global class BatchClassPledgeTransaction implements Database.batchable<sObject> {
    final String query;
    list<Transaction__c> transList = new list<Transaction__c>();
    
	// constructor
	global BatchClassPledgeTransaction() {
		query = 'SELECT Id, ' +
					   'Name, ' +
					   'Duration__c, ' +
					   'Start_Date__c, ' +
					   'End_Date__c ' +
				'FROM Pledge__c';
	}
	
	// Start Method
    global Database.querylocator start(Database.BatchableContext BC){
        return Database.getQueryLocator(query);
    }
    
	// Execute Logic
    global void execute(Database.BatchableContext BC, List<Pledge__c> Scope){
		Map<String, Schema.RecordTypeInfo> pledgeRecordTypeInfosByNameMap = Schema.SObjectType.Pledge__c.getRecordTypeInfosByName();
		Map<String, Schema.RecordTypeInfo> transactionRecordTypeInfosByNameMap = Schema.SObjectType.Transaction__c.getRecordTypeInfosByName();
		
		Id PledgeRecTypeCard = pledgeRecordTypeInfosByNameMap.get('Card').getRecordTypeId();
        Id PledgeRecTypeGIRO = pledgeRecordTypeInfosByNameMap.get('GIRO').getRecordTypeId();
        Id PledgeRecTypeOnline = pledgeRecordTypeInfosByNameMap.get('Online').getRecordTypeId();
        Id PledgeRecTypeRecurringCash = pledgeRecordTypeInfosByNameMap.get('Recurring Cash').getRecordTypeId();
        Id PledgeRecTypeRecurringCheque = pledgeRecordTypeInfosByNameMap.get('Recurring Cheque').getRecordTypeId();
        
		Id TransactionRecTypeCard = transactionRecordTypeInfosByNameMap.get('Card').getRecordTypeId();
        Id TransactionRecTypeGIRO = transactionRecordTypeInfosByNameMap.get('GIRO').getRecordTypeId();
        Id TransactionRecTypeOnline = transactionRecordTypeInfosByNameMap.get('Online').getRecordTypeId();
        Id TransactionRecTypeRecurringCash = transactionRecordTypeInfosByNameMap.get('Recurring Cash').getRecordTypeId();
        Id TransactionRecTypeRecurringCheque = transactionRecordTypeInfosByNameMap.get('Recurring Cheque').getRecordTypeId();
		
		Set<Id> pledgeIdSet = new Map<Id,SObject>(Scope).keySet()
		
		// Query once per batch job
		// SOQL limits
		AggregateResult[] numberOfTransactionsPerPledge = [SELECT COUNT(id)
														   FROM Transaction__c
														   WHERE Pledge__c IN :pledgeIdSet
														   GROUP BY Pledge__c];
		
        for (Pledge__c plg : Scope){
			// make sure that we even need to create transactions. 
			// avoid going over
			if (numberOfTransactionsPerPledge.get(plg.Id) < integer.valueof(plg.Duration__c)) {
				Integer j = integer.valueof(plg.Duration__c) - 12;
			
				for (Integer i = 0; i <= j; i++){
					Transaction__c tran = new Transaction__c();
					
					// Transactions start where trigger left off
					tran.Transaction_Date__c = plg.Start_Date__c.addMonths(i + 12); 
					tran.Pledge__c = plg.id;
					tran.Amount_Reconciled__c = plg.Amount__c;
					tran.Donor__c = plg.Account__c;
					tran.Status__c = plg.Status__c;
						  
					if (plg.recordtypeid == PledgeRecTypeCard){
						tran.recordtypeid = TransactionRecTypeCard;
					} 
								
					if (plg.recordtypeid == PledgeRecTypeGIRO){
						tran.recordtypeid = TransactionRecTypeGIRO;
					} 
							   
					if (plg.recordtypeid == PledgeRecTypeOnline){
						tran.recordtypeid = TransactionRecTypeOnline;
					} 
							   
					if (plg.recordtypeid == PledgeRecTypeRecurringCash){
						tran.recordtypeid = TransactionRecTypeRecurringCash;
					} 
							   
					if (plg.recordtypeid == PledgeRecTypeRecurringCheque){
						tran.recordtypeid = TransactionRecTypeRecurringCheque;
					} 
					
					transList.add(tran);
				}
			}
		}
		
		// insert all at once
		// DML limits
		insert transList;
    }
    
	// finish
	global void finish(Database.BatchableContext BC){}
}

// Sample call from anonymous apex window:
//
// Seconds Minutes Hours Day_of_month Month Day_of_week optional_year
// example last day of the month at 12am
// String cronStr = '0 0 0 ? * L'; 
// BatchClassPledgeTransactionSchedule sched = BatchClassPledgeTransactionSchedule();
// System.schedule('BatchClassPledgeTransaction ', cronStr, sched);
global class BatchClassPledgeTransactionSchedule implements Schedulable {
	global void execute(SchedulableContext sc) {
        //  Instantiate batch class 
		Id batchInstanceId = Database.executeBatch(new BatchClassPledgeTransaction());
    }
}