using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using OrpaonVision.Core.Results;
using OrpaonVision.SiteApp.Runtime.Contracts;
using OrpaonVision.SiteApp.Runtime.Services;
using System.Diagnostics;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;

namespace OrpaonVision.SiteApp.Runtime.Services;

/// <summary>
/// YOLO推理服务实现。
/// 注意：这是一个基于模拟的实现，实际使用时需要替换为YoloDotNet或其他YOLO库的真实调用。
/// </summary>
public sealed class YoloInferenceService : IYoloInferenceService, IDisposable
{
    private readonly ILogger<YoloInferenceService> _logger;
    private readonly YoloInferenceOptions _options;
    private readonly object _lockObject = new();
    private bool _isInitialized;
    private readonly List<string> _classNames = new();
    private readonly Random _random = new();
    private YoloModelInfo _modelInfo = new();

    /// <summary>
    /// 构造函数。
    /// </summary>
    public YoloInferenceService(ILogger<YoloInferenceService> logger, IOptions<YoloInferenceOptions> options)
    {
        _logger = logger;
        _options = options.Value;
        _logger.LogInformation("YOLO推理服务已初始化（模拟模式）");
    }

    /// <inheritdoc />
    public Result Initialize()
    {
        lock (_lockObject)
        {
            try
            {
                if (_isInitialized)
                {
                    return Result.Success(message: "YOLO模型已初始化。");
                }

                _logger.LogInformation("正在初始化YOLO模型: {ModelPath}", _options.ModelPath);

                var stopwatch = Stopwatch.StartNew();

                // 模拟模型加载 - 实际实现需要调用YoloDotNet或其他YOLO库
                Thread.Sleep(1000); // 模拟加载时间

                // 模拟加载类别标签
                _classNames.Clear();
                if (File.Exists(_options.LabelsPath))
                {
                    var lines = File.ReadAllLines(_options.LabelsPath);
                    foreach (var line in lines)
                    {
                        var className = line.Trim();
                        if (!string.IsNullOrEmpty(className))
                        {
                            _classNames.Add(className);
                        }
                    }
                }
                else
                {
                    // 使用默认类别
                    _classNames.AddRange(new[]
                    {
                        "大电容", "螺丝", "铜排", "小电容", "电阻", "连接器", "散热片", "PCB板"
                    });
                }

                // 设置模型信息
                _modelInfo = new YoloModelInfo
                {
                    ModelName = Path.GetFileNameWithoutExtension(_options.ModelPath),
                    ModelVersion = "1.0.0",
                    InputSize = (_options.InputWidth, _options.InputHeight),
                    ClassCount = _classNames.Count,
                    ClassNames = _classNames.ToList(),
                    UseGpu = _options.UseGpu,
                    LoadTimeMs = stopwatch.Elapsed.TotalMilliseconds,
                    ModelFileSize = File.Exists(_options.ModelPath) ? new FileInfo(_options.ModelPath).Length : 0
                };

                _isInitialized = true;
                stopwatch.Stop();

                _logger.LogInformation("YOLO模型初始化成功，耗时: {ElapsedMs:F2}ms，类别数: {ClassCount}", 
                    stopwatch.Elapsed.TotalMilliseconds, _classNames.Count);

                // 执行预热
                if (_options.EnableWarmup)
                {
                    var warmupResult = Warmup(_options.WarmupCount);
                    if (!warmupResult.Succeeded)
                    {
                        _logger.LogWarning("模型预热失败: {Message}", warmupResult.Message);
                    }
                }

                return Result.Success(message: "YOLO模型初始化成功。");
            }
            catch (Exception ex)
            {
                var traceId = Guid.NewGuid().ToString("N");
                _logger.LogError(ex, "YOLO模型初始化失败。TraceId: {TraceId}", traceId);
                var result = Result.FromException(ex, "YOLO_INIT_FAILED", "YOLO模型初始化失败。", traceId);
                return Result.FailWithTrace(result.Code, result.Message, result.TraceId ?? traceId, result.Errors.ToArray());
            }
        }
    }

    /// <inheritdoc />
    public Result<IReadOnlyList<YoloDetectionResult>> Predict(byte[] imageData, int width, int height, string pixelFormat = "BGR8Packed")
    {
        if (!_isInitialized)
        {
            var initResult = Initialize();
            if (!initResult.Succeeded)
            {
                return Result<IReadOnlyList<YoloDetectionResult>>.Fail(initResult.Code, initResult.Message, initResult.Errors.ToArray());
            }
        }

        try
        {
            _logger.LogDebug("开始YOLO推理，图像尺寸: {Width}x{Height}", width, height);

            var stopwatch = Stopwatch.StartNew();

            // 模拟推理过程 - 实际实现需要调用YoloDotNet的Predict方法
            Thread.Sleep(50); // 模拟推理时间

            var results = new List<YoloDetectionResult>();

            // 生成模拟检测结果
            var detectionCount = _random.Next(0, 5); // 随机生成0-4个检测结果
            for (int i = 0; i < detectionCount; i++)
            {
                var classId = _random.Next(0, _classNames.Count);
                var confidence = (float)(_random.NextDouble() * 0.4 + 0.6); // 0.6-1.0的置信度

                var x = _random.Next(0, width / 2);
                var y = _random.Next(0, height / 2);
                var w = _random.Next(width / 8, width / 4);
                var h = _random.Next(height / 8, height / 4);

                results.Add(new YoloDetectionResult
                {
                    ClassId = classId,
                    ClassName = _classNames[classId],
                    Confidence = confidence,
                    X = x,
                    Y = y,
                    Width = w,
                    Height = h
                });
            }

            // 按置信度排序
            results.Sort((a, b) => b.Confidence.CompareTo(a.Confidence));

            stopwatch.Stop();
            _modelInfo.InferenceTimeMs = stopwatch.Elapsed.TotalMilliseconds;

            _logger.LogDebug("YOLO推理完成，检测到 {Count} 个目标，耗时: {ElapsedMs:F2}ms", 
                results.Count, stopwatch.Elapsed.TotalMilliseconds);

            return Result<IReadOnlyList<YoloDetectionResult>>.Success(results, message: "YOLO推理成功。");
        }
        catch (Exception ex)
        {
            var traceId = Guid.NewGuid().ToString("N");
            _logger.LogError(ex, "YOLO推理失败。TraceId: {TraceId}", traceId);
            var result = Result.FromException(ex, "YOLO_PREDICT_FAILED", "YOLO推理失败。", traceId);
            return Result<IReadOnlyList<YoloDetectionResult>>.FailWithTrace(result.Code, result.Message, result.TraceId ?? traceId, result.Errors.ToArray());
        }
    }

    /// <inheritdoc />
    public Result<IReadOnlyList<IReadOnlyList<YoloDetectionResult>>> PredictBatch(
        IReadOnlyList<byte[]> imageBatch, 
        IReadOnlyList<(int width, int height)> dimensions, 
        string pixelFormat = "BGR8Packed")
    {
        if (!_isInitialized)
        {
            var initResult = Initialize();
            if (!initResult.Succeeded)
            {
                return Result<IReadOnlyList<IReadOnlyList<YoloDetectionResult>>>.Fail(initResult.Code, initResult.Message, initResult.Errors.ToArray());
            }
        }

        if (imageBatch.Count != dimensions.Count)
        {
            return Result<IReadOnlyList<IReadOnlyList<YoloDetectionResult>>>.Fail(
                "YOLO_BATCH_SIZE_MISMATCH", "图像批次与维度信息数量不匹配。");
        }

        try
        {
            _logger.LogDebug("开始YOLO批量推理，批次大小: {BatchSize}", imageBatch.Count);

            var results = new List<IReadOnlyList<YoloDetectionResult>>();

            for (int i = 0; i < imageBatch.Count; i++)
            {
                var predictResult = Predict(imageBatch[i], dimensions[i].width, dimensions[i].height, pixelFormat);
                if (!predictResult.Succeeded)
                {
                    return Result<IReadOnlyList<IReadOnlyList<YoloDetectionResult>>>.Fail(
                        predictResult.Code, $"第{i+1}张图像推理失败: {predictResult.Message}", predictResult.Errors.ToArray());
                }

                results.Add(predictResult.Data);
            }

            _logger.LogDebug("YOLO批量推理完成，处理了 {Count} 张图像", results.Count);

            return Result<IReadOnlyList<IReadOnlyList<YoloDetectionResult>>>.Success(results, message: "YOLO批量推理成功。");
        }
        catch (Exception ex)
        {
            var traceId = Guid.NewGuid().ToString("N");
            _logger.LogError(ex, "YOLO批量推理失败。TraceId: {TraceId}", traceId);
            var result = Result.FromException(ex, "YOLO_BATCH_PREDICT_FAILED", "YOLO批量推理失败。", traceId);
            return Result<IReadOnlyList<IReadOnlyList<YoloDetectionResult>>>.FailWithTrace(result.Code, result.Message, result.TraceId ?? traceId, result.Errors.ToArray());
        }
    }

    /// <inheritdoc />
    public IReadOnlyList<string> GetSupportedClasses()
    {
        return _classNames.ToList();
    }

    /// <inheritdoc />
    public YoloModelInfo GetModelInfo()
    {
        return _modelInfo;
    }

    /// <inheritdoc />
    public bool IsInitialized => _isInitialized;

    /// <inheritdoc />
    public Result Warmup(int warmupCount = 3)
    {
        if (!_isInitialized)
        {
            return Result.Fail("YOLO_NOT_INITIALIZED", "YOLO模型未初始化。");
        }

        try
        {
            _logger.LogInformation("开始YOLO模型预热，预热次数: {WarmupCount}", warmupCount);

            // 生成模拟图像数据
            var dummyImage = new byte[_options.InputWidth * _options.InputHeight * 3]; // BGR格式

            for (int i = 0; i < warmupCount; i++)
            {
                var warmupResult = Predict(dummyImage, _options.InputWidth, _options.InputHeight);
                if (!warmupResult.Succeeded)
                {
                    return Result.Fail(warmupResult.Code, $"预热第{i+1}次失败: {warmupResult.Message}");
                }
            }

            _logger.LogInformation("YOLO模型预热完成");
            return Result.Success(message: "YOLO模型预热完成。");
        }
        catch (Exception ex)
        {
            var traceId = Guid.NewGuid().ToString("N");
            _logger.LogError(ex, "YOLO模型预热失败。TraceId: {TraceId}", traceId);
            var result = Result.FromException(ex, "YOLO_WARMUP_FAILED", "YOLO模型预热失败。", traceId);
            return Result.FailWithTrace(result.Code, result.Message, result.TraceId ?? traceId, result.Errors.ToArray());
        }
    }

    /// <summary>
    /// 释放资源。
    /// </summary>
    public void Dispose()
    {
        try
        {
            lock (_lockObject)
            {
                if (_isInitialized)
                {
                    // 模拟资源释放 - 实际实现需要释放YOLO模型资源
                    _isInitialized = false;
                    _logger.LogInformation("YOLO推理服务资源已释放");
                }
            }
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "释放YOLO推理服务资源时发生异常");
        }
    }
}