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

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, Vector2 position, float depth, float size, IBrush brush)
        {
            Vector2 radius = new Vector2(0.5f * size);
            Box2d bounds = new Box2d(position - radius, position + radius);

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

        public static void Line(this DrawQueue queue, Vector2 start, Vector2 end, float depth, float size, IBrush brush)
        {
            Vector2 radius = new Vector2(size / 2f);
            Vector2 min = Vector2.Min(start, end) - radius;
            Vector2 max = Vector2.Max(start, end) + radius;
            Box2d bounds = new Box2d(min, max);

            IDrawController controller = queue.GetController(DbBaseCommands.Instance);
            controller.EnsureBounds(bounds, depth);
            controller.Write(DbBaseCommands.Instance.DrawLine, new LineCommandArgs(start, end, depth, size, brush));
        }

        public static void Rect(this DrawQueue queue, Vector2 start, Vector2 end, float depth, IBrush fillBrush)
        {
            IDrawController controller = queue.GetController(DbBaseCommands.Instance);
            Vector2 min = Vector2.Min(start, end);
            Vector2 max = Vector2.Max(start, end);
            controller.EnsureBounds(new Box2d(min, max), depth);
            controller.Write(DbBaseCommands.Instance.DrawRectF, new RectCommandArgs(start, end, depth, fillBrush));
        }

        public static void Rect(this DrawQueue queue, Vector2 start, Vector2 end, float depth, IBrush strikeBrush, float strikeSize,
            BorderKind kind = BorderKind.Center)
        {
            IDrawController controller = queue.GetController(DbBaseCommands.Instance);
            Vector2 min = Vector2.Min(start, end);
            Vector2 max = Vector2.Max(start, end);
            controller.EnsureBounds(new Box2d(min, max), depth);
            controller.Write(DbBaseCommands.Instance.DrawRectF, new RectCommandArgs(start, end, depth, strikeBrush, strikeSize, kind));
        }

        public static void Rect(this DrawQueue queue, Vector2 start, Vector2 end, float depth,  IBrush fillBrush, IBrush strikeBrush,
            float strikeSize, BorderKind kind = BorderKind.Center)
        {
            IDrawController controller = queue.GetController(DbBaseCommands.Instance);
            Vector2 min = Vector2.Min(start, end);
            Vector2 max = Vector2.Max(start, end);
            controller.EnsureBounds(new Box2d(min, max), depth);
            controller.Write(DbBaseCommands.Instance.DrawRectF, new RectCommandArgs(start, end, depth, fillBrush, strikeBrush, strikeSize, kind));
        }

        public static void Text(this DrawQueue queue, Vector3 position, IBrush brush, string text, IFont font,
            Anchor anchor = Anchor.Left)
        {
            IDrawController controller = queue.GetController(DbBaseCommands.Instance);
            controller.EnsureBounds(new Box2d(position.X, position.Y, position.X, position.Y), position.Z);
            controller.Write(TextExtension.Instance.TextCommand, new TextCommandArgs(font, brush, anchor, position, text));
        }

        public static void Text(this DrawQueue queue, Vector3 position, IBrush textBrush, IBrush borderBrush,
            float borderRadius, string text, IFont font, Anchor anchor = Anchor.Left, BorderKind borderKind = BorderKind.Outset)
        {
            IDrawController controller = queue.GetController(DbBaseCommands.Instance);
            controller.EnsureBounds(new Box2d(position.X, position.Y, position.X, position.Y), position.Z);
            controller.Write(TextExtension.Instance.TextCommand, new TextCommandArgs(font, textBrush, anchor, position, text)
            {
                BorderBrush = borderBrush,
                BorderRadius = borderRadius,
                BorderKind = borderKind,
            });
        }
    }
}