using System.Collections.Generic;
using SlimDX;
using SlimDX.DirectInput;

namespace BizHawk.MultiClient
{
    public static class KeyInput
    {
        private static DirectInput dinput;
        private static Keyboard keyboard;
        private static KeyboardState state = new KeyboardState();
        private static List<Key> unpressedKeys = new List<Key>();

        public static void Initialize()
        {
            if (dinput == null)
                dinput = new DirectInput();

            if (keyboard == null || keyboard.Disposed)
                keyboard = new Keyboard(dinput);

            keyboard.SetCooperativeLevel(Global.MainForm.Handle, CooperativeLevel.Foreground | CooperativeLevel.Nonexclusive);
        }

        public static void Update()
        {
            if (keyboard.Acquire().IsFailure)
                return;
            if (keyboard.Poll().IsFailure)
                return;

            state = keyboard.GetCurrentState();
            if (Result.Last.IsFailure)
                return;

            unpressedKeys.RemoveAll(key => state.IsReleased(key));
        }

        public static KeyboardState State { get { return state; } }

        public static void Unpress(Key key)
        {
            if (unpressedKeys.Contains(key))
                return;
            unpressedKeys.Add(key);
        }

        public static bool IsPressed(Key key)
        {
            if (unpressedKeys.Contains(key))
                return false;
            if (state.IsPressed(key)) 
                return true;
            if (key == Key.UpArrow && state.IsPressed(Key.NumberPad8))
                return true;
            if (key == Key.DownArrow && state.IsPressed(Key.NumberPad2))
                return true;
            if (key == Key.LeftArrow && state.IsPressed(Key.NumberPad4))
                return true;
            if (key == Key.RightArrow && state.IsPressed(Key.NumberPad6))
                return true;
            return false;
        }

        public static Key? GetPressedKey()
        {
            // TODO uhh this will return the same key over and over though.
            if (state.PressedKeys.Count == 0)
                return null;
            if (state.PressedKeys[0] == Key.NumberPad8)
                return Key.UpArrow;
            if (state.PressedKeys[0] == Key.NumberPad2)
                return Key.DownArrow;
            if (state.PressedKeys[0] == Key.NumberPad4)
                return Key.LeftArrow;
            if (state.PressedKeys[0] == Key.NumberPad6)
                return Key.RightArrow;
            return state.PressedKeys[0];
        }
    }
}