trigger updatevalueonOpportunity on OpportunityLineItem (before insert) {

    Set<id> prid = new Set<id>();
    Set<id> oppid = new Set<id>();
    for(OpportunityLineItem ol : Trigger.new){
        prid.add(ol.product2id);
        oppid.add(ol.OpportunityId);
    }

    list<product2> Products = [select id,PIM_Type__c from product2 where id IN:prid and (PIM_Type__c='Cloud Flexibility Mode'or PIM_Type__c='Cloud Serenity Mode')];
    list<opportunity> Opps  = [select id,PIMtype__c,HasOpportunityLineItem from opportunity where id IN:oppid];

    if(Products.size()>0)
    {
        string prodPimtype = Products[0].PIM_Type__c;
        for(OpportunityLineItem ol1 : Trigger.new){
            for(product2 prods:Products){
                for(opportunity upOpp:Opps){
                    if(upOpp.HasOpportunityLineItem == false)
                    {
                        if(prodPimtype == prods.PIM_Type__c && upOpp.id==ol1.Opportunityid){
                            upOpp.PIMtype__c = prods.PIM_Type__c ;
                        }else{
                            ol1.addError('All OpportunityProducts are should be same PIM Type');
                        }
                    }else{
                        if(upOpp.PIMtype__c==prods.PIM_Type__c){
                            upOpp.PIMtype__c = prods.PIM_Type__c ;
                        }else{
                            ol1.addError('All OpportunityProducts are should be same PIM Type');
                        }
                    }
                }
            }

        }
        update Opps;
    }
}

Trigger updatevalueonOpportunity on OpportunityLineItem (before insert) {

    Set<Id> PrdId = new set<Id>();
    Set<Id> OppId = new set<Id>();
    for(OpportunityLineItem OppLine : Trigger.new){
        PrdId.add(OppLine.product2id);
        OppId.add(OppLine.OpportunityId);
    }

    Map<Id,Product2> CloudProductsmap = new map<Id,Product2>([Select id,PIM_Type__c from product2 where Id In:PrdId and (PIM_Type__c='Cloud Flexibility Mode' or PIM_Type__c='Cloud Serenity Mode')]);
    List<OpportunityLineItem> OppLinelst = [select id,product2id,Opportunityid from OpportunityLineItem where Opportunityid In:oppid];
    Map<Id,Opportunity> OppMap = new map<Id,Opportunity>([select id,HasOpportunityLineItem,PIMType__c from Opportunity where id In:oppid]);
    Map<Id,OpportunityLineItem> OppLineMap = new Map<Id,OpportunityLineItem>();
    List<Opportunity> UpdateOpportunity = new list<Opportunity>();

    for(OpportunityLineItem OppItems : OppLinelst){
        OppLineMap.put(OppItems.Opportunityid,OppItems);
    }

    if(CloudProductsmap.size()>0)
    {
        for(OpportunityLineItem Oppline1 : Trigger.new){
            if(OppMap.get(Oppline1.Opportunityid).HasOpportunityLineItem){
                if(OppMap.get(Oppline1.Opportunityid).PIMtype__c != null)
                String Pimtype = OppMap.get(Oppline1.Opportunityid).PIMtype__c;
                if(Pimtype!= CloudProductsmap.get(Oppline2.product2id).PIM_Type__c){
                    Oppline1.addError('Product PIM type should be same as Existing product PIM type.');
                }
            }else{

                string Pimtype1 = CloudProductsmap.get(Oppline1.product2id).PIM_Type__c;
                for(OpportunityLineItem Oppline2 : Trigger.new){

                    if(Pimtype1 == CloudProductsmap.get(Oppline2.product2id).PIM_Type__c){
                        OppMap.get(Oppline2.Opportunityid).PIMType__c = Pimtype1;

                        Opp.PIMType__c = loudProductsmap.get(Oppline2.product2id).PIM_Type__c;

                    }else{
                        Oppline1.addError('All OpportunityProducts first are should be same PIM Type');
                    }
                }
            }
        }

        update OppMap.values();
    }
}