trigger CaseInvokeWithOpp on Opportunity (after insert, after update) {
	 
    List<Opportunity> oppLst = Trigger.New;
    
    //list for account Ids
    List<Id> AccIds = new List<Id>();
    //list for owner Ids
    List<Id> ownerIds = new List<Id>();
    
    //list to create new cases
    List<Case> newCases = new List<Case>();
    
    //Map to set account details related opportunity
    Map<Id, String> accountInfo = new Map<Id, String>();
	Map<Id, String> accountAdditionalInfo = new Map<Id, String>(); 
    
    //Map to set owner's first name and the last name
    Map<Id, String> ownerFirstName = new Map<Id, String>();
    Map<Id, String> ownerLastName = new Map<Id, String>();
   
    
    //Get account Id and owner Id from opportunities
    for(Opportunity opp : oppLst)
    {
        AccIds.add(opp.AccountId);
        ownerIds.add(opp.OwnerId);
    }
    
    List<Account> relatedAcc = [SELECT Name, AccountNumber FROM Account WHERE Id IN: AccIds];
    List<User> relatedUserLst = [SELECT FirstName, LastName FROM User WHERE Id IN: ownerIds];
    
    //Set account name and account number
    for(Account ac : relatedAcc){
        accountInfo.put(ac.Id, ac.Name);
        accountAdditionalInfo.put(ac.Id, ac.AccountNumber);
    }
    
    //set owner first name and the last name
    for(User usr: relatedUserLst){
        
        ownerFirstName.put(usr.Id, usr.FirstName);
    	ownerLastName.put(usr.Id, usr.LastName);
    }
        
    for(Opportunity opp : oppLst)
    {
        //Check whether the opportunity's Stage=Closed Won, Type=Upgrade and Setup Needed=Yes
        if(opp.StageName == 'Closed Won' && opp.Type == 'Upgrade' && opp.Setup_Needed__c == true){
            
            case newcase = new case();
            newcase.AccountId = opp.AccountId;
            //Case with Subject containing Opportunity Name and Account Name
            newcase.Subject = opp.Name + ' ' + accountInfo.get(opp.AccountId);
            //Customer: {!Account.Name}
            newcase.Customer__c = accountInfo.get(opp.AccountId);
            //AccountNumber: {!Account.AccountNumber__c}
            newcase.Account_Number__c = accountAdditionalInfo.get(opp.AccountId);
            //Sold By: {!Opportunity.OwnerFullName}
            newcase.Sold_By__c = ownerFirstName.get(opp.OwnerId) + ' '+ ownerLastName.get(opp.OwnerId);
            newcase.Status = 'New';
            newCases.add(newcase);
        }
        
        insert newCases;
    }
}