#ifndef LAYER1_TX_H
#define LAYER1_TX_H

#include <complex.h>

#include <stddef.h>
#include <stdint.h>

#include "results.h"
#include "transmission.h"
#include "packet_mod.h"

typedef struct
{
	float complex *samples;
	size_t         samples_allocated;
	size_t         samples_used;

	float carrier_frequency_offset;

	transmission_ctx_t transmission;
	packet_mod_ctx_t   pmod;
} layer1_tx_t;


/*!
 * \brief Initialize the transmitter.
 *
 * \param tx    Pointer to the transmitter context.
 * \returns     The result of the initialization.
 */
result_t layer1_tx_init(layer1_tx_t *tx);


/*!
 * \brief Shut the transmitter down. Frees all memory.
 *
 * \param tx    Pointer to the transmitter context.
 * \returns     The result of the shutdown.
 */
result_t layer1_tx_shutdown(layer1_tx_t *tx);


/*!
 * \brief Reset the transmitter.
 *
 * Logically removes all internal data, but does not free memory.
 *
 * \param tx    Pointer to the transmitter context.
 * \returns     The result of the reset.
 */
result_t layer1_tx_reset(layer1_tx_t *tx);


/*!
 * \brief Add a packet to the burst.
 *
 * Encodes the raw data, modulates it, applies pulse filtering and appends the
 * result to the internal buffer.
 *
 * If the buffer is empty (after init or reset), it first generates a ramp-up
 * sequence.
 *
 * You can add arbitrarily many packets, the only limit is the available memory.
 *
 * \param tx      Pointer to the transmitter context.
 * \param data    Pointer to the packet’s raw data.
 * \param length  The number of bytes in the data array.
 * \returns       The result of the operation.
 */
result_t layer1_tx_add_packet_to_burst(layer1_tx_t *tx, const uint8_t *data, size_t length);


/*!
 * \brief Generate the ramp-down sequence.
 *
 * The burst is considered complete after calling this function. You should
 * retrieve the generated samples and call \ref layer1_tx_reset() before adding
 * further packets.
 *
 * \param tx    Pointer to the transmitter context.
 * \returns     The result of the finalization.
 */
result_t layer1_tx_finalize_burst(layer1_tx_t *tx);


/*!
 * \brief Retrieve the number of generated samples.
 *
 * \param tx    Pointer to the transmitter context.
 * \returns     The number of samples returned by \ref layer1_tx_get_sample_data().
 */
size_t layer1_tx_get_sample_count(const layer1_tx_t *tx);

/*!
 * \brief Retrieve the generated samples.
 *
 * Calling this after \ref layer1_tx_finalize_burst() returns the complete burst ready for transmission.
 *
 * \param tx    Pointer to the transmitter context.
 * \returns     A pointer to the generated samples.
 */
const float complex* layer1_tx_get_sample_data(const layer1_tx_t *tx);

/*!
 * \brief Set the carrier frequency correction in the RRC-filtered domain.
 *
 * The carrier frequency is measured in radians per sample in the RRC-filtered baseband domain, i.e. the sampling rate is SYMBOL_RATE * RRC_SPS.
 *
 * \param tx    Pointer to the transmitter context.
 * \param freq  The carrier frequency offset to use.
 */
void layer1_tx_set_carrier_frequency_offset(layer1_tx_t *tx, float freq);

#endif // LAYER1_TX_H