/* Прямой stream-протокол: канонический big-endian заголовок, пути и подписанный END.
 * IDs ETCP определены только в etcp_api.h. Указатели parser заимствованы до освобождения кодограммы. */
#ifndef STREAM_WIRE_H
#define STREAM_WIRE_H

#include "stream_proto.h"
#include "stream_metrics.h"

#ifdef __cplusplus
extern "C" {
#endif

#define STREAM_WIRE_VERSION 4
#define STREAM_WIRE_HEADER 52
#define STREAM_PATH_MAX 32
#define STREAM_END_SIZE 106
#define STREAM_METRIC_WIRE_SIZE 49
#define STREAM_INFO_METRIC_OFF 36
#define STREAM_INFO_OFFER_OFF (STREAM_INFO_METRIC_OFF + STREAM_METRIC_WIRE_SIZE)
#define STREAM_INFO_PATH_OFF (STREAM_INFO_OFFER_OFF + 25)
#define STREAM_INFO_SIZE (STREAM_INFO_PATH_OFF + 1) /* probe:8, границы/FEC:28, метрики:49, предложение:25, count:1 */
#define STREAM_OVERLOAD_MAX 64
#define STREAM_OVERLOAD_HEADER 18

enum stream_command {
    STREAM_CMD_INFO_REQ = 1, STREAM_CMD_INFO_RESP, STREAM_CMD_SUBSCRIBE, STREAM_CMD_ACCEPT,
    STREAM_CMD_REJECT, STREAM_CMD_RENEW, STREAM_CMD_UNSUBSCRIBE, STREAM_CMD_CLOSED,
    STREAM_CMD_DATA, STREAM_CMD_GAP, STREAM_CMD_END, STREAM_CMD_REVERSE_REQ, STREAM_CMD_OVERLOAD, STREAM_CMD_OVERLOAD_SELECT,
    STREAM_CMD_RELAY_REQUEST, STREAM_CMD_RELAY_STATUS, STREAM_CMD_RELAY_CANCEL
};
/* Routed помощь: handle — nonce запроса; эпохи запроса/сервиса независимы от raw ETCP-сессии. */
enum stream_relay_status { STREAM_RELAY_STARTING = 1, STREAM_RELAY_READY, STREAM_RELAY_BOUND,
                           STREAM_RELAY_REJECTED, STREAM_RELAY_ENDED, STREAM_RELAY_CANCELLED };
enum stream_reject {
    STREAM_REASON_STOPPED = 1, STREAM_REASON_POSITION, STREAM_REASON_EXPIRED, STREAM_REASON_STALE,
    STREAM_REASON_CONFLICT, STREAM_REASON_LIMIT, STREAM_REASON_LOOP, STREAM_REASON_TRANSPORT,
    STREAM_REASON_LEASE, STREAM_REASON_MEMBER, STREAM_REASON_PROTOCOL, STREAM_REASON_OVERLOAD
};
struct stream_path { uint64_t nodes[STREAM_PATH_MAX]; uint8_t count; };
struct stream_message {
    struct stream_descriptor descriptor;
    uint64_t sender_epoch, receiver_epoch, handle;
    uint8_t command, subblock;
    const uint8_t *payload;
    size_t length;
};

/* Проверяет размер, версию, ненулевые ключи/epoch и известный command; payload разбирает диспетчер. */
int stream_wire_parse(const uint8_t *wire, size_t length, struct stream_message *message);
void stream_wire_header(uint8_t *wire, const struct stream_message *message);
/* Путь без нулей/повторов, начинается источником и заканчивается отправителем; forbidden не входит в него. */
int stream_path_validate(const struct stream_path *path, uint64_t source, uint64_t sender, uint64_t forbidden);
int stream_path_parse(const uint8_t *wire, size_t length, struct stream_path *path, size_t *used);
size_t stream_path_write(uint8_t *wire, const struct stream_path *path);
void stream_metric_write(uint8_t *wire, const struct stream_metric_snapshot *snapshot, int valid);
int stream_metric_read(const uint8_t *wire, struct stream_metric_snapshot *snapshot, int *valid);
int stream_end_sign(const struct stream_descriptor *descriptor, uint64_t last, const uint8_t key[32], uint8_t wire[STREAM_END_SIZE]);
int stream_end_verify(const struct stream_descriptor *descriptor, const uint8_t key[32], const uint8_t *wire, size_t length,
                      uint64_t *last);
#ifdef __cplusplus
}
#endif
#endif