#![feature(asm)]
#![no_std]

pub use self::arch::*;
pub use self::error::*;

#[cfg(target_arch = "x86")]
#[path="x86.rs"]
pub mod arch;

#[cfg(target_arch = "x86_64")]
#[path="x86_64.rs"]
pub mod arch;

pub mod error;

pub const SYS_BRK: usize = 45;
pub const SYS_CHDIR: usize = 12;
pub const SYS_CLONE: usize = 120;
    pub const CLONE_VM: usize = 0x100;
    pub const CLONE_FS: usize = 0x200;
    pub const CLONE_FILES: usize = 0x400;
    pub const CLONE_VFORK: usize = 0x4000;
    /// Mark this clone as supervised.
    ///
    /// This means that the process can run in supervised mode, even not being connected to
    /// a supervisor yet. In other words, the parent can later on supervise the process and handle
    /// the potential blocking syscall.
    ///
    /// This is an important security measure, since otherwise the process would be able to fork it
    /// self right after starting, making supervising it impossible.
    pub const CLONE_SUPERVISE: usize = 0x400000;
pub const SYS_CLOSE: usize = 6;
pub const SYS_CLOCK_GETTIME: usize = 265;
    pub const CLOCK_REALTIME: usize = 1;
    pub const CLOCK_MONOTONIC: usize = 4;
pub const SYS_DUP: usize = 41;
pub const SYS_EXECVE: usize = 11;
pub const SYS_EXIT: usize = 1;
pub const SYS_FPATH: usize = 928;
pub const SYS_FSTAT: usize = 28;
    pub const MODE_DIR: u16 = 0x4000;
    pub const MODE_FILE: u16 = 0x8000;
    pub const MODE_ALL: u16 = MODE_DIR | MODE_FILE;
pub const SYS_FSYNC: usize = 118;
pub const SYS_FTRUNCATE: usize = 93;
pub const SYS_FUTEX: usize = 240;
    pub const FUTEX_WAIT: usize = 0;
    pub const FUTEX_WAKE: usize = 1;
    pub const FUTEX_REQUEUE: usize = 2;
pub const SYS_GETPID: usize = 20;
pub const SYS_IOPL: usize = 110;
pub const SYS_LINK: usize = 9;
pub const SYS_LSEEK: usize = 19;
    pub const SEEK_SET: usize = 0;
    pub const SEEK_CUR: usize = 1;
    pub const SEEK_END: usize = 2;
pub const SYS_MKDIR: usize = 39;
pub const SYS_NANOSLEEP: usize = 162;
pub const SYS_OPEN: usize = 5;
    pub const O_RDONLY: usize = 0;
    pub const O_WRONLY: usize = 1;
    pub const O_RDWR: usize = 2;
    pub const O_NONBLOCK: usize = 4;
    pub const O_APPEND: usize = 8;
    pub const O_SHLOCK: usize = 0x10;
    pub const O_EXLOCK: usize = 0x20;
    pub const O_ASYNC: usize = 0x40;
    pub const O_FSYNC: usize = 0x80;
    pub const O_CREAT: usize = 0x200;
    pub const O_TRUNC: usize = 0x400;
    pub const O_EXCL: usize = 0x800;
pub const SYS_PIPE2: usize = 331;
pub const SYS_READ: usize = 3;
pub const SYS_RMDIR: usize = 84;
pub const SYS_UNLINK: usize = 10;
pub const SYS_WAITPID: usize = 7;
pub const SYS_WRITE: usize = 4;
pub const SYS_YIELD: usize = 158;

#[derive(Copy, Clone, Debug, Default)]
#[repr(packed)]
pub struct Stat {
    pub st_dev: u16,
    pub st_ino: u16,
    pub st_mode: u16,
    pub st_nlink: u16,
    pub st_uid: u16,
    pub st_gid: u16,
    pub st_rdev: u16,
    pub st_size: u32,
    pub st_atime: u32,
    pub st_mtime: u32,
    pub st_ctime: u32
}

#[derive(Copy, Clone, Debug, Default)]
#[repr(packed)]
pub struct TimeSpec {
    pub tv_sec: i64,
    pub tv_nsec: i32,
}

pub unsafe fn brk(addr: usize) -> Result<usize> {
    syscall1(SYS_BRK, addr)
}

pub fn chdir(path: &str) -> Result<usize> {
    unsafe { syscall2(SYS_CHDIR, path.as_ptr() as usize, path.len()) }
}

pub unsafe fn clone(flags: usize) -> Result<usize> {
    syscall1(SYS_CLONE, flags)
}

pub fn close(fd: usize) -> Result<usize> {
    unsafe { syscall1(SYS_CLOSE, fd) }
}

pub fn clock_gettime(clock: usize, tp: &mut TimeSpec) -> Result<usize> {
    unsafe { syscall2(SYS_CLOCK_GETTIME, clock, tp as *mut TimeSpec as usize) }
}

pub fn dup(fd: usize) -> Result<usize> {
    unsafe { syscall1(SYS_DUP, fd) }
}

pub unsafe fn execve(path: *const u8, args: *const *const u8) -> Result<usize> {
    syscall2(SYS_EXECVE, path as usize, args as usize)
}

pub fn exit(status: usize) -> Result<usize> {
    unsafe { syscall1(SYS_EXIT, status) }
}

pub fn fpath(fd: usize, buf: &mut [u8]) -> Result<usize> {
    unsafe { syscall3(SYS_FPATH, fd, buf.as_mut_ptr() as usize, buf.len()) }
}

pub fn fstat(fd: usize, stat: &mut Stat) -> Result<usize> {
    unsafe { syscall2(SYS_FSTAT, fd, stat as *mut Stat as usize) }
}

pub fn fsync(fd: usize) -> Result<usize> {
    unsafe { syscall1(SYS_FSYNC, fd) }
}

pub fn ftruncate(fd: usize, len: usize) -> Result<usize> {
    unsafe { syscall2(SYS_FTRUNCATE, fd, len) }
}

pub unsafe fn futex(addr: *mut i32, op: usize, val: i32, val2: usize, addr2: *mut i32) -> Result<usize> {
    syscall5(SYS_FUTEX, addr as usize, op, (val as isize) as usize, val2, addr2 as usize)
}

pub fn getpid() -> Result<usize> {
    unsafe { syscall0(SYS_GETPID) }
}

pub unsafe fn iopl(level: usize) -> Result<usize> {
    syscall1(SYS_IOPL, level)
}

pub unsafe fn link(old: *const u8, new: *const u8) -> Result<usize> {
    syscall2(SYS_LINK, old as usize, new as usize)
}

pub fn lseek(fd: usize, offset: isize, whence: usize) -> Result<usize> {
    unsafe { syscall3(SYS_LSEEK, fd, offset as usize, whence) }
}

pub fn mkdir(path: &str, mode: usize) -> Result<usize> {
    unsafe { syscall3(SYS_MKDIR, path.as_ptr() as usize, path.len(), mode) }
}

pub fn nanosleep(req: &TimeSpec, rem: &mut TimeSpec) -> Result<usize> {
    unsafe { syscall2(SYS_NANOSLEEP, req as *const TimeSpec as usize, rem as *mut TimeSpec as usize) }
}

pub fn open(path: &str, flags: usize) -> Result<usize> {
    unsafe { syscall3(SYS_OPEN, path.as_ptr() as usize, path.len(), flags) }
}

pub fn pipe2(fds: &mut [usize; 2], flags: usize) -> Result<usize> {
    unsafe { syscall2(SYS_PIPE2, fds.as_ptr() as usize, flags) }
}

pub fn read(fd: usize, buf: &mut [u8]) -> Result<usize> {
    unsafe { syscall3(SYS_READ, fd, buf.as_mut_ptr() as usize, buf.len()) }
}

pub fn rmdir(path: &str) -> Result<usize> {
    unsafe { syscall2(SYS_RMDIR, path.as_ptr() as usize, path.len()) }
}

pub fn unlink(path: &str) -> Result<usize> {
    unsafe { syscall2(SYS_UNLINK, path.as_ptr() as usize, path.len()) }
}

pub fn waitpid(pid: usize, status: &mut usize, options: usize) -> Result<usize> {
    unsafe { syscall3(SYS_WAITPID, pid, status as *mut usize as usize, options) }
}

pub fn write(fd: usize, buf: &[u8]) -> Result<usize> {
    unsafe { syscall3(SYS_WRITE, fd, buf.as_ptr() as usize, buf.len()) }
}

pub fn sched_yield() -> Result<usize> {
    unsafe { syscall0(SYS_YIELD) }
}