using System;
using System.Collections;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Reflection;
using Unity.Netcode;
using UnityEditor.Events;
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.InputSystem;
using UnityEngine.UIElements;
using UnityEngine.Windows;


/// This script is for networking the player with reconciliation

[RequireComponent(typeof(ClientNetworkTransform))]
public class ReconciliationPlayerControllerMiddleman : NetworkBehaviour, IMoveData
{
    // Current
    private InputPayload currentInputState;
    private int currentTick => NetworkManager.Singleton.NetworkTickSystem.LocalTime.Tick;
    private int bufferIndex => currentTick % BUFFER_SIZE;
    private PlayerInput inputSource;


    // Shared
    private const int BUFFER_SIZE = 1024;

    // Local
    private StatePayload[] stateBuffer;
    private InputPayload[] inputBuffer;
    private StatePayload latestServerState;
    private StatePayload lastProcessedState;

    private Queue<InputPayload> inputQueue = new Queue<InputPayload>();

    private ClientNetworkTransform clientNetworkTransform;


    [Header("Debug")]
    [SerializeField] private bool ForceEnableComponent = false;

    public event Action<MoveData> OnNewMoveData;

    void OnEnable()
    {
        if (NetworkManager.Singleton == null)
        {
            Debug.Log("[Movement] No network manager found. Ignoring reconciliation.");
            if (!ForceEnableComponent)
            {
                this.enabled = false;
                return;
            }
        }

        if (!TryGetComponent(out inputSource))
        {
            Debug.LogError("[Movement] No player input found. Ignoring reconciliation.");
            this.enabled = false;
            return;
        }

        stateBuffer = new StatePayload[BUFFER_SIZE];
        inputBuffer = new InputPayload[BUFFER_SIZE];

        currentInputState = new InputPayload();
        inputSource.OnNewMoveData += (moveData) => currentInputState.moveData = moveData;

        clientNetworkTransform = GetComponent<ClientNetworkTransform>();
        SwitchAuthorityMode(AuthorityMode.Client);
    }

    private void Update()
    {
        if (IsServer)
            ServerTick();

        if (IsOwner)
            ClientTick();
    }

    private void ServerTick()
    {
        foreach (InputPayload payload in inputQueue)
        {
            stateBuffer[bufferIndex] = ProcessMovement(payload);
        }

        OnServerStateRecieved_ServerRpc(stateBuffer[bufferIndex]);
    }

    private void ClientTick()
    {
        if (!latestServerState.Equals(default(StatePayload)) &&
            (lastProcessedState.Equals(default(StatePayload)) ||
            !latestServerState.Equals(lastProcessedState)))
        {
            Reconciliation();
        }

        // Add payload to inputBuffer
        InputPayload payload = new InputPayload();
        payload.tick = currentTick;
        payload.moveData = currentInputState.moveData;
        inputBuffer[bufferIndex] = payload;

        stateBuffer[bufferIndex] = ProcessMovement(payload);

        if (!(IsHost || IsServer))
            OnClientInput_ClientRpc(payload);
    }

    [ClientRpc]
    private void OnClientInput_ClientRpc(InputPayload payload)
    {
        inputQueue.Enqueue(payload);
    }

    
    [ServerRpc]
    private void OnServerStateRecieved_ServerRpc(StatePayload serverState)
    {
        if (!IsOwner) return;
        latestServerState = serverState;
    }

    private void Reconciliation()
    {
        lastProcessedState = latestServerState;

        int serverStateBufferIndex = latestServerState.tick % BUFFER_SIZE;
        float positionError = Vector3.Distance(latestServerState.position, stateBuffer[serverStateBufferIndex].position);

        if (positionError > 0.001f)
        {
            transform.position = latestServerState.position;

            stateBuffer[serverStateBufferIndex] = latestServerState;

            int tickToProcess = latestServerState.tick + 1;

            for (; tickToProcess < currentTick; tickToProcess++)
            {
                // Reprocess movement
                StatePayload reprocessedState = ProcessMovement(inputBuffer[tickToProcess]);

                // Update buffer with reprocessed state
                int bufferIndex = tickToProcess % BUFFER_SIZE;
                stateBuffer[bufferIndex] = reprocessedState;
            }

            Debug.Log($"[{latestServerState.tick}] Reconciliated");
        }
    }

    private void SwitchAuthorityMode(AuthorityMode mode)
    {
        clientNetworkTransform.authorityMode = mode;
        bool shouldSync = mode == AuthorityMode.Client;
        clientNetworkTransform.SyncPositionX = shouldSync;
        clientNetworkTransform.SyncPositionY = shouldSync;
        clientNetworkTransform.SyncPositionZ = shouldSync;
    }


    private StatePayload ProcessMovement(InputPayload payload)
    {
        OnNewMoveData?.Invoke(payload.moveData);

        return new StatePayload()
        {
            tick = payload.tick,
            position = transform.position
        };
    }
}

public struct InputPayload : INetworkSerializable
{
    public int tick;
    public MoveData moveData;

    public void NetworkSerialize<T>(BufferSerializer<T> serializer) where T : IReaderWriter
    {
        serializer.SerializeValue(ref tick);
        serializer.SerializeValue(ref moveData);
    }
}

public struct StatePayload : INetworkSerializable
{
    public int tick;
    public Vector3 position;

    public void NetworkSerialize<T>(BufferSerializer<T> serializer) where T : IReaderWriter
    {
        serializer.SerializeValue(ref tick);
        serializer.SerializeValue(ref position);
    }
}