// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
// Some deserializer fields are only used on Unix and Windows build fails without it
use super::io::StdFileResource;
use super::utils::into_string;
use crate::fs_util::canonicalize_path;
use crate::permissions::Permissions;
use deno_core::error::custom_error;
use deno_core::error::type_error;
use deno_core::error::AnyError;
use deno_core::op;
use deno_core::CancelFuture;
use deno_core::CancelHandle;
use deno_core::ZeroCopyBuf;

use deno_core::Extension;
use deno_core::OpState;
use deno_core::ResourceId;
use deno_crypto::rand::thread_rng;
use deno_crypto::rand::Rng;
use log::debug;
use serde::Deserialize;
use serde::Serialize;
use std::borrow::Cow;
use std::cell::RefCell;
use std::convert::From;
use std::env::current_dir;
use std::env::set_current_dir;
use std::env::temp_dir;
use std::io;
use std::io::Error;
use std::io::Seek;
use std::io::SeekFrom;
use std::io::Write;
use std::path::Path;
use std::path::PathBuf;
use std::rc::Rc;
use std::time::SystemTime;
use std::time::UNIX_EPOCH;

#[cfg(not(unix))]
use deno_core::error::generic_error;
#[cfg(not(unix))]
use deno_core::error::not_supported;

pub fn init() -> Extension {
    Extension::builder()
        .ops(vec![
            op_open_sync::decl(),
            op_open_async::decl(),
            op_write_file_sync::decl(),
            op_write_file_async::decl(),
            op_seek_sync::decl(),
            op_seek_async::decl(),
            op_fdatasync_sync::decl(),
            op_fdatasync_async::decl(),
            op_fsync_sync::decl(),
            op_fsync_async::decl(),
            op_fstat_sync::decl(),
            op_fstat_async::decl(),
            op_flock_sync::decl(),
            op_flock_async::decl(),
            op_funlock_sync::decl(),
            op_funlock_async::decl(),
            op_umask::decl(),
            op_chdir::decl(),
            op_mkdir_sync::decl(),
            op_mkdir_async::decl(),
            op_chmod_sync::decl(),
            op_chmod_async::decl(),
            op_chown_sync::decl(),
            op_chown_async::decl(),
            op_remove_sync::decl(),
            op_remove_async::decl(),
            op_copy_file_sync::decl(),
            op_copy_file_async::decl(),
            op_stat_sync::decl(),
            op_stat_async::decl(),
            op_realpath_sync::decl(),
            op_realpath_async::decl(),
            op_read_dir_sync::decl(),
            op_read_dir_async::decl(),
            op_rename_sync::decl(),
            op_rename_async::decl(),
            op_link_sync::decl(),
            op_link_async::decl(),
            op_symlink_sync::decl(),
            op_symlink_async::decl(),
            op_read_link_sync::decl(),
            op_read_link_async::decl(),
            op_ftruncate_sync::decl(),
            op_ftruncate_async::decl(),
            op_truncate_sync::decl(),
            op_truncate_async::decl(),
            op_make_temp_dir_sync::decl(),
            op_make_temp_dir_async::decl(),
            op_make_temp_file_sync::decl(),
            op_make_temp_file_async::decl(),
            op_cwd::decl(),
            op_futime_sync::decl(),
            op_futime_async::decl(),
            op_utime_sync::decl(),
            op_utime_async::decl(),
            op_readfile_sync::decl(),
            op_readfile_text_sync::decl(),
            op_readfile_async::decl(),
            op_readfile_text_async::decl(),
        ])
        .build()
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct OpenArgs {
    path: String,
    mode: Option<u32>,
    options: OpenOptions,
}

#[derive(Deserialize, Default, Debug)]
#[serde(rename_all = "camelCase")]
#[serde(default)]
pub struct OpenOptions {
    read: bool,
    write: bool,
    create: bool,
    truncate: bool,
    append: bool,
    create_new: bool,
}

fn open_helper(
    state: &mut OpState,
    args: &OpenArgs,
) -> Result<(PathBuf, std::fs::OpenOptions), AnyError> {
    let path = Path::new(&args.path).to_path_buf();

    let mut open_options = std::fs::OpenOptions::new();

    if let Some(mode) = args.mode {
        // mode only used if creating the file on Unix
        // if not specified, defaults to 0o666
        #[cfg(unix)]
        {
            use std::os::unix::fs::OpenOptionsExt;
            open_options.mode(mode & 0o777);
        }
        #[cfg(not(unix))]
        let _ = mode; // avoid unused warning
    }

    let permissions = state.borrow_mut::<Permissions>();
    let options = &args.options;

    if options.read {
        permissions.read.check(&path)?;
    }

    if options.write || options.append {
        permissions.write.check(&path)?;
    }

    open_options
        .read(options.read)
        .create(options.create)
        .write(options.write)
        .truncate(options.truncate)
        .append(options.append)
        .create_new(options.create_new);

    Ok((path, open_options))
}

#[op]
fn op_open_sync(state: &mut OpState, args: OpenArgs) -> Result<ResourceId, AnyError> {
    let (path, open_options) = open_helper(state, &args)?;
    let std_file = open_options
        .open(&path)
        .map_err(|err| Error::new(err.kind(), format!("{}, open '{}'", err, path.display())))?;
    let resource = StdFileResource::fs_file(std_file);
    let rid = state.resource_table.add(resource);
    Ok(rid)
}

#[op]
async fn op_open_async(
    state: Rc<RefCell<OpState>>,
    args: OpenArgs,
) -> Result<ResourceId, AnyError> {
    let (path, open_options) = open_helper(&mut state.borrow_mut(), &args)?;
    let std_file = tokio::task::spawn_blocking(move || {
        open_options
            .open(path.clone())
            .map_err(|err| Error::new(err.kind(), format!("{}, open '{}'", err, path.display())))
    })
    .await?;
    let resource = StdFileResource::fs_file(std_file?);
    let rid = state.borrow_mut().resource_table.add(resource);
    Ok(rid)
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct WriteFileArgs {
    path: String,
    mode: Option<u32>,
    append: bool,
    create: bool,
    data: ZeroCopyBuf,
    cancel_rid: Option<ResourceId>,
}

impl WriteFileArgs {
    fn into_open_args_and_data(self) -> (OpenArgs, ZeroCopyBuf) {
        (
            OpenArgs {
                path: self.path,
                mode: self.mode,
                options: OpenOptions {
                    read: false,
                    write: true,
                    create: self.create,
                    truncate: !self.append,
                    append: self.append,
                    create_new: false,
                },
            },
            self.data,
        )
    }
}

#[op]
fn op_write_file_sync(state: &mut OpState, args: WriteFileArgs) -> Result<(), AnyError> {
    let (open_args, data) = args.into_open_args_and_data();
    let (path, open_options) = open_helper(state, &open_args)?;
    write_file(&path, open_options, &open_args, data)
}

#[op]
async fn op_write_file_async(
    state: Rc<RefCell<OpState>>,
    args: WriteFileArgs,
) -> Result<(), AnyError> {
    let cancel_handle = match args.cancel_rid {
        Some(cancel_rid) => state
            .borrow_mut()
            .resource_table
            .get::<CancelHandle>(cancel_rid)
            .ok(),
        None => None,
    };
    let (open_args, data) = args.into_open_args_and_data();
    let (path, open_options) = open_helper(&mut *state.borrow_mut(), &open_args)?;
    let write_future =
        tokio::task::spawn_blocking(move || write_file(&path, open_options, &open_args, data));
    if let Some(cancel_handle) = cancel_handle {
        write_future.or_cancel(cancel_handle).await???;
    } else {
        write_future.await??;
    }
    Ok(())
}

fn write_file(
    path: &Path,
    open_options: std::fs::OpenOptions,
    _open_args: &OpenArgs,
    data: ZeroCopyBuf,
) -> Result<(), AnyError> {
    let mut std_file = open_options
        .open(path)
        .map_err(|err| Error::new(err.kind(), format!("{}, open '{}'", err, path.display())))?;

    // need to chmod the file if it already exists and a mode is specified
    #[cfg(unix)]
    if let Some(mode) = &_open_args.mode {
        use std::os::unix::fs::PermissionsExt;
        let permissions = PermissionsExt::from_mode(mode & 0o777);
        std_file
            .set_permissions(permissions)
            .map_err(|err: Error| {
                Error::new(err.kind(), format!("{}, chmod '{}'", err, path.display()))
            })?;
    }

    std_file.write_all(&data)?;
    Ok(())
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct SeekArgs {
    rid: ResourceId,
    offset: i64,
    whence: i32,
}

fn seek_helper(args: SeekArgs) -> Result<(u32, SeekFrom), AnyError> {
    let rid = args.rid;
    let offset = args.offset;
    let whence = args.whence as u32;
    // Translate seek mode to Rust repr.
    let seek_from = match whence {
        0 => SeekFrom::Start(offset as u64),
        1 => SeekFrom::Current(offset),
        2 => SeekFrom::End(offset),
        _ => {
            return Err(type_error(format!("Invalid seek mode: {}", whence)));
        }
    };

    Ok((rid, seek_from))
}

#[op]
fn op_seek_sync(state: &mut OpState, args: SeekArgs) -> Result<u64, AnyError> {
    let (rid, seek_from) = seek_helper(args)?;
    StdFileResource::with_file(state, rid, |std_file| {
        std_file.seek(seek_from).map_err(AnyError::from)
    })
}

#[op]
async fn op_seek_async(state: Rc<RefCell<OpState>>, args: SeekArgs) -> Result<u64, AnyError> {
    let (rid, seek_from) = seek_helper(args)?;

    StdFileResource::with_file_blocking_task(state, rid, move |std_file| {
        std_file.seek(seek_from).map_err(AnyError::from)
    })
    .await
}

#[op]
fn op_fdatasync_sync(state: &mut OpState, rid: ResourceId) -> Result<(), AnyError> {
    StdFileResource::with_file(state, rid, |std_file| {
        std_file.sync_data().map_err(AnyError::from)
    })
}

#[op]
async fn op_fdatasync_async(state: Rc<RefCell<OpState>>, rid: ResourceId) -> Result<(), AnyError> {
    StdFileResource::with_file_blocking_task(state, rid, move |std_file| {
        std_file.sync_data().map_err(AnyError::from)
    })
    .await
}

#[op]
fn op_fsync_sync(state: &mut OpState, rid: ResourceId) -> Result<(), AnyError> {
    StdFileResource::with_file(state, rid, |std_file| {
        std_file.sync_all().map_err(AnyError::from)
    })
}

#[op]
async fn op_fsync_async(state: Rc<RefCell<OpState>>, rid: ResourceId) -> Result<(), AnyError> {
    StdFileResource::with_file_blocking_task(state, rid, move |std_file| {
        std_file.sync_all().map_err(AnyError::from)
    })
    .await
}

#[op]
fn op_fstat_sync(state: &mut OpState, rid: ResourceId) -> Result<FsStat, AnyError> {
    let metadata = StdFileResource::with_file(state, rid, |std_file| {
        std_file.metadata().map_err(AnyError::from)
    })?;
    Ok(get_stat(metadata))
}

#[op]
async fn op_fstat_async(state: Rc<RefCell<OpState>>, rid: ResourceId) -> Result<FsStat, AnyError> {
    let metadata = StdFileResource::with_file_blocking_task(state, rid, move |std_file| {
        std_file.metadata().map_err(AnyError::from)
    })
    .await?;
    Ok(get_stat(metadata))
}

#[op]
fn op_flock_sync(state: &mut OpState, rid: ResourceId, exclusive: bool) -> Result<(), AnyError> {
    use fs3::FileExt;
    super::check_unstable(state, "Deno.flockSync");

    StdFileResource::with_file(state, rid, |std_file| {
        if exclusive {
            std_file.lock_exclusive()?;
        } else {
            std_file.lock_shared()?;
        }
        Ok(())
    })
}

#[op]
async fn op_flock_async(
    state: Rc<RefCell<OpState>>,
    rid: ResourceId,
    exclusive: bool,
) -> Result<(), AnyError> {
    use fs3::FileExt;
    super::check_unstable2(&state, "Deno.flock");

    StdFileResource::with_file_blocking_task(state, rid, move |std_file| {
        if exclusive {
            std_file.lock_exclusive()?;
        } else {
            std_file.lock_shared()?;
        }
        Ok(())
    })
    .await
}

#[op]
fn op_funlock_sync(state: &mut OpState, rid: ResourceId) -> Result<(), AnyError> {
    use fs3::FileExt;
    super::check_unstable(state, "Deno.funlockSync");

    StdFileResource::with_file(state, rid, |std_file| {
        std_file.unlock()?;
        Ok(())
    })
}

#[op]
async fn op_funlock_async(state: Rc<RefCell<OpState>>, rid: ResourceId) -> Result<(), AnyError> {
    use fs3::FileExt;
    super::check_unstable2(&state, "Deno.funlock");

    StdFileResource::with_file_blocking_task(state, rid, move |std_file| {
        std_file.unlock()?;
        Ok(())
    })
    .await
}

#[op]
fn op_umask(state: &mut OpState, mask: Option<u32>) -> Result<u32, AnyError> {
    super::check_unstable(state, "Deno.umask");
    // TODO implement umask for Windows
    // see https://github.com/nodejs/node/blob/master/src/node_process_methods.cc
    // and https://docs.microsoft.com/fr-fr/cpp/c-runtime-library/reference/umask?view=vs-2019
    #[cfg(not(unix))]
    {
        let _ = mask; // avoid unused warning.
        Err(not_supported())
    }
    #[cfg(unix)]
    {
        use nix::sys::stat::mode_t;
        use nix::sys::stat::umask;
        use nix::sys::stat::Mode;
        let r = if let Some(mask) = mask {
            // If mask provided, return previous.
            umask(Mode::from_bits_truncate(mask as mode_t))
        } else {
            // If no mask provided, we query the current. Requires two syscalls.
            let prev = umask(Mode::from_bits_truncate(0o777));
            let _ = umask(prev);
            prev
        };
        Ok(r.bits() as u32)
    }
}

#[op]
fn op_chdir(state: &mut OpState, directory: String) -> Result<(), AnyError> {
    let d = PathBuf::from(&directory);
    state.borrow_mut::<Permissions>().read.check(&d)?;
    set_current_dir(&d)
        .map_err(|err| Error::new(err.kind(), format!("{}, chdir '{}'", err, directory)))?;
    Ok(())
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct MkdirArgs {
    path: String,
    recursive: bool,
    mode: Option<u32>,
}

#[op]
fn op_mkdir_sync(state: &mut OpState, args: MkdirArgs) -> Result<(), AnyError> {
    let path = Path::new(&args.path).to_path_buf();
    let mode = args.mode.unwrap_or(0o777) & 0o777;
    state.borrow_mut::<Permissions>().write.check(&path)?;
    debug!("op_mkdir {} {:o} {}", path.display(), mode, args.recursive);
    let mut builder = std::fs::DirBuilder::new();
    builder.recursive(args.recursive);
    #[cfg(unix)]
    {
        use std::os::unix::fs::DirBuilderExt;
        builder.mode(mode);
    }
    builder
        .create(&path)
        .map_err(|err| Error::new(err.kind(), format!("{}, mkdir '{}'", err, path.display())))?;
    Ok(())
}

#[op]
async fn op_mkdir_async(state: Rc<RefCell<OpState>>, args: MkdirArgs) -> Result<(), AnyError> {
    let path = Path::new(&args.path).to_path_buf();
    let mode = args.mode.unwrap_or(0o777) & 0o777;

    {
        let mut state = state.borrow_mut();
        state.borrow_mut::<Permissions>().write.check(&path)?;
    }

    tokio::task::spawn_blocking(move || {
        debug!("op_mkdir {} {:o} {}", path.display(), mode, args.recursive);
        let mut builder = std::fs::DirBuilder::new();
        builder.recursive(args.recursive);
        #[cfg(unix)]
        {
            use std::os::unix::fs::DirBuilderExt;
            builder.mode(mode);
        }
        builder.create(&path).map_err(|err| {
            Error::new(err.kind(), format!("{}, mkdir '{}'", err, path.display()))
        })?;
        Ok(())
    })
    .await
    .unwrap()
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct ChmodArgs {
    path: String,
    mode: u32,
}

#[op]
fn op_chmod_sync(state: &mut OpState, args: ChmodArgs) -> Result<(), AnyError> {
    let path = Path::new(&args.path);
    let mode = args.mode & 0o777;

    state.borrow_mut::<Permissions>().write.check(path)?;
    debug!("op_chmod_sync {} {:o}", path.display(), mode);
    raw_chmod(path, mode)
}

#[op]
async fn op_chmod_async(state: Rc<RefCell<OpState>>, args: ChmodArgs) -> Result<(), AnyError> {
    let path = Path::new(&args.path).to_path_buf();
    let mode = args.mode & 0o777;

    {
        let mut state = state.borrow_mut();
        state.borrow_mut::<Permissions>().write.check(&path)?;
    }

    tokio::task::spawn_blocking(move || {
        debug!("op_chmod_async {} {:o}", path.display(), mode);
        raw_chmod(&path, mode)
    })
    .await
    .unwrap()
}

fn raw_chmod(path: &Path, _raw_mode: u32) -> Result<(), AnyError> {
    let err_mapper =
        |err: Error| Error::new(err.kind(), format!("{}, chmod '{}'", err, path.display()));
    #[cfg(unix)]
    {
        use std::os::unix::fs::PermissionsExt;
        let permissions = PermissionsExt::from_mode(_raw_mode);
        std::fs::set_permissions(&path, permissions).map_err(err_mapper)?;
        Ok(())
    }
    // TODO Implement chmod for Windows (#4357)
    #[cfg(not(unix))]
    {
        // Still check file/dir exists on Windows
        let _metadata = std::fs::metadata(&path).map_err(err_mapper)?;
        Err(not_supported())
    }
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct ChownArgs {
    path: String,
    uid: Option<u32>,
    gid: Option<u32>,
}

#[op]
fn op_chown_sync(state: &mut OpState, args: ChownArgs) -> Result<(), AnyError> {
    let path = Path::new(&args.path).to_path_buf();
    state.borrow_mut::<Permissions>().write.check(&path)?;
    debug!(
        "op_chown_sync {} {:?} {:?}",
        path.display(),
        args.uid,
        args.gid,
    );
    #[cfg(unix)]
    {
        use crate::errors::get_nix_error_class;
        use nix::unistd::{chown, Gid, Uid};
        let nix_uid = args.uid.map(Uid::from_raw);
        let nix_gid = args.gid.map(Gid::from_raw);
        chown(&path, nix_uid, nix_gid).map_err(|err| {
            custom_error(
                get_nix_error_class(&err),
                format!("{}, chown '{}'", err.desc(), path.display()),
            )
        })?;
        Ok(())
    }
    // TODO Implement chown for Windows
    #[cfg(not(unix))]
    {
        Err(generic_error("Not implemented"))
    }
}

#[op]
async fn op_chown_async(state: Rc<RefCell<OpState>>, args: ChownArgs) -> Result<(), AnyError> {
    let path = Path::new(&args.path).to_path_buf();

    {
        let mut state = state.borrow_mut();
        state.borrow_mut::<Permissions>().write.check(&path)?;
    }

    tokio::task::spawn_blocking(move || {
        debug!(
            "op_chown_async {} {:?} {:?}",
            path.display(),
            args.uid,
            args.gid,
        );
        #[cfg(unix)]
        {
            use crate::errors::get_nix_error_class;
            use nix::unistd::{chown, Gid, Uid};
            let nix_uid = args.uid.map(Uid::from_raw);
            let nix_gid = args.gid.map(Gid::from_raw);
            chown(&path, nix_uid, nix_gid).map_err(|err| {
                custom_error(
                    get_nix_error_class(&err),
                    format!("{}, chown '{}'", err.desc(), path.display()),
                )
            })?;
            Ok(())
        }
        // TODO Implement chown for Windows
        #[cfg(not(unix))]
        Err(not_supported())
    })
    .await
    .unwrap()
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct RemoveArgs {
    path: String,
    recursive: bool,
}

#[op]
fn op_remove_sync(state: &mut OpState, args: RemoveArgs) -> Result<(), AnyError> {
    let path = PathBuf::from(&args.path);
    let recursive = args.recursive;

    state.borrow_mut::<Permissions>().write.check(&path)?;

    #[cfg(not(unix))]
    use std::os::windows::prelude::MetadataExt;

    let err_mapper =
        |err: Error| Error::new(err.kind(), format!("{}, remove '{}'", err, path.display()));
    let metadata = std::fs::symlink_metadata(&path).map_err(err_mapper)?;

    debug!("op_remove_sync {} {}", path.display(), recursive);
    let file_type = metadata.file_type();
    if file_type.is_file() {
        std::fs::remove_file(&path).map_err(err_mapper)?;
    } else if recursive {
        std::fs::remove_dir_all(&path).map_err(err_mapper)?;
    } else if file_type.is_symlink() {
        #[cfg(unix)]
        std::fs::remove_file(&path).map_err(err_mapper)?;
        #[cfg(not(unix))]
        {
            use winapi::um::winnt::FILE_ATTRIBUTE_DIRECTORY;
            if metadata.file_attributes() & FILE_ATTRIBUTE_DIRECTORY != 0 {
                std::fs::remove_dir(&path).map_err(err_mapper)?;
            } else {
                std::fs::remove_file(&path).map_err(err_mapper)?;
            }
        }
    } else if file_type.is_dir() {
        std::fs::remove_dir(&path).map_err(err_mapper)?;
    } else {
        // pipes, sockets, etc...
        std::fs::remove_file(&path).map_err(err_mapper)?;
    }
    Ok(())
}

#[op]
async fn op_remove_async(state: Rc<RefCell<OpState>>, args: RemoveArgs) -> Result<(), AnyError> {
    let path = PathBuf::from(&args.path);
    let recursive = args.recursive;

    {
        let mut state = state.borrow_mut();
        state.borrow_mut::<Permissions>().write.check(&path)?;
    }

    tokio::task::spawn_blocking(move || {
        #[cfg(not(unix))]
        use std::os::windows::prelude::MetadataExt;
        let err_mapper =
            |err: Error| Error::new(err.kind(), format!("{}, remove '{}'", err, path.display()));
        let metadata = std::fs::symlink_metadata(&path).map_err(err_mapper)?;

        debug!("op_remove_async {} {}", path.display(), recursive);
        let file_type = metadata.file_type();
        if file_type.is_file() {
            std::fs::remove_file(&path).map_err(err_mapper)?;
        } else if recursive {
            std::fs::remove_dir_all(&path).map_err(err_mapper)?;
        } else if file_type.is_symlink() {
            #[cfg(unix)]
            std::fs::remove_file(&path).map_err(err_mapper)?;
            #[cfg(not(unix))]
            {
                use winapi::um::winnt::FILE_ATTRIBUTE_DIRECTORY;
                if metadata.file_attributes() & FILE_ATTRIBUTE_DIRECTORY != 0 {
                    std::fs::remove_dir(&path).map_err(err_mapper)?;
                } else {
                    std::fs::remove_file(&path).map_err(err_mapper)?;
                }
            }
        } else if file_type.is_dir() {
            std::fs::remove_dir(&path).map_err(err_mapper)?;
        } else {
            // pipes, sockets, etc...
            std::fs::remove_file(&path).map_err(err_mapper)?;
        }
        Ok(())
    })
    .await
    .unwrap()
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct CopyFileArgs {
    from: String,
    to: String,
}

#[op]
fn op_copy_file_sync(state: &mut OpState, args: CopyFileArgs) -> Result<(), AnyError> {
    let from = PathBuf::from(&args.from);
    let to = PathBuf::from(&args.to);

    let permissions = state.borrow_mut::<Permissions>();
    permissions.read.check(&from)?;
    permissions.write.check(&to)?;

    debug!("op_copy_file_sync {} {}", from.display(), to.display());
    // On *nix, Rust reports non-existent `from` as ErrorKind::InvalidInput
    // See https://github.com/rust-lang/rust/issues/54800
    // Once the issue is resolved, we should remove this workaround.
    if cfg!(unix) && !from.is_file() {
        return Err(custom_error(
            "NotFound",
            format!(
                "File not found, copy '{}' -> '{}'",
                from.display(),
                to.display()
            ),
        ));
    }

    let err_mapper = |err: Error| {
        Error::new(
            err.kind(),
            format!("{}, copy '{}' -> '{}'", err, from.display(), to.display()),
        )
    };
    // returns size of from as u64 (we ignore)
    std::fs::copy(&from, &to).map_err(err_mapper)?;
    Ok(())
}

#[op]
async fn op_copy_file_async(
    state: Rc<RefCell<OpState>>,
    args: CopyFileArgs,
) -> Result<(), AnyError> {
    let from = PathBuf::from(&args.from);
    let to = PathBuf::from(&args.to);

    {
        let mut state = state.borrow_mut();
        let permissions = state.borrow_mut::<Permissions>();
        permissions.read.check(&from)?;
        permissions.write.check(&to)?;
    }

    debug!("op_copy_file_async {} {}", from.display(), to.display());
    tokio::task::spawn_blocking(move || {
        // On *nix, Rust reports non-existent `from` as ErrorKind::InvalidInput
        // See https://github.com/rust-lang/rust/issues/54800
        // Once the issue is resolved, we should remove this workaround.
        if cfg!(unix) && !from.is_file() {
            return Err(custom_error(
                "NotFound",
                format!(
                    "File not found, copy '{}' -> '{}'",
                    from.display(),
                    to.display()
                ),
            ));
        }

        let err_mapper = |err: Error| {
            Error::new(
                err.kind(),
                format!("{}, copy '{}' -> '{}'", err, from.display(), to.display()),
            )
        };
        // returns size of from as u64 (we ignore)
        std::fs::copy(&from, &to).map_err(err_mapper)?;
        Ok(())
    })
    .await
    .unwrap()
}

fn to_msec(maybe_time: Result<SystemTime, io::Error>) -> Option<u64> {
    match maybe_time {
        Ok(time) => {
            let msec = time
                .duration_since(UNIX_EPOCH)
                .map(|t| t.as_millis() as u64)
                .unwrap_or_else(|err| err.duration().as_millis() as u64);
            Some(msec)
        }
        Err(_) => None,
    }
}

#[derive(Serialize)]
#[serde(rename_all = "camelCase")]
pub struct FsStat {
    is_file: bool,
    is_directory: bool,
    is_symlink: bool,
    size: u64,
    // In milliseconds, like JavaScript. Available on both Unix or Windows.
    mtime: Option<u64>,
    atime: Option<u64>,
    birthtime: Option<u64>,
    // Following are only valid under Unix.
    dev: u64,
    ino: u64,
    mode: u32,
    nlink: u64,
    uid: u32,
    gid: u32,
    rdev: u64,
    blksize: u64,
    blocks: u64,
}

#[inline(always)]
fn get_stat(metadata: std::fs::Metadata) -> FsStat {
    // Unix stat member (number types only). 0 if not on unix.
    macro_rules! usm {
        ($member:ident) => {{
            #[cfg(unix)]
            {
                metadata.$member()
            }
            #[cfg(not(unix))]
            {
                0
            }
        }};
    }

    #[cfg(unix)]
    use std::os::unix::fs::MetadataExt;
    FsStat {
        is_file: metadata.is_file(),
        is_directory: metadata.is_dir(),
        is_symlink: metadata.file_type().is_symlink(),
        size: metadata.len(),
        // In milliseconds, like JavaScript. Available on both Unix or Windows.
        mtime: to_msec(metadata.modified()),
        atime: to_msec(metadata.accessed()),
        birthtime: to_msec(metadata.created()),
        // Following are only valid under Unix.
        dev: usm!(dev),
        ino: usm!(ino),
        mode: usm!(mode),
        nlink: usm!(nlink),
        uid: usm!(uid),
        gid: usm!(gid),
        rdev: usm!(rdev),
        blksize: usm!(blksize),
        blocks: usm!(blocks),
    }
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct StatArgs {
    path: String,
    lstat: bool,
}

#[op]
fn op_stat_sync(state: &mut OpState, args: StatArgs) -> Result<FsStat, AnyError> {
    let path = PathBuf::from(&args.path);
    let lstat = args.lstat;
    state.borrow_mut::<Permissions>().read.check(&path)?;
    debug!("op_stat_sync {} {}", path.display(), lstat);
    let err_mapper =
        |err: Error| Error::new(err.kind(), format!("{}, stat '{}'", err, path.display()));
    let metadata = if lstat {
        std::fs::symlink_metadata(&path).map_err(err_mapper)?
    } else {
        std::fs::metadata(&path).map_err(err_mapper)?
    };
    Ok(get_stat(metadata))
}

#[op]
async fn op_stat_async(state: Rc<RefCell<OpState>>, args: StatArgs) -> Result<FsStat, AnyError> {
    let path = PathBuf::from(&args.path);
    let lstat = args.lstat;

    {
        let mut state = state.borrow_mut();
        state.borrow_mut::<Permissions>().read.check(&path)?;
    }

    tokio::task::spawn_blocking(move || {
        debug!("op_stat_async {} {}", path.display(), lstat);
        let err_mapper =
            |err: Error| Error::new(err.kind(), format!("{}, stat '{}'", err, path.display()));
        let metadata = if lstat {
            std::fs::symlink_metadata(&path).map_err(err_mapper)?
        } else {
            std::fs::metadata(&path).map_err(err_mapper)?
        };
        Ok(get_stat(metadata))
    })
    .await
    .unwrap()
}

#[op]
fn op_realpath_sync(state: &mut OpState, path: String) -> Result<String, AnyError> {
    let path = PathBuf::from(&path);

    let permissions = state.borrow_mut::<Permissions>();
    permissions.read.check(&path)?;
    if path.is_relative() {
        permissions.read.check_blind(&current_dir()?, "CWD")?;
    }

    debug!("op_realpath_sync {}", path.display());
    // corresponds to the realpath on Unix and
    // CreateFile and GetFinalPathNameByHandle on Windows
    let realpath = canonicalize_path(&path)?;
    let realpath_str = into_string(realpath.into_os_string())?;
    Ok(realpath_str)
}

#[op]
async fn op_realpath_async(state: Rc<RefCell<OpState>>, path: String) -> Result<String, AnyError> {
    let path = PathBuf::from(&path);

    {
        let mut state = state.borrow_mut();
        let permissions = state.borrow_mut::<Permissions>();
        permissions.read.check(&path)?;
        if path.is_relative() {
            permissions.read.check_blind(&current_dir()?, "CWD")?;
        }
    }

    tokio::task::spawn_blocking(move || {
        debug!("op_realpath_async {}", path.display());
        // corresponds to the realpath on Unix and
        // CreateFile and GetFinalPathNameByHandle on Windows
        let realpath = canonicalize_path(&path)?;
        let realpath_str = into_string(realpath.into_os_string())?;
        Ok(realpath_str)
    })
    .await
    .unwrap()
}

#[derive(Serialize)]
#[serde(rename_all = "camelCase")]
pub struct DirEntry {
    name: String,
    is_file: bool,
    is_directory: bool,
    is_symlink: bool,
}

#[op]
fn op_read_dir_sync(state: &mut OpState, path: String) -> Result<Vec<DirEntry>, AnyError> {
    let path = PathBuf::from(&path);

    state.borrow_mut::<Permissions>().read.check(&path)?;

    debug!("op_read_dir_sync {}", path.display());
    let err_mapper =
        |err: Error| Error::new(err.kind(), format!("{}, readdir '{}'", err, path.display()));
    let entries: Vec<_> = std::fs::read_dir(&path)
        .map_err(err_mapper)?
        .filter_map(|entry| {
            let entry = entry.unwrap();
            // Not all filenames can be encoded as UTF-8. Skip those for now.
            if let Ok(name) = into_string(entry.file_name()) {
                Some(DirEntry {
                    name,
                    is_file: entry
                        .file_type()
                        .map_or(false, |file_type| file_type.is_file()),
                    is_directory: entry
                        .file_type()
                        .map_or(false, |file_type| file_type.is_dir()),
                    is_symlink: entry
                        .file_type()
                        .map_or(false, |file_type| file_type.is_symlink()),
                })
            } else {
                None
            }
        })
        .collect();

    Ok(entries)
}

#[op]
async fn op_read_dir_async(
    state: Rc<RefCell<OpState>>,
    path: String,
) -> Result<Vec<DirEntry>, AnyError> {
    let path = PathBuf::from(&path);
    {
        let mut state = state.borrow_mut();
        state.borrow_mut::<Permissions>().read.check(&path)?;
    }
    tokio::task::spawn_blocking(move || {
        debug!("op_read_dir_async {}", path.display());
        let err_mapper =
            |err: Error| Error::new(err.kind(), format!("{}, readdir '{}'", err, path.display()));
        let entries: Vec<_> = std::fs::read_dir(&path)
            .map_err(err_mapper)?
            .filter_map(|entry| {
                let entry = entry.unwrap();
                // Not all filenames can be encoded as UTF-8. Skip those for now.
                if let Ok(name) = into_string(entry.file_name()) {
                    Some(DirEntry {
                        name,
                        is_file: entry
                            .file_type()
                            .map_or(false, |file_type| file_type.is_file()),
                        is_directory: entry
                            .file_type()
                            .map_or(false, |file_type| file_type.is_dir()),
                        is_symlink: entry
                            .file_type()
                            .map_or(false, |file_type| file_type.is_symlink()),
                    })
                } else {
                    None
                }
            })
            .collect();

        Ok(entries)
    })
    .await
    .unwrap()
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct RenameArgs {
    oldpath: String,
    newpath: String,
}

#[op]
fn op_rename_sync(state: &mut OpState, args: RenameArgs) -> Result<(), AnyError> {
    let oldpath = PathBuf::from(&args.oldpath);
    let newpath = PathBuf::from(&args.newpath);

    let permissions = state.borrow_mut::<Permissions>();
    permissions.read.check(&oldpath)?;
    permissions.write.check(&oldpath)?;
    permissions.write.check(&newpath)?;
    debug!("op_rename_sync {} {}", oldpath.display(), newpath.display());
    let err_mapper = |err: Error| {
        Error::new(
            err.kind(),
            format!(
                "{}, rename '{}' -> '{}'",
                err,
                oldpath.display(),
                newpath.display()
            ),
        )
    };
    std::fs::rename(&oldpath, &newpath).map_err(err_mapper)?;
    Ok(())
}

#[op]
async fn op_rename_async(state: Rc<RefCell<OpState>>, args: RenameArgs) -> Result<(), AnyError> {
    let oldpath = PathBuf::from(&args.oldpath);
    let newpath = PathBuf::from(&args.newpath);
    {
        let mut state = state.borrow_mut();
        let permissions = state.borrow_mut::<Permissions>();
        permissions.read.check(&oldpath)?;
        permissions.write.check(&oldpath)?;
        permissions.write.check(&newpath)?;
    }
    tokio::task::spawn_blocking(move || {
        debug!(
            "op_rename_async {} {}",
            oldpath.display(),
            newpath.display()
        );
        let err_mapper = |err: Error| {
            Error::new(
                err.kind(),
                format!(
                    "{}, rename '{}' -> '{}'",
                    err,
                    oldpath.display(),
                    newpath.display()
                ),
            )
        };
        std::fs::rename(&oldpath, &newpath).map_err(err_mapper)?;
        Ok(())
    })
    .await
    .unwrap()
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct LinkArgs {
    oldpath: String,
    newpath: String,
}

#[op]
fn op_link_sync(state: &mut OpState, args: LinkArgs) -> Result<(), AnyError> {
    let oldpath = PathBuf::from(&args.oldpath);
    let newpath = PathBuf::from(&args.newpath);

    let permissions = state.borrow_mut::<Permissions>();
    permissions.read.check(&oldpath)?;
    permissions.write.check(&oldpath)?;
    permissions.read.check(&newpath)?;
    permissions.write.check(&newpath)?;

    debug!("op_link_sync {} {}", oldpath.display(), newpath.display());
    let err_mapper = |err: Error| {
        Error::new(
            err.kind(),
            format!(
                "{}, link '{}' -> '{}'",
                err,
                oldpath.display(),
                newpath.display()
            ),
        )
    };
    std::fs::hard_link(&oldpath, &newpath).map_err(err_mapper)?;
    Ok(())
}

#[op]
async fn op_link_async(state: Rc<RefCell<OpState>>, args: LinkArgs) -> Result<(), AnyError> {
    let oldpath = PathBuf::from(&args.oldpath);
    let newpath = PathBuf::from(&args.newpath);

    {
        let mut state = state.borrow_mut();
        let permissions = state.borrow_mut::<Permissions>();
        permissions.read.check(&oldpath)?;
        permissions.write.check(&oldpath)?;
        permissions.read.check(&newpath)?;
        permissions.write.check(&newpath)?;
    }

    tokio::task::spawn_blocking(move || {
        debug!("op_link_async {} {}", oldpath.display(), newpath.display());
        let err_mapper = |err: Error| {
            Error::new(
                err.kind(),
                format!(
                    "{}, link '{}' -> '{}'",
                    err,
                    oldpath.display(),
                    newpath.display()
                ),
            )
        };
        std::fs::hard_link(&oldpath, &newpath).map_err(err_mapper)?;
        Ok(())
    })
    .await
    .unwrap()
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct SymlinkArgs {
    oldpath: String,
    newpath: String,
    #[cfg(not(unix))]
    options: Option<SymlinkOptions>,
}

#[cfg(not(unix))]
#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct SymlinkOptions {
    _type: String,
}

#[op]
fn op_symlink_sync(state: &mut OpState, args: SymlinkArgs) -> Result<(), AnyError> {
    let oldpath = PathBuf::from(&args.oldpath);
    let newpath = PathBuf::from(&args.newpath);

    state.borrow_mut::<Permissions>().write.check_all()?;
    state.borrow_mut::<Permissions>().read.check_all()?;

    debug!(
        "op_symlink_sync {} {}",
        oldpath.display(),
        newpath.display()
    );
    let err_mapper = |err: Error| {
        Error::new(
            err.kind(),
            format!(
                "{}, symlink '{}' -> '{}'",
                err,
                oldpath.display(),
                newpath.display()
            ),
        )
    };
    #[cfg(unix)]
    {
        use std::os::unix::fs::symlink;
        symlink(&oldpath, &newpath).map_err(err_mapper)?;
        Ok(())
    }
    #[cfg(not(unix))]
    {
        use std::os::windows::fs::{symlink_dir, symlink_file};

        match args.options {
            Some(options) => match options._type.as_ref() {
                "file" => symlink_file(&oldpath, &newpath).map_err(err_mapper)?,
                "dir" => symlink_dir(&oldpath, &newpath).map_err(err_mapper)?,
                _ => return Err(type_error("unsupported type")),
            },
            None => {
                let old_meta = std::fs::metadata(&oldpath);
                match old_meta {
          Ok(metadata) => {
            if metadata.is_file() {
              symlink_file(&oldpath, &newpath).map_err(err_mapper)?
            } else if metadata.is_dir() {
              symlink_dir(&oldpath, &newpath).map_err(err_mapper)?
            }
          }
          Err(_) => return Err(type_error("you must pass a `options` argument for non-existent target path in windows".to_string())),
        }
            }
        };
        Ok(())
    }
}

#[op]
async fn op_symlink_async(state: Rc<RefCell<OpState>>, args: SymlinkArgs) -> Result<(), AnyError> {
    let oldpath = PathBuf::from(&args.oldpath);
    let newpath = PathBuf::from(&args.newpath);

    {
        let mut state = state.borrow_mut();
        state.borrow_mut::<Permissions>().write.check_all()?;
        state.borrow_mut::<Permissions>().read.check_all()?;
    }

    tokio::task::spawn_blocking(move || {
    debug!("op_symlink_async {} {}", oldpath.display(), newpath.display());
    let err_mapper = |err: Error| {
      Error::new(
        err.kind(),
        format!(
          "{}, symlink '{}' -> '{}'",
          err,
          oldpath.display(),
          newpath.display()
        ),
      )
    };
    #[cfg(unix)]
    {
      use std::os::unix::fs::symlink;
      symlink(&oldpath, &newpath).map_err(err_mapper)?;
      Ok(())
    }
    #[cfg(not(unix))]
    {
      use std::os::windows::fs::{symlink_dir, symlink_file};

      match args.options {
        Some(options) => match options._type.as_ref() {
          "file" => symlink_file(&oldpath, &newpath).map_err(err_mapper)?,
          "dir" => symlink_dir(&oldpath, &newpath).map_err(err_mapper)?,
          _ => return Err(type_error("unsupported type")),
        },
        None => {
          let old_meta = std::fs::metadata(&oldpath);
          match old_meta {
            Ok(metadata) => {
              if metadata.is_file() {
                symlink_file(&oldpath, &newpath).map_err(err_mapper)?
              } else if metadata.is_dir() {
                symlink_dir(&oldpath, &newpath).map_err(err_mapper)?
              }
            }
            Err(_) => return Err(type_error("you must pass a `options` argument for non-existent target path in windows".to_string())),
          }
        }
      };
      Ok(())
    }
  })
  .await
  .unwrap()
}

#[op]
fn op_read_link_sync(state: &mut OpState, path: String) -> Result<String, AnyError> {
    let path = PathBuf::from(&path);

    state.borrow_mut::<Permissions>().read.check(&path)?;

    debug!("op_read_link_value {}", path.display());
    let err_mapper = |err: Error| {
        Error::new(
            err.kind(),
            format!("{}, readlink '{}'", err, path.display()),
        )
    };
    let target = std::fs::read_link(&path)
        .map_err(err_mapper)?
        .into_os_string();
    let targetstr = into_string(target)?;
    Ok(targetstr)
}

#[op]
async fn op_read_link_async(state: Rc<RefCell<OpState>>, path: String) -> Result<String, AnyError> {
    let path = PathBuf::from(&path);
    {
        let mut state = state.borrow_mut();
        state.borrow_mut::<Permissions>().read.check(&path)?;
    }
    tokio::task::spawn_blocking(move || {
        debug!("op_read_link_async {}", path.display());
        let err_mapper = |err: Error| {
            Error::new(
                err.kind(),
                format!("{}, readlink '{}'", err, path.display()),
            )
        };
        let target = std::fs::read_link(&path)
            .map_err(err_mapper)?
            .into_os_string();
        let targetstr = into_string(target)?;
        Ok(targetstr)
    })
    .await
    .unwrap()
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct FtruncateArgs {
    rid: ResourceId,
    len: i32,
}

#[op]
fn op_ftruncate_sync(state: &mut OpState, args: FtruncateArgs) -> Result<(), AnyError> {
    let rid = args.rid;
    let len = args.len as u64;
    StdFileResource::with_file(state, rid, |std_file| {
        std_file.set_len(len).map_err(AnyError::from)
    })?;
    Ok(())
}

#[op]
async fn op_ftruncate_async(
    state: Rc<RefCell<OpState>>,
    args: FtruncateArgs,
) -> Result<(), AnyError> {
    let rid = args.rid;
    let len = args.len as u64;

    StdFileResource::with_file_blocking_task(state, rid, move |std_file| {
        std_file.set_len(len)?;
        Ok(())
    })
    .await
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct TruncateArgs {
    path: String,
    len: u64,
}

#[op]
fn op_truncate_sync(state: &mut OpState, args: TruncateArgs) -> Result<(), AnyError> {
    let path = PathBuf::from(&args.path);
    let len = args.len;

    state.borrow_mut::<Permissions>().write.check(&path)?;

    debug!("op_truncate_sync {} {}", path.display(), len);
    let err_mapper = |err: Error| {
        Error::new(
            err.kind(),
            format!("{}, truncate '{}'", err, path.display()),
        )
    };
    let f = std::fs::OpenOptions::new()
        .write(true)
        .open(&path)
        .map_err(err_mapper)?;
    f.set_len(len).map_err(err_mapper)?;
    Ok(())
}

#[op]
async fn op_truncate_async(
    state: Rc<RefCell<OpState>>,
    args: TruncateArgs,
) -> Result<(), AnyError> {
    let path = PathBuf::from(&args.path);
    let len = args.len;
    {
        let mut state = state.borrow_mut();
        state.borrow_mut::<Permissions>().write.check(&path)?;
    }
    tokio::task::spawn_blocking(move || {
        debug!("op_truncate_async {} {}", path.display(), len);
        let err_mapper = |err: Error| {
            Error::new(
                err.kind(),
                format!("{}, truncate '{}'", err, path.display()),
            )
        };
        let f = std::fs::OpenOptions::new()
            .write(true)
            .open(&path)
            .map_err(err_mapper)?;
        f.set_len(len).map_err(err_mapper)?;
        Ok(())
    })
    .await
    .unwrap()
}

fn make_temp(
    dir: Option<&Path>,
    prefix: Option<&str>,
    suffix: Option<&str>,
    is_dir: bool,
) -> std::io::Result<PathBuf> {
    let prefix_ = prefix.unwrap_or("");
    let suffix_ = suffix.unwrap_or("");
    let mut buf: PathBuf = match dir {
        Some(p) => p.to_path_buf(),
        None => temp_dir(),
    }
    .join("_");
    let mut rng = thread_rng();
    loop {
        let unique = rng.gen::<u32>();
        buf.set_file_name(format!("{}{:08x}{}", prefix_, unique, suffix_));
        let r = if is_dir {
            #[allow(unused_mut)]
            let mut builder = std::fs::DirBuilder::new();
            #[cfg(unix)]
            {
                use std::os::unix::fs::DirBuilderExt;
                builder.mode(0o700);
            }
            builder.create(buf.as_path())
        } else {
            let mut open_options = std::fs::OpenOptions::new();
            open_options.write(true).create_new(true);
            #[cfg(unix)]
            {
                use std::os::unix::fs::OpenOptionsExt;
                open_options.mode(0o600);
            }
            open_options.open(buf.as_path())?;
            Ok(())
        };
        match r {
            Err(ref e) if e.kind() == std::io::ErrorKind::AlreadyExists => continue,
            Ok(_) => return Ok(buf),
            Err(e) => return Err(e),
        }
    }
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct MakeTempArgs {
    dir: Option<String>,
    prefix: Option<String>,
    suffix: Option<String>,
}

#[op]
fn op_make_temp_dir_sync(state: &mut OpState, args: MakeTempArgs) -> Result<String, AnyError> {
    let dir = args.dir.map(|s| PathBuf::from(&s));
    let prefix = args.prefix.map(String::from);
    let suffix = args.suffix.map(String::from);

    state
        .borrow_mut::<Permissions>()
        .write
        .check(dir.clone().unwrap_or_else(temp_dir).as_path())?;

    // TODO(piscisaureus): use byte vector for paths, not a string.
    // See https://github.com/denoland/deno/issues/627.
    // We can't assume that paths are always valid utf8 strings.
    let path = make_temp(
        // Converting Option<String> to Option<&str>
        dir.as_deref(),
        prefix.as_deref(),
        suffix.as_deref(),
        true,
    )?;
    let path_str = into_string(path.into_os_string())?;

    Ok(path_str)
}

#[op]
async fn op_make_temp_dir_async(
    state: Rc<RefCell<OpState>>,
    args: MakeTempArgs,
) -> Result<String, AnyError> {
    let dir = args.dir.map(|s| PathBuf::from(&s));
    let prefix = args.prefix.map(String::from);
    let suffix = args.suffix.map(String::from);
    {
        let mut state = state.borrow_mut();
        state
            .borrow_mut::<Permissions>()
            .write
            .check(dir.clone().unwrap_or_else(temp_dir).as_path())?;
    }
    tokio::task::spawn_blocking(move || {
        // TODO(piscisaureus): use byte vector for paths, not a string.
        // See https://github.com/denoland/deno/issues/627.
        // We can't assume that paths are always valid utf8 strings.
        let path = make_temp(
            // Converting Option<String> to Option<&str>
            dir.as_deref(),
            prefix.as_deref(),
            suffix.as_deref(),
            true,
        )?;
        let path_str = into_string(path.into_os_string())?;

        Ok(path_str)
    })
    .await
    .unwrap()
}

#[op]
fn op_make_temp_file_sync(state: &mut OpState, args: MakeTempArgs) -> Result<String, AnyError> {
    let dir = args.dir.map(|s| PathBuf::from(&s));
    let prefix = args.prefix.map(String::from);
    let suffix = args.suffix.map(String::from);

    state
        .borrow_mut::<Permissions>()
        .write
        .check(dir.clone().unwrap_or_else(temp_dir).as_path())?;

    // TODO(piscisaureus): use byte vector for paths, not a string.
    // See https://github.com/denoland/deno/issues/627.
    // We can't assume that paths are always valid utf8 strings.
    let path = make_temp(
        // Converting Option<String> to Option<&str>
        dir.as_deref(),
        prefix.as_deref(),
        suffix.as_deref(),
        false,
    )?;
    let path_str = into_string(path.into_os_string())?;

    Ok(path_str)
}

#[op]
async fn op_make_temp_file_async(
    state: Rc<RefCell<OpState>>,
    args: MakeTempArgs,
) -> Result<String, AnyError> {
    let dir = args.dir.map(|s| PathBuf::from(&s));
    let prefix = args.prefix.map(String::from);
    let suffix = args.suffix.map(String::from);
    {
        let mut state = state.borrow_mut();
        state
            .borrow_mut::<Permissions>()
            .write
            .check(dir.clone().unwrap_or_else(temp_dir).as_path())?;
    }
    tokio::task::spawn_blocking(move || {
        // TODO(piscisaureus): use byte vector for paths, not a string.
        // See https://github.com/denoland/deno/issues/627.
        // We can't assume that paths are always valid utf8 strings.
        let path = make_temp(
            // Converting Option<String> to Option<&str>
            dir.as_deref(),
            prefix.as_deref(),
            suffix.as_deref(),
            false,
        )?;
        let path_str = into_string(path.into_os_string())?;

        Ok(path_str)
    })
    .await
    .unwrap()
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct FutimeArgs {
    rid: ResourceId,
    atime: (i64, u32),
    mtime: (i64, u32),
}

#[op]
fn op_futime_sync(state: &mut OpState, args: FutimeArgs) -> Result<(), AnyError> {
    super::check_unstable(state, "Deno.futimeSync");
    let rid = args.rid;
    let atime = filetime::FileTime::from_unix_time(args.atime.0, args.atime.1);
    let mtime = filetime::FileTime::from_unix_time(args.mtime.0, args.mtime.1);

    StdFileResource::with_file(state, rid, |std_file| {
        filetime::set_file_handle_times(std_file, Some(atime), Some(mtime)).map_err(AnyError::from)
    })?;

    Ok(())
}

#[op]
async fn op_futime_async(state: Rc<RefCell<OpState>>, args: FutimeArgs) -> Result<(), AnyError> {
    super::check_unstable2(&state, "Deno.futime");
    let rid = args.rid;
    let atime = filetime::FileTime::from_unix_time(args.atime.0, args.atime.1);
    let mtime = filetime::FileTime::from_unix_time(args.mtime.0, args.mtime.1);

    StdFileResource::with_file_blocking_task(state, rid, move |std_file| {
        filetime::set_file_handle_times(std_file, Some(atime), Some(mtime))?;
        Ok(())
    })
    .await
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct UtimeArgs {
    path: String,
    atime: (i64, u32),
    mtime: (i64, u32),
}

#[op]
fn op_utime_sync(state: &mut OpState, args: UtimeArgs) -> Result<(), AnyError> {
    super::check_unstable(state, "Deno.utime");

    let path = PathBuf::from(&args.path);
    let atime = filetime::FileTime::from_unix_time(args.atime.0, args.atime.1);
    let mtime = filetime::FileTime::from_unix_time(args.mtime.0, args.mtime.1);

    state.borrow_mut::<Permissions>().write.check(&path)?;
    filetime::set_file_times(&path, atime, mtime)
        .map_err(|err| Error::new(err.kind(), format!("{}, utime '{}'", err, path.display())))?;
    Ok(())
}

#[op]
async fn op_utime_async(state: Rc<RefCell<OpState>>, args: UtimeArgs) -> Result<(), AnyError> {
    super::check_unstable(&state.borrow(), "Deno.utime");

    let path = PathBuf::from(&args.path);
    let atime = filetime::FileTime::from_unix_time(args.atime.0, args.atime.1);
    let mtime = filetime::FileTime::from_unix_time(args.mtime.0, args.mtime.1);

    state
        .borrow_mut()
        .borrow_mut::<Permissions>()
        .write
        .check(&path)?;

    tokio::task::spawn_blocking(move || {
        filetime::set_file_times(&path, atime, mtime).map_err(|err| {
            Error::new(err.kind(), format!("{}, utime '{}'", err, path.display()))
        })?;
        Ok(())
    })
    .await
    .unwrap()
}

#[op]
fn op_cwd(state: &mut OpState) -> Result<String, AnyError> {
    let path = current_dir()?;
    state
        .borrow_mut::<Permissions>()
        .read
        .check_blind(&path, "CWD")?;
    let path_str = into_string(path.into_os_string())?;
    Ok(path_str)
}

#[op]
fn op_readfile_sync(state: &mut OpState, path: String) -> Result<ZeroCopyBuf, AnyError> {
    let permissions = state.borrow_mut::<Permissions>();
    let path = Path::new(&path);
    permissions.read.check(path)?;
    Ok(std::fs::read(path)?.into())
}

#[op]
fn op_readfile_text_sync(state: &mut OpState, path: String) -> Result<String, AnyError> {
    let permissions = state.borrow_mut::<Permissions>();
    let path = Path::new(&path);
    permissions.read.check(path)?;
    Ok(string_from_utf8_lossy(std::fs::read(path)?))
}

#[op]
async fn op_readfile_async(
    state: Rc<RefCell<OpState>>,
    path: String,
    cancel_rid: Option<ResourceId>,
) -> Result<ZeroCopyBuf, AnyError> {
    {
        let path = Path::new(&path);
        let mut state = state.borrow_mut();
        state.borrow_mut::<Permissions>().read.check(path)?;
    }
    let fut = tokio::task::spawn_blocking(move || {
        let path = Path::new(&path);
        Ok(std::fs::read(path).map(ZeroCopyBuf::from)?)
    });
    if let Some(cancel_rid) = cancel_rid {
        let cancel_handle = state
            .borrow_mut()
            .resource_table
            .get::<CancelHandle>(cancel_rid);
        if let Ok(cancel_handle) = cancel_handle {
            return fut.or_cancel(cancel_handle).await??;
        }
    }
    fut.await?
}

#[op]
async fn op_readfile_text_async(
    state: Rc<RefCell<OpState>>,
    path: String,
    cancel_rid: Option<ResourceId>,
) -> Result<String, AnyError> {
    {
        let path = Path::new(&path);
        let mut state = state.borrow_mut();
        state.borrow_mut::<Permissions>().read.check(path)?;
    }
    let fut = tokio::task::spawn_blocking(move || {
        let path = Path::new(&path);
        Ok(string_from_utf8_lossy(std::fs::read(path)?))
    });
    if let Some(cancel_rid) = cancel_rid {
        let cancel_handle = state
            .borrow_mut()
            .resource_table
            .get::<CancelHandle>(cancel_rid);
        if let Ok(cancel_handle) = cancel_handle {
            return fut.or_cancel(cancel_handle).await??;
        }
    }
    fut.await?
}

// Like String::from_utf8_lossy but operates on owned values
fn string_from_utf8_lossy(buf: Vec<u8>) -> String {
    match String::from_utf8_lossy(&buf) {
        // buf contained non-utf8 chars than have been patched
        Cow::Owned(s) => s,
        // SAFETY: if Borrowed then the buf only contains utf8 chars,
        // we do this instead of .into_owned() to avoid copying the input buf
        Cow::Borrowed(_) => unsafe { String::from_utf8_unchecked(buf) },
    }
}