using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Input;
using Microsoft.DirectX.DirectInput;

namespace Maelstrom_Engine.Input
{
    /// <summary>
    /// Represents a standard DirectInput controller.
    /// </summary>
    public class NormalGamepad : GamepadDevice
    {
        #region - Variables Fields

        /// <summary>
        /// Maps the first 12 pc gamepad buttons to the matching
        /// bit positions of Microsoft.Xna.Framework.Input.Buttons
        /// </summary>
        private int[] GenericButtonMappings = new int[] { 14, 12, 13, 15, 8, 9, 23, 22, 4, 5, 7, 8 };

        private GamePadState _CurrentState;
        private GamePadState _PreviousState;

        //Device information:
        protected Device _Device;
        protected DeviceCaps _Caps;


        //The current joystick state!
        private JoystickState _JoyState;

        //Used to calculate thumbstick data.
        private const float CENTER = 32767.5f;


        //Is the controller connected?
        private bool _IsConnected = true;

        #endregion

        #region - Initilize NormalGamepad

        public NormalGamepad(Guid gamepadInstanceGuid)
        {
            //Aquire the device and capabilties.
            _Device = new Device(gamepadInstanceGuid);
            _Device.SetDataFormat(DeviceDataFormat.Joystick);
            _Device.Acquire();
            _Caps = _Device.Caps;
        }

        #endregion

        #region - Override LThumbstick Method from GamepadDevice

        public override Vector2 LThumbstick
        {
            get { return _CurrentState.ThumbSticks.Left; }
        }

        #endregion

        #region - Override RThumbstick Method from GamepadDevice

        public override Vector2 RThumbstick
        {
            get { return _CurrentState.ThumbSticks.Right; }
        }

        #endregion

        #region - Override Connected Method from GamepadDevice

        public override bool Connected
        {
            get { return _IsConnected; }
        }

        #endregion

        #region - Override IsButtonDown Method from GamepadDevice

        public override bool IsButtonDown(Buttons button)
        {
            if (_CurrentState.IsButtonDown(button))
                return true;
            else
                return false;
        }

        #endregion

        #region - Override IsButtonUp Method from GamepadDevice

        public override bool IsButtonUp(Buttons button)
        {
            if (_CurrentState.IsButtonUp(button))
                return true;
            else
                return false;
        }

        #endregion

        #region - Override WasButtonHeld Method from GamepadDevice

        public override bool WasButtonHeld(Buttons button)
        {
            if (_CurrentState.IsButtonDown(button) && _PreviousState.IsButtonDown(button))
                return true;
            else
                return false;
        }

        #endregion

        #region - Override WasButtonPressed Method from GamepadDevice

        public override bool WasButtonPressed(Buttons button)
        {
            if (_CurrentState.IsButtonDown(button) && _PreviousState.IsButtonUp(button))
                return true;
            else
                return false;
        }

        #endregion

        #region - Override WasButtonReleased Method from GamepadDevice

        public override bool WasButtonReleased(Buttons button)
        {
            if (_PreviousState.IsButtonDown(button) && _CurrentState.IsButtonUp(button))
                return true;
            else
                return false;
        }

        #endregion

        #region - Override Update Method from GamepadDevice

        public override void Update()
        {

            //Now, if the controller is connected update the states.
            if (Connected)
            {

                #region Is controller connected? Needs a faster implementation eventuallly.
                //Set the device to connected
                _IsConnected = true;
                try
                {
                    _JoyState = _Device.CurrentJoystickState;
                }

                catch (Exception)
                {
                    //If the device errors out, it is no longer connected... error.
                    _IsConnected = false;
                }
                #endregion

                _PreviousState = _CurrentState;
                _CurrentState = GetState();
            }
        }

        #endregion

        #region - Internal Deadzone Set

        private float ApplyDeadzone(float value)
        {
            if (value < 0.01f && value > -0.1f)
                value = 0f;

            return value;
        }

        #endregion

        #region - Take all the info from NormalGamepad and set a knew gamepadstate for generic gamepads

        private GamePadState GetState()
        {
            byte[] btns = _JoyState.GetButtons();

            // Point Of View = DPad
            int pov = _JoyState.GetPointOfView()[0];

            // Map the DirectInput buttons to XNA Buttons enum values
            Buttons padBtns = (Buttons)0;
            int btnCount = Math.Min(_Caps.NumberButtons, 12);
            for (int i = 0; i < btnCount; i++)
            {
                if (btns[i] != 0)
                    padBtns |= (Buttons)(1 << GenericButtonMappings[i]);
            }

            float LeftX = ApplyDeadzone((_JoyState.X - CENTER) / CENTER);
            float LeftY = ApplyDeadzone((_JoyState.Y - CENTER) / CENTER);
            float RightX = ApplyDeadzone((_JoyState.Z - CENTER) / CENTER);
            float RightY = ApplyDeadzone((_JoyState.Rz - CENTER) / CENTER);

            GamePadState _GamepadState =
                  new GamePadState(

                      new GamePadThumbSticks(
                  _Caps.NumberAxes <= 0 ? Vector2.Zero :
                      new Vector2(LeftX, LeftY),
                  _Caps.NumberAxes <= 2 ? Vector2.Zero :
                      new Vector2(RightX, RightY)),

                      new GamePadTriggers(
                  (0 != (int)(Buttons.LeftTrigger & padBtns)) ? 1.0f : 0.0f,
                  (0 != (int)(Buttons.RightTrigger & padBtns)) ? 1.0f : 0.0f),

                  new GamePadButtons(padBtns),
              (pov < 0) ? new GamePadDPad() : new GamePadDPad(
                  (pov > 27000 || pov < 9000) ? ButtonState.Pressed : ButtonState.Released,
                  (9000 < pov && pov < 27000) ? ButtonState.Pressed : ButtonState.Released,
                  (18000 < pov) ? ButtonState.Pressed : ButtonState.Released,
                  (0 < pov && pov < 18000) ? ButtonState.Pressed : ButtonState.Released));

            return _GamepadState;
        }

        #endregion
    }
}