using System.Collections.Concurrent;
using Microsoft.Extensions.Logging;

namespace ConsoleApp2.Services;

/// <summary>
/// 快速批量创建和等待任务
/// </summary>
public class TaskManager
{
    private readonly ConcurrentBag<Task> _tasks;
    private readonly ILogger _logger;

    public int TaskCount => _tasks.Count;
    public int RunningTaskCount => _tasks.Count(task => !task.IsCompleted);
    public IReadOnlyCollection<Task> Tasks => _tasks;

    public TaskManager(ILogger<TaskManager> logger)
    {
        _tasks = new ConcurrentBag<Task>();
        _logger = logger;
    }

    public void CreateTask<TResult>(Func<TResult> func, CancellationToken cancellationToken = default)
    {
        var task = Task.Factory.StartNew(func, cancellationToken);
        _tasks.Add(task);
        _logger.LogDebug("New task created");
    }

    public async Task WaitAll()
    {
        await Task.WhenAll(_tasks);
    }

    public void ClearTask()
    {
        if(RunningTaskCount != 0)
            throw new InvalidOperationException("Unable to clear task. There are still running tasks");
        _tasks.Clear();
    }
}