#ifndef CST_NET_H
#define CST_NET_H

/* Minimal TCP sockets for the embedded HTTP server (src/net.c).
 *
 * The point of this layer is that src/http_srv.c and src/webui.c never
 * include a socket header: Unix file descriptors and Windows SOCKETs differ
 * in type, close() and error reporting, and Windows needs WSAStartup before
 * anything works. */

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

#ifdef __cplusplus
extern "C" {
#endif

#ifdef _WIN32
typedef intptr_t os_socket_t;
#define OS_SOCKET_BAD ((os_socket_t)-1)
#else
typedef int os_socket_t;
#define OS_SOCKET_BAD (-1)
#endif

/* Longest "address:port" os_net_peer writes (IPv6 hosts are bracketed so a
 * URL built from it stays unambiguous). */
#define OS_NET_ADDR_MAX 64

/* Winsock startup (no-op on Unix, which also ignores SIGPIPE so a client
 * that hangs up cannot kill the process). 0 / -1. */
int os_net_init(void);
void os_net_cleanup(void);

/* Bind and listen on host:port. host may be NULL/"" (then "127.0.0.1"),
 * "0.0.0.0"/"::" (every interface) or any literal address / name; port 0
 * picks a free one. Returns the listening socket, or OS_SOCKET_BAD with a
 * short reason in err. */
os_socket_t os_net_listen(const char *host, int port, char *err, size_t err_sz);
/* The port actually bound (0 when unknown). */
int os_net_port(os_socket_t s);
/* A one-line "host:port" for messages. */
void os_net_peer(os_socket_t s, char *out, size_t out_sz);

/* Connect to host:port, waiting up to timeout_ms: the socket, or
 * OS_SOCKET_BAD. Used by the tests and by anything that drives the WebUI
 * API from inside the process. */
os_socket_t os_net_connect(const char *host, int port, int timeout_ms);

/* Accept one connection, waiting up to timeout_ms (<0 = forever).
 * Returns the socket, OS_SOCKET_BAD on error, or OS_SOCKET_BAD with
 * *timed_out set when the wait ran out. */
os_socket_t os_net_accept(os_socket_t s, int timeout_ms, int *timed_out);

/* Read at most n bytes, waiting up to timeout_ms: bytes read, 0 at EOF,
 * -1 on error, -2 when nothing arrived in time. */
long os_net_recv(os_socket_t s, void *buf, size_t n, int timeout_ms);
/* Write everything (timeout_ms per call): 0 / -1. */
int os_net_send_all(os_socket_t s, const void *buf, size_t n, int timeout_ms);
/* Wake up a thread blocked in recv/send on this socket (shutdown, no close). */
void os_net_shutdown(os_socket_t s);
void os_net_close(os_socket_t s);

#ifdef __cplusplus
}
#endif

#endif /* CST_NET_H */