using System;
using System.Collections;
using System.Collections.Generic;
using Kill.UI.Components;
using UnityEngine;
using UnityEngine.UI;

namespace Kill.UI.Pages
{
    /// <summary>
    /// 二维码扫描器 - 调用摄像头扫描二维码
    /// </summary>
    public class ScanQRcode : MonoBehaviour
    {
        [Header("UI组件")]
        public RawImage cameraPreview;  // 摄像头预览
        [Header("扫描设置")]
        public float scanInterval = 0.2f; // 扫描间隔（秒）

        // 摄像头相关
        private WebCamTexture webCamTexture;
        private bool isScanning = false;

        // 扫描结果回调
        public event Action<string> OnQRCodeScanned;

        void OnEnable()
        {
            StartScan();
        }

        void OnDisable()
        {
            StopScan();
        }

        /// <summary>
        /// 开始扫描
        /// </summary>
        public void StartScan()
        {
            if (isScanning) return;

            StartCoroutine(InitializeCamera());
        }

        /// <summary>
        /// 停止扫描
        /// </summary>
        public void StopScan()
        {
            isScanning = false;
            StopAllCoroutines();

            if (webCamTexture != null && webCamTexture.isPlaying)
            {
                webCamTexture.Stop();
                webCamTexture = null;
            }
        }

        /// <summary>
        /// 关闭扫码界面
        /// </summary>
        public void Close()
        {
            StopScan();
            gameObject.SetActive(false);
        }

        /// <summary>
        /// 初始化摄像头
        /// </summary>
        private IEnumerator InitializeCamera()
        {
            // Android 使用 Permission API 请求权限
#if UNITY_ANDROID && !UNITY_EDITOR
            if (!UnityEngine.Android.Permission.HasUserAuthorizedPermission(UnityEngine.Android.Permission.Camera))
            {
                UnityEngine.Android.Permission.RequestUserPermission(UnityEngine.Android.Permission.Camera);
                // 等待权限请求结果
                yield return new WaitUntil(() => UnityEngine.Android.Permission.HasUserAuthorizedPermission(UnityEngine.Android.Permission.Camera));
            }
            
            if (!UnityEngine.Android.Permission.HasUserAuthorizedPermission(UnityEngine.Android.Permission.Camera))
            {
                UpdateStatus("100085");
                yield break;
            }
#else
            // 其他平台使用传统方式
            yield return Application.RequestUserAuthorization(UserAuthorization.WebCam);

            if (!Application.HasUserAuthorization(UserAuthorization.WebCam))
            {
                UpdateStatus("100085");
                yield break;
            }
#endif

            // 获取后置摄像头
            WebCamDevice[] devices = WebCamTexture.devices;
            if (devices.Length == 0)
            {
                UpdateStatus("100086");
                yield break;
            }

            // 优先使用后置摄像头
            string deviceName = devices[0].name;
            for (int i = 0; i < devices.Length; i++)
            {
                if (!devices[i].isFrontFacing)
                {
                    deviceName = devices[i].name;
                    break;
                }
            }

            // 创建摄像头纹理
            webCamTexture = new WebCamTexture(deviceName, 1280, 720, 30);
            cameraPreview.texture = webCamTexture;

            // 开始播放
            webCamTexture.Play();

            // 等待摄像头启动
            yield return new WaitUntil(() => webCamTexture.width > 100);

            // 调整预览画面比例
            AdjustPreviewAspect();

            isScanning = true;
            // 开始扫描
            StartCoroutine(ScanCoroutine());
        }

        /// <summary>
        /// 调整预览画面比例
        /// </summary>
        private void AdjustPreviewAspect()
        {
            if (webCamTexture == null) return;

            float videoRatio = (float)webCamTexture.width / webCamTexture.height;
            float screenRatio = (float)Screen.width / Screen.height;

            // 根据摄像头方向调整
            int rotation = webCamTexture.videoRotationAngle;
            cameraPreview.rectTransform.localEulerAngles = new Vector3(0, 0, -rotation);

            // 调整缩放以适应屏幕
            if (rotation == 90 || rotation == 270)
            {
                videoRatio = 1f / videoRatio;
            }

            // 保持比例填充
            if (videoRatio > screenRatio)
            {
                cameraPreview.rectTransform.localScale = new Vector3(screenRatio / videoRatio, 1, 1);
            }
            else
            {
                cameraPreview.rectTransform.localScale = new Vector3(1, videoRatio / screenRatio, 1);
            }
        }

        /// <summary>
        /// 扫描协程
        /// </summary>
        private IEnumerator ScanCoroutine()
        {
            // 等待一帧确保摄像头已准备好
            yield return null;

            while (isScanning && webCamTexture != null && webCamTexture.isPlaying)
            {
                // 获取当前帧
                Texture2D snapshot = GetSnapshot();
                if (snapshot != null)
                {
                    // 解析二维码
                    string result = DecodeQRCode(snapshot);
                    Destroy(snapshot);

                    if (!string.IsNullOrEmpty(result))
                    {
                        // 从结果中提取 MAC 地址
                        string macAddress = ExtractMacAddress(result);
                        if (!string.IsNullOrEmpty(macAddress))
                        {
                            // 扫描成功，仅回传 MAC 地址
                            OnQRCodeScanned?.Invoke(macAddress);
                            yield break;
                        }
                        else
                        {
                            // 二维码不符合要求，显示提示
                            UpdateStatus("100084");
                        }
                    }
                }

                yield return new WaitForSeconds(scanInterval);
            }
        }

        /// <summary>
        /// 获取摄像头当前帧
        /// </summary>
        private Texture2D GetSnapshot()
        {
            if (webCamTexture == null || !webCamTexture.isPlaying) return null;

            try
            {
                Texture2D snapshot = new Texture2D(webCamTexture.width, webCamTexture.height);
                snapshot.SetPixels(webCamTexture.GetPixels());
                snapshot.Apply();
                return snapshot;
            }
            catch
            {
                return null;
            }
        }

        /// <summary>
        /// 解析二维码
        /// </summary>
        private string DecodeQRCode(Texture2D texture)
        {
            try
            {
                int width = texture.width;
                int height = texture.height;

                // 获取像素数据
                Color32[] pixels = texture.GetPixels32();
                
                // 转换为灰度图
                byte[] grayscale = new byte[width * height];
                for (int i = 0; i < pixels.Length; i++)
                {
                    // 使用标准亮度公式: Y = 0.299R + 0.587G + 0.114B
                    grayscale[i] = (byte)(0.299f * pixels[i].r + 0.587f * pixels[i].g + 0.114f * pixels[i].b);
                }

                // 创建 LuminanceSource
                var luminanceSource = new ZXing.PlanarYUVLuminanceSource(
                    grayscale, 
                    width, 
                    height,
                    0, 
                    0, 
                    width, 
                    height,
                    false
                );

                // 创建 BinaryBitmap
                var binarizer = new ZXing.Common.HybridBinarizer(luminanceSource);
                var binaryBitmap = new ZXing.BinaryBitmap(binarizer);

                // 解码
                var reader = new ZXing.QrCode.QRCodeReader();
                var hints = new Dictionary<ZXing.DecodeHintType, object>
                {
                    { ZXing.DecodeHintType.TRY_HARDER, true }
                };
                
                var result = reader.decode(binaryBitmap, hints);
                return result?.Text;
            }
            catch (Exception ex)
            {
                Debug.LogError($"二维码解析失败: {ex.Message}");
                return null;
            }
        }

        /// <summary>
        /// 从字符串中提取 MAC 地址（格式如 98:EA:A0:02:4E:06）
        /// </summary>
        private string ExtractMacAddress(string input)
        {
            if (string.IsNullOrEmpty(input))
                return null;

            // MAC 地址正则表达式：匹配 XX:XX:XX:XX:XX:XX 格式（X 为十六进制字符）
            System.Text.RegularExpressions.Regex macRegex = 
                new System.Text.RegularExpressions.Regex(@"[0-9A-Fa-f]{2}:[0-9A-Fa-f]{2}:[0-9A-Fa-f]{2}:[0-9A-Fa-f]{2}:[0-9A-Fa-f]{2}:[0-9A-Fa-f]{2}");
            
            System.Text.RegularExpressions.Match match = macRegex.Match(input);
            if (match.Success)
            {
                // 返回大写的 MAC 地址
                return match.Value.ToUpper();
            }

            return null;
        }

        /// <summary>
        /// 更新状态文字
        /// </summary>
        private void UpdateStatus(string code)
        {
           ToastUI.Show(code);
        }

        void OnDestroy()
        {
            StopScan();
            gameObject.SetActive(false);
        }
    }
}