using Azimuth;
using Blacklight.Core;
using Blacklight.Core.Drawables;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;

namespace Glass.Blacklight
{
    public class SpriteSheetRenderer
    {
        public SpriteSheetAttribute Source;
        
        public SpriteSheet SpriteSheet;

        public static Vector MirrorY(Vector vector)
        {
            return new Vector(vector.X, -vector.Y);            
        }

        public void Render(Cel cel, SpriteMaterial material, Rect rect, AffineMatrix transform)
        {
            var sprite = new Shard
            {
                Sheet = SpriteSheet,
                Frame = material.CellLocation,
                Vertices = new Vector[4] {
                    MirrorY(rect.BottomLeft),
                    MirrorY(rect.BottomRight),
                    MirrorY(rect.TopRight),
                    MirrorY(rect.TopLeft),
                },
            };
            cel.AddEntity(new Entity<Shard>(sprite, transform));
        }

        public static SpriteSheet LoadSpriteSheet(SpriteSheetAttribute spriteSheetAttribute, WindowHandle window)
        {
            var assembly = Assembly.GetEntryAssembly();
            using (var stream = assembly.GetManifestResourceStream(spriteSheetAttribute.SpriteSheetSource))
            {
                if (stream == null)
                {
                    return null;
                }

                return window.CreateSpriteSheet(stream,
                    new System.Drawing.Size(spriteSheetAttribute.SpriteSize.X, spriteSheetAttribute.SpriteSize.Y),
                    spriteSheetAttribute.BorderSize);
            }
        }

        public static SpriteSheetRenderer SpriteSheetBuilder(
            Type type,
            WindowHandle windowHandle,
            SpriteSheetAttribute spriteSheetAttribute)
        {
            string source = spriteSheetAttribute.SpriteSheetSource;
            if (source == null)
            {
                throw new ArgumentException(
                    $"Type {type} had a MaterialLibraryAttribute with a null PackSheetSource.");
            }

            SpriteSheet spriteSheet = LoadSpriteSheet(spriteSheetAttribute, windowHandle);
            if (spriteSheet == null)
            {
                throw new ArgumentException(
                    $"Could not load the pack sheet {spriteSheetAttribute.SpriteSheetSource} for Type {type}.");
            }

            return new SpriteSheetRenderer
            {
                Source = spriteSheetAttribute,
                SpriteSheet = spriteSheet,
            };
        }
    }
}