collection<CustomField> fieldsToUpdate = findDueDateIndicatorFields(customFieldManager.getCustomFieldObjects(issue));

        if (eventTypeId.equals(EventType.ISSUE_CREATED_ID)
                || eventTypeId.equals(EventType.ISSUE_UPDATED_ID)) {
            log.info("Issue Listener from Due Date Indivator Plugin");

            if(issueEvent.getChangeLog() != null && issueEvent.getChangeLog().getLong("id") != null){
                ChangeHistory history = changeHistoryManager.getChangeHistoryById(issueEvent.getChangeLog().getLong("id"));
                for (ChangeItemBean changeItem : history.getChangeItemBeans() ) {
                    if(changeItem.getField().contains("duedate")){
                        log.info("Due date has been updated. Custom field will be updated.");
                        //implement logic here to update due date
                        if(issue.getResolution() == null)
                        {
                            for (CustomField field : fieldsToUpdate) {
                                String valueToSet = null;
                                if (changeItem.getTo() != null){
                                    Instant t1 = Instant.now();
                                    Instant t2 = Instant.ofEpochMilli(issue.getDueDate().getTime());
                                    valueToSet = Long.toString(ChronoUnit.MILLIS.between(t1, t2));
                                }
                                issueInputParameters.addCustomFieldValue(field.getIdAsLong(), valueToSet);
                                updateValidationResult = issueService.validateUpdate(ComponentAccessor.getJiraAuthenticationContext().getLoggedInUser(), issue.getId(), issueInputParameters);
                                updateIssue(updateValidationResult);
                            }
                        }
                    }
                }
            }
        }

        if(eventTypeId.equals(EventType.ISSUE_RESOLVED_ID)
                || eventTypeId.equals(EventType.ISSUE_CLOSED_ID)
                || eventTypeId.equals(EventType.ISSUE_GENERICEVENT_ID)){
            //Set Over Due field value to null if issue has been resolved
            if(issueEvent.getChangeLog() != null && issueEvent.getChangeLog().getLong("id") != null){
                ChangeHistory history = changeHistoryManager.getChangeHistoryById(issueEvent.getChangeLog().getLong("id"));
                for (ChangeItemBean changeItem : history.getChangeItemBeans() ) {
                    if(changeItem.getField().contains("resolution")){
                        log.info("Resolution been updated. Custom field will be updated.");
                        //implement logic here to update due date
                        for (CustomField field : fieldsToUpdate) {
                            String valueToSet = null;
                            if (changeItem.getTo() == null){
                                Instant t1 = Instant.now();
                                Instant t2 = Instant.ofEpochMilli(issue.getDueDate().getTime());
                                valueToSet = Long.toString(ChronoUnit.MILLIS.between(t1, t2));
                            }
                            issueInputParameters.addCustomFieldValue(field.getIdAsLong(), valueToSet);
                            updateValidationResult = issueService.validateUpdate(ComponentAccessor.getJiraAuthenticationContext().getLoggedInUser(), issue.getId(), issueInputParameters);
                            updateIssue(updateValidationResult);
                        }
                    }
                }
            }
        }
    }

    private void updateIssue(IssueService.UpdateValidationResult updateValidationResult){
        if (updateValidationResult.isValid()) {
            IssueService.IssueResult updateResult = issueService.update(ComponentAccessor.getJiraAuthenticationContext().getLoggedInUser(), updateValidationResult);
            if (!updateResult.isValid()) {
                log.info("ISSUE has NOT been updated. Errors: {}\n", updateResult.getErrorCollection().toString());
            } else {
                log.info("ISSUE has been updated.\n");
            }
        } else {
            log.info("ISSUE has NOT been updated. Errors: {}\n", updateValidationResult.getErrorCollection().toString());
        }
    }

    private Collection<CustomField> findDueDateIndicatorFields(Collection<CustomField> fields){
        Collection<CustomField> found = new ArrayList<CustomField>();
        for(CustomField field:fields){
            if(field.getCustomFieldType().getKey().equalsIgnoreCase("com.stygian.jira.plugins.overdue:over-due-custom-field")){
                found.add(field);
            }
        }
        return found;
    }
}