<apex:form id="form">

    <apex:pageBlock title="Appointments Tables" id="TableDoctors">
        <apex:pageBlock >
            <apex:selectList value="{!selectedname}" size="1" multiselect="false" onChange="updateDoctors(this.value)">
                <h1>
                    Select a doctor name:
                </h1>
                <apex:selectOptions value="{!selectedDocnamefields}"/>
            </apex:selectList>
        </apex:pageBlock>

        <apex:pageBlock >
            <apex:commandButton action="{!URLFOR("/apex/DoctorCreate")}" value="Add new doctor"/>
        </apex:pageBlock>

        <apex:pageBlock >
            <apex:pageBlockSection title="Working hours" id="TableDoctors">

                <apex:repeat value="{!Doctors}" var="d" rows="1">
                    <apex:outputField value="{!d.Doctor__r.Working_Hours_Start__c}"/>
                    <apex:outputField value="{!d.Doctor__r.Working_Hours_End__c}"/>
                </apex:repeat>
            </apex:pageBlockSection>
        </apex:pageBlock>

        <apex:pageBlock >
            <apex:selectList value="{!selectedPatientname}" size="1" multiselect="false" onChange="updatePatients(this.value)">
                <h1>
                    Select a Patient name:
                </h1>
                <apex:selectOptions value="{!selectedPatnamefields}" />
            </apex:selectList>
        </apex:pageBlock>

        <apex:pageBlock >
            <apex:commandButton action="{!URLFOR("/apex/PatientCreate")}" value="Add new patient"/>
        </apex:pageBlock>

    <apex:pageBlock mode="edit">
        <apex:pageMessages />
        <apex:pageBlockSection id="TableDoctors" >
            <apex:inputField value="{!CreateAppointment.Appointment_Date__c}"/>
            <apex:inputField value="{!CreateAppointment.Duration_in_minutes__c}"/>
        </apex:pageBlockSection>
        <apex:pageBlockButtons location="bottom">
            <apex:commandButton value="Save" action="{!save}"/>
        </apex:pageBlockButtons>
    </apex:pageBlock>

        <apex:pageBlockTable value="{! Doctors }" var="d" columns="5" id="TableDoctors" >

            <apex:column value="{! d.Doctor__c }" />
            <apex:column value="{! d.Doctor__r.Name }"/>
            <apex:column value="{! d.Patient__r.Name }"/>
            <apex:column value="{! d.Appointment_Date__c }"/>
            <apex:column value="{! d.Duration_in_minutes__c }"/>

        </apex:pageBlockTable>
    </apex:pageBlock>
         <apex:actionFunction name="updateDoctors" action="{!getDoctors}" rerender="TableDoctors" immediate="false">
         <apex:param name="selectedDoc" assignTo="{!selectedname}" value="" />
     </apex:actionFunction>
</apex:form>

public class AppointmentsListController {



    public List<Appointment__c> Doctors   {get;set;}
    public string selectedname{

        get{
            if(selectedname == null)
                selectedname ='Model API';
            return selectedname;
        }
        set;}

        Public List<Selectoption> getselectedDocnamefields(){
            List<Selectoption> Doctornamesel = new List<selectoption>();
            Doctornamesel.add(new selectOption('', '- None -'));
            for(Appointment__c Doc :[SELECT Id, Doctor__r.Name, Doctor__r.Working_Hours_Start__c, Doctor__r.Working_Hours_End__c, Patient__r.Name, Appointment_Date__c, Duration_in_minutes__c FROM Appointment__c Where Doctor__r.Name!=Null]){
            Doctornamesel.add(new selectoption(Doc.Doctor__r.id, Doc.Doctor__r.Name));
            }
        return Doctornamesel;
      }

    public void getDoctors() {

        system.debug('SelectedName is: ' + selectedname);
        Doctors = [SELECT Doctor__r.Name, Doctor__r.Working_Hours_Start__c, Doctor__r.Working_Hours_End__c,  Patient__r.Name, Appointment_Date__c, Duration_in_minutes__c  FROM Appointment__c Where Doctor__c =: selectedname ];

    }


    public List<Appointment__c> Patients   {get;set;}
    public string selectedPatientname{

        get{
            if(selectedPatientname == null)
                selectedPatientname ='Model API';
            return selectedPatientname;
        }
        set;}

        Public List<Selectoption> getselectedPatnamefields(){
            List<Selectoption> Patientnamesel = new List<selectoption>();
            Patientnamesel.add(new selectOption('', '- None -'));
            for(Appointment__c Pat :[SELECT Id, Patient__r.Name FROM Appointment__c Where Doctor__r.Name!=Null]){
            Patientnamesel.add(new selectoption(Pat.Patient__r.id, Pat.Patient__r.Name));
            }
        return Patientnamesel;
      }



    public void getPatients() {

        system.debug('selectedPatientname is: ' + selectedPatientname);
        Patients = [SELECT Patient__r.Name  FROM Appointment__c Where Patient__c =: selectedPatientname ];

    }




    public Appointment__c CreateAppointment { get; private set; }

    public AppointmentsListController() {
        Id id = ApexPages.currentPage().getParameters().get('id');
        CreateAppointment = (id == null) ? new Appointment__c() :
            [SELECT Doctor__r.Name, Patient__r.Name, Appointment_Date__c, Duration_in_minutes__c FROM Appointment__c WHERE Id = :id and Doctor__c = :selectedname and Patient__c = :selectedPatientname ];
    }

    public PageReference save() {
        try {
            upsert(CreateAppointment);
        } catch(System.DMLException e) {
            ApexPages.addMessages(e);
            return null;
        }
        //  After successful Save, navigate to the default view page
        PageReference redirectSuccess = new ApexPages.StandardController(CreateAppointment).view();
        return (redirectSuccess);
    }




}