/*
    NEWLIB syscall implementations

    Copyright (c) 2021 Earle F. Philhower, III <earlephilhower@yahoo.com>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

#include <Arduino.h>
#include <stdint.h>
#include <errno.h>
#include <_syslist.h>
#include <sys/times.h>
#include <sys/unistd.h>
#include <pico/stdlib.h>
#include <pico/multicore.h>

#undef errno


// TODO - check the fd, create a VFS, etc.

extern "C" int errno;

extern "C"
__attribute((weak))
ssize_t _write(int fd, const void *buf, size_t count) {
#if defined DEBUG_RP2040_PORT
    (void) fd;
    return DEBUG_RP2040_PORT.write((const char *)buf, count);
#else
    (void) fd;
    (void) buf;
    (void) count;
    return 0;
#endif
}

extern "C"
__attribute((weak))
int _chown(const char *path, uid_t owner, gid_t group) {
    (void) path;
    (void) owner;
    (void) group;
    errno = ENOSYS;
    return -1;
}

extern "C"
__attribute((weak))
int _close(int fd) {
    (void) fd;
    errno = ENOSYS;
    return -1;
}

extern "C" int _execve(char  *name, char **argv, char **env) {
    (void) name;
    (void) argv;
    (void) env;
    errno = ENOSYS;
    return -1;
}

extern "C" int _fork(void) {
    errno = ENOSYS;
    return -1;
}

extern "C"
__attribute((weak))
int _fstat(int fd, struct stat *st) {
    (void) fd;
    (void) st;
    errno = ENOSYS;
    return -1;
}

extern "C" int _getpid(void) {
    errno = ENOSYS;
    return -1;
}

static int64_t __timedelta_us = 0.0;

extern "C" int _gettimeofday(struct timeval *tv, void *tz) {
    (void) tz;
    uint64_t now_us = to_us_since_boot(get_absolute_time()) + __timedelta_us;
    if (tv) {
        tv->tv_sec = now_us / 1'000'000L;
        tv->tv_usec = now_us % 1'000'000L;
    }
    return 0;
}

extern "C" int settimeofday(const struct timeval *tv, const struct timezone *tz) {
    (void) tz;
    uint64_t now_us = to_us_since_boot(get_absolute_time());
    if (tv) {
        uint64_t newnow_us;
        newnow_us = tv->tv_sec * 1'000'000L;
        newnow_us += tv->tv_usec;
        __timedelta_us = newnow_us - now_us;
    }
    return 0;
}

// For NTP
extern "C" void __setSystemTime(unsigned long long sec, unsigned long usec) {
    uint64_t now_us = to_us_since_boot(get_absolute_time());
    uint64_t newnow_us = sec * 1'000'000LL + usec;
    __timedelta_us = newnow_us - now_us;
}

extern "C"
__attribute((weak))
int _isatty(int file) {
    (void) file;
    errno = ENOSYS;
    return 0;
}

extern "C" int _kill(int pid, int sig) {
    (void) pid;
    (void) sig;
    errno = ENOSYS;
    return -1;
}

extern "C"
__attribute((weak))
int _link(char *existing, char *newlink) {
    (void) existing;
    (void) newlink;
    errno = ENOSYS;
    return -1;
}

extern "C"
__attribute((weak))
int _lseek(int   file, int   ptr, int   dir) {
    (void) file;
    (void) ptr;
    (void) dir;
    errno = ENOSYS;
    return -1;
}

extern "C"
__attribute((weak))
int _open(char *file, int   flags, int   mode) {
    (void) file;
    (void) flags;
    (void) mode;
    errno = ENOSYS;
    return -1;
}

extern "C"
__attribute((weak))
int _read(int   file, char *ptr, int   len) {
    (void) file;
    (void) ptr;
    (void) len;
    //    return Serial.read(ptr, len);
    return -1;
}

extern "C"
__attribute((weak))
int _readlink(const char *path, char *buf, size_t bufsize) {
    (void) path;
    (void) buf;
    (void) bufsize;
    errno = ENOSYS;
    return -1;
}

extern "C"
__attribute((weak))
int _stat(const char  *file, struct stat *st) {
    (void) file;
    (void) st;
    errno = ENOSYS;
    return -1;
}

extern "C"
__attribute((weak))
int _symlink(const char *path1, const char *path2) {
    (void) path1;
    (void) path2;
    errno = ENOSYS;
    return -1;
}

extern "C" clock_t _times(struct tms *buf) {
    (void) buf;
    errno = ENOSYS;
    return -1;
}

extern "C"
__attribute((weak))
int _unlink(char *name) {
    (void) name;
    errno = ENOSYS;
    return -1;
}

extern "C" int _wait(int  *status) {
    (void) status;
    errno = ENOSYS;
    return -1;
}