I am modifying an existing triggger and I am new to development. Need your help with the following error: Error: Compile Error: Variable does not exist: opp.Distributor_Performing_Integration__c at line 6 column 66
 

trigger CMR_OpportunityLineItemUpdated on OpportunityLineItem (after insert, after update, after delete, after undelete,before update, before insert) { 
    //Added before insert and before update events for Case 00076809
    //Added if condition for Case 00076809
    Opportunity I = trigger.new [0]; 
    if(I.RecordType.Name =='NewBDChannelOppRecordType'){
    if(I.RecordType.Name =='DesignChannelOpportunityRecordType'&&opp.Distributor_Performing_Integration__c==false&&opp.Distributor_Performing_Integration__c==true){
    if(trigger.IsAfter){
        string OpportunityId = '';
        if(trigger.isDelete) {
            OpportunityId = trigger.old[0].OpportunityId;
        } else {
            OpportunityId = trigger.new[0].OpportunityId;
        }
        Opportunity opp = new Opportunity(Id=OpportunityId);
        opp.CSG__c = false;
        opp.LMG__c = false;
        opp.NXN__c = false;
        opp.SPG__c = false;
        opp.SSG__c = false;
        opp.STI__c = false;
        opp.SIG__c = false;
        opp.EPG__c = false;
        List<OpportunityLineItem> prods = [Select PricebookEntry.Product2.Oracle_LOB__c From OpportunityLineItem Where PricebookEntry.IsActive = True And PricebookEntry.IsDeleted = False And PricebookEntry.Product2.IsActive = True And PricebookEntry.Product2.IsDeleted = False And OpportunityId = :OpportunityId];
        
        for(OpportunityLineItem oli:prods) {
            Product2 p2 = oli.PricebookEntry.Product2;

            if(p2.Oracle_LOB__c == 'CSG') {
                opp.CSG__c = true;
            } else if(p2.Oracle_LOB__c == 'LMG') {
                opp.LMG__c = true;
            } else if(p2.Oracle_LOB__c == 'NXN') {
                opp.NXN__c = true;
            } else if(p2.Oracle_LOB__c == 'SPG') {
                opp.SPG__c = true;
            } else if(p2.Oracle_LOB__c == 'SSG') {
                opp.SSG__c = true;
            } else if(p2.Oracle_LOB__c == 'STI') {
                opp.STI__c = true;
            } else if(p2.Oracle_LOB__c == 'SIG') {
                opp.SIG__c = true;
            } else if(p2.Oracle_LOB__c == 'EPG') {
                opp.EPG__c = true;
            }
           
        }
        update opp;
    }
    
    // Added for Case 00076809
    if(trigger.IsBefore){
        Set<String> products = new Set<String>{'SPG_SWITCH_TEST', 'SSG_ROUTER_TEST','PRF1-105XXC','PRF3-105XXC'};
        
        Map<Id,OpportunityLineItem> oliMap = new Map<Id,OpportunityLineItem>([Select Id, PricebookEntry.Product2.Name,PricebookEntry.Product2Id, Discount__c from OpportunityLineItem where Id in:trigger.New and (PricebookEntry.Product2.name in: products or PricebookEntry.Product2.Name like '%-MO-%')]);
        system.debug('**oliMap**'+oliMap );
        for(OpportunityLineItem oli: trigger.new){
            system.debug('**inside for**' );
            if(oliMap!= null && oliMap.get(oli.Id)!=null){
            system.debug('**inside if**' );
            oli.Discount__c = 0;
            }
        }   
    }
  }
 }
}

Thanks!

Beth