using OpenTK.Input;

namespace RecrownedGTK.Game {
    public interface IState
    {
        /// <summary>
        /// Called when this state is going to be shown.
        /// </summary>
        /// <param name="gameManager">The instance of the game manager that is requesting this.</param>
        /// <returns>True of it's ready to be displayed, false otherwise.</returns>
        bool Shown(GameEngine gameManager);

        /// <summary>
        /// Called on updating the state.
        /// </summary>
        /// <param name="time">The time that has passed since the last update in seconds.</param>
        void Update(double time);

        /// <summary>
        /// Called for rendering things.
        /// </summary>
        /// <param name="time">The time that has elapsed since last rendering in seconds.</param>
        void Render(double time);

        /// <summary>
        /// Called when this state is no longer being displayed.
        /// </summary>
        void Hidden();

        /// <summary>
        /// Called when the game window size is updated.
        /// </summary>
        /// <param name="width">The new width</param>
        /// <param name="height">The new height</param>
        void WindowSizeUpdate(int width, int height);

        /// <summary>
        /// When the game is being requested to be closed.
        /// </summary>
        /// <returns>True if closing is acceptable, or false otherwise.</returns>
        bool CloseRequested();

        /// <summary>
        /// Called every update in the case that there should be a state change.
        /// </summary>
        /// <returns>Another state if ready to change states, or null if not.</returns>
        IState ChangeState();
        
    }
}