using System.Text;
using FarseerPhysics.Dynamics;
using FarseerPhysics.Factories;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;

namespace FarseerPhysics.SamplesFramework
{
    internal class SimpleDemo8 : PhysicsGameScreen, IDemoScreen
    {
        private Border _border;
        private Body[] _circle = new Body[6];
        private Sprite _circleSprite;

        #region IDemoScreen Members

        public string GetTitle()
        {
            return "Restitution";
        }

        public string GetDetails()
        {
            StringBuilder sb = new StringBuilder();
            sb.AppendLine("This demo shows several bodys with varying restitution.");
            sb.AppendLine(string.Empty);
            sb.AppendLine("GamePad:");
            sb.AppendLine("  - Move cursor: left thumbstick");
            sb.AppendLine("  - Grab object (beneath cursor): A button");
            sb.AppendLine("  - Drag grabbed object: left thumbstick");
            sb.AppendLine("  - Exit to menu: Back button");
            sb.AppendLine(string.Empty);
            sb.AppendLine("Keyboard:");
            sb.AppendLine("  - Exit to menu: Escape");
            sb.AppendLine(string.Empty);
            sb.AppendLine("Mouse / Touchscreen");
            sb.AppendLine("  - Grab object (beneath cursor): Left click");
            sb.AppendLine("  - Drag grabbed object: move mouse / finger");
            return sb.ToString();
        }

        #endregion

        public override void LoadContent()
        {
            base.LoadContent();

            World.Gravity = new Vector2(0f, 20f);

            _border = new Border(World, this, ScreenManager.GraphicsDevice.Viewport);

            Vector2 _position = new Vector2(-15f, -8f);
            float _restitution = 0f;

            for (int i = 0; i < 6; ++i)
            {
                _circle[i] = BodyFactory.CreateCircle(World, 1.5f, 1f, _position);
                _circle[i].BodyType = BodyType.Dynamic;
                _circle[i].Restitution = _restitution;
                _position.X += 6f;
                _restitution += 0.2f;
            }

            // create sprite based on body
            _circleSprite = new Sprite(ScreenManager.Assets.TextureFromShape(_circle[0].FixtureList[0].Shape,
                                                                             MaterialType.Waves,
                                                                             Color.Brown, 1f));
        }

        public override void Draw(GameTime gameTime)
        {
            ScreenManager.SpriteBatch.Begin(0, null, null, null, null, null, Camera.View);
            for (int i = 0; i < 6; ++i)
            {
                ScreenManager.SpriteBatch.Draw(_circleSprite.Texture, ConvertUnits.ToDisplayUnits(_circle[i].Position),
                                               null,
                                               Color.White, _circle[i].Rotation, _circleSprite.Origin, 1f,
                                               SpriteEffects.None, 0f);
            }
            ScreenManager.SpriteBatch.End();
            _border.Draw();
            base.Draw(gameTime);
        }
    }
}