using System;
using System.Net;
using System.Net.Sockets;
using FloodSWE.Streaming;
using FloodSWE.TileGraph;
using UnityEngine;

namespace FloodSWE.Networking
{
    public sealed class SweQuestStreamClient : MonoBehaviour
    {
        [Header("Network")]
        public int listenPort = 29011;

        [Header("Interpolation")]
        public float frameDurationSeconds = 0.1f;

        [Header("Filter")]
        public bool filterByTile = false;
        public int expectedLod = 1;
        public int expectedTileX = 1;
        public int expectedTileY = 1;

        [Header("Output")]
        public Material targetMaterial;
        public string textureProperty = "_HeightTex";

        public Texture2D outputTexture;
        public HeightmapPacket lastPacket;

        private readonly HeightmapInterpolator interpolator = new HeightmapInterpolator();
        private UdpClient socket;
        private IPEndPoint endpoint;
        private int outputResolution;

        private void OnEnable()
        {
            interpolator.Reset();
            interpolator.FrameDurationSeconds = Mathf.Max(0.01f, frameDurationSeconds);

            try
            {
                socket = new UdpClient(listenPort);
                socket.Client.Blocking = false;
                endpoint = new IPEndPoint(IPAddress.Any, 0);
            }
            catch (Exception ex)
            {
                Debug.LogError($"SweQuestStreamClient: failed to open UDP port {listenPort}. {ex.Message}");
                enabled = false;
            }
        }

        private void OnDisable()
        {
            if (socket != null)
            {
                socket.Close();
                socket = null;
            }
        }

        private void Update()
        {
            PollFrames();
            interpolator.Step(Time.deltaTime);
            TryUpdateOutputTexture();
        }

        private void PollFrames()
        {
            if (socket == null)
            {
                return;
            }

            while (socket.Available > 0)
            {
                byte[] payload;
                try
                {
                    payload = socket.Receive(ref endpoint);
                }
                catch (SocketException)
                {
                    break;
                }

                if (!SweUdpProtocol.TryDecodeFrame(payload, out HeightmapPacket packet))
                {
                    continue;
                }

                if (filterByTile)
                {
                    TileId expected = new TileId(expectedLod, expectedTileX, expectedTileY);
                    if (packet.Tile != expected)
                    {
                        continue;
                    }
                }

                interpolator.PushPacket(packet);
                lastPacket = packet;
            }
        }

        private void TryUpdateOutputTexture()
        {
            if (!interpolator.TryGetHeights(out float[] heights) || heights == null || heights.Length == 0)
            {
                return;
            }

            int resolution = Mathf.RoundToInt(Mathf.Sqrt(heights.Length));
            if (resolution <= 0 || resolution * resolution != heights.Length)
            {
                return;
            }

            EnsureOutputTexture(resolution);
            outputTexture.SetPixelData(heights, 0);
            outputTexture.Apply(false, false);

            if (targetMaterial != null)
            {
                targetMaterial.SetTexture(textureProperty, outputTexture);
            }
        }

        private void EnsureOutputTexture(int resolution)
        {
            if (outputTexture != null && outputResolution == resolution)
            {
                return;
            }

            if (outputTexture != null)
            {
                Destroy(outputTexture);
            }

            outputTexture = new Texture2D(resolution, resolution, TextureFormat.RFloat, false, true)
            {
                wrapMode = TextureWrapMode.Clamp,
                filterMode = FilterMode.Bilinear,
                name = "SWE_StreamedHeight"
            };

            outputResolution = resolution;
        }
    }
}