using Quik.Media;
using Quik.Media.Font;
using System;
using System.Collections.Generic;
using System.Linq;

namespace Quik.Typography
{
    /// <summary>
    /// The font provider is a caching object that provides fonts for typesetting classes.
    /// </summary>
    public class FontProvider : IDisposable
    {
        private Dictionary<FontFace, QFont> Fonts { get; } = new Dictionary<FontFace, QFont>();
        private HashSet<QFont> UsedFonts { get; } = new HashSet<QFont>();
        public readonly FontRasterizerOptions RasterizerOptions;
        private readonly QuikApplication App;

        public QFont this[FontFace info]
        {
            get
            {
                if (!Fonts.TryGetValue(info, out QFont font))
                {
                    font = (QFont)App.GetMedia(info, MediaHint.Font);
                    Fonts[info] = font;
                }

                UsedFonts.Add(font);
                return font;
            }
        }

        public FontProvider(QuikApplication app, in FontRasterizerOptions options)
        {
            RasterizerOptions = options;
            App = app;
        }
        public FontProvider(QuikApplication app)
            : this(app, FontRasterizerOptions.Default)
        {
        }

        /// <summary>
        /// Tracks the use of fonts used by this typesetter and removes any that haven't been referenced since the last cycle.
        /// </summary>
        public void Collect()
        {
            // foreach (FontJar jar in Fonts.Values.ToArray())
            // {
            //     if (!UsedFonts.Contains(jar))
            //     {
            //         Fonts.Remove(jar.Info);
            //     }
            // }
            // UsedFonts.Clear();
        }

        private bool isDisposed = false;
        public void Dispose()
        {
            if (isDisposed) return;

            isDisposed = true;
            foreach (QFont font in Fonts.Values)
            {
                font.Dispose();
            }
        }
    }
}