using System;
using UnityEngine;
using Valve.VR;
using UnityEngine.Events;

public class InputController : MonoBehaviour {
    public UnityEvent OnWakeUp; 

    ulong actionSetHandle = 0;
    ulong actionHandle = 0;

    private void Start() {
        OpenVRUtil.System.InitOpenVR();

        var error = OpenVR.Input.SetActionManifestPath(Application.streamingAssetsPath + "/SteamVR/actions.json");
        if (error != EVRInputError.None) {
            throw new Exception("Failed to set action manifest path: " + error);
        }

        error = OpenVR.Input.GetActionSetHandle("/actions/Watch", ref actionSetHandle);
        if (error != EVRInputError.None) {
            throw new Exception("Failed to get action set /actions/Watch: " + error);
        }

        error = OpenVR.Input.GetActionHandle($"/actions/Watch/in/WakeUp", ref actionHandle);
        if (error != EVRInputError.None) {
            throw new Exception("Faild to get action /actions/Watch/in/WakeUp: " + error);
        }
    }

    private void Update() {
        // Action set list to update
        var actionSetList = new VRActiveActionSet_t[] {
            // This time, Watch action only.
            new VRActiveActionSet_t() {
                // Pass Watch action set handle
                ulActionSet =  actionSetHandle,
                ulRestrictedToDevice = OpenVR.k_ulInvalidInputValueHandle,
            }
        };

        var activeActionSize = (uint)System.Runtime.InteropServices.Marshal.SizeOf(typeof(VRActiveActionSet_t));
        var error = OpenVR.Input.UpdateActionState(actionSetList, activeActionSize);
        if (error != EVRInputError.None) {
            throw new Exception("Failed to update action state: " + error);
        }

        var result = new InputDigitalActionData_t();
        var digitalActionSize = (uint)System.Runtime.InteropServices.Marshal.SizeOf(typeof(InputDigitalActionData_t));
        error = OpenVR.Input.GetDigitalActionData(actionHandle, ref result, digitalActionSize, OpenVR.k_ulInvalidInputValueHandle);
        if (error != EVRInputError.None) {
            throw new Exception("Failed to get WakeUp action data: " + error);
        }

        if (result.bState && result.bChanged) {
            OnWakeUp.Invoke();
        }
    }

    private void Destroy() {
        OpenVRUtil.System.ShutdownOpenVR();
    }
}