using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Reflection.Metadata;

namespace Features
{
    class Program
    {
        // Modelling a company in this project
        static void Main(string[] args)
        {
            /* Generic Delegate & Lambda Expression */
            Func<int, int> square = x => x*x;// Define a generic delegate functions named square for square operation
            Func<int, int, int> add = (x, y) =>
            {
                int temp = x + y;
                return temp;
            };

            Action<int> write = x => Console.WriteLine(x);
            write(square(add(3, 5)));
            
            /* LINQ & C# */

            IEnumerable<Employee> developers = new Employee[]
            {
                new Employee {Id = 1, Name = "Scott"},
                new Employee {Id = 2, Name = "Chris"}
            };

            List<Employee> sales = new List<Employee>()
            {
                new Employee {Id = 3, Name = "Alex"}
            };
            
            Console.WriteLine(sales.MyLinqCount());

            var enumerator = developers.GetEnumerator();

            while (enumerator.MoveNext())
            {
                Console.WriteLine(enumerator.Current.Name); // .Current return value of current enumerator
            }
                
            foreach (var person in developers) 
            {
                Console.WriteLine();
            }

            foreach (var employee in developers
                .Where(e => e.Name.Length == 5)
                .OrderBy(e => e.Name))
            {
                Console.WriteLine(employee.Name);
            }

            // LINQ (Method syntax)
            var query = developers.Where(e => e.Name.Length == 5)
                .OrderBy(e => e.Name);
            
            // LINQ (Query syntax)
            var query2 = from developer in developers
                where developer.Name.Length == 5
                orderby developer.Name descending 
                select developer;

            foreach (var employee in query)
            {
                Console.WriteLine(employee.Name);
            }

            foreach (var employee in query2)
            {
                Console.WriteLine(employee.Name);
            }
        }
    }
}