/* tracker.h — HTTP and UDP tracker clients (BEP-3/BEP-23, BEP-15).
 *
 * Split into pure codec (URL building, bencode response parsing, UDP packet
 * encode/decode — all unit-testable without a socket) and thin blocking fetch
 * helpers used by the swarm app. HTTPS/TLS is deferred to a later transport
 * backend; the built-ins in this phase are plaintext HTTP and UDP.
 */
#ifndef NAUT_TRACKER_H
#define NAUT_TRACKER_H

#include "naut/common.h"

/* IPv4 compact peer (BEP-23). IPv6 (BEP-7) is a later addition. */
typedef struct { uint8_t ip[4]; uint16_t port; } naut_peer_addr;

typedef enum {
    NAUT_TEV_NONE = 0, NAUT_TEV_COMPLETED = 1, NAUT_TEV_STARTED = 2, NAUT_TEV_STOPPED = 3
} naut_tracker_event;   /* values match BEP-15 UDP event codes */

typedef struct {
    uint8_t  info_hash[20];
    uint8_t  peer_id[20];
    uint16_t port;
    uint64_t uploaded, downloaded, left;
    naut_tracker_event event;
    int32_t  numwant;       /* -1 for default */
    uint32_t key;
} naut_announce_req;

typedef struct {
    int32_t         interval;
    int32_t         seeders, leechers;   /* -1 if absent */
    naut_peer_addr *peers;
    size_t          num_peers;
    char           *failure;             /* tracker "failure reason", or NULL */
} naut_tracker_response;

void naut_tracker_response_free(naut_tracker_response *r);

/* --- HTTP --- */
/* Build the full announce GET URL (base?...params) with percent-encoded binary
 * info_hash/peer_id. Returns bytes written (excl NUL) or 0 on overflow. */
size_t naut_tracker_http_url(const char *base, const naut_announce_req *req,
                             char *out, size_t outsz);
/* Parse a bencoded HTTP tracker response body (compact or dict peer list). */
naut_err naut_tracker_parse_http(const uint8_t *body, size_t len,
                                 naut_tracker_response *out);

/* --- UDP (BEP-15): pure packet codec --- */
#define NAUT_UDP_CONNECT_REQ_LEN   16
#define NAUT_UDP_ANNOUNCE_REQ_LEN  98
void     naut_udp_build_connect(uint8_t out[16], uint32_t txid);
naut_err naut_udp_parse_connect(const uint8_t *in, size_t len, uint32_t txid,
                                uint64_t *connection_id);
void     naut_udp_build_announce(uint8_t out[98], uint64_t connection_id,
                                 uint32_t txid, const naut_announce_req *req);
naut_err naut_udp_parse_announce(const uint8_t *in, size_t len, uint32_t txid,
                                 naut_tracker_response *out);

/* --- live fetch helpers (blocking) --- */
/* HTTP GET the announce URL; fills out. Only http:// (no TLS yet). */
naut_err naut_tracker_announce_http(const char *url, naut_tracker_response *out);
/* Full UDP connect+announce handshake against host:port. */
naut_err naut_tracker_announce_udp(const char *host, uint16_t port,
                                   const naut_announce_req *req,
                                   naut_tracker_response *out);

#endif /* NAUT_TRACKER_H */