#ifndef __DSSS_DEMOD_H__
#define __DSSS_DEMOD_H__

#define DSSS_GOLD_CODE_LENGTH   ((1<<DSSS_GOLD_CODE_NBITS) - 1)
#define DSSS_GOLD_CODE_COUNT    ((1<<DSSS_GOLD_CODE_NBITS) + 1)
#define DSSS_CORRELATION_LENGTH (DSSS_GOLD_CODE_LENGTH * DSSS_DECIMATION)

struct iir_biquad {
    float a[2];
    float b[3];
};

struct iir_biquad_state {
    float reg[2];
};

struct cwt_iir_filter_state {
    struct iir_biquad_state st[3];
};

struct dsss_demod_state {
    float signal[DSSS_CORRELATION_LENGTH];
    size_t signal_wpos;

    float correlation[DSSS_GOLD_CODE_COUNT][DSSS_WAVELET_LUT_SIZE];
    size_t correlation_wpos;

    struct cwt_iir_filter_state cwt_filter[DSSS_GOLD_CODE_COUNT];

    struct {
        int len; /* length of group in samples */
        float max; /* signed value of largest peak in group on any channel */
        int max_idx; /* position of above peak counted from start of group */
        int max_ch; /* channel (gold sequence index) of above peak */
    } group;
};

#ifdef SIMULATION
void dsss_demod_step(struct dsss_demod_state *st, float new_value, size_t sim_pos, int record_channel);
#else /* SIMULATION */
void dsss_demod_step(struct dsss_demod_state *st, float new_value);
#endif /* SIMULATION */

#endif /* __DSSS_DEMOD_H__ */