using Core.Input;
using TowerDefense.UI.HUD;
using State = TowerDefense.UI.HUD.EndlessGameUI.State;

namespace TowerDefense.UI
{
    /// <summary>
    /// TD Specific input switcher that also disables controls when the game is paused
    /// PVE 无尽模式使用
    /// </summary>
    public class EndlessTowerDefenseInputSchemeSwitcher : InputSchemeSwitcher
    {
        /// <summary>
        /// Gets whether the game is in a paused state
        /// </summary>
        public bool isPaused
        {
            get { return EndlessGameUI.instance.state == State.Paused; }
        }

        /// <summary>
        /// Register GameUI's stateChanged event
        /// </summary>
        protected virtual void Start()
        {
            if (EndlessGameUI.instanceExists)
                EndlessGameUI.instance.stateChanged += OnUIStateChanged;
        }

        /// <summary>
        /// Do nothing when game is paused
        /// </summary>
        protected override void Update()
        {
            if (isPaused)
                return;

            base.Update();
        }

        /// <summary>
        /// Unregister from GameUI's stateChanged event
        /// </summary>
        protected virtual void OnDestroy()
        {
            if (EndlessGameUI.instanceExists)
                EndlessGameUI.instance.stateChanged -= OnUIStateChanged;
        }

        /// <summary>
        /// Activate or deactivate the current input scheme when the game pauses/unpauses
        /// </summary>
        void OnUIStateChanged(State oldState, State newState)
        {
            if (m_CurrentScheme == null)
                return;

            if (newState == State.Paused)
                m_CurrentScheme.Deactivate(null);
            else
                m_CurrentScheme.Activate(null);
        }
    }
}