using System.Collections.Generic;
using OlympicGames.Core.Commands.Abstracts;
using OlympicGames.Core.Contracts;
using OlympicGames.Olympics.Contracts;
using System.Linq;
using System.Text;

namespace OlympicGames.Core.Commands
{
    public class ListOlympiansCommand : Command
    {
        public ListOlympiansCommand(IList<string> commandLine, IOlympicCommittee committee)
            : base(commandLine, committee)
        {
        }

        private List<IOlympian> Print(string name = "firstname", string order = "asc")
        {
            var orderedList = new List<IOlympian>();
            switch (CommandParameters.Count)
            {
                case 1:
                    if (Equals(name, "firstname"))
                    {
                        return orderedList = Committee.Olympians.OrderBy(x => x.FirstName).ToList();
                    }

                    if (Equals(name, "lastname"))
                    {
                        return orderedList = Committee.Olympians.OrderBy(x => x.LastName).ToList();
                    }
                    return orderedList = Committee.Olympians.OrderBy(x => x.Country).ToList();
                case 2:
                    if (Equals(order, "asc"))
                    {
                        if (Equals(name, "firstname"))
                        {
                            return orderedList = Committee.Olympians.OrderBy(x => x.FirstName).ToList();
                        }
                        if (Equals(name, "lastname"))
                        {
                            return orderedList = Committee.Olympians.OrderBy(x => x.LastName).ToList();
                        }
                        return orderedList = Committee.Olympians.OrderBy(x => x.Country).ToList();
                    }

                    if (Equals(name, "firstname"))
                    {
                        return orderedList = Committee.Olympians.OrderByDescending(x => x.FirstName).ToList();
                    }
                    if (Equals(name, "lastname"))
                    {
                        return orderedList = Committee.Olympians.OrderByDescending(x => x.LastName).ToList();
                    }
                    return orderedList = Committee.Olympians.OrderByDescending(x => x.Country).ToList();
                default: return Committee.Olympians.OrderBy(x => x.FirstName).ToList();
            }
        }

        public override string Execute()
        {
            var count = CommandParameters.Count;

            var result = count switch
                {
                1 => Print(CommandParameters[0]),
                2 => Print(CommandParameters[0], CommandParameters[2]),
                _ => Print()
                };
            if (Equals(result.Count, 0))
            {
                return "NO OLYMPIANS ADDED";
            }
            var sb = new StringBuilder();
            foreach (var olympian in result)
            {
                sb.AppendLine(olympian.Print());
            }

            return sb.ToString().Trim();
        }
    }
}