package libc

when ODIN_OS == "windows" {
	foreign import libc "system:libucrt.lib"
} else {
	foreign import libc "system:c"
}

// 7.21 Input/output

FILE :: struct {};

// MSVCRT compatible.
when ODIN_OS == "windows" {
	_IOFBF       :: 0x0000;
	_IONBF       :: 0x0004;
	_IOLBF       :: 0x0040;

	BUFSIZ       :: 512;

	EOF          :: int(-1);

	FOPEN_MAX    :: 20;

	FILENAME_MAX :: 260;

	L_tmpnam     :: 15; // "\\" + 12 + NUL

	SEEK_SET     :: 0;
	SEEK_CUR     :: 1;
	SEEK_END     :: 2;

	TMP_MAX      :: 32767; // SHRT_MAX

	fpos_t       :: distinct i64;

	@(private="file")
	@(default_calling_convention="c")
	foreign libc {
		__acrt_iob_func :: proc (index: uint) -> ^FILE ---;
	}

	stdin  := __acrt_iob_func(0);
	stdout := __acrt_iob_func(1);
	stderr := __acrt_iob_func(2);
}

// GLIBC and MUSL compatible.
when ODIN_OS == "linux" {
	fpos_t        :: struct #raw_union { _: [16]char, _: longlong, _: double, };

	_IOFBF        :: 0;
	_IOLBF        :: 1;
	_IONBF        :: 2;

	BUFSIZ        :: 1024;

	EOF           :: int(-1);

	FOPEN_MAX     :: 1000;

	FILENAME_MAX  :: 4096;

	L_tmpnam      :: 20;

	SEEK_SET      :: 0;
	SEEK_CUR      :: 1;
	SEEK_END      :: 2;

	TMP_MAX       :: 10000;

	foreign libc {
		stderr: ^FILE;
		stdin:  ^FILE;
		stdout: ^FILE;
	}
}

@(default_calling_convention="c")
foreign libc {
	// 7.21.4 Operations on files
	remove    :: proc(filename: cstring) -> int ---;
	rename    :: proc(old, new: cstring) -> int ---;
	tmpfile   :: proc() -> ^FILE ---;
	tmpnam    :: proc(s: ^char) -> ^char ---;

	// 7.21.5 File access functions
	fclose    :: proc(stream: ^FILE) -> int ---;
	fflush    :: proc(stream: ^FILE) -> int ---;
	fopen     :: proc(filename, mode: cstring) -> ^FILE ---;
	freopen   :: proc(filename, mode: cstring, stream: ^FILE) -> ^FILE ---;
	setbuf    :: proc(stream: ^FILE, buf: ^char) ---;
	setvbuf   :: proc(stream: ^FILE, buf: ^char, mode: int, size: size_t) -> int ---;

	// 7.21.6 Formatted input/output functions
	fprintf   :: proc(stream: ^FILE, format: cstring, #c_vararg args: ..any) -> int ---;
	fscanf    :: proc(stream: ^FILE, format: cstring, #c_vararg args: ..any) -> int ---;
	printf    :: proc(format: cstring, #c_vararg args: ..any) -> int ---;
	scanf     :: proc(format: cstring, #c_vararg args: ..any) -> int ---;
	snprintf  :: proc(s: ^char, format: cstring, #c_vararg args: ..any) -> int ---;
	sscanf    :: proc(s, format: cstring, #c_vararg args: ..any) -> int ---;
	vfprintf  :: proc(stream: ^FILE, format: cstring, arg: ^va_list) -> int ---;
	vfscanf   :: proc(stream: ^FILE, format: cstring, arg: ^va_list) -> int ---;
	vprintf   :: proc(format: cstring, arg: ^va_list) -> int ---;
	vscanf    :: proc(format: cstring, arg: ^va_list) -> int ---;
	vsnprintf :: proc(s: ^char, n: size_t, format: cstring, arg: ^va_list) -> int ---;
	vsprintf  :: proc(s: ^char, format: cstring, arg: ^va_list) -> int ---;
	vsscanf   :: proc(s, format: cstring, arg: ^va_list) -> int ---;

	// 7.21.7 Character input/output functions
	fgetc     :: proc(stream: ^FILE) -> int ---;
	fgets     :: proc(s: ^char, n: int, stream: ^FILE) -> ^char ---;
	fputc     :: proc(s: cstring, stream: ^FILE) -> int ---;
	getc      :: proc(stream: ^FILE) -> int ---;
	getchar   :: proc() -> int ---;
	putc      :: proc(c: int, stream: ^FILE) -> int ---;
	putchar   :: proc() -> int ---;
	puts      :: proc(s: cstring) -> int ---;
	ungetc    :: proc(c: int, stream: ^FILE) -> int ---;
	fread     :: proc(ptr: rawptr, size: size_t, stream: ^FILE) -> size_t ---;
	fwrite    :: proc(ptr: rawptr, size: size_t, nmemb: size_t, stream: ^FILE) -> size_t ---;

	// 7.21.9 File positioning functions
	fgetpos   :: proc(stream: ^FILE, pos: ^fpos_t) -> int ---;
	fseek     :: proc(stream: ^FILE, offset: long, whence: int) -> int ---;
	fsetpos   :: proc(stream: ^FILE, pos: ^fpos_t) -> int ---;
	ftell     :: proc(stream: ^FILE) -> long ---;
	rewind    :: proc(stream: ^FILE) ---;

	// 7.21.10 Error-handling functions
	clearerr  :: proc(stream: ^FILE) ---;
	feof      :: proc(stream: ^FILE) -> int ---;
	ferror    :: proc(stream: ^FILE) -> int ---;
	perror    :: proc(s: cstring) ---;
}