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

#include "platform.h"

#include "common/axis.h"
#include "common/maths.h"

#include "drivers/accgyro_common.h"
#include "flight_common.h"
#include "sensors_common.h"
#include "statusindicator.h"
#include "boardalignment.h"

#include "sensors_gyro.h"

uint16_t calibratingG = 0;
uint16_t acc_1G = 256;          // this is the 1G measured acceleration.
gyro_t gyro;                      // gyro access functions
sensor_align_e gyroAlign = 0;

void gyroSetCalibrationCycles(uint16_t calibrationCyclesRequired)
{
    calibratingG = calibrationCyclesRequired;
}

bool isGyroCalibrationComplete(void)
{
    return calibratingG == 0;
}

bool isOnFinalGyroCalibrationCycle(void)
{
    return calibratingG == 1;
}

bool isOnFirstGyroCalibrationCycle(void)
{
    return calibratingG == CALIBRATING_GYRO_CYCLES;
}

static void performAcclerationCalibration(uint8_t gyroMovementCalibrationThreshold)
{
    int8_t axis;
    static int32_t g[3];
    static stdev_t var[3];

    for (axis = 0; axis < 3; axis++) {

        // Reset g[axis] at start of calibration
        if (isOnFirstGyroCalibrationCycle()) {
            g[axis] = 0;
            devClear(&var[axis]);
        }

        // Sum up CALIBRATING_GYRO_CYCLES readings
        g[axis] += gyroADC[axis];
        devPush(&var[axis], gyroADC[axis]);

        // Reset global variables to prevent other code from using un-calibrated data
        gyroADC[axis] = 0;
        gyroZero[axis] = 0;

        if (isOnFinalGyroCalibrationCycle()) {
            float dev = devStandardDeviation(&var[axis]);
            // check deviation and startover if idiot was moving the model
            if (gyroMovementCalibrationThreshold && dev > gyroMovementCalibrationThreshold) {
                gyroSetCalibrationCycles(CALIBRATING_GYRO_CYCLES);
                return;
            }
            gyroZero[axis] = (g[axis] + (CALIBRATING_GYRO_CYCLES / 2)) / CALIBRATING_GYRO_CYCLES;
            blinkLedAndSoundBeeper(10, 15, 1);
        }
    }
    calibratingG--;
}

static void applyGyroZero(void)
{
    int8_t axis;
    for (axis = 0; axis < 3; axis++) {
        gyroADC[axis] -= gyroZero[axis];
    }
}

void gyroGetADC(uint8_t gyroMovementCalibrationThreshold)
{
    // range: +/- 8192; +/- 2000 deg/sec
    gyro.read(gyroADC);
    alignSensors(gyroADC, gyroADC, gyroAlign);

    if (!isGyroCalibrationComplete()) {
        performAcclerationCalibration(gyroMovementCalibrationThreshold);
    }

    applyGyroZero();
}