/// Credit Simon (darkside) Jackson
/// Sourced from - UI SIM source and My Brain

namespace UnityEngine.EventSystems
{
    [AddComponentMenu("Event/Extensions/GamePad Input Module")]
    public class GamePadInputModule : BaseInputModule
    {
        private float m_PrevActionTime;
        Vector2 m_LastMoveVector;
        int m_ConsecutiveMoveCount = 0;

        protected GamePadInputModule()
        {}

        [SerializeField]
        private string m_HorizontalAxis = "Horizontal";

        /// <summary>
        /// Name of the vertical axis for movement (if axis events are used).
        /// </summary>
        [SerializeField]
        private string m_VerticalAxis = "Vertical";

        /// <summary>
        /// Name of the submit button.
        /// </summary>
        [SerializeField]
        private string m_SubmitButton = "Submit";

        /// <summary>
        /// Name of the submit button.
        /// </summary>
        [SerializeField]
        private string m_CancelButton = "Cancel";

        [SerializeField]
        private float m_InputActionsPerSecond = 10;

        [SerializeField]
        private float m_RepeatDelay = 0.1f;

        public float inputActionsPerSecond
        {
            get { return m_InputActionsPerSecond; }
            set { m_InputActionsPerSecond = value; }
        }

        public float repeatDelay
        {
            get { return m_RepeatDelay; }
            set { m_RepeatDelay = value; }
        }

        /// <summary>
        /// Name of the horizontal axis for movement (if axis events are used).
        /// </summary>
        public string horizontalAxis
        {
            get { return m_HorizontalAxis; }
            set { m_HorizontalAxis = value; }
        }

        /// <summary>
        /// Name of the vertical axis for movement (if axis events are used).
        /// </summary>
        public string verticalAxis
        {
            get { return m_VerticalAxis; }
            set { m_VerticalAxis = value; }
        }

        public string submitButton
        {
            get { return m_SubmitButton; }
            set { m_SubmitButton = value; }
        }

        public string cancelButton
        {
            get { return m_CancelButton; }
            set { m_CancelButton = value; }
        }

        public override bool ShouldActivateModule()
        {
            if (!base.ShouldActivateModule())
                return false;

            var shouldActivate = true;
            shouldActivate |= Input.GetButtonDown(m_SubmitButton);
            shouldActivate |= Input.GetButtonDown(m_CancelButton);
            shouldActivate |= !Mathf.Approximately(Input.GetAxisRaw(m_HorizontalAxis), 0.0f);
            shouldActivate |= !Mathf.Approximately(Input.GetAxisRaw(m_VerticalAxis), 0.0f);
            return shouldActivate;
        }

        public override void ActivateModule()
        {
            StandaloneInputModule StandAloneSystem = GetComponent<StandaloneInputModule>();

            if (StandAloneSystem && StandAloneSystem.enabled)
            {
                Debug.LogError("StandAloneInputSystem should not be used with the GamePadInputModule, " +
                    "please remove it from the Event System in this scene or disable it when this module is in use");
            }

            base.ActivateModule();

            var toSelect = eventSystem.currentSelectedGameObject;
            if (toSelect == null)
                toSelect = eventSystem.firstSelectedGameObject;

            eventSystem.SetSelectedGameObject(toSelect, GetBaseEventData());
        }

        public override void DeactivateModule()
        {
            base.DeactivateModule();
        }

        public override void Process()
        {
            bool usedEvent = SendUpdateEventToSelectedObject();

            if (eventSystem.sendNavigationEvents)
            {
                if (!usedEvent)
                    usedEvent |= SendMoveEventToSelectedObject();

                if (!usedEvent)
                    SendSubmitEventToSelectedObject();
            }
        }

        /// <summary>
        /// Process submit keys.
        /// </summary>
        protected bool SendSubmitEventToSelectedObject()
        {
            if (eventSystem.currentSelectedGameObject == null)
                return false;

            var data = GetBaseEventData();
            if (Input.GetButtonDown(m_SubmitButton))
                ExecuteEvents.Execute(eventSystem.currentSelectedGameObject, data, ExecuteEvents.submitHandler);

            if (Input.GetButtonDown(m_CancelButton))
                ExecuteEvents.Execute(eventSystem.currentSelectedGameObject, data, ExecuteEvents.cancelHandler);
            return data.used;
        }

        private Vector2 GetRawMoveVector()
        {
            Vector2 move = Vector2.zero;
            move.x = Input.GetAxisRaw(m_HorizontalAxis);
            move.y = Input.GetAxisRaw(m_VerticalAxis);

            if (Input.GetButtonDown(m_HorizontalAxis))
            {
                if (move.x < 0)
                    move.x = -1f;
                if (move.x > 0)
                    move.x = 1f;
            }
            if (Input.GetButtonDown(m_VerticalAxis))
            {
                if (move.y < 0)
                    move.y = -1f;
                if (move.y > 0)
                    move.y = 1f;
            }
            return move;
        }

        /// <summary>
        /// Process events.
        /// </summary>
        protected bool SendMoveEventToSelectedObject()
        {
            float time = Time.unscaledTime;

            Vector2 movement = GetRawMoveVector();
            if (Mathf.Approximately(movement.x, 0f) && Mathf.Approximately(movement.y, 0f))
            {
                m_ConsecutiveMoveCount = 0;
                return false;
            }

            // If user pressed key again, always allow event
            bool allow = Input.GetButtonDown(m_HorizontalAxis) || Input.GetButtonDown(m_VerticalAxis);
            bool similarDir = (Vector2.Dot(movement, m_LastMoveVector) > 0);
            if (!allow)
            {
                // Otherwise, user held down key or axis.
                // If direction didn't change at least 90 degrees, wait for delay before allowing consequtive event.
                if (similarDir && m_ConsecutiveMoveCount == 1)
                    allow = (time > m_PrevActionTime + m_RepeatDelay);
                // If direction changed at least 90 degree, or we already had the delay, repeat at repeat rate.
                else
                    allow = (time > m_PrevActionTime + 1f / m_InputActionsPerSecond);
            }
            if (!allow)
                return false;

            var axisEventData = GetAxisEventData(movement.x, movement.y, 0.6f);
            ExecuteEvents.Execute(eventSystem.currentSelectedGameObject, axisEventData, ExecuteEvents.moveHandler);
            if (!similarDir)
                m_ConsecutiveMoveCount = 0;
            m_ConsecutiveMoveCount++;
            m_PrevActionTime = time;
            m_LastMoveVector = movement;
            return axisEventData.used;
        }

        protected bool SendUpdateEventToSelectedObject()
        {
            if (eventSystem.currentSelectedGameObject == null)
                return false;

            var data = GetBaseEventData();
            ExecuteEvents.Execute(eventSystem.currentSelectedGameObject, data, ExecuteEvents.updateSelectedHandler);
            return data.used;
        }
    }
}
