using System;
using System.Collections.Generic;
using System.Linq;
using Spectre.Console.Rendering;

namespace Spectre.Console
{
    internal sealed class FallbackStatusRenderer : ProgressRenderer
    {
        private readonly object _lock;
        private IRenderable? _renderable;
        private string? _lastStatus;

        public override TimeSpan RefreshRate => TimeSpan.FromMilliseconds(100);

        public FallbackStatusRenderer()
        {
            _lock = new object();
        }

        public override void Update(ProgressContext context)
        {
            lock (_lock)
            {
                var task = context.GetTasks().SingleOrDefault();
                if (task != null)
                {
                    // Not same description?
                    if (_lastStatus != task.Description)
                    {
                        _lastStatus = task.Description;
                        _renderable = new Markup(task.Description + "\n");
                        return;
                    }
                }

                _renderable = null;
                return;
            }
        }

        public override IEnumerable<IRenderable> Process(RenderContext context, IEnumerable<IRenderable> renderables)
        {
            lock (_lock)
            {
                var result = new List<IRenderable>();
                result.AddRange(renderables);

                if (_renderable != null)
                {
                    result.Add(_renderable);
                }

                _renderable = null;

                return result;
            }
        }
    }
}