using System.Collections.Generic;
using System.Collections.Immutable;
using System.Drawing;
using System.Linq;
using System.Numerics;

namespace Dashboard.Drawing
{
    /// <summary>
    /// Interface for all drawing extensions.
    /// </summary>
    public interface IDrawExtension
    {
        /// <summary>
        /// Name of this extension.
        /// </summary>
        public string Name { get; }

        public IReadOnlyList<IDrawExtension> Requires { get; }

        /// <summary>
        /// The list of commands this extension defines, if any.
        /// </summary>
        public IReadOnlyList<IDrawCommand> Commands { get; }
    }

    /// <summary>
    /// A simple draw extension.
    /// </summary>
    public class DrawExtension : IDrawExtension
    {
        private readonly List<IDrawCommand> _drawCommands = new List<IDrawCommand>();

        public string Name { get; }

        public IReadOnlyList<IDrawCommand> Commands { get; }

        public IReadOnlyList<IDrawExtension> Requires { get; }

        public DrawExtension(string name, IEnumerable<IDrawExtension>? requires = null)
        {
            Name = name;
            Commands = _drawCommands.AsReadOnly();
            Requires = (requires ?? Enumerable.Empty<IDrawExtension>()).ToImmutableList();
        }

        protected void AddCommand(IDrawCommand command)
        {
            _drawCommands.Add(command);
        }
    }

    public static class DrawExtensionClass
    {
        /// <summary>
        /// Get the draw controller for the given queue.
        /// </summary>
        /// <param name="extension">The extension instance.</param>
        /// <param name="queue">The draw queue.</param>
        /// <returns>The draw controller for this queue.</returns>
        public static IDrawController GetController(this IDrawExtension extension, DrawQueue queue)
        {
            return queue.GetController(extension);
        }

        public static void Point(this DrawQueue queue, Vector3 position, float size, IBrush brush)
        {
            Vector3 radius = new Vector3(size / 2f);
            Box3d bounds = new Box3d(position - radius, position + radius);

            var controller = queue.GetController(DbBaseCommands.Instance);
            controller.EnsureBounds(bounds);
            controller.Write(DbBaseCommands.Instance.DrawPoint, new PointCommandArgs(position, size, brush));
        }
    }
}