using dodohold.core;
using Microsoft.Extensions.Logging;
using System.Diagnostics;
using System.Text;


namespace molilian.core
{
    public static class SystemMonitor
    {
        private static Timer _monitorTimer;
        public static void StartMonitoring(int intervalSeconds = 30)
        {
            _monitorTimer = new Timer(
                CollectMetrics,
                null,
                TimeSpan.Zero,
                TimeSpan.FromSeconds(intervalSeconds)
            );
        }

        private static void CollectMetrics(object state)
        {
            try
            {
                var metrics = new StringBuilder();

                // 线程池信息
                ThreadPool.GetMaxThreads(out int maxWorkerThreads, out int maxIoThreads);
                ThreadPool.GetAvailableThreads(out int availWorkerThreads, out int availIoThreads);
                ThreadPool.GetMinThreads(out int minWorkerThreads, out int minIoThreads);

                var usedWorkerThreads = maxWorkerThreads - availWorkerThreads;
                var usedIoThreads = maxIoThreads - availIoThreads;

                metrics.AppendLine("=== Thread Pool Stats ===");
                metrics.AppendLine($"Worker Threads: {usedWorkerThreads}/{maxWorkerThreads} (used/max)");
                metrics.AppendLine($"IO Threads: {usedIoThreads}/{maxIoThreads} (used/max)");
                metrics.AppendLine($"Min Worker Threads: {minWorkerThreads}");
                metrics.AppendLine($"Min IO Threads: {minIoThreads}");
                metrics.AppendLine($"Thread Pool Queue Length: {ThreadPool.PendingWorkItemCount}");
                metrics.AppendLine();

                // 内存信息
                var process = Process.GetCurrentProcess();
                var gcInfo = GC.GetGCMemoryInfo();

                metrics.AppendLine("=== Memory Stats ===");
                metrics.AppendLine($"Working Set: {process.WorkingSet64 / 1024 / 1024} MB");
                metrics.AppendLine($"Private Memory: {process.PrivateMemorySize64 / 1024 / 1024} MB");
                metrics.AppendLine($"GC Heap Size: {GC.GetTotalMemory(false) / 1024 / 1024} MB");
                metrics.AppendLine($"Gen 0 Collections: {GC.CollectionCount(0)}");
                metrics.AppendLine($"Gen 1 Collections: {GC.CollectionCount(1)}");
                metrics.AppendLine($"Gen 2 Collections: {GC.CollectionCount(2)}");
                metrics.AppendLine($"Memory Load: {gcInfo.MemoryLoadBytes / 1024 / 1024} MB");

                // 记录日志
                _ = new LoggerLibrary("debug", "metrics").Info(metrics.ToString()).SaveAsync();

                // 检查是否需要报警
                CheckAlertConditions(
                    usedWorkerThreads, maxWorkerThreads,
                    process.WorkingSet64,
                    ThreadPool.PendingWorkItemCount
                );
            }
            catch (Exception ex)
            {
                _ = new LoggerLibrary("debug", "metrics_error")
                    .Info($"Error collecting system metrics: {ex}").SaveAsync();
            }
        }

        private static void CheckAlertConditions(
            int usedWorkerThreads,
            int maxWorkerThreads,
            long workingSet,
            long pendingWork)
        {
            var alerts = new List<string>();

            // 线程池使用率超过80%
            if ((double)usedWorkerThreads / maxWorkerThreads > 0.8)
            {
                alerts.Add($"High thread pool usage: {usedWorkerThreads}/{maxWorkerThreads}");
            }

            // 内存使用超过2GB
            if (workingSet > 2L * 1024 * 1024 * 1024)
            {
                alerts.Add($"High memory usage: {workingSet / 1024 / 1024} MB");
            }

            // 线程池队列堆积
            if (pendingWork > 100)
            {
                alerts.Add($"High thread pool queue length: {pendingWork}");
            }

            if (alerts.Any())
            {
                NotifyCore.Notify($"System alerts:\n{string.Join("\n", alerts)}");
            }
        }

        public static void StopMonitoring()
        {
            _monitorTimer?.Dispose();
        }
    }
}