using Godot;
using Network.PacketHandling;
using Network.PacketHandling.Packets;
using System.Collections.Generic;
using Util;

namespace Network.Syncing {
    public class ConnectionHandler {

        public readonly Connection Connection;

        private readonly Peer Peer;

        private int LastUnreliableIDReceived = -1;
        private int LastReliableIDReceived = -1;
        
        private int LastReliableIDTheyReceived = -1;

        private float TimeSinceLastPacket = 0;

        private List<Serializable> ReliableQueue = new List<Serializable>();
        private List<Serializable> UnreliableQueue = new List<Serializable>();

        public ConnectionHandler(Peer peer, Connection connection) {
            Peer = peer;
            Connection = connection;
        }

        public void Update(float delta) {
            TimeSinceLastPacket += delta;
            if (TimeSinceLastPacket > Peer.TIMEOUT) {
                Peer.Disconnect(Connection, DisconnectReason.TIMEOUT);
            }
        }

        public void SerializeAndSendQueues(int UnreliableSyncID) {
            PacketBuffer Buffer = PacketBuffer.WithSignature();

            SyncPkt Sync = new SyncPkt();
            Sync.Metadata.Reliable = false;
            Sync.Metadata.ID = UnreliableSyncID;

            Sync.LastReliableIDReceived = LastReliableIDReceived;

            // Add Queues
            var Unreliables = UnreliableQueue.ToArray();
            var Reliables = ReliableQueue.ToArray();

            Sync.AmountOfPackets = Unreliables.Length + Reliables.Length;
            
            Sync.Serialize(Buffer);

            foreach (Serializable Unreliable in Unreliables) {
                Unreliable.Serialize(Buffer);
            }
            foreach (Serializable Reliable in Reliables) {
                Reliable.Serialize(Buffer);
            }

            Peer.SendBuffer(Buffer, Connection);

            // Clear unreliables-queue

            UnreliableQueue.Clear();
        }

        public void ReceiveBuffer(PacketBuffer packetBuffer) {
            TimeSinceLastPacket = 0;

            SyncPkt Sync = new SyncPkt();
            Sync.Deserialize(packetBuffer);
            
            LastReliableIDTheyReceived = Sync.LastReliableIDReceived;

            RemoveRedundantReliables();

            // Read Queues

            int AmountOfPackets = Sync.AmountOfPackets;

            List<Serializable> Packets = new List<Serializable>();

            for (int i = 0; i < AmountOfPackets; i++) {
                var Metadata = new SerializableMetadata(0);
                Metadata.Deserialize(packetBuffer);
                Packets.Add(Peer.Protocol.DeserializePacket(packetBuffer, Metadata));
            }

            int BiggestReliableIDReceived = -1;
            int BiggestUnreliableIDReceived = -1;

            for (int i = 0; i < Packets.Count; i++) {
                Serializable Curr = Packets[i];
                if (Curr.Metadata.Reliable) {
                    if (Curr.Metadata.ID <= LastReliableIDReceived) {
                        continue;
                    } else if (Curr.Metadata.ID > BiggestReliableIDReceived) {
                        BiggestReliableIDReceived = Curr.Metadata.ID;
                    }
                } else {
                    if (Curr.Metadata.ID <= LastUnreliableIDReceived) {
                        continue;
                    } else if (Curr.Metadata.ID > BiggestUnreliableIDReceived) {
                        BiggestUnreliableIDReceived = Curr.Metadata.ID;
                    }
                }

                LastReliableIDReceived = BiggestReliableIDReceived;
                LastUnreliableIDReceived = BiggestUnreliableIDReceived;

                Peer.Protocol.HandleSerializable(Curr);
            }

        }

        public void AddReliable(Serializable serializable, int ReliableID) {
            serializable.Metadata.Reliable = true;
            serializable.Metadata.ID = ReliableID;
            ReliableQueue.Add(serializable);
        }

        public void AddUnreliable(Serializable serializable, int UnreliableID) {
            serializable.Metadata.Reliable = false;
            serializable.Metadata.ID = UnreliableID;
            UnreliableQueue.Add(serializable);
        }

        private void RemoveRedundantReliables() {
            ReliableQueue = ReliableQueue.FindAll(Packet => Packet.Metadata.ID > LastReliableIDTheyReceived);
        }


    }
}