#ifndef IMU_SENSOR_H
#define IMU_SENSOR_H

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

#include "imu/imu_calibration.h"
#include "imu/imu_sample.h"

typedef enum {
	IMU_SENSOR_NONE = 0,
	IMU_SENSOR_TDK_ICM42688,
	IMU_SENSOR_ST_LSM6DSOX,
	IMU_SENSOR_BACKEND_COUNT
} imu_sensor_backend_t;

typedef struct {
	/* Zero selects the active backend's safe default.  A non-zero target may
	 * be quantized to a nearby hardware ODR; diagnostics reports both values. */
	uint32_t odr_hz;
	unsigned int accel_full_scale_g;
	unsigned int gyro_full_scale_dps;
	/* Auto-detected devices must never share board-specific calibration. */
	imu_calibration_t calibration_by_backend[IMU_SENSOR_BACKEND_COUNT];
} imu_sensor_config_t;

typedef struct {
	uint64_t irq_count;
	uint64_t sample_count;
	uint64_t invalid_sample_count;
	uint64_t spurious_irq_count;
	uint64_t queue_overflow_count;
	uint64_t estimated_missed_sample_count;
	uint64_t last_timestamp_ticks;
	uint32_t requested_odr_hz;
	uint32_t configured_odr_hz;
	uint8_t who_am_i;
	imu_sensor_backend_t backend;
	bool initialized;
	bool running;
	bool foreground_polling;
} imu_sensor_diagnostics_t;

void imu_sensor_default_config(imu_sensor_config_t* config);

/* Probe the compiled backend(s), select one, validate the requested ODR/range
 * and prepare calibration.  This does not enable data-ready interrupts. */
bool imu_sensor_init(const imu_sensor_config_t* config);

/* Configure streaming and enable BSP_PMOD_IRQ.  The application must attach
 * imu_sensor_irq_handler to the active machine-interrupt router first. */
bool imu_sensor_start(void);
void imu_sensor_stop(void);

/* PLIC/ISR half: read and timestamp one raw sample, then enqueue it. */
void imu_sensor_irq_handler(void);

/* Foreground half. Safe no-op for the current interrupt-driven backends. */
void imu_sensor_service(void);
bool imu_sensor_requires_foreground_service(void);

/* Pop the oldest sample, convert to SI/common axes and apply the selected
 * backend's calibration.  No averaging or motion decision occurs here. */
bool imu_sensor_take_measurement(imu_sample_t* measurement_out);
void imu_sensor_get_diagnostics(imu_sensor_diagnostics_t* diagnostics_out);
imu_sensor_backend_t imu_sensor_active_backend(void);
const char* imu_sensor_backend_name(imu_sensor_backend_t backend);
#endif