using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Input;

class InputHelper
{
    /* 
     * current and previous mouse/keyboard states
     */
    MouseState currentMouseState, previousMouseState;
    KeyboardState currentKeyboardState, previousKeyboardState;

    /*
     * time passed since the last key press
     */
    double timeSinceLastKeyPress;

    /*
     * time interval to read separate keypresses when holding a key
     */
    double keyPressInterval;

    /*
     * constructor method
     */
    public InputHelper()
    {
        keyPressInterval = 100;
        timeSinceLastKeyPress = 0;
    }
        
    /*
     * updates the input helper object by updating the mouse and keyboard states and updating the timeSinceLastKeyPress variable
     */
    public void Update(GameTime gameTime)
    {
        // check if keys are pressed and update the timeSinceLastKeyPress variable
        Keys[] prevKeysDown = previousKeyboardState.GetPressedKeys();
        Keys[] currKeysDown = currentKeyboardState.GetPressedKeys();
        if (currKeysDown.Length != 0 && (prevKeysDown.Length == 0 || timeSinceLastKeyPress > keyPressInterval))
            timeSinceLastKeyPress = 0;
        else
            timeSinceLastKeyPress += gameTime.ElapsedGameTime.TotalMilliseconds;

        // update the mouse and keyboard states
        previousMouseState = currentMouseState;
        previousKeyboardState = currentKeyboardState;
        currentMouseState = Mouse.GetState();
        currentKeyboardState = Keyboard.GetState();
    }

    /*
     * returns the current mouse position
     */
    public Vector2 MousePosition
    {
        get { return new Vector2(currentMouseState.X, currentMouseState.Y); }
    }

    /*
     * indicates whether the left mouse button is pressed
     */
    public bool MouseLeftButtonPressed()
    {
        return currentMouseState.LeftButton == ButtonState.Pressed && previousMouseState.LeftButton == ButtonState.Released;
    }

    /*
     * indicates whether the player has pressed the key k in the current update, a key press is detected
     * if either the key wasn't pressed in the previous state, or enough time has passed since the last time the key press
     * was detected
     */
    public bool KeyPressed(Keys k, bool detecthold = true)
    {
        return currentKeyboardState.IsKeyDown(k) && (previousKeyboardState.IsKeyUp(k) || (timeSinceLastKeyPress > keyPressInterval && detecthold));
    }

    /*
     * indicates whether key k is currently down
     */
    public bool IsKeyDown(Keys k)
    {
        return currentKeyboardState.IsKeyDown(k);
    }
}