#ifndef _GLSCALIBRATION_HPP
#define _GLSCALIBRATION_HPP
/*-------------------------------------------------------------------------
 * drawElements Quality Program OpenGL (ES) Module
 * -----------------------------------------------
 *
 * Copyright 2014 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 *//*!
 * \file
 * \brief Calibration tools.
 *//*--------------------------------------------------------------------*/

#include "tcuDefs.hpp"
#include "tcuTestCase.hpp"
#include "tcuTestLog.hpp"
#include "tcuVector.hpp"
#include "gluRenderContext.hpp"

#include <limits>

namespace deqp
{
namespace gls
{

struct LineParameters
{
	float offset;
	float coefficient;

	LineParameters (float offset_, float coefficient_) : offset(offset_), coefficient(coefficient_) {}
};

// Basic Theil-Sen linear estimate. Calculates median of all possible slope coefficients through two of the data points
// and median of offsets corresponding with the median slope
LineParameters theilSenLinearRegression (const std::vector<tcu::Vec2>& dataPoints);

struct LineParametersWithConfidence
{
	float offset;
	float offsetConfidenceUpper;
	float offsetConfidenceLower;

	float coefficient;
	float coefficientConfidenceUpper;
	float coefficientConfidenceLower;

	float confidence;
};

// Median-of-medians version of Theil-Sen estimate. Calculates median of medians of slopes through a point and all other points.
// Confidence interval is given as the range that contains the given fraction of all slopes/offsets
LineParametersWithConfidence theilSenSiegelLinearRegression (const std::vector<tcu::Vec2>& dataPoints, float reportedConfidence);

struct MeasureState
{
	MeasureState (void)
		: maxNumFrames			(0)
		, frameShortcutTime		(std::numeric_limits<float>::infinity())
		, numDrawCalls			(0)
	{
	}

	void		clear				(void);
	void		start				(int maxNumFrames, float frameShortcutTime, int numDrawCalls);

	bool		isDone				(void) const;
	deUint64	getTotalTime		(void) const;

	int						maxNumFrames;
	float					frameShortcutTime;
	int						numDrawCalls;
	std::vector<deUint64>	frameTimes;
};

struct CalibrateIteration
{
	CalibrateIteration (int numDrawCalls_, float frameTime_)
		: numDrawCalls	(numDrawCalls_)
		, frameTime		(frameTime_)
	{
	}

	CalibrateIteration (void)
		: numDrawCalls	(0)
		, frameTime		(0.0f)
	{
	}

	int		numDrawCalls;
	float	frameTime;
};

struct CalibratorParameters
{
	CalibratorParameters (int		numInitialCalls_,
						  int		maxCalibrateIterationFrames_,			//!< Maximum (and default) number of frames per one calibrate iteration.
						  float		calibrateIterationShortcutThresholdMs_,	//!< If the times of two consecutive frames exceed this, stop the iteration even if maxCalibrateIterationFrames isn't reached.
						  int		maxCalibrateIterations_,
						  float		targetFrameTimeMs_,
						  float		frameTimeCapMs_,
						  float		targetMeasureDurationMs_)
		: numInitialCalls						(numInitialCalls_)
		, maxCalibrateIterationFrames			(maxCalibrateIterationFrames_)
		, calibrateIterationShortcutThreshold	(1000.0f*calibrateIterationShortcutThresholdMs_)
		, maxCalibrateIterations				(maxCalibrateIterations_)
		, targetFrameTimeUs						(1000.0f*targetFrameTimeMs_)
		, frameTimeCapUs						(1000.0f*frameTimeCapMs_)
		, targetMeasureDurationUs				(1000.0f*targetMeasureDurationMs_)
	{
	}

	int		numInitialCalls;
	int		maxCalibrateIterationFrames;
	float	calibrateIterationShortcutThreshold;
	int		maxCalibrateIterations;
	float	targetFrameTimeUs;
	float	frameTimeCapUs;
	float	targetMeasureDurationUs;
};

class TheilSenCalibrator
{
public:
	enum State
	{
		STATE_RECOMPUTE_PARAMS = 0,
		STATE_MEASURE,
		STATE_FINISHED,

		STATE_LAST
	};

											TheilSenCalibrator		(void);
											TheilSenCalibrator		(const CalibratorParameters& params);
											~TheilSenCalibrator		(void);

	void									clear					(void);
	void									clear					(const CalibratorParameters& params);

	State									getState				(void) const;
	int										getCallCount			(void) const { return m_measureState.numDrawCalls;	}

	// Should be called when getState() returns STATE_RECOMPUTE_PARAMS
	void									recomputeParameters		(void);

	// Should be called when getState() returns STATE_MEASURE
	void									recordIteration			(deUint64 frameTime);

	const CalibratorParameters&				getParameters			(void) const { return m_params;					}
	const MeasureState&						getMeasureState			(void) const { return m_measureState;			}
	const std::vector<CalibrateIteration>&	getCalibrationInfo		(void) const { return m_calibrateIterations;	}

private:
	enum InternalState
	{
		INTERNALSTATE_CALIBRATING = 0,
		INTERNALSTATE_RUNNING,
		INTERNALSTATE_FINISHED,

		INTERNALSTATE_LAST
	};

	CalibratorParameters					m_params;

	InternalState							m_state;
	MeasureState							m_measureState;

	std::vector<CalibrateIteration>			m_calibrateIterations;
};

void logCalibrationInfo (tcu::TestLog& log, const TheilSenCalibrator& calibrator);

} // gls
} // deqp

#endif // _GLSCALIBRATION_HPP