using System.Diagnostics;
using ConsoleApp2.Const;
using ConsoleApp2.Services;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;

namespace ConsoleApp2.HostedServices;

/// <summary>
/// 任务监控
/// </summary>
public class TaskMonitorService : BackgroundService
{
    private readonly IHostApplicationLifetime _lifetime;
    private readonly ILogger<TaskMonitorService> _logger;
    private readonly ProcessContext _context;
    private readonly DataRecordQueue _producerQueue;
    private readonly DataRecordQueue _consumerQueue;

    public TaskMonitorService(IHostApplicationLifetime lifetime,
        ILogger<TaskMonitorService> logger,
        ProcessContext context,
        [FromKeyedServices(ProcessStep.Producer)]
        DataRecordQueue producerQueue,
        [FromKeyedServices(ProcessStep.Consumer)]
        DataRecordQueue consumerQueue)
    {
        _lifetime = lifetime;
        _logger = logger;
        _context = context;
        _producerQueue = producerQueue;
        _consumerQueue = consumerQueue;
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        await Task.Factory.StartNew(Monitor, stoppingToken);
    }

    private async Task Monitor()
    {
        var sw = Stopwatch.StartNew();
        var lastTime = sw.ElapsedMilliseconds;
        var lastInputCount = _context.InputCount;
        var lastTransformCount = _context.TransformCount;
        var lastOutputCount = _context.OutputCount;

        bool endCheck = false;
        while (true)
        {
            EndCheck:
            // var running = 0;
            // var error = 0;
            // var completed = 0;
            // var canceled = 0;
            // foreach (var task in _taskManager.Tasks)
            // {
            //     switch (task.Status)
            //     {
            //         case TaskStatus.Canceled:
            //             canceled++;
            //             break;
            //         case TaskStatus.Faulted:
            //             error++;
            //             break;
            //         case TaskStatus.RanToCompletion:
            //             completed++;
            //             break;
            //         default:
            //             running++;
            //             break;
            //     }
            // }

            var time = sw.ElapsedMilliseconds;
            var inputCount = _context.InputCount;
            var transformCount = _context.TransformCount;
            var outputCount = _context.OutputCount;
            
            var elapseTime = (time - lastTime) / 1000f;
            var inputSpeed = (inputCount - lastInputCount) / elapseTime;
            var transformSpeed = (transformCount - lastTransformCount) / elapseTime;
            var outputSpeed = (outputCount - lastOutputCount) / elapseTime;

            // _logger.LogInformation(
            //     "Task monitor: running: {Running}, error: {Error}, completed: {Completed}, canceled: {Canceled}, outputSpeed: {Speed} records/s",
            //     running, error, completed, canceled, outputSpeed);
            _logger.LogInformation(
                "Process monitor: input: {inputStatus}, transform: {transformStatus}, output: {outputStatus}\nInput: {InputCount}, Transform: {TransformCount}, Output: {OutputCount}",
                _context.IsInputCompleted ? "completed" : $"running {inputSpeed:F2} records/s",
                _context.IsTransformCompleted ? "completed" : $"running {transformSpeed:F2} records/s",
                _context.IsOutputCompleted ? "completed" : $"running {outputSpeed:F2} records/s",
                inputCount,
                transformCount,
                outputCount);
            _logger.LogInformation("Queue monitor: producer queue: {ProducerQueue}, consumer queue: {ConsumerQueue}",
                _producerQueue.Count, _consumerQueue.Count);

            await Task.Delay(5000);

            lastTime = time;
            lastInputCount = inputCount;
            lastTransformCount = transformCount;
            lastOutputCount = outputCount;

            if (_context is { IsInputCompleted: true, IsTransformCompleted: true, IsOutputCompleted: true })
            {
                if (!endCheck)
                {
                    endCheck = true;
                    goto EndCheck;
                }
                break;
            }
        }
        
        _logger.LogInformation("***** All tasks completed *****");
        _logger.LogInformation("***** ElapseTime: {Time}", (sw.ElapsedMilliseconds / 1000f).ToString("F3"));
        // _lifetime.StopApplication();
    }
}