#include <init/stdlib.h>
#include <init/tar.h>
#include <shared/flags.h>
#include <shared/syscalls.h>
#include <stdint.h>

#define argify(str) str, sizeof(str) - 1

extern char _bss_start; // provided by the linker
extern char _bss_end;
extern char _initrd;

int tty_fd;

void read_file(const char *path, size_t len);
void fs_test(void);
void test_await(void);

__attribute__((section(".text.startup")))
int main(void) {
	// allocate bss
	_syscall_memflag(&_bss_start, &_bss_end - &_bss_start, MEMFLAG_PRESENT);

	tty_fd = _syscall_open("/tty", sizeof("/tty") - 1);
	if (tty_fd < 0)
		_syscall_exit(1);

	fs_test();
	test_await();

	char c;
	while (_syscall_read(tty_fd, &c, 1, 0))
		_syscall_write(tty_fd, &c, 1, 0);

	_syscall_exit(0);
}

void read_file(const char *path, size_t len) {
	int fd = _syscall_open(path, len);
	static char buf[64];
	int buf_len = 64;

	_syscall_write(tty_fd, path, len, 0);
	printf(": ");
	if (fd < 0) {
		printf("couldn't open.\n");
		return;
	}

	buf_len = _syscall_read(fd, buf, buf_len, 0);
	_syscall_write(tty_fd, buf, buf_len, 0);

	_syscall_close(fd);
}

void fs_test(void) {
	handle_t front, back;
	front = _syscall_fs_create(&back);

	if (_syscall_fork()) {
		// child: is the fs server
		tar_driver(back, &_initrd);
		return;
	}

	// parent: accesses the fs
	printf("\n\n");
	// the trailing slash should be ignored by mount()
	_syscall_mount(front, argify("/init/"));
	read_file(argify("/init/fake.txt"));
	read_file(argify("/init/1.txt"));
	read_file(argify("/init/2.txt"));
	read_file(argify("/init/dir/3.txt"));

	printf("\nshadowing /init/dir...\n");
	_syscall_mount(-1, argify("/init/dir"));
	read_file(argify("/init/fake.txt"));
	read_file(argify("/init/1.txt"));
	read_file(argify("/init/2.txt"));
	read_file(argify("/init/dir/3.txt"));

	printf("\n");
}

void test_await(void) {
	int ret;

	// regular exit()s
	if (!_syscall_fork()) _syscall_exit(69);
	if (!_syscall_fork()) _syscall_exit(420);

	// faults
	if (!_syscall_fork()) { // invalid memory access
		asm volatile("movb $69, 0" ::: "memory");
		printf("this shouldn't happen");
		_syscall_exit(-1);
	}
	if (!_syscall_fork()) { // #GP
		asm volatile("hlt" ::: "memory");
		printf("this shouldn't happen");
		_syscall_exit(-1);
	}

	while ((ret = _syscall_await()) != ~0)
		printf("await returned: %x\n", ret);
	printf("await: no more children\n");
}