using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Hermes.Objects;

namespace Hermes.Selectors
{
    class UniqueHighestSpeedTwoNodeSelector : UniqueRouteSelector, IRouteSelector
    {
        public UniqueHighestSpeedTwoNodeSelector()
            : base()
        {}
        
        #region IRouteSelector Members

        public Circuit CreateNewCircuit()
        {
            Random rand = new Random();
            Circuit circuit = new Circuit();
            GetPoolReaderLock();
            {
                lock (UsedRouters)
                {
                    //Try to use unused routers
                    IEnumerable<Router> nonExits = RouterPool.Where(p => !p.Flags.Contains("Exit") && !UsedRouters.Contains(p));
                    if (nonExits.Count() == 0)
                    {
                        nonExits = RouterPool.Where(p => !p.Flags.Contains("Exit"));
                        circuit.AddNextRouter(nonExits.ElementAt(rand.Next(nonExits.Count())));
                    }
                    else
                        circuit.AddNextRouter(nonExits.OrderByDescending(p => p.BandwidthObserved).First());

                    IEnumerable<Router> exits = RouterPool.Where(p => p.Flags.Contains("Exit") && !UsedRouters.Contains(p));
                    if (exits.Count() == 0)
                    {
                        exits = RouterPool.Where(p => p.Flags.Contains("Exit"));
                        circuit.AddNextRouter(exits.ElementAt(rand.Next(exits.Count())));
                    }
                    else
                        circuit.AddNextRouter(exits.OrderByDescending(p => p.BandwidthObserved).First());

                    UsedRouters.AddRange(circuit.Routers.Values.ToList());
                }
            }
            ReleasePoolReaderLock();
            return circuit;
        }
        public Circuit CreateNewCircuit(System.Net.IPEndPoint destination)
        {
            Random rand = new Random();
            Circuit circuit = new Circuit();

            GetPoolReaderLock();
            {
                lock (UsedRouters)
                {
                    //Try to use unused routers
                    IEnumerable<Router> nonExits = RouterPool.Where(p => !p.Flags.Contains("Exit") && !UsedRouters.Contains(p));
                    if (nonExits.Count() == 0)
                    {
                        nonExits = RouterPool.Where(p => !p.Flags.Contains("Exit"));
                        circuit.AddNextRouter(nonExits.ElementAt(rand.Next(nonExits.Count())));
                    }
                    else
                        circuit.AddNextRouter(nonExits.OrderByDescending(p => p.BandwidthObserved).First());

                    IEnumerable<Router> exits = RouterPool.Where(p => p.Flags.Contains("Exit") && p.ExitPolicy != null && p.ExitPolicy.IsAcceptableDestination(destination) && !UsedRouters.Contains(p));
                    if (exits.Count() == 0)
                    {
                        exits = RouterPool.Where(p => p.Flags.Contains("Exit") && p.ExitPolicy != null && p.ExitPolicy.IsAcceptableDestination(destination));
                        circuit.AddNextRouter(exits.ElementAt(rand.Next(exits.Count())));
                    }
                    else
                        circuit.AddNextRouter(exits.OrderByDescending(p => p.BandwidthObserved).First());

                    UsedRouters.AddRange(circuit.Routers.Values.ToList());
                }
            }
            ReleasePoolReaderLock();
            return circuit;
        }

        #endregion
    }
}