using System.Numerics;
using MesETL.App.HostedServices.Abstractions;
using MesETL.App.Services;
using Microsoft.Extensions.Logging;

namespace MesETL.App.HostedServices;

// 空输出服务，测试用
public class VoidOutputService : IOutputService
{
    private readonly ILogger _logger;
    private readonly RecordQueuePool _queuePool;
    private readonly ProcessContext _context;

    private BigInteger _total;

    public VoidOutputService(
        ProcessContext context, ILogger<VoidOutputService> logger, RecordQueuePool queuePool)
    {
        _context = context;
        _logger = logger;
        _queuePool = queuePool;
    }

    public Task ExecuteAsync(CancellationToken ct)
    {
        _logger.LogInformation("***** Void Output Service Started *****");
        while (!_context.IsTransformCompleted || _queuePool.Queues.Count > 0)
        {
            foreach (var pair in _queuePool.Queues)
            {
                if (_context.IsTransformCompleted && pair.Value.Count == 0)
                {
                    _queuePool.RemoveQueue(pair.Key);
                    continue;
                }

                if (!pair.Value.TryDequeue(out var record))
                    continue;
                
                _total += record.FieldCharCount;
                _context.AddOutput();
            }
        }

        _context.CompleteOutput();
        _logger.LogInformation("***** Void Output Service Stopped *****");
        _logger.LogInformation("平均列字符数：{Number}", _total / _context.OutputCount);
        return Task.CompletedTask;
    }
}