using System.Collections.Generic;
using System.IO;
using System.Xml;

namespace Otter {
    /// <summary>
    /// Class used for loading textures from an Atlas, or a set of Atlases. This class is built to support
    /// atlases created with Sparrow/Starling exporting from TexturePacker http://www.codeandweb.com/texturepacker
    /// </summary>
    public class Atlas {

        #region Static Fields

        static Dictionary<string, SFML.Graphics.Texture> textures = new Dictionary<string, SFML.Graphics.Texture>();

        #endregion

        #region Private Fields

        Dictionary<string, AtlasTexture> subtextures = new Dictionary<string, AtlasTexture>();

        #endregion

        #region Constructors

        /// <summary>
        /// Designed for Sparrow/Starling exporting from TexturePacker http://www.codeandweb.com/texturepacker
        /// </summary>
        /// <param name="source">The reltive path to the atlas data file.  The png should also be in the same directory.</param>
        public Atlas(string source = "") {
            if (source != "") {
                Add(source);
            }
        }

        #endregion

        #region Indexers

        /// <summary>
        /// Get an AtlasTexture by name.
        /// </summary>
        /// <param name="name">The name of the image in the atlas data.</param>
        /// <returns>An AtlasTexture.</returns>
        public AtlasTexture this[string name] {
            get {
                return GetTexture(name);
            }
        }

        #endregion

        #region Public Methods

        /// <summary>
        /// Add another atlas to the collection of textures.  Duplicate names will destroy this.
        /// </summary>
        /// <param name="source">The relative path to the data file.  The png should be in the same directory.</param>
        public Atlas Add(string source) {
            var xml = new XmlDocument();
            xml.Load(source);

            var atlas = xml.GetElementsByTagName("TextureAtlas");

            var imagePath = Path.GetDirectoryName(source) + "/";

            if (imagePath == "/") imagePath = "";

            foreach (XmlElement a in xml.GetElementsByTagName("TextureAtlas")) {
                foreach (XmlElement e in xml.GetElementsByTagName("SubTexture")) {
                    var name = e.AttributeString("name");
                    var uniqueName = true;

                    foreach (var atest in subtextures.Values) {
                        if (atest.Name == name) {
                            uniqueName = false;
                            break;
                        }
                    }

                    if (uniqueName) {
                        var atext = new AtlasTexture();
                        atext.X = e.AttributeInt("x");
                        atext.Y = e.AttributeInt("y");
                        atext.Width = e.AttributeInt("width");
                        atext.Height = e.AttributeInt("height");
                        atext.FrameHeight = e.AttributeInt("frameHeight", atext.Height);
                        atext.FrameWidth = e.AttributeInt("frameWidth", atext.Width);
                        atext.FrameX = e.AttributeInt("frameX", 0);
                        atext.FrameY = e.AttributeInt("frameY", 0);
                        atext.Name = name;
                        atext.Source = imagePath + a.AttributeString("imagePath");
                        atext.Texture = new Texture(atext.Source);
                        subtextures.Add(e.AttributeString("name"), atext);
                    }
                }
            }
            return this;
        }

        /// <summary>
        /// Add multiple sources to the Atlas.
        /// </summary>
        /// <param name="sources">The file path to the sources.</param>
        /// <returns>The Atlas.</returns>
        public Atlas AddMultiple(params string[] sources) {
            foreach (string s in sources) {
                Add(s);
            }
            return this;
        }

        /// <summary>
        /// Add multiple atlases from a set created by texture packer.
        /// Note: This only supports up to 10 atlases (0 - 9)
        /// </summary>
        /// <param name="source">The path until the number.  For example: "assets/atlas" if the path is "assets/atlas0.xml"</param>
        /// <param name="extension">The extension of the source without a dot</param>
        /// <returns>The Atlas.</returns>
        public Atlas AddNumbered(string source, string extension = "xml") {
            var i = 0;

            while (File.Exists(source + i + "." + extension)) {
                Add(source + i + "." + extension);
                i++;
            }

            return this;
        }

        /// <summary>
        /// Creates a new Image from an AtlasTexture.
        /// </summary>
        /// <param name="name">The name of the texture in the atlas data.</param>
        /// <returns>The created Image.</returns>
        public Image CreateImage(string name) {
            return new Image(this[name]);
        }

        /// <summary>
        /// Creates a new Spritemap from an AtlasTexture.
        /// </summary>
        /// <typeparam name="T">The type to use to reference animations.</typeparam>
        /// <param name="name">The name of the texture in the atlas data.</param>
        /// <param name="width">The width of the cell on the sprite sheet.</param>
        /// <param name="height">The height of the cell on the sprite sheet.</param>
        /// <returns>The new Spritemap.</returns>
        public Spritemap<T> CreateSpritemap<T>(string name, int width, int height) {
            return new Spritemap<T>(this[name], width, height);
        }

        

        /// <summary>
        /// Get an AtlasTexture by name.
        /// </summary>
        /// <param name="name">The name of the image in the atlas data.</param>
        /// <returns>An AtlasTexture.</returns>
        public AtlasTexture GetAtlasTexture(string name) {
            return GetTexture(name);
        }

        /// <summary>
        /// Tests if a texture by the specified name exists in the atlas data.
        /// </summary>
        /// <param name="name">The name of the texture to test.</param>
        /// <returns>True if the atlas data contains a texture by the specified name.</returns>
        public bool Exists(string name) {
            return subtextures.ContainsKey(name);
        }

        #endregion

        #region Internal

        internal AtlasTexture GetTexture(string name) {
            var a = subtextures[name];

            return a;
        }

        #endregion
    }

    /// <summary>
    /// Class used for representing a texture on a texture atlas.
    /// </summary>
    public class AtlasTexture {

        #region Public Fields

        /// <summary>
        /// The X position of the texture in the atlas.
        /// </summary>
        public int X;

        /// <summary>
        /// The Y position of the texture in the atlas.
        /// </summary>
        public int Y;

        /// <summary>
        /// The width of the texture in the atlas.
        /// </summary>
        public int Width;

        /// <summary>
        /// The height of the texture in the atlas.
        /// </summary>
        public int Height;

        /// <summary>
        /// The frame width of the texture in the atlas (used in Trim mode.)
        /// Trim is not supported yet.
        /// </summary>
        public int FrameWidth;

        /// <summary>
        /// The frame height of the texture in the atlas (used in Trim mode.)
        /// Trim is not supported yet.
        /// </summary>
        public int FrameHeight;

        /// <summary>
        /// The frame X position of the texture in the atlas (used in Trim mode.)
        /// Trim is not supported yet.
        /// </summary>
        public int FrameX;

        /// <summary>
        /// The frame Y position of the texture in the atlas (used in Trim mode.)
        /// Trim is not supported yet.
        /// </summary>
        public int FrameY;

        /// <summary>
        /// The name of the texture in the atlas.
        /// </summary>
        public string Name;

        /// <summary>
        /// The file path source of the texture.
        /// </summary>
        public string Source;

        /// <summary>
        /// The texture loaded for this atlas texture.
        /// </summary>
        public Texture Texture;

        #endregion

        #region Public Properties

        /// <summary>
        /// The rectangle region of the texture in the atlas.
        /// </summary>
        public Rectangle Region {
            get {
                return new Rectangle(X, Y, Width, Height);
            }
        }

        #endregion

        #region Public Methods

        public override string ToString() {
            return Name + " " + Source + " X: " + X + " Y: " + Y + " Width: " + Width + " Height: " + Height + " FrameX: " + FrameX + " FrameY: " + FrameY + " FrameWidth: " + FrameWidth + " FrameHeight: " + FrameHeight;
        }

        #endregion

    }
}