using System;
using System.Text.Json;
using System.Collections.ObjectModel;
using System.Text.Json.Serialization;

namespace STJTest;

class Program
{

	static void Main(string[] args)
	{
		var employeeBob = new Employee() { Id = 1, Name = "Bob" };
		var employeeJane = new Employee() { Id = 2, Name = "Jane" };

		var department = new Department() { Id = 1 };
		department.Employees.Add(employeeBob);
		department.Employees.Add(employeeJane);
		
		// Serialize without the serializer context.
		var serializedWithoutContext = JsonSerializer.Serialize(department);

		Console.WriteLine("Serialized without context:");
		Console.WriteLine(serializedWithoutContext);

		var jsonText = "{\"Id\":2,\"Employees\":[{\"Id\":3,\"Name\":\"Sally\"},{\"Id\":2,\"Name\":\"Gordon\"}]}";

		// Deserialize without the serializer context.
		var deserializedWithoutContext = (Department) JsonSerializer.Deserialize(jsonText, typeof(Department));

		Console.WriteLine("Deserialized without context:");
		foreach (var employee in deserializedWithoutContext.Employees)
		{
			Console.WriteLine("{0} - {1}", employee.Id, employee.Name);
		}

		// Serialize with the context.  This will fail with "The given key '0' was not present in the dictionary".
		var serializedWithContext = JsonSerializer.Serialize(department, typeof(Department), DepartmentContext.Default);

		Console.WriteLine("Serialized with context:");
		Console.WriteLine(serializedWithContext);

		// Deserialize with the context.  This will work correctly.
		var deserializedWithContext = (Department) JsonSerializer.Deserialize(jsonText, typeof(Department), DepartmentContext.Default);

		Console.WriteLine("Deserialized with context:");
		foreach (var employee in deserializedWithContext.Employees)
		{
			Console.WriteLine("{0} - {1}", employee.Id, employee.Name);
		}

		Console.ReadKey();
	}
}


[JsonSerializable(typeof(Department))]
internal partial class DepartmentContext : JsonSerializerContext
{
}

public class Department
{
	public int Id {	get; set; }
	
	[JsonObjectCreationHandling(JsonObjectCreationHandling.Populate)]
	public EmployeeCollection Employees { get; private set; }
	
	public Department()
	{
		Employees = new EmployeeCollection();
	}
}

public class Employee
{
	public int Id {	get; set; }
	public string Name { get; set; }
}


public class EmployeeCollection : KeyedCollection<int, Employee>
{
	protected override int GetKeyForItem(Employee item)
	{
		return item.Id;
	}
}