using System;
using LightGlue.Unity.Networking;
using LightGlue.Unity.Bridge;
using LightGlue.Unity.Game;
using UnityEngine;
using UnityEngine.UI;

namespace LightGlue.Unity.Demo
{
    /// <summary>
    /// Demo: 从 HardwareToPythonUdpBridge 共享 JPEG 接收器，在 RawImage 上显示硬件图像。
    /// 仅支持 Shared 模式（强制复用 Bridge 的 UDPJpegReceiver，避免端口冲突）。
    /// </summary>
    public sealed class HardwareUdpJpegViewer : MonoBehaviour
    {
        [Header("Source (Shared Only)")]
        [Tooltip("HardwareToPythonUdpBridge组件（共享其JPEG接收器，避免端口冲突）")]
        public HardwareToPythonUdpBridge bridge;

        [Header("UI")]
        public RawImage target;

        [Tooltip("是否在没有贴图时自动创建 Texture2D。")]
        public bool autoCreateTexture = true;
        private Texture2D _tex;

        private void Start()
        {
            // 优先从全局 LightGlueManager 获取 Bridge（如果未在 Inspector 指定）
            if (bridge == null && LightGlueManager.Instance != null)
            {
                bridge = LightGlueManager.Instance.bridge;
            }

            if (bridge == null)
            {
                Debug.LogWarning("[Viewer] HardwareUdpJpegViewer 需要 HardwareToPythonUdpBridge 引用，请在 Inspector 中指定或确保存在 LightGlueManager 实例。");
            }
            else
            {
                Debug.Log("[Viewer] Using shared receiver from HardwareToPythonUdpBridge (no port conflict)");
            }
        }

        private void OnDisable()
        {
            // Shared 模式下不管理 Bridge 内部的接收器，这里无需额外清理
        }

        private float _lastDecodeFailLogTime = -1f;

        private void Update()
        {
            byte[] latest = null;

            if (bridge == null) return;
            latest = bridge.GetLatestJpeg();
            if (latest == null || latest.Length < 4) return;
            // 只尝试解码形似完整 JPEG 的缓冲（SOI+EOI），避免对 UDP 组帧残片反复解码并刷日志
            if (latest[0] != 0xFF || latest[1] != 0xD8 || latest[latest.Length - 2] != 0xFF || latest[latest.Length - 1] != 0xD9)
                return;

            if (target == null) return;

            if (_tex == null)
            {
                if (!autoCreateTexture) return;
                _tex = new Texture2D(2, 2, TextureFormat.RGB24, mipChain: false);
                _tex.wrapMode = TextureWrapMode.Clamp;
                _tex.filterMode = FilterMode.Bilinear;
                target.texture = _tex;
            }

            bool ok = _tex.LoadImage(latest, markNonReadable: false);
            if (!ok)
            {
                if (Time.unscaledTime - _lastDecodeFailLogTime >= 1f)
                {
                    _lastDecodeFailLogTime = Time.unscaledTime;
                    Debug.LogWarning($"[Viewer] Failed to decode JPEG (size: {latest.Length} bytes)");
                }
            }
        }
    }
}