#ifndef _XAS_SYNTH_H
#define _XAS_SYNTH_H

#include <stdint.h>
#include <sys/types.h>

#include <xas/object.h>
#include <xas/audio.h>

#define XAS_SYNTH_DEFAULT_GAIN      1.0f
#define XAS_SYNTH_DEFAULT_DUTY      0.5f
#define XAS_SYNTH_DEFAULT_FREQUENCY 2600 /* Hz */

enum xas_synth_type {
    XAS_SYNTH_SINE,
    XAS_SYNTH_SQUARE,
    XAS_SYNTH_TRIANGLE,
    XAS_SYNTH_SAWTOOTH
};

enum xas_synth_state {
    XAS_SYNTH_IDLE,
    XAS_SYNTH_ACTIVE
};

typedef struct _xas_synth xas_synth;

typedef int16_t (*xas_synth_sample_callback)(xas_synth *synth);

struct _xas_synth {
    xas_object obj;

    enum xas_synth_type  type;
    enum xas_synth_state state;

    xas_audio_format format;
    size_t buffer_size;

    xas_synth_sample_callback sample;

    float phase,
          gain,
          duty;

    size_t frequency;
};

xas_synth *xas_synth_new(xas_audio_format format,
                             size_t buffer_size,
                             enum xas_synth_type type);

void xas_synth_destroy(xas_synth *synth);

void xas_synth_set_gain(xas_synth *synth, float gain);

void xas_synth_set_duty(xas_synth *synth, float duty);

void xas_synth_set_frequency(xas_synth *synth, size_t frequency);

void xas_synth_set_type(xas_synth *synth, enum xas_synth_type type);

void xas_synth_start(xas_synth *synth);

void xas_synth_stop(xas_synth *synth);

xas_audio_stream *xas_synth_stream_new(xas_synth *synth);

xas_audio_stream *xas_synth_stream_new_poly(xas_synth **synths,
                                                size_t count);

#endif /* _XAS_SYNTH_H */