namespace Pilz.UI
{
    public class PaintingObjectLayering
    {
        public PaintingObject PaintingObject { get; private set; }

        /// <summary>
    /// Get the current object list from the painting object.
    /// </summary>
    /// <returns>Returns the current object list from the painting object.</returns>
        public PaintingObjectList ObjectList
        {
            get
            {
                return PaintingObject.Parent.PaintingObjects;
            }
        }

        /// <summary>
    /// Create a new instance of object layer managing.
    /// </summary>
    /// <param name="obj"></param>
        public PaintingObjectLayering(PaintingObject obj)
        {
            PaintingObject = obj;
        }

        /// <summary>
    /// Moves the object by the given number of indicies.
    /// </summary>
    /// <param name="count">The number how many objects it should be moved.</param>
        public void MoveObject(int count)
        {
            int oldIndex = ObjectList.IndexOf(PaintingObject);
            int newIndex = oldIndex + count;
            MoveObjectTo(newIndex);
        }

        /// <summary>
    /// Moves the object to the new index.
    /// </summary>
    /// <param name="newIndex"></param>
        public void MoveObjectTo(int newIndex)
        {
            var list = ObjectList;

            // Check & make index valid
            if (newIndex >= ObjectList.Count)
            {
                newIndex = ObjectList.Count - 1;
            }
            else if (newIndex < 0)
            {
                newIndex = 0;
            }

            // Remove object
            list.Remove(PaintingObject);

            // Insert object at new index
            list.Insert(newIndex, PaintingObject);

            // Order all objects again
            list.Layering.OrderAll();
        }

        /// <summary>
    /// Moves the object to the front.
    /// </summary>
        public void BringToTop()
        {
            MoveObjectTo(ObjectList.Count - 1);
        }

        /// <summary>
    /// Moves the object to the back.
    /// </summary>
        public void SendToBack()
        {
            MoveObjectTo(0);
        }

        /// <summary>
    /// Moves the object fordward by one
    /// </summary>
        public void OneToTop()
        {
            MoveObject(+1);
        }

        /// <summary>
    /// Moves the object backward by one
    /// </summary>
        public void OneToBack()
        {
            MoveObject(-1);
        }
    }
}