#ifndef GAINPUTINPUTDEVICEBUILTINANDROID_H_
#define GAINPUTINPUTDEVICEBUILTINANDROID_H_

#include <android/sensor.h>

namespace gainput
{

class InputDeviceBuiltInImplAndroid : public InputDeviceBuiltInImpl
{
public:
	InputDeviceBuiltInImplAndroid(InputManager& manager, InputDevice& device, unsigned index, InputState& state, InputState& previousState) :
		manager_(manager),
		device_(device),
		state_(state),
		previousState_(previousState),
		deviceState_(InputDevice::DS_UNAVAILABLE),
		buttonDialect_(manager_.GetAllocator()),
		sensorManager_(0),
		accelerometerSensor_(0),
		gyroscopeSensor_(0),
		sensorEventQueue_(0),
		gravityInitialized_(false)
	{
		ALooper* looper = ALooper_forThread();
		if (!looper)
		{
			looper = ALooper_prepare(ALOOPER_PREPARE_ALLOW_NON_CALLBACKS);
		}

		if (!looper)
		{
			return;
		}

		sensorManager_ = ASensorManager_getInstance();
		if (!sensorManager_)
		{
			return;
		}

		sensorEventQueue_ = ASensorManager_createEventQueue(sensorManager_, looper, ALOOPER_POLL_CALLBACK, NULL, NULL);
		if (!sensorEventQueue_)
		{
			return;
		}

		accelerometerSensor_ = ASensorManager_getDefaultSensor(sensorManager_, ASENSOR_TYPE_ACCELEROMETER);
		if (accelerometerSensor_)
		{
			ASensorEventQueue_setEventRate(sensorEventQueue_, accelerometerSensor_, ASensor_getMinDelay(accelerometerSensor_));
			ASensorEventQueue_enableSensor(sensorEventQueue_, accelerometerSensor_);
		}

		gyroscopeSensor_ = ASensorManager_getDefaultSensor(sensorManager_, ASENSOR_TYPE_GYROSCOPE);
		if (gyroscopeSensor_)
		{
			ASensorEventQueue_setEventRate(sensorEventQueue_, gyroscopeSensor_, ASensor_getMinDelay(gyroscopeSensor_));
			ASensorEventQueue_enableSensor(sensorEventQueue_, gyroscopeSensor_);
		}

		magneticFieldSensor_ = ASensorManager_getDefaultSensor(sensorManager_, ASENSOR_TYPE_MAGNETIC_FIELD);
		if (magneticFieldSensor_)
		{
			ASensorEventQueue_setEventRate(sensorEventQueue_, magneticFieldSensor_, ASensor_getMinDelay(magneticFieldSensor_));
			ASensorEventQueue_enableSensor(sensorEventQueue_, magneticFieldSensor_);
		}

		deviceState_ = InputDevice::DS_OK;
	}

	~InputDeviceBuiltInImplAndroid()
	{
		if (!sensorManager_)
		{
			return;
		}

		if (!sensorEventQueue_)
		{
			return;
		}


		if (accelerometerSensor_)
		{
			ASensorEventQueue_disableSensor(sensorEventQueue_, accelerometerSensor_);
		}

		if (gyroscopeSensor_)
		{
			ASensorEventQueue_disableSensor(sensorEventQueue_, gyroscopeSensor_);
		}

		if (magneticFieldSensor_)
		{
			ASensorEventQueue_disableSensor(sensorEventQueue_, magneticFieldSensor_);
		}

		ASensorManager_destroyEventQueue(sensorManager_, sensorEventQueue_);
	}

	InputDevice::DeviceVariant GetVariant() const
	{
		return InputDevice::DV_STANDARD;
	}

	void Update(InputDeltaState* delta)
	{
		ASensorEvent event;

		while (ASensorEventQueue_getEvents(sensorEventQueue_, &event, 1) > 0)
		{
			if (event.type == ASENSOR_TYPE_ACCELEROMETER)
			{
				// https://developer.android.com/reference/android/hardware/SensorEvent.html#values
				static const float kAlpha = 0.8f;

				if (!gravityInitialized_)
				{
					gravity_[0] = event.acceleration.x / ASENSOR_STANDARD_GRAVITY;
					gravity_[1] = event.acceleration.y / ASENSOR_STANDARD_GRAVITY;
					gravity_[2] = event.acceleration.z / ASENSOR_STANDARD_GRAVITY;
					gravityInitialized_ = true;
				}

				gravity_[0] = kAlpha * gravity_[0] + (1.0f - kAlpha) * (event.acceleration.x / ASENSOR_STANDARD_GRAVITY);
				gravity_[1] = kAlpha * gravity_[1] + (1.0f - kAlpha) * (event.acceleration.y / ASENSOR_STANDARD_GRAVITY);
				gravity_[2] = kAlpha * gravity_[2] + (1.0f - kAlpha) * (event.acceleration.z / ASENSOR_STANDARD_GRAVITY);

				float accel[3];
				accel[0] = (event.acceleration.x / ASENSOR_STANDARD_GRAVITY) - gravity_[0];
				accel[1] = (event.acceleration.y / ASENSOR_STANDARD_GRAVITY) - gravity_[1];
				accel[2] = (event.acceleration.z / ASENSOR_STANDARD_GRAVITY) - gravity_[2];

				HandleAxis(device_, state_, delta, BuiltInButtonGravityX, gravity_[0]);
				HandleAxis(device_, state_, delta, BuiltInButtonGravityY, gravity_[1]);
				HandleAxis(device_, state_, delta, BuiltInButtonGravityZ, gravity_[2]);
				HandleAxis(device_, state_, delta, BuiltInButtonAccelerationX, accel[0]);
				HandleAxis(device_, state_, delta, BuiltInButtonAccelerationY, accel[1]);
				HandleAxis(device_, state_, delta, BuiltInButtonAccelerationZ, accel[2]);
			}
			else if (event.type == ASENSOR_TYPE_GYROSCOPE)
			{
				HandleAxis(device_, state_, delta, BuiltInButtonGyroscopeX, event.vector.x / ASENSOR_STANDARD_GRAVITY);
				HandleAxis(device_, state_, delta, BuiltInButtonGyroscopeY, event.vector.y / ASENSOR_STANDARD_GRAVITY);
				HandleAxis(device_, state_, delta, BuiltInButtonGyroscopeZ, event.vector.z / ASENSOR_STANDARD_GRAVITY);
			}
			else if (event.type == ASENSOR_TYPE_MAGNETIC_FIELD)
			{
				HandleAxis(device_, state_, delta, BuiltInButtonMagneticFieldX, event.magnetic.x / ASENSOR_MAGNETIC_FIELD_EARTH_MAX);
				HandleAxis(device_, state_, delta, BuiltInButtonMagneticFieldY, event.magnetic.y / ASENSOR_MAGNETIC_FIELD_EARTH_MAX);
				HandleAxis(device_, state_, delta, BuiltInButtonMagneticFieldZ, event.magnetic.z / ASENSOR_MAGNETIC_FIELD_EARTH_MAX);
			}
		}
	}

	InputDevice::DeviceState GetState() const
	{
		return deviceState_;
	}

	bool IsValidButton(DeviceButtonId deviceButton) const
	{
		if (deviceButton <= BuiltInButtonAccelerationZ && accelerometerSensor_)
		{
			return true;
		}
		
		if (deviceButton >= BuiltInButtonGyroscopeX && deviceButton <= BuiltInButtonGyroscopeZ && gyroscopeSensor_)
		{
			return true;
		}

		if (deviceButton >= BuiltInButtonMagneticFieldX && deviceButton <= BuiltInButtonMagneticFieldZ && magneticFieldSensor_)
		{
			return true;
		}

		return false;
	}

private:
	InputManager& manager_;
	InputDevice& device_;
	InputState& state_;
	InputState& previousState_;
	InputDevice::DeviceState deviceState_;
	HashMap<unsigned, DeviceButtonId> buttonDialect_;
	ASensorManager* sensorManager_;
	const ASensor* accelerometerSensor_;
	const ASensor* gyroscopeSensor_;
	const ASensor* magneticFieldSensor_;
	ASensorEventQueue* sensorEventQueue_;
	float gravity_[3];
	bool gravityInitialized_;
};

}

#endif