global class PMProcessingBatch implements Database.Batchable<sObject>, Schedulable, Database.Stateful {

    //Variable Section
    global FINAL String strQuery;
    global List<String> errorMessages = new List<String>();
    
    global PMProcessingBatch() { 
        this.strQuery = getBatchQuery();
    }
    
    //Returns the Query String to Batch constructor to fetch right records.
    private String getBatchQuery() {
        String strQuery = 'SELECT Id, Name FROM Personnel_Management__c'; 
        return strQuery;
    }
    
    //Batch Start method
    global Database.QueryLocator start(Database.BatchableContext BC) {
        return Database.getQueryLocator(strQuery);
    }

    //Batch Execute method
    global void execute(Database.BatchableContext BC, List<sObject> scopeList) {
        System.debug(LoggingLevel.INFO, '== scopeList size ==' + scopeList.size());
        
        List<Personnel_Management__c> pmList = (List<Personnel_Management__c>) scopeList;
		
		try {                    
			Database.SaveResult[] saveResults = Database.update(pmList, false);
			for (Database.SaveResult sr : SaveResults) {
				if(!sr.isSuccess()) {
					for (Database.Error err : sr.getErrors()) {
						errorMessages.add('Error: ' + err.getStatusCode() + ': ' + err.getMessage());
					}
					system.debug(sr.getErrors()[0].getMessage());
				}
			}
			System.debug('errorMessages: '+errorMessages);
		} catch (System.Exception ex) {
			System.debug('An error occurred while updating PM: ' + ex.getMessage());
			return;
		}
    }  

    //Batch Finish method for after execution of batch work
    global void finish(Database.BatchableContext BC) { 
        AsyncApexJob aaj = [Select Id, Status, NumberOfErrors, JobItemsProcessed, MethodName, TotalJobItems, CreatedBy.Email from AsyncApexJob where Id =:BC.getJobId()];
        
        // Send an email to the Apex job's submitter notifying of job completion.
        Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
        String[] toAddresses = new String[] {aaj.CreatedBy.Email};
        mail.setToAddresses(toAddresses);
        mail.setSubject('JOB Salesforce PM Processing Batch: ' + aaj.Status);
        String bodyText='Total Job Items ' + aaj.TotalJobItems + ' Number of records processed ' + aaj.JobItemsProcessed + ' with '+ aaj.NumberOfErrors + ' failures.\n';
        bodyText += 'Number of Error Messages ' + errorMessages.size() + '\n';
        bodyText += 'Error Message' + String.join(errorMessages, '\n');
        mail.setPlainTextBody(bodyText);
        Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail });
    }
    
    //Method which schedules the PMProcessingBatch
    global void execute(SchedulableContext sc) {        
        PMProcessingBatch pmBatch = new PMProcessingBatch();
        ID batchprocessid = Database.executeBatch(pmBatch);
    }
}

/**
 * This class contains unit tests for validating the behavior of AccountTeamCreationBatch
 * and AccountRelationshipUtils.
 *
 */
@isTest
private class PMProcessingBatchTest {
    
   
    public static String CRON_EXP = = '0 0 1 * * ?';
    

    static testMethod void pmBatchTest() {
        
        Personnel_Management__c pm = new Personnel_Management__c();
        pm.Name = 'Test PM';
        
        insert pm;
        
        Test.startTest();
        PMProcessingBatch batch = new PMProcessingBatch();
        Database.executeBatch(batch);        
        Test.stopTest();
        
        String jobId = System.schedule('PMProcessingBatch', CRON_EXP, new PMProcessingBatch());
         
        CronTrigger ct = [SELECT Id, CronExpression, TimesTriggered, NextFireTime FROM CronTrigger WHERE id = :jobId];

        System.assertEquals(CRON_EXP, ct.CronExpression);
        System.assertEquals(0, ct.TimesTriggered);
    }
}