trigger insertAcc on Factura__c (before insert) {



if(Trigger.isBefore)
{
    if(Trigger.isInsert)
    {
    
         /*
            1.-  I'm guessing that you would like to do this code in isInsert as you are using Trigger.New
            2.-  I'm gessing for this line of code that Empresa_cliente is a Lookup to an object called Empresa_Cliente
            and you would like to access to a field that is in it called CodigoNAF that after that you need to use
            to get the accounts that match the values of this
            trigger.New[0].Empresa_Cliente__r.CodigoNAF__c;  
        */
        
        List<Factura__c> facturas = Trigger.new;
        
        List<Id> empresaIds = new List<Id> (); 
        Map<Id, String> facturaEmpresaCompanias = new Map<Id,String> ();
        for(Factura__c f: facturas)
        {
            // for later use at the time to create accounts
            /*Notice!!! -- I'm guessing that 1 Empresa will have only one Company, if the same Empresa has different
            companies then I won't do anything! I'll STOP
            May be you could like to make it the other way round , if there is no CodigoNAF then do nothing, Stop!
            you can change this behaviour if you wish*/
            if(f.Empresa_Cliente__c!=null)
            {
                empresaIds.add(f.Empresa_Cliente__c);
               if( !facturaEmpresaCompanias.containsKey(f.Empresa_Cliente__c))
                   facturaEmpresaCompanias.put(f.Empresa_Cliente__c, f.Compania__c);
               else
               {
                  if(facturaEmpresaCompanias.containsKey(f.Empresa_Cliente__c) && facturaEmpresaCompanias.get(f.Empresa_Cliente__c)!= f.Compania__c)
                       throw new FacturaException('There is another Factura that contains a Empresa_Cliente with different Compania and that is not allowed. Lo sentimos. ');
               }
            }
            
        }
        
        List<Empresa_Cliente__c> empresas = [Select Id, CodigoNAF__c from Empresa_Cliente__c where Id IN : empresaIds];
        
        // Now I need to get the CodigoNAF__c for each empresa
        //I also need to set up each Compania with their CodigoNAF
        Map<String, String> companiaCodigoNAF = new Map<String, String> ();
       // Map<Id, String> empresasCodigos = new Map<Id, String> ();
        for(Empresa_Cliente__c e:empresas)
        {
            //empresasCodigos.put(e.Id,e.CodigoNAF__c);
            companiaCodigoNAF.put(facturaEmpresaCompanias.get(e.Id), e.CodigoNAF__c);
        }
        
        List<String> codigos = companiaCodigoNAF.values();
        
        List<Account> accounts = [select name, CodigoNAF__c from account where CodigoNAF__c IN :codigos];
       
        //throw new FacturaException('hola'+accounts);
        List<Account> newAccounts = new List<Account>();
       
       /* Now I create accounts for all the facturas?? that don't have account
       ( maybe you would like for all the codigos or for all the empresas.. that's for you to decide here and implement in the way you wish) 
       To have in count!!! OJO!!!
       if I create an account per each Factura, maybe you will have duplicate values
        then what I'll do is use Company, Codigo as map to check I don't create duplicate Accounts
       */
       if(accounts.isEmpty()) // accounts.isEmpty()
       {
           for(String compania: companiaCodigoNAF.keyset())
           {
              Account acc = new Account();
              acc.Name = compania;
              acc.CodigoNAF__c= companiaCodigoNAF.get(compania);
              newAccounts.add(acc);
           }
       }
       if(accounts.size() != codigos.size())
       {
           // you should also check which Codes have account Representation
       }
       
        insert newAccounts;

    } 
    else if(Trigger.isUpdate){}// you should do the same may be for Update? 
    else if(Trigger.isDelete) {}
}
else
{
    
}


public class FacturaException extends Exception {}


}