using SFML.Graphics;
using SFML.System;
using SFML.Window;

namespace Otter {
    /// <summary>
    /// Graphic type that is used to represent a static image.
    /// </summary>
    public class Image : Graphic {

        #region Static Fields

        /// <summary>
        /// The amount of points to use when rendering a circle shape.
        /// </summary>
        public static int CirclePointCount = 24;

        #endregion

        #region Static Methods

        /// <summary>
        /// Creates a rectangle.
        /// </summary>
        /// <param name="width">The width of the rectangle.</param>
        /// <param name="height">The height of the rectangle.</param>
        /// <param name="color">The color of the rectangle.</param>
        /// <returns>A new image containing the rectangle.</returns>
        static public Image CreateRectangle(int width, int height, Color color) {
            Image img = new Image(width, height);

            img.Color = color;

            img.Width = width;
            img.Height = height;

            img.rectWidth = width;
            img.rectHeight = height;

            img.isShape = true;
            img.Batchable = false; // Cant batch rectangles for now

            img.OutlineColor = Color.None;

            return img;
        }

        /// <summary>
        /// Creates a rectangle the size of the active Game window.
        /// </summary>
        /// <param name="color">The color of the rectangle.</param>
        /// <returns>A new image containing the rectangle.</returns>
        static public Image CreateRectangle(Color color) {
            int w = Game.Instance.Width;
            int h = Game.Instance.Height;
            return Image.CreateRectangle(w, h, color);
        }

        /// <summary>
        /// Creates a simple black rectangle the size of the active Game window.
        /// </summary>
        /// <returns>A new image containing the rectangle.</returns>
        static public Image CreateRectangle() {
            return Image.CreateRectangle(Color.Black);
        }

        /// <summary>
        /// Creates a rectangle.
        /// </summary>
        /// <param name="width">The width of the rectangle.</param>
        /// <param name="height">The height of the rectangle.</param>
        /// <returns>A new image containing the rectangle.</returns>
        static public Image CreateRectangle(int width, int height) {
            return CreateRectangle(width, height, Color.White);
        }

        /// <summary>
        /// Creates a rectangle.
        /// </summary>
        /// <param name="size">The width and height of the rectangle.</param>
        /// <returns>A new image containing the rectangle.</returns>
        static public Image CreateRectangle(int size) {
            return CreateRectangle(size, size);
        }

        /// <summary>
        /// Creates a rectangle.
        /// </summary>
        /// <param name="size">The width and height of the rectangle.</param>
        /// <param name="color">The color of the rectangle.</param>
        /// <returns>A new image containing the rectangle.</returns>
        static public Image CreateRectangle(int size, Color color) {
            return CreateRectangle(size, size, color);
        }

        /// <summary>
        /// Create a circle.
        /// </summary>
        /// <param name="radius">The radius of the circle.</param>
        /// <param name="color">The color of the circle.</param>
        /// <returns>A new image containing the circle.</returns>
        static public Image CreateCircle(int radius, Color color) {
            Image img = new Image();

            img.Width = radius * 2;
            img.Height = radius * 2;
            img.Color = color;

            img.radius = radius;

            img.OutlineColor = Color.None;

            img.isCircle = true;
            img.isShape = true;
            img.Batchable = false;

            return img;
        }

        /// <summary>
        /// Create a white circle.
        /// </summary>
        /// <param name="radius">The radius of the circle.</param>
        /// <returns>A new image containing the circle.</returns>
        static public Image CreateCircle(int radius) {
            return CreateCircle(radius, Color.White);
        }

        #endregion

        #region Public Properties

        /// <summary>
        /// Defines which area of the Image to show.
        /// </summary>
        public Rectangle ClippingRegion {
            get {
                return clippingRegion;
            }
            set {
                clippingRegion = value;
                NeedsUpdate = true;
            }
        }

        /// <summary>
        /// Flip the texture coordinates on the X axis.
        /// </summary>
        public bool FlippedX {
            get { return flippedX; }
            set {
                flippedX = value;
                NeedsUpdate = true;
            }
        }

        /// <summary>
        /// Flip the texture coordinates on the Y axis.
        /// </summary>
        public bool FlippedY {
            get { return flippedY; }
            set {
                flippedY = value;
                NeedsUpdate = true;
            }
        }

        /// <summary>
        /// The outline color of the Image (only applies to circles and rectangles.)
        /// </summary>
        public Color OutlineColor {
            get {
                if (outlineColor == null) return Color.None;
                return outlineColor;
            }
            set {
                OutlineColor.Graphic = null;
                outlineColor = value;
                outlineColor.Graphic = this;
                NeedsUpdate = true;
            }
        }

        /// <summary>
        /// The outline thickness of the Image (only applies to circles and rectangles.)
        /// </summary>
        public float OutlineThickness {
            get {
                return outlineThickness;
            }
            set {
                outlineThickness = value;
                NeedsUpdate = true;
            }
        }

        #endregion

        #region Private Fields

        bool flippedX;
        bool flippedY;
        Rectangle clippingRegion;

        protected bool
            flipX = false,
            flipY = false;

        bool isCircle;

        bool isShape;

        // Keep track of radius becuase of outline thickness weirdness.
        int radius;

        // Keep track of shape w and h because of outline thickness weirdness.
        int rectWidth;
        int rectHeight;

        Color outlineColor;
        float outlineThickness;

        #endregion

        #region Constructors

        /// <summary>
        /// Creates a new Image using a filepath to a texture.  
        /// </summary>
        /// <param name="source">The filepath of the texture.</param>
        /// <param name="clip">Where to clip the texture.</param>
        public Image(string source = null) : base() {
            SetTexture(new Texture(source));
            Initialize();
        }

        protected Image() : base() {
            Initialize();
        }

        /// <summary>
        /// Creates a new Image using a Texture.
        /// </summary>
        /// <param name="texture">The Texture to use.</param>
        public Image(Texture texture) : base() {
            SetTexture(texture);
            Initialize();
        }

        /// <summary>
        /// Creates a new Image using an AtlasTexture.
        /// </summary>
        /// <param name="texture">The AtlasTexture to use.</param>
        public Image(AtlasTexture texture) : base() {
            SetTexture(texture);
            Initialize();
        }

        /// <summary>
        /// Creates a new Image using a specified width and height.
        /// </summary>
        /// <param name="width">The width of the Image.</param>
        /// <param name="height">The hight of the Image.</param>
        public Image(int width, int height) : base() {
            Initialize();
            Width = width;
            Height = height;
        }

        #endregion

        #region Private Methods

        void Initialize() {
            Name = "Image";

            // Proper sprite batching coming soon.
            //Batchable = true;

            Width = TextureRegion.Width;
            Height = TextureRegion.Height;

            ClippingRegion = TextureRegion;
        }

        protected override void TextureChanged() {
            base.TextureChanged();

            Width = TextureRegion.Width;
            Height = TextureRegion.Height;

            ClippingRegion = TextureRegion;
        }

        protected override void UpdateDrawable() {
            base.UpdateDrawable();

            if (isCircle) {
                var circle = new SFML.Graphics.CircleShape(radius);
                circle.OutlineThickness = OutlineThickness;
                circle.OutlineColor = OutlineColor.SFMLColor;
                circle.FillColor = Color.SFMLColor;
                circle.SetPointCount((uint)CirclePointCount);
                SFMLDrawable = circle;
                Width = (int)circle.GetLocalBounds().Width;
                Height = (int)circle.GetLocalBounds().Height;
            }
            else {
                if (isShape) {
                    var rect = new SFML.Graphics.RectangleShape(new Vector2f(rectWidth, rectHeight));
                    rect.OutlineColor = OutlineColor.SFMLColor;
                    rect.OutlineThickness = OutlineThickness;
                    rect.FillColor = Color.SFMLColor;
                    SFMLDrawable = rect;
                    Width = (int)rect.GetLocalBounds().Width;
                    Height = (int)rect.GetLocalBounds().Height;
                }
                else {
                    SFMLVertices.Clear();

                    float x1, y1, x2, y2, u1, v1, u2, v2, cx1, cy1, cx2, cy2;

                    cx1 = ClippingRegion.Left;
                    cy1 = ClippingRegion.Top;
                    cx2 = ClippingRegion.Right;
                    cy2 = ClippingRegion.Bottom;

                    x1 = Util.Max(0, cx1);
                    u1 = TextureLeft + x1;

                    if (FlippedX) {
                        u1 = TextureRegion.Width - u1 + TextureLeft + TextureRegion.Left;
                    }

                    y1 = Util.Max(0, cy1);
                    v1 = TextureTop + y1;

                    if (FlippedY) {
                        v1 = TextureRegion.Height - v1 + TextureTop + TextureRegion.Top;
                    }

                    x2 = Util.Min(TextureRegion.Right, cx2);
                    u2 = TextureLeft + x2;

                    if (FlippedX) {
                        u2 = TextureRegion.Width - u2 + TextureLeft + TextureRegion.Left;
                    }

                    y2 = Util.Min(TextureRegion.Bottom, cy2);
                    v2 = TextureTop + y2;

                    if (FlippedY) {
                        v2 = TextureRegion.Height - v2 + TextureTop + TextureRegion.Top;
                    }

                    SFMLVertices.Append(x1, y1, Color, u1, v1);
                    SFMLVertices.Append(x1, y2, Color, u1, v2);
                    SFMLVertices.Append(x2, y2, Color, u2, v2);
                    SFMLVertices.Append(x2, y1, Color, u2, v1);

                    Width = TextureRegion.Width;
                    Height = TextureRegion.Height;
                }
            }
        }

        #endregion

        #region Internal

        internal VertexArray GetVertices() {
            return SFMLVertices;
        }

        #endregion

    }
}