/*
	Copyright 2016 - 2019 Benjamin Vedder	benjamin@vedder.se

	This file is part of the VESC firmware.

	The VESC firmware is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    The VESC firmware is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
    */

#ifndef UTILS_H_
#define UTILS_H_

#include <stdbool.h>
#include <stdint.h>
#include "datatypes.h"

void utils_step_towards(float *value, float goal, float step);
float utils_calc_ratio(float low, float high, float val);
void utils_norm_angle(float *angle);
void utils_norm_angle_rad(float *angle);
int utils_truncate_number(float *number, float min, float max);
int utils_truncate_number_int(int *number, int min, int max);
int utils_truncate_number_abs(float *number, float max);
float utils_map(float x, float in_min, float in_max, float out_min, float out_max);
int utils_map_int(int x, int in_min, int in_max, int out_min, int out_max);
void utils_deadband(float *value, float tres, float max);
float utils_angle_difference(float angle1, float angle2);
float utils_angle_difference_rad(float angle1, float angle2);
float utils_avg_angles_rad_fast(float *angles, float *weights, int angles_num);
float utils_middle_of_3(float a, float b, float c);
int utils_middle_of_3_int(int a, int b, int c);
float utils_fast_inv_sqrt(float x);
float utils_fast_atan2(float y, float x);
bool utils_saturate_vector_2d(float *x, float *y, float max);
void utils_fast_sincos(float angle, float *sin, float *cos);
void utils_fast_sincos_better(float angle, float *sin, float *cos);
float utils_min_abs(float va, float vb);
float utils_max_abs(float va, float vb);
void utils_byte_to_binary(int x, char *b);
float utils_throttle_curve(float val, float curve_acc, float curve_brake, int mode);
void utils_sys_lock_cnt(void);
void utils_sys_unlock_cnt(void);
uint32_t utils_crc32c(uint8_t *data, uint32_t len);
void utils_fft32_bin0(float *real_in, float *real, float *imag);
void utils_fft32_bin1(float *real_in, float *real, float *imag);
void utils_fft32_bin2(float *real_in, float *real, float *imag);
void utils_fft16_bin0(float *real_in, float *real, float *imag);
void utils_fft16_bin1(float *real_in, float *real, float *imag);
void utils_fft16_bin2(float *real_in, float *real, float *imag);
void utils_fft8_bin0(float *real_in, float *real, float *imag);
void utils_fft8_bin1(float *real_in, float *real, float *imag);
void utils_fft8_bin2(float *real_in, float *real, float *imag);
uint8_t utils_second_motor_id(void);
int utils_read_hall(bool is_second_motor, int samples);
float utils_batt_liion_norm_v_to_capacity(float norm_v);
uint16_t utils_median_filter_uint16_run(uint16_t *buffer,
		unsigned int *buffer_index, unsigned int filter_len, uint16_t sample);
const char* utils_hw_type_to_string(HW_TYPE hw);

// Return the sign of the argument. -1 if negative, 1 if zero or positive.
#define SIGN(x)				((x < 0) ? -1 : 1)

// Squared
#define SQ(x)				((x) * (x))

// Return the age of a timestamp in seconds
#define UTILS_AGE_S(x)		((float)chVTTimeElapsedSinceX(x) / (float)CH_CFG_ST_FREQUENCY)

// nan and infinity check for floats
#define UTILS_IS_INF(x)		((x) == (1.0 / 0.0) || (x) == (-1.0 / 0.0))
#define UTILS_IS_NAN(x)		((x) != (x))
#define UTILS_NAN_ZERO(x)	(x = UTILS_IS_NAN(x) ? 0.0 : x)

// Handy conversions for radians/degrees and RPM/radians-per-second
#define DEG2RAD_f(deg) ((deg) * (float)(M_PI / 180.0))
#define RAD2DEG_f(rad) ((rad) * (float)(180.0 / M_PI))
#define RPM2RADPS_f(rpm) ((rpm) * (float)((2.0 * M_PI) / 60.0))
#define RADPS2RPM_f(rad_per_sec) ((rad_per_sec) * (float)(60.0 / (2.0 * M_PI)))




/**
 * A simple low pass filter.
 *
 * @param value
 * The filtered value.
 *
 * @param sample
 * Next sample.
 *
 * @param filter_constant
 * Filter constant. Range 0.0 to 1.0, where 1.0 gives the unfiltered value.
 */
#define UTILS_LP_FAST(value, sample, filter_constant)	(value -= (filter_constant) * ((value) - (sample)))

/**
 * A fast approximation of a moving average filter with N samples. See
 * https://en.wikipedia.org/wiki/Moving_average#Exponential_moving_average
 * https://en.wikipedia.org/wiki/Exponential_smoothing
 *
 * It is not entirely the same as it behaves like an IIR filter rather than a FIR filter, but takes
 * much less memory and is much faster to run.
 */
#define UTILS_LP_MOVING_AVG_APPROX(value, sample, N)	UTILS_LP_FAST(value, sample, 2.0 / ((N) + 1.0))

// Constants
#define ONE_BY_SQRT3			(0.57735026919)
#define TWO_BY_SQRT3			(2.0f * 0.57735026919)
#define SQRT3_BY_2				(0.86602540378)
#define COS_30_DEG				(0.86602540378)
#define SIN_30_DEG				(0.5)
#define COS_MINUS_30_DEG		(0.86602540378)
#define SIN_MINUS_30_DEG		(-0.5)

// Tables
extern const float utils_tab_sin_32_1[];
extern const float utils_tab_sin_32_2[];
extern const float utils_tab_cos_32_1[];
extern const float utils_tab_cos_32_2[];

#endif /* UTILS_H_ */