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use super::*;
use crate::syscalls::*;

/// ### `path_open()`
/// Open file located at the given path
/// Inputs:
/// - `Fd dirfd`
///     The fd corresponding to the directory that the file is in
/// - `LookupFlags dirflags`
///     Flags specifying how the path will be resolved
/// - `char *path`
///     The path of the file or directory to open
/// - `u32 path_len`
///     The length of the `path` string
/// - `Oflags o_flags`
///     How the file will be opened
/// - `Rights fs_rights_base`
///     The rights of the created file descriptor
/// - `Rights fs_rightsinheriting`
///     The rights of file descriptors derived from the created file descriptor
/// - `Fdflags fs_flags`
///     The flags of the file descriptor
/// Output:
/// - `Fd* fd`
///     The new file descriptor
/// Possible Errors:
/// - `Errno::Access`, `Errno::Badf`, `Errno::Fault`, `Errno::Fbig?`, `Errno::Inval`, `Errno::Io`, `Errno::Loop`, `Errno::Mfile`, `Errno::Nametoolong?`, `Errno::Nfile`, `Errno::Noent`, `Errno::Notdir`, `Errno::Rofs`, and `Errno::Notcapable`
#[instrument(level = "trace", skip_all, fields(%dirfd, path = field::Empty, follow_symlinks = field::Empty, ret_fd = field::Empty), ret)]
pub fn path_open<M: MemorySize>(
    mut ctx: FunctionEnvMut<'_, WasiEnv>,
    dirfd: WasiFd,
    dirflags: LookupFlags,
    path: WasmPtr<u8, M>,
    path_len: M::Offset,
    o_flags: Oflags,
    fs_rights_base: Rights,
    fs_rights_inheriting: Rights,
    fs_flags: Fdflags,
    fd: WasmPtr<WasiFd, M>,
) -> Result<Errno, WasiError> {
    if dirflags & __WASI_LOOKUP_SYMLINK_FOLLOW != 0 {
        Span::current().record("follow_symlinks", true);
    }
    let env = ctx.data();
    let (memory, mut state, mut inodes) =
        unsafe { env.get_memory_and_wasi_state_and_inodes(&ctx, 0) };
    /* TODO: find actual upper bound on name size (also this is a path, not a name :think-fish:) */
    let path_len64: u64 = path_len.into();
    if path_len64 > 1024u64 * 1024u64 {
        return Ok(Errno::Nametoolong);
    }

    if path_len64 == 0 {
        return Ok(Errno::Noent);
    }

    // o_flags:
    // - __WASI_O_CREAT (create if it does not exist)
    // - __WASI_O_DIRECTORY (fail if not dir)
    // - __WASI_O_EXCL (fail if file exists)
    // - __WASI_O_TRUNC (truncate size to 0)

    let path_string = unsafe { get_input_str_ok!(&memory, path, path_len) };
    Span::current().record("path", path_string.as_str());

    let out_fd = wasi_try_ok!(path_open_internal(
        &mut ctx,
        dirfd,
        dirflags,
        &path_string,
        o_flags,
        fs_rights_base,
        fs_rights_inheriting,
        fs_flags,
        Fdflagsext::empty(),
        None,
    )?);
    let env = ctx.data();

    #[cfg(feature = "journal")]
    if env.enable_journal {
        JournalEffector::save_path_open(
            &mut ctx,
            out_fd,
            dirfd,
            dirflags,
            path_string,
            o_flags,
            fs_rights_base,
            fs_rights_inheriting,
            fs_flags,
            Fdflagsext::empty(),
        )
        .map_err(|err| {
            tracing::error!("failed to save unlink event - {}", err);
            WasiError::Exit(ExitCode::from(Errno::Fault))
        })?;
    }

    let env = ctx.data();
    let (memory, mut state, mut inodes) =
        unsafe { env.get_memory_and_wasi_state_and_inodes(&ctx, 0) };

    Span::current().record("ret_fd", out_fd);

    let fd_ref = fd.deref(&memory);
    wasi_try_mem_ok!(fd_ref.write(out_fd));

    Ok(Errno::Success)
}