using System;

using System.Collections.Generic;

using System.Linq;

public class Program

    {

        static void Main(string[] args)

        {

        var createdOnOrder1 = new DateTime(2016, 12, 31);

        var createdOnOrder2 = new DateTime(2017, 12, 31);

        var orderLinesList1 = new List<OrderLine>()

                    {

                        new OrderLine()

                        {

                            Id = 1,

                            Name = "FirstOrderFirstOL",

                            OrderId = 1,

                            StatusId = (int)OrderLineStatusEnum.Executed

                        },

                        new OrderLine()

                        {

                            Id = 4,

                            Name = "FirstOrderSecondOL",

                            OrderId = 1,

                            StatusId = (int)OrderLineStatusEnum.InProgress

                        },

                        new OrderLine()

                        {

                            Id = 5,

                            Name = "FirstOrderThirdOL",

                            OrderId = 1,

                            StatusId = (int)OrderLineStatusEnum.InProgress

                        }

                    };

​

            var orderLinesList2 = new List<OrderLine>()

                    {

                        new OrderLine()

                        {

                            Id = 2,

                            Name = "SecondOrderFirstOL",

                            OrderId = 2,

                            StatusId = (int)OrderLineStatusEnum.Executed

                        },

                        new OrderLine()

                        {

                            Id = 6,

                            Name = "SecondOrderSecondOL",

                            OrderId = 2,

                            StatusId = (int)OrderLineStatusEnum.InProgress

                        },

                        new OrderLine()

                        {

                            Id = 7,

                            Name = "SecondOrderThirdOL",

                            OrderId = 2,

                            StatusId = (int)OrderLineStatusEnum.Executed

                        }

                    };

​

​

            List<Order> orders = new List<Order>()

            {

                new Order()

                {

                    Id = 1,

                    OrderLines = orderLinesList1,

                    CreatedOn = createdOnOrder1

                },

                new Order()

                {

                    Id = 2,

                    OrderLines = orderLinesList2,

                    CreatedOn = createdOnOrder2

                }

            };

​

            orderLinesList1.ForEach(x => x.Order = orders.First());

            orderLinesList2.ForEach(x => x.Order = orders.Skip(1).First());

​

            var orderLines = new List<OrderLine>();

​

            orderLines.AddRange(orderLinesList1);

            orderLines.AddRange(orderLinesList2);

​

            var sortedOrderLines = orderLines.GroupBy(x => x.OrderId).OrderBy(g => g.Min(s => s.StatusId)).ThenByDescending(g => g.Max(s => s.Order.CreatedOn)).SelectMany(ol => ol).OrderBy(p => 0).ToList();

​

            sortedOrderLines.ForEach(ol => Console.WriteLine(ol.Name));

        }

    }

​

    public class OrderLine

    {

        public int Id { get; set; }

        public string Name { get; set; }

        public int OrderId { get; set; }

        public int StatusId { get; set; }

        public Order Order { get; set; }

    }

​

    public class Order

    {

        public int Id { get; set; }

        public List<OrderLine> OrderLines { get; set; }

        public DateTime CreatedOn { get; set; }

    }

​

    public enum OrderLineStatusEnum

    {

        New = 1,

        InProgress = 2,

        Executed = 3,

    }