namespace OpenTraffic.Model.Simulator.Queue
{
    using System.Collections.Generic;
    using OpenTraffic.Model.Result;

    class FastLink : Link
    {
        public FastLink(OpenTraffic.Model.TrafficModelLink link, bool giveaway, bool oneClass, bool shockwave)
            : base(link, giveaway, oneClass, shockwave)
        {
        }

        public override bool PreSimulate(float startTime, float stopTime, ResultData result, TrafficModel model)
        {

            cachedNumberFreeSlots = FreeSlots;

            updateShockwave(startTime);
            if (startTime > nextSwitch)
            {
                estimatedFlow = this.carPassedFlowEstimated / (startTime - (nextSwitch - timeStep));
                nextSwitch = startTime + timeStep;
                carPassedFlowEstimated = 0;
            }

            MoveAllVehiclesToQueuePart(startTime, stopTime, result);


            bool ok = numberVehiclesInQueue > 0;
            if (ok)
            {
                maxCarsToLeave += trafficModelLink.SaturationExitFlow * (stopTime - startTime);
            }
            else
            {
                maxCarsToLeave = 0;
            }

            return false;

        }

        public override bool Simulate(float startTime, float stopTime, ResultData result, TrafficModel model)
        {
            if (queue.Count == 0) return false;

            if (IsFull()) return false;
            if (queue.Count == 1)
            {
                
                KeyValuePair<Turning, TurnQueue> kv;
                IEnumerator<KeyValuePair<Turning, TurnQueue>> q = queue.GetEnumerator();
                q.MoveNext();
                kv = q.Current;

                
                q = null;
                Turning t = kv.Key;
                FastLink l = (FastLink)t.Origin.Simulator;
                while (l.HasWaitingVehicles(stopTime, kv.Value))
                {
                    l.MoveVehicleToNextLinkFromQueue(t, startTime, result, queue);
                    if (IsFull()) return false;
                }
            }
            else
            {

                List<Turning> possible = new List<Turning>();
                foreach (KeyValuePair<Turning, TurnQueue> kv in queue)
                {
                    Turning t = kv.Key;
                    FastLink l = (FastLink)t.Origin.Simulator;
                    if (l.HasWaitingVehicles(stopTime, kv.Value))
                    {
                        possible.Add(t);
                    }
                }
                if (possible.Count == 0) return false;
                while (true)
                {
                    Turning t = possible[rand.Next(possible.Count)];
                    FastLink l = (FastLink)t.Origin.Simulator;
                    l.MoveVehicleToNextLinkFromQueue(t, startTime, result, queue);
                    TurnQueue q;
                    queue.TryGetValue(t, out q);
                    if (!l.HasWaitingVehicles(stopTime, q)) possible.Remove(t);
                    if (possible.Count == 0 || IsFull()) return false;
                }
            }
            return false;
        }

        public bool HasWaitingVehicles(float stopTime, TurnQueue q)
        {
            // First car not yet reached flare(?)
            if (q == null) return false;
            if (giveaway && maxCarsToLeave < 1) return false;
            return q.HasWaitingVehicles(stopTime, vehicleLeft + vehicleLookBack);

        }

        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1062:Validate arguments of public methods", MessageId = "0")]
        protected override TurnQueue GetQueue(Turning t)
        {
            FastLink fl = (FastLink)t.Destination.Simulator;
            TurnQueue q = null;
            if (fl.queue.TryGetValue(t, out q)) return q;
            q = new TurnQueue(t);
            fl.queue.Add(t, q);
            return q;
        }
    }
}