#include "sys.h"

void *sys_alloc(u64 length)
{
	assert(length);
	void *result = VirtualAlloc(0, length, MEM_COMMIT|MEM_RESERVE, PAGE_READWRITE);
	return result;
}

void sys_free(void *memory, u64 length)
{
	assert(memory);
	assert(length);
	assert(VirtualFree(memory, 0, MEM_RELEASE));
}

void die(const char *error_string, ...)
{
	va_list args;
	va_start(args, error_string);
	printf("error: ");
	vprintf(error_string, args);
	printf("\n");
	va_end(args);
	exit(1);
}

void info(const char *format, ...)
{
	va_list args;
	va_start(args, format);
	vprintf(format, args);
	putchar('\n');
	va_end(args);
}

char *read_entire_file(struct arena *arena, u64 *len, const char *filename)
{
	HANDLE file = CreateFile(filename, GENERIC_READ, FILE_SHARE_READ,
		0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
	if (file == INVALID_HANDLE_VALUE)
		return 0;
	LARGE_INTEGER lisize;
	if (!GetFileSizeEx(file, &lisize))
		goto error;
	*len = lisize.QuadPart;
	if (!*len)
		goto error;
	char *buffer = push_arena(arena, *len + 1);
	DWORD bytes_read;
	if (!ReadFile(file, *buffer, size, &bytes_read, 0)) {
		pop_arena(arena, *len + 1);
		goto error;
	}
	CloseHandle(file);
	buffer[*len] = 0;
	return buffer;
error:
	CloseHandle(file);
	return 0;
}

char *get_exe_path(arena_t *arena)
{
	char path[max_path_len] = {0};
	u32 len = GetModuleFileName(0, path, max_path_len);
	if (!len)
		return 0;
	char *dir = strrchr(path, '\\');
	if (!dir)
		return path;
	len = dir - path;
	dir = push_arena(arena, len + 1);
	memmove(dir, path, len);
	dir[len] = 0;
	return dir;
}