/*
 * <unistd.h> overlay for the MontaukOS git port.
 *
 * The Montauk libc's own <unistd.h> is pulled in with #include_next -- this
 * file only ADDS the POSIX calls git expects and the libc does not declare.
 * Keeping them here rather than in the libc is deliberate: each one below is
 * either meaningless on MontaukOS today (there is one user, no groups, no
 * symlinks in the ramdisk) or needs kernel support that does not exist, and a
 * libc declaration would promise more than the system delivers.
 *
 * Implementations in montauk-compat.c, each documented there with what it
 * actually does.
 */
#ifndef _MONTAUK_GIT_UNISTD_H_
#define _MONTAUK_GIT_UNISTD_H_

#include_next <unistd.h>

#include <sys/types.h>

/* Identity. MontaukOS runs everything as the session user; these report a
 * single fixed non-root id so that git's "am I root?" and "does this repo
 * belong to me?" checks answer sensibly (yes, it is mine; no, I am not root). */
uid_t getuid(void);
uid_t geteuid(void);
gid_t getgid(void);
gid_t getegid(void);
pid_t getppid(void);

int gethostname(char *name, size_t len);

/* No interval timers and no SIGALRM delivery, so this arms nothing.
 * upload-pack's idle timeout is its only caller here, and upload-pack cannot
 * run without sockets anyway. */
unsigned int alarm(unsigned int seconds);

/* Symlinks. Neither the ramdisk nor the VFS represents them, so these fail;
 * git falls back to writing a regular file with the link text, which is what
 * core.symlinks=false already asks for. */
int     symlink(const char *target, const char *linkpath);
ssize_t readlink(const char *path, char *buf, size_t bufsiz);
int     link(const char *oldpath, const char *newpath);

/* Ownership. No uid/gid model to change anything to. */
int chown(const char *path, uid_t owner, gid_t group);
int lchown(const char *path, uid_t owner, gid_t group);
int fchown(int fd, uid_t owner, gid_t group);

/* Durability. The kernel writes through its block cache on close; there is no
 * per-descriptor flush syscall, so these report success rather than failing a
 * commit that is in fact on disk. See SYS_FS_SYNC for the whole-filesystem
 * flush that shutdown uses. */
int fsync(int fd);
int fdatasync(int fd);

int setsid(void);

/* Process groups. MontaukOS has none: a process is its own group, and a
 * program reading the terminal is by definition the foreground one. These
 * answer consistently so that progress.c's "am I in the foreground?" test
 * (tcgetpgrp(fd) == getpgid(0)) says yes and the progress meter is drawn. */
pid_t getpgid(pid_t pid);
pid_t getpgrp(void);
pid_t tcgetpgrp(int fd);
int   setpgid(pid_t pid, pid_t pgid);

/* The variadic exec forms. The libc has execv/execvp (both of which fail:
 * MontaukOS spawns rather than execs), so these only repack their arguments
 * and hand them over -- they exist because `git help` calls execlp() to run
 * the man viewer. */
int execl(const char *path, const char *arg, ...);
int execlp(const char *file, const char *arg, ...);

/* Reads a line from the terminal. It CANNOT suppress echo -- see the
 * implementation. compat/terminal.c calls it for every interactive prompt on
 * a platform without /dev/tty, which is what MontaukOS is. */
char *getpass(const char *prompt);

#endif /* _MONTAUK_GIT_UNISTD_H_ */