trigger ddi_Account_Trigger on Account (before insert) {
    switch on Trigger.operationType {
        when  Before_Insert{
             //List<Account> accountList =[SELECT Id, Name, MultiSelect_State__c,Account_Email__c, createddate FROM Account Order By createddate Desc Limit 1];
            ddiAccountTriggerHandler.getDDIAccount( trigger.new );
        }
    }
}



===========================================================================


public class ddiAccountTriggerHandler {
    
    public static void getDDIAccount(List<Account> accountList){
        //List<Account> accountList =[SELECT Id, Name, MultiSelect_State__c,Account_Email__c, createddate FROM Account Order By createddate Desc Limit 1];
        if (accountList != Null && accountList.size()>0){
            System.debug('@@@' +accountList);
            for(Account ac : accountList){
                System.debug('@@@'+ac.MultiSelect_State__c);
                List<String> States = ac.MultiSelect_State__c.split(';');
                System.debug('@@@' +States);
                System.debug('@@@'+States.size());
                for(integer i = 0; i < states.size(); i++){
                    String state = states[i];
                    String email = ac.Account_Email__c;
                    //Url u = https://iaaicsr--parvathy.my.salesforce.com/sfc/p/2i0000000rP7/a/2i0000009JVE/vIRIVQqXM1Ib31jKcU6kFD1qWryC2jPP7yNTfYwErYs;
                    
                    switch on state{
                        when 'Maharashtra'{
                           // Blob b = https://iaaicsr--sahil.my.salesforce.com/one/one.app#/alohaRedirect/08123000000BN09?isdtp=p1;
                           
                            System.debug('@@@Hurray Maharashtra' );
                            ddiAccountEmailSend.sendEmail(state, email);
                            
                        }
                        when 'Gujarat'{
                            System.debug('@@@Hurray Gujarat');
                            ddiAccountEmailSend.sendEmail(state, email);
                            
                        }
                        when 'Tamil Nadu'{
                            System.debug('@@@Hurray Tamil Nadu');
                            ddiAccountEmailSend.sendEmail(state, email);
                            
                        }
                        when 'Himachal'{
                            System.debug('@@@Hurray Himachal');
                            ddiAccountEmailSend.sendEmail(state, email);
                            
                        }
                        
                    }
                    
                }
                
                
            }
            
        }
        
    }
}


=================================================================


public class ddiAccountEmailSend {
    public static void sendEmail(String state, String email, String u){
        // creating an instance of SingleEmailMessage
        Messaging.SingleEmailMessage objEmail = new Messaging.SingleEmailMessage();
        
        // Setting the body for the email
        objEmail.setPlainTextBody('This is a Plain Text');
        
        // Setting the Subject for the email
        objEmail.setSubject('Interested States Related Pdf');
        //
        // Setting up the Address to whom we needed to send an Email
        objEmail.setToAddresses(new String[] {email});
        
        Messaging.EmailFileAttachment[] attachments  = new Messaging.EmailFileAttachment[1];
        
        Messaging.EmailFileAttachment attachment = new Messaging.EmailFileAttachment();
        
        //Getting an Attachments from the Static Resource
        List<StaticResource> objPDF = [Select body, name from StaticResource where Name =: state];
        
        // setting the body of an attachment
        attachment.setBody(objPDF[0].body); 
        
        // setting up the file name of an attachment
        attachment.setFileName(objPDF[0].name +'.pdf');
        
        //Assinging the single attachment to a list  
        attachments[0] = attachment;
        
        objEmail.setFileAttachments( attachments);
        
        
        // Finally Send the Email
        
        List<Messaging.Sendemailresult> objER = Messaging.sendEmail(new Messaging.SingleEmailMessage[] {objEmail});
        
        if (!objER[0].isSuccess()){
            // Error handling;
        }
        
        
        
        
    }
    
    
}