#ifndef OMNI_PROTOCOL_H
#define OMNI_PROTOCOL_H

#include "omni_common.h"

#ifdef __cplusplus
extern "C" {
#endif

typedef enum message_type {
    MSG_TYPE_TEXT = 0,
    MSG_TYPE_FILE = 1,
    MSG_TYPE_REGISTER = 2,
    MSG_TYPE_ERROR = 3,
    MSG_TYPE_BINARY = 4,
    MSG_TYPE_INVALID = 255
} message_type_t;

#define SERVER_PEER_ID "server"

typedef struct message {
    message_type_t type;
    uint64_t id;
    char from[OMNI_MAX_PEER_ID];
    char to[OMNI_MAX_PEER_ID];
    char file_name[OMNI_MAX_FILE_NAME];
    uint8_t *body;
    size_t body_len;
} message_t;

typedef struct protocol_frame_decoder {
    uint8_t *buffer;
    size_t len;
    size_t cap;
} protocol_frame_decoder_t;

const char *protocol_message_type_name(message_type_t type);
int protocol_message_type_from_name(const char *raw, message_type_t *out);

void protocol_message_init(message_t *msg);
void protocol_message_clear(message_t *msg);
int protocol_message_copy(message_t *dst, const message_t *src);

int protocol_validate_message(const message_t *msg, char *err, size_t err_len);

int protocol_encode_message_datagram(const message_t *msg, uint8_t **out, size_t *out_len);
int protocol_decode_message_datagram(const uint8_t *data, size_t data_len, message_t *out_msg, char *err, size_t err_len);

int protocol_encode_message_stream(const message_t *msg, uint8_t **out, size_t *out_len);
int protocol_decode_message_stream_payload(const uint8_t *payload, size_t payload_len, message_t *out_msg, char *err, size_t err_len);

void protocol_frame_decoder_init(protocol_frame_decoder_t *decoder);
void protocol_frame_decoder_reset(protocol_frame_decoder_t *decoder);
void protocol_frame_decoder_destroy(protocol_frame_decoder_t *decoder);
int protocol_frame_decoder_feed(protocol_frame_decoder_t *decoder, const uint8_t *data, size_t data_len);
int protocol_frame_decoder_next(protocol_frame_decoder_t *decoder, uint8_t **payload, size_t *payload_len);

#ifdef __cplusplus
}
#endif

#endif