<apex:page controller="Page3_Controller">
    <script type="text/javascript">
        function selectAllCheckboxes(obj,receivedInputID){
            var inputCheckBox = document.getElementsByTagName("input");
            for(var i=0; i<inputCheckBox.length; i++){
                if(inputCheckBox[i].id.indexOf(receivedInputID)!=-1){
                    inputCheckBox[i].checked = obj.checked;
                }
            }
        }
    </script>
    <apex:form >
        <apex:pageBlock >
        	<apex:pageBlockSection >
                	Society:<apex:selectList value="{!selectedSociety}" size="1">
                        <apex:selectOptions value="{!records}"/>
                    </apex:selectList>
                    
                    Year:<apex:selectList value="{!selectedYear}" size="1">
                        <apex:selectOptions value="{!years}"/>
                    </apex:selectList>
                    
                    Month:<apex:selectList value="{!selectedMonth}" size="1">
                        <apex:selectOptions value="{!months}"/>
                    </apex:selectList>
                <apex:commandButton action="{!showRecords}" value="View Defaulters" rerender="pbt"/>
                <apex:commandButton action="{!addDues}" value="Add Dues" rerender="pbt1"/>
            </apex:pageBlockSection>
            
            <apex:pageBlockSection columns="2" title="Select defaulters to send email to">
            	<apex:pageBlockTable value="{!wrapDuesList}" var="d" id="pbt" >
                    <apex:column >
                        <apex:facet name="header">
                            <apex:inputCheckbox onclick="selectAllCheckboxes(this,'inputId')"/>
                        </apex:facet>
                        <apex:inputCheckbox value="{!d.checked}" id="inputId"/>
                    </apex:column>
                  <apex:column value="{!d.due.Member_Name__c}" />
                  <apex:column value="{!d.due.Dues_Remaining__c}"/>
            </apex:pageBlockTable>
                
                <apex:pageBlockTable id="id1" value="{!checkedDues}" var="d">
            	<apex:column value="{!d.Member_Name__c}" />
                  <apex:column value="{!d.Dues_Remaining__c}"/>
            </apex:pageBlockTable>
            
            <apex:commandButton value="Show selected" action="{!showRecords}" rerender="id1"/>
            <apex:commandButton value="Send Reminder Email" action="{!sendReminderEmail}"/>
            
            
            </apex:pageBlockSection>
            
            <apex:pageBlockSection title="Add Dues">
            	<apex:pageBlockTable value="{!defaulters1}" var="d" id="pbt1">
            	<apex:column value="{!d.Member_Name__c}"/>
                <apex:column value="{!d.Total_dues__c}"/>
                <apex:column value="{!d.Dues_Remaining__c}"/>
                <apex:column headerValue="Dues Paid">                            
                	<apex:inputText value="{!d.Dues_Paid__c}" />                    
          	  	</apex:column>
            	</apex:pageBlockTable>
                <br/>
            	<apex:commandButton value="Add" action="{!add}"/>
            </apex:pageBlockSection>
            
            
        </apex:pageBlock>
    </apex:form>
</apex:page>

public class Page3_Controller {
	public string selectedSociety{get;set;}
    public string selectedYear{get;set;}
    public string selectedMonth{get;set;}
    
    public List<wrapDues> wrapDuesList{get;set;}
    public List<Due__c> checkedDues{get;set;}
    
   	public list<selectOption> records{get;set;}
    public list<selectOption> years{get;set;}
    public list<selectOption> months{get;set;}
    
    public list<String> yearsToAdd=new List<String>{'2015','2016','2017','2018','2019','2020','2021'};
    
    public list<String> monthsToAdd=new List<String>{'Jan','Feb','March','April','May','June','July','Aug','Sept','Oct','Nov','Dec'};
        
   	public list<Due__c> defaulters{get;set;}
    public list<Due__c> defaulters1{get;set;}
    public list<Society__c> societies;
   
   
   	public Page3_Controller(){
   
       defaulters=new List<Due__c>();
       
       records=new List<selectOption>();
       years=new List<selectOption>();
       months=new List<selectOption>();
       
       societies=[select id, name from Society__c];
        for(Society__c a:societies){
            records.add(new selectoption(a.id,a.name));
        }
        
        for(String y:yearsToAdd){
            years.add(new selectoption(y,y));
        }
        
        for(String m:monthsToAdd){
            months.add(new selectoption(m,m));
        }
        

   	}
    
    public class wrapDues{
        public Due__c due{get;set;}
        public Boolean checked{get;set;}
        public wrapDues(Due__c d){
            due=d;
            checked=false;
        }
    }
    
   public pageReference showRecords(){
       defaulters=[select id, member_name__c, dues_remaining__c,Member_Name__r.Name, Member_Name__r.Email__c, Month__c from Due__c where 
                   society_name__c=:selectedSociety and year__c=:selectedYear and month__c=:selectedMonth and dues_remaining__c>0];
       if(wrapDuesList==null){
           wrapDuesList = new List<wrapDues>();
            for(Due__c a: defaulters) {
                wrapDuesList.add(new wrapDues(a));
            }
        }
       checkedDues=new List<Due__c>();
       for(wrapDues wrapDuesObj:wrapDuesList){
           if(wrapDuesObj.checked == true) {
                checkedDues.add(wrapDuesObj.due);
            }
       }
   		return null;
   }
    
    public PageReference sendReminderEmail(){
        List<Messaging.SingleEmailMessage> mails = new List<Messaging.SingleEmailMessage>();
        for(Due__c d:checkedDues){
            if(d.Member_Name__r.Email__c!=null){
                Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
                List<String> sendTo = new List<String>();
      			sendTo.add(d.Member_Name__r.Email__c);
      			mail.setToAddresses(sendTo);
                
                mail.setReplyTo('saie_shendage@persistent.com');
      			mail.setSenderDisplayName('Secretary of the Society');
    			mail.setSubject('Remaining Dues Not Paid');
              String body = 'Dear ' + d.Member_Name__r.Name + ', ';
              body += 'Your remaining dues are '+d.Dues_Remaining__c+' for the month of '+d.Month__c;
              body += ' Please pay the dues Asap, otherwise penalty would be added.';
              mail.setHtmlBody(body);
            
              // Step 5. Add your email to the master list
              mails.add(mail);
            }
        }
        Messaging.sendEmail(mails);
        return null;
    }
    
    public PageReference addDues(){
        defaulters1=[select id, member_name__c,Total_Dues__c, dues_remaining__c,Dues_Paid__c from Due__c where 
                   society_name__c=:selectedSociety and year__c=:selectedYear and month__c=:selectedMonth and dues_remaining__c>0];
      	return null;
    }
    
    public void add(){
        update defaulters1;
    }
    
}