// Example demonstrating class hierarchies and inheritance
// Extension of Lecture 3, using Reflection for a generic from of serialisation
// This version uses properties to simplify access
// -----------------------------------------------------------------------------

using System;
using System.Text;
using System.Reflection;
using System.IO;
using System.Runtime.CompilerServices;
using System.Diagnostics; 

// The base class: generic information on a person
class Person{
  // private data fields for Person; uses a mixture of access modifiers for demonstration
  private string _fName;
  private string _lName;
  private string _address;

  // public properties to access the data
  public string fName {
    get { return _fName; }
    set { _fName = value; } }

  public string lName {
    get { return _lName; }
    set { _lName = value; } }

  public string address {
    get { return _address; }
    set { _address = value; } }

  public Person(string fName, string lName, string address){
    this.fName = fName;
    this.lName = lName;
    this.address = address;
  }

  public override string ToString() {
    return String.Format("Name: {0} {1}\tAddress: {2}", this.fName, this.lName, this.address);
  }
  public virtual string Serialise() { return "Person.Serialise: To be implemented"; }
}

// Student is a sub-class of Person, and inherits its data-fields and methods
class Student: Person{
  // the private data for Student
  private string _matricNo;
  private string _degree; 

  // the properties to access the data
  public string degree 
  {
    get { return _degree; }
    set { _degree = value; } }

  public string matricNo 
  {
    get { return _matricNo; }
    set { _matricNo = value; } } 

  // constructor
  public Student(string fName, string lName, string address, string matricNo, string degree): base(fName, lName, address) {
    this.matricNo = matricNo;
    this.degree = degree;
  }
  
  // override ToString as an example of serialisation
  public override string ToString() {
    string base_str = base.ToString();
    string this_str = String.Format("MatricNo: {0}\tDegree: {1}", this.matricNo, this.degree);
    return base_str+"\n"+this_str;
  }
  // A different way to implement ToString; it is less generic, 
  // because it relies on knowledge of the field in all parent classes
  public string ToString0() {
    return String.Format("Name: {0} {1}\tAddress: {2}\nMatricNo: {3}\tDegree: {4}", 
			 this.fName, this.lName, this.address, this.matricNo, this.degree);
  }
}

// Lecturer is another sub-class of Person, and inherits its data-fields and methods
class Lecturer: Person{
  // the pivate data
  private string _officeNo;
  // the property to access the data
  public string officeNo {
    get { return _officeNo; }
    // set { _officeNo = value; } }
    set {  // for debugging, a setter that prints changes and callers
      StackTrace stackTrace = new StackTrace();
      MethodBase methodBase = stackTrace.GetFrame(1).GetMethod();
      Console.WriteLine("setter for officeNo was called by : " + methodBase.Name);
      _officeNo = value;
    }
  }
  
  
  public Lecturer(string fName, string lName, string address, string officeNo): base(fName, lName, address) {
    this.officeNo = officeNo;
  }
  // override ToString as an example of serialisation
  public override string ToString() {
    string base_str = base.ToString();
    string this_str = String.Format("OfficeNo: {0}", this.officeNo);
    return base_str+"\n"+this_str;
  }
  public override string Serialise() {
    string str = "";
    Type type = this.GetType();
    Console.WriteLine("\nDoing {0}.Serialise() ...", type.Name);
    PropertyInfo[] properties = type.GetProperties();
    Console.WriteLine("Found {0} fields ...", properties.Length);
    foreach(PropertyInfo propertyInfo in properties) {
      str += String.Format("\t{0}: {1}", propertyInfo.Name, propertyInfo.GetValue(this, null));
    }
    return str;
  }
  public string Serialise1() {
    string str = "";
    Type type = this.GetType();
    Console.WriteLine("\nDoing {0}.Serialise1() ...", type.Name);
    MethodInfo methodInfo = type.GetMethod("ToString");
    str += methodInfo.Invoke(this, null);
    /*
    ConstructorInfo ctor = type.GetConstructor(System.Type.EmptyTypes);
    if(ctor != null) {
      object instance = ctor.Invoke(null);
      MethodInfo methodInfo = type.GetMethod("ToString");
      str += methodInfo.Invoke(instance, null);
    }
    */
    return str;
  }
}

class Test{
    public static void Main(){
      Person p = new Person("John", "Smith", "Edinburgh");
      Student s = new Student("Brian", "Hillman", "London", "99124678", "CS");
      Lecturer l = new Lecturer("Hans-Wolfgang", "Loidl", "Edinburgh", "G48");
      Console.WriteLine("\nHere we use the overriden ToString() method, implemented as a generic serialisation method:");
      Console.WriteLine("Student: {0} ", s.ToString0());
      Console.WriteLine("Student: {0} ", s.ToString());
      Console.WriteLine("Lecturer: {0} ", l.ToString());
      Console.WriteLine("\nNow we use Reflection in order to implement a generic serialisation function:");
      Console.WriteLine("Lecturer: {0} ", l.Serialise());
      l.officeNo = "G59"; // move office; trace it with messages in the setter
      Console.WriteLine("Lecturer: {0} ", l.Serialise());
      Console.WriteLine("Lecturer: {0} ", l.Serialise1());
      Console.WriteLine("Person: {0} ", p.Serialise());
    }
}