// Copyright (c) 2021 Christoffer Lerno. All rights reserved.
// Use of this source code is governed by the MIT license
// a copy of which can be found in the LICENSE_STDLIB file.
module libc;
// stdlib


// Constants need to be per os/arch
const int EXIT_FAILURE = 1;
const int EXIT_SUCCESS = 0;
const int RAND_MAX = 0x7fffffff;

struct DivResult
{
    int quot;
    int rem;
}

struct LongDivResult
{
    long quot;
    long rem;
}



fn Errno errno()
{
    $if (env::OS_TYPE == OsType.WIN32):
        return (Errno)windows::errno();
    $elif (env::OS_TYPE == OsType.MACOSX):
        return (Errno)macos::errno();
    $elif (env::OS_TYPE == OsType.LINUX):
        return (Errno)linux::errno();
    $else:
        return errno::ENOTRECOVERABLE;
    $endif;
}


define TerminateFunction = fn void();
define CompareFunction = fn int(void*, void*);
extern fn double atof(char* str);
extern fn int atoi(char* str);
extern fn CLongLong atoll(char* str);
extern fn double strtod(char* str, char** endptr);
extern fn CLong strtol(char* str, char** endptr, int base);
extern fn CULong stroul(char* str, char** endptr, int base);
extern fn void abort();
extern fn void atexit(TerminateFunction f);
extern fn void exit(int status);
extern fn char* getenv(char* name);
extern fn int system(char* str);
extern fn void bsearch(void* key, void *base, usize items, usize size, CompareFunction compare);
extern fn void qsort(void* base, usize items, usize size, CompareFunction compare);
extern fn int abs(int x);
extern fn DivResult div(int numer, int denom);
extern fn long labs(long x);
extern fn LongDivResult ldiv(long number, long denom);
extern fn int rand();
extern fn void srand(uint seed);

// MB functions omitted

// string
extern fn void* memchr(void* str, int c, usize n);
extern fn int memcmp(void* str1, void* str2, usize n);
extern fn void* memcpy(void* dest, void* src, usize n);
extern fn void* memmove(void* dest, void* src, usize n);
extern fn void* memset(void* dest, usize n);
extern fn char* strcat(char* dest, char* src);
extern fn char* strncat(char* dest, char* src, usize n);
extern fn char* strchr(char* str, int c);
extern fn int strcmp(char* str1, char* str2);
extern fn int strncmp(char* str1, char* str2, usize n);
extern fn int strcoll(char* str1, char* str2);
extern fn char* strcpy(char* dst, char* src);
extern fn char* strncpy(char* dst, char* src, usize n);
extern fn usize strcspn(char* str1, char* str2);
extern fn char* strerror(int errn);
extern fn usize strlen(char* str);
extern fn char* strpbrk(char* str1, char* str2);
extern fn usize strspn(char* str1, char* str2);
extern fn char* strstr(char* haystack, char* needle);
extern fn char* strtok(char* str, char* delim);
extern fn usize strxfrm(char* dest, char* src, usize n);

// malloc
extern fn void* malloc(usize size);
extern fn void* calloc(usize count, usize size);
extern fn void* free(void*);
extern fn void* realloc(void* ptr, usize size);

// stdio

define Fpos = long;
define CFile = void*;

$switch (env::OS_TYPE):
$case OsType.LINUX:
    extern CFile __stdin @extname("stdin");
    extern CFile __stdout @extname("stdout");
    extern CFile __stderr @extname("stderr");
    extern fn usize malloc_usable_size(void* ptr);
    macro usize malloc_size(void* ptr) { return malloc_usable_size(ptr); }
	extern fn void* aligned_alloc(usize align, usize size);
    macro CFile stdin() { return __stdin; }
    macro CFile stdout() { return __stdout; }
    macro CFile stderr() { return __stderr; }
$case OsType.MACOSX:
    extern CFile __stdinp;
    extern CFile __stdoutp;
    extern CFile __stderrp;
    extern fn usize malloc_size(void* ptr);
    extern fn void* aligned_alloc(usize align, usize size);
	macro CFile stdin() { return __stdinp; }
    macro CFile stdout() { return __stdoutp; }
    macro CFile stderr() { return __stderrp; }
$case OsType.WIN32:
    extern fn CFile __acrt_iob_func(CInt c);
    extern fn usize _msize(void* ptr);
    macro usize malloc_size(void* ptr) { return _msize(ptr); }
    macro CFile stdin() { return __acrt_iob_func(0); }
    macro CFile stdout() { return __acrt_iob_func(1); }
    macro CFile stderr() { return __acrt_iob_func(2); }
$default:
    macro CFile stdin() { return (CFile*)(uptr)0; }
    macro CFile stdout() { return (CFile*)(uptr)1; }
    macro CFile stderr() { return (CFile*)(uptr)2; }
$endswitch;

const HAS_MALLOC_SIZE =
	env::OS_TYPE == OsType.LINUX
	|| env::OS_TYPE == OsType.WIN32
	|| env::OS_TYPE == OsType.MACOSX;

// The following needs to be set per arch+os
// For now I have simply pulled the defaults from MacOS
const int SEEK_SET = 0;
const int SEEK_CUR = 1;
const int SEEK_END = 2;
const int _IOFBF = 0; // Fully buffered
const int _IOLBF = 1; // Line buffered
const int _IONBF = 2; // Unbuffered
const int BUFSIZ = 1024;
const int EOF = -1;
const int FOPEN_MAX = 20;
const int FILENAME_MAX = 1024;

define Errno = distinct CInt;
define SeekIndex = CLong;

extern fn int fclose(CFile stream);
extern fn void clearerr(CFile stream);
extern fn int feof(CFile stream);
extern fn int ferror(CFile stream);
extern fn int fflush(CFile stream);
extern fn int fgetpos(CFile stream, Fpos* pos);
extern fn CFile fopen(char* filename, char* mode);
extern fn usize fread(void* ptr, usize size, usize nmemb, CFile stream);
extern fn CFile freopen(char* filename, char* mode, CFile stream);
extern fn int fseek(CFile stream, SeekIndex offset, int whence);
extern fn int fsetpos(CFile stream, Fpos* pos);
extern fn SeekIndex ftell(CFile stream);
extern fn usize fwrite(void* ptr, usize size, usize nmemb, CFile stream);
extern fn int remove(char* filename);
extern fn int rename(char* old_name, char* new_name);
extern fn void rewind(CFile stream);
extern fn void setbuf(CFile stream, char* buffer);
extern fn void setvbuf(CFile stream, char* buffer, int mode, usize size);
extern fn CFile tmpnam(char* str);
extern fn int fprintf(CFile stream, char* format, ...);
extern fn int printf(char* format, ...);
extern fn int sprintf(char* str, char* format, ...);
extern fn int snprintf(char* str, usize size, char* format, ...);
extern fn int fscanf(CFile stream, char* format, ...);
extern fn int scanf(char* format, ...);
extern fn int sscanf(char* str, char* format, ...);
extern fn int fgetc(CFile stream);
extern fn char* fgets(char* str, int n, CFile stream);
extern fn int fputc(int c, CFile stream);
extern fn int getc(CFile stream);
extern fn int getchar();
extern fn int putc(char c, CFile stream);
extern fn int putchar(int c);
extern fn int puts(char* str);
extern fn int ungetc(int c, CFile stream);
extern fn void perror(char* str);
extern fn isize getline(char** linep, usize* linecapp, CFile stream);

// vsprintf vprintf not supported

// time.h

define TimeOffset = CLong;

struct Tm
{
	int	tm_sec;		/* seconds after the minute [0-60] */
	int	tm_min;		/* minutes after the hour [0-59] */
	int	tm_hour;	/* hours since midnight [0-23] */
	int	tm_mday;	/* day of the month [1-31] */
	int	tm_mon;		/* months since January [0-11] */
	int	tm_year;	/* years since 1900 */
	int	tm_wday;	/* days since Sunday [0-6] */
	int	tm_yday;	/* days since January 1 [0-365] */
	int	tm_isdst;	/* Daylight Savings Time flag */
	TimeOffset tm_gmtoff;	/* offset from UTC in seconds */
    char *tm_zone;	/* timezone abbreviation */
}

// Likely wrong, must be per platform.
const CLOCKS_PER_SEC = 1000000;

// Time also needs to be per platform
define Time = long;
define Clock = ulong;

extern fn char* asctime(Tm *timeptr);
extern fn Clock clock();
extern fn char* ctime(Time *timer);
extern fn double difftime(Time time1, Time time2);
extern fn Tm* gmtime(Time *timer);
extern fn Tm* localtime(Time *timer);
extern fn Time mktime(Tm *timeptr);
extern fn usize strftime(char* str, usize maxsize, char* format, Tm *timeptr);
extern fn Time time(Time *timer);

// signal
define SignalFunction = fn void(int);
extern fn SignalFunction signal(int sig, SignalFunction function);
// Incomplete

module libc::errno;

const Errno EPERM = 1;  /* Operation not permitted */
const Errno ENOENT = 2;  /* No such file or directory */
const Errno ESRCH = 3;  /* No such process */
const Errno EINTR = 4;  /* Interrupted system call */
const Errno EIO = 5;  /* I/O error */
const Errno ENXIO = 6;  /* No such device or address */
const Errno E2BIG = 7;  /* Argument list too long */
const Errno ENOEXEC = 8;  /* Exec format error */
const Errno EBADF = 9;  /* Bad file number */
const Errno ECHILD = 10;  /* No child processes */
const Errno EAGAIN = 11;  /* Try again */
const Errno ENOMEM = 12;  /* Out of memory */
const Errno EACCES = 13;  /* Permission denied */
const Errno EFAULT = 14;  /* Bad address */
const Errno ENOTBLK = 15;  /* Block device required */
const Errno EBUSY = 16;  /* Device or resource busy */
const Errno EEXIST = 17;  /* File exists */
const Errno EXDEV = 18;  /* Cross-device link */
const Errno ENODEV = 19;  /* No such device */
const Errno ENOTDIR = 20;  /* Not a directory */
const Errno EISDIR = 21;  /* Is a directory */
const Errno EINVAL = 22;  /* Invalid argument */
const Errno ENFILE = 23;  /* File table overflow */
const Errno EMFILE = 24;  /* Too many open files */
const Errno ENOTTY = 25;  /* Not a typewriter */
const Errno ETXTBSY = 26;  /* Text file busy */
const Errno EFBIG = 27;  /* File too large */
const Errno ENOSPC = 28;  /* No space left on device */
const Errno ESPIPE = 29;  /* Illegal seek */
const Errno EROFS = 30;  /* Read-only file system */
const Errno EMLINK = 31;  /* Too many links */
const Errno EPIPE = 32;  /* Broken pipe */
const Errno EDOM = 33;  /* Math argument out of domain of func */
const Errno ERANGE = 34;  /* Math result not representable */
const Errno EDEADLK = 35;  /* Resource deadlock would occur */
const Errno ENAMETOOLONG = 36;  /* File name too long */
const Errno ENOLCK = 37;  /* No record locks available */
const Errno ENOSYS = 38;  /* Function not implemented */
const Errno ENOTEMPTY = 39;  /* Directory not empty */
const Errno ELOOP = 40;  /* Too many symbolic links encountered */

const Errno ENOMSG = 42;  /* No message of desired type */
const Errno EIDRM = 43;  /* Identifier removed */
const Errno ECHRNG = 44;  /* Channel number out of range */
const Errno EL2NSYNC = 45;  /* Level 2 not synchronized */
const Errno EL3HLT = 46;  /* Level 3 halted */
const Errno EL3RST = 47;  /* Level 3 reset */
const Errno ELNRNG = 48;  /* Link number out of range */
const Errno EUNATCH = 49;  /* Protocol driver not attached */
const Errno ENOCSI = 50;  /* No CSI structure available */
const Errno EL2HLT = 51;  /* Level 2 halted */
const Errno EBADE = 52;  /* Invalid exchange */
const Errno EBADR = 53;  /* Invalid request descriptor */
const Errno EXFULL = 54;  /* Exchange full */
const Errno ENOANO = 55;  /* No anode */
const Errno EBADRQC = 56;  /* Invalid request code */
const Errno EBADSLT = 57;  /* Invalid slot */

const Errno EBFONT = 59;  /* Bad font file format */
const Errno ENOSTR = 60;  /* Device not a stream */
const Errno ENODATA = 61;  /* No data available */
const Errno ETIME = 62;  /* Timer expired */
const Errno ENOSR = 63;  /* Out of streams resources */
const Errno ENONET = 64;  /* Machine is not on the network */
const Errno ENOPKG = 65;  /* Package not installed */
const Errno EREMOTE = 66;  /* Object is remote */
const Errno ENOLINK = 67;  /* Link has been severed */
const Errno EADV = 68;  /* Advertise error */
const Errno ESRMNT = 69;  /* Srmount error */
const Errno ECOMM = 70;  /* Communication error on send */
const Errno EPROTO = 71;  /* Protocol error */
const Errno EMULTIHOP = 72;  /* Multihop attempted */
const Errno EDOTDOT = 73;  /* RFS specific error */
const Errno EBADMSG = 74;  /* Not a data message */
const Errno EOVERFLOW = 75;  /* Value too large for defined data type */
const Errno ENOTUNIQ = 76;  /* Name not unique on network */
const Errno EBADFD = 77;  /* File descriptor in bad state */
const Errno EREMCHG = 78;  /* Remote address changed */
const Errno ELIBACC = 79;  /* Can not access a needed shared library */
const Errno ELIBBAD = 80;  /* Accessing a corrupted shared library */
const Errno ELIBSCN = 81;  /* .lib section in a.out corrupted */
const Errno ELIBMAX = 82;  /* Attempting to link in too many shared libraries */
const Errno ELIBEXEC = 83;  /* Cannot exec a shared library directly */
const Errno EILSEQ = 84;  /* Illegal byte sequence */
const Errno ERESTART = 85;  /* Interrupted system call should be restarted */
const Errno ESTRPIPE = 86;  /* Streams pipe error */
const Errno EUSERS = 87;  /* Too many users */
const Errno ENOTSOCK = 88;  /* Socket operation on non-socket */
const Errno EDESTADDRREQ = 89;  /* Destination address required */
const Errno EMSGSIZE = 90;  /* Message too long */
const Errno EPROTOTYPE = 91;  /* Protocol wrong type for socket */
const Errno ENOPROTOOPT = 92;  /* Protocol not available */
const Errno EPROTONOSUPPORT = 93;  /* Protocol not supported */
const Errno ESOCKTNOSUPPORT = 94;  /* Socket type not supported */
const Errno EOPNOTSUPP = 95;  /* Operation not supported on transport endpoint */
const Errno EPFNOSUPPORT = 96;  /* Protocol family not supported */
const Errno EAFNOSUPPORT = 97;  /* Address family not supported by protocol */
const Errno EADDRINUSE = 98;  /* Address already in use */
const Errno EADDRNOTAVAIL = 99;  /* Cannot assign requested address */
const Errno ENETDOWN = 100; /* Network is down */
const Errno ENETUNREACH = 101; /* Network is unreachable */
const Errno ENETRESET = 102; /* Network dropped connection because of reset */
const Errno ECONNABORTED = 103; /* Software caused connection abort */
const Errno ECONNRESET = 104; /* Connection reset by peer */
const Errno ENOBUFS = 105; /* No buffer space available */
const Errno EISCONN = 106; /* Transport endpoint is already connected */
const Errno ENOTCONN = 107; /* Transport endpoint is not connected */
const Errno ESHUTDOWN = 108; /* Cannot send after transport endpoint shutdown */
const Errno ETOOMANYREFS = 109; /* Too many references: cannot splice */
const Errno ETIMEDOUT = 110; /* Connection timed out */
const Errno ECONNREFUSED = 111; /* Connection refused */
const Errno EHOSTDOWN = 112; /* Host is down */
const Errno EHOSTUNREACH = 113; /* No route to host */
const Errno EALREADY = 114; /* Operation already in progress */
const Errno EINPROGRESS = 115; /* Operation now in progress */
const Errno ESTALE = 116; /* Stale NFS file handle */
const Errno EUCLEAN = 117; /* Structure needs cleaning */
const Errno ENOTNAM = 118; /* Not a XENIX named type file */
const Errno ENAVAIL = 119; /* No XENIX semaphores available */
const Errno EISNAM = 120; /* Is a named type file */
const Errno EREMOTEIO = 121; /* Remote I/O error */
const Errno EDQUOT = 122; /* Quota exceeded */

const Errno ENOMEDIUM = 123; /* No medium found */
const Errno EMEDIUMTYPE = 124; /* Wrong medium type */
const Errno ECANCELED = 125; /* Operation Canceled */
const Errno ENOKEY = 126; /* Required key not available */
const Errno EKEYEXPIRED = 127; /* Key has expired */
const Errno EKEYREVOKED = 128; /* Key has been revoked */
const Errno EKEYREJECTED = 129; /* Key was rejected by service */

const Errno EOWNERDEAD = 130; /* Owner died */
const Errno ENOTRECOVERABLE = 131; /* State not recoverable */