pub(crate) mod monitoring;

use crate::{Py, PyPayload, PyResult, VirtualMachine, builtins::PyModule, convert::ToPyObject};

#[cfg(all(not(feature = "host_env"), feature = "stdio"))]
pub(crate) use sys::SandboxStdio;
pub(crate) use sys::{DOC, MAXSIZE, RUST_MULTIARCH, UnraisableHookArgsData, module_def, multiarch};

#[pymodule(name = "_jit")]
mod sys_jit {
    /// Return True if the current Python executable supports JIT compilation,
    /// and False otherwise.
    #[pyfunction]
    const fn is_available() -> bool {
        false // RustPython has no JIT
    }

    /// Return True if JIT compilation is enabled for the current Python process,
    /// and False otherwise.
    #[pyfunction]
    const fn is_enabled() -> bool {
        false // RustPython has no JIT
    }

    /// Return True if the topmost Python frame is currently executing JIT code,
    /// and False otherwise.
    #[pyfunction]
    const fn is_active() -> bool {
        false // RustPython has no JIT
    }
}

#[pymodule]
mod sys {
    use crate::{
        AsObject, PyObject, PyObjectRef, PyPayload, PyRef, PyRefExact, PyResult,
        builtins::{
            PyBaseExceptionRef, PyDictRef, PyFrozenSet, PyNamespace, PyStr, PyStrRef, PyTuple,
            PyTupleRef, PyTypeRef, PyUtf8StrRef,
        },
        common::{
            ascii,
            hash::{PyHash, PyUHash},
        },
        convert::ToPyObject,
        frame::{Frame, FrameRef},
        function::{FuncArgs, KwArgs, OptionalArg, PosArgs},
        stdlib::{_warnings::warn, builtins},
        types::PyStructSequence,
        version,
        vm::{Settings, VirtualMachine},
    };
    use core::sync::atomic::Ordering;
    use num_traits::ToPrimitive;
    use std::{
        env::{self, VarError},
        io::{IsTerminal, Read, Write},
    };

    #[cfg(windows)]
    use windows_sys::Win32::{
        Foundation::MAX_PATH,
        Storage::FileSystem::{
            GetFileVersionInfoSizeW, GetFileVersionInfoW, VS_FIXEDFILEINFO, VerQueryValueW,
        },
        System::LibraryLoader::{GetModuleFileNameW, GetModuleHandleW},
    };

    // Rust target triple (e.g., "x86_64-unknown-linux-gnu")
    pub(crate) const RUST_MULTIARCH: &str = env!("RUSTPYTHON_TARGET_TRIPLE");

    /// Convert Rust target triple to CPython-style multiarch
    /// e.g., "x86_64-unknown-linux-gnu" -> "x86_64-linux-gnu"
    pub(crate) fn multiarch() -> String {
        RUST_MULTIARCH.replace("-unknown", "")
    }

    #[pymodule(name = "monitoring", with(super::monitoring::sys_monitoring))]
    pub(super) mod monitoring {}

    #[pyclass(no_attr, name = "_BootstrapStderr")]
    #[derive(Debug, PyPayload)]
    pub(super) struct BootstrapStderr;

    #[pyclass]
    impl BootstrapStderr {
        #[pymethod]
        fn write(&self, s: PyStrRef) -> PyResult<usize> {
            let bytes = s.as_bytes();
            let _ = std::io::stderr().write_all(bytes);
            Ok(bytes.len())
        }

        #[pymethod]
        fn flush(&self) -> PyResult<()> {
            let _ = std::io::stderr().flush();
            Ok(())
        }
    }

    /// Lightweight stdio wrapper for sandbox mode (no host_env).
    /// Directly uses Rust's std::io for stdin/stdout/stderr without FileIO.
    #[pyclass(no_attr, name = "_SandboxStdio")]
    #[derive(Debug, PyPayload)]
    pub struct SandboxStdio {
        pub fd: i32,
        pub name: String,
        pub mode: String,
    }

    #[pyclass]
    impl SandboxStdio {
        #[pymethod]
        fn write(&self, s: PyStrRef, vm: &VirtualMachine) -> PyResult<usize> {
            if self.fd == 0 {
                return Err(vm.new_os_error("not writable".to_owned()));
            }
            let bytes = s.as_bytes();
            if self.fd == 2 {
                std::io::stderr()
                    .write_all(bytes)
                    .map_err(|e| vm.new_os_error(e.to_string()))?;
            } else {
                std::io::stdout()
                    .write_all(bytes)
                    .map_err(|e| vm.new_os_error(e.to_string()))?;
            }
            Ok(bytes.len())
        }

        #[pymethod]
        fn readline(&self, size: OptionalArg<isize>, vm: &VirtualMachine) -> PyResult<String> {
            if self.fd != 0 {
                return Err(vm.new_os_error("not readable".to_owned()));
            }
            let size = size.unwrap_or(-1);
            if size == 0 {
                return Ok(String::new());
            }
            let mut line = String::new();
            std::io::stdin()
                .read_line(&mut line)
                .map_err(|e| vm.new_os_error(e.to_string()))?;
            if size > 0 {
                line.truncate(size as usize);
            }
            Ok(line)
        }

        #[pymethod]
        fn flush(&self, vm: &VirtualMachine) -> PyResult<()> {
            match self.fd {
                1 => {
                    std::io::stdout()
                        .flush()
                        .map_err(|e| vm.new_os_error(e.to_string()))?;
                }
                2 => {
                    std::io::stderr()
                        .flush()
                        .map_err(|e| vm.new_os_error(e.to_string()))?;
                }
                _ => {}
            }
            Ok(())
        }

        #[pymethod]
        fn fileno(&self) -> i32 {
            self.fd
        }

        #[pymethod]
        fn isatty(&self) -> bool {
            match self.fd {
                0 => std::io::stdin().is_terminal(),
                1 => std::io::stdout().is_terminal(),
                2 => std::io::stderr().is_terminal(),
                _ => false,
            }
        }

        #[pymethod]
        fn readable(&self) -> bool {
            self.fd == 0
        }

        #[pymethod]
        fn writable(&self) -> bool {
            self.fd == 1 || self.fd == 2
        }

        #[pygetset]
        fn closed(&self) -> bool {
            false
        }

        #[pygetset]
        fn encoding(&self) -> String {
            "utf-8".to_owned()
        }

        #[pygetset]
        fn errors(&self) -> String {
            if self.fd == 2 {
                "backslashreplace"
            } else {
                "strict"
            }
            .to_owned()
        }

        #[pygetset(name = "name")]
        fn name_prop(&self) -> String {
            self.name.clone()
        }

        #[pygetset(name = "mode")]
        fn mode_prop(&self) -> String {
            self.mode.clone()
        }
    }

    #[pyattr(name = "_rustpython_debugbuild")]
    const RUSTPYTHON_DEBUGBUILD: bool = cfg!(debug_assertions);

    #[cfg(not(windows))]
    #[pyattr(name = "abiflags")]
    const ABIFLAGS_ATTR: &str = "t"; // 't' for free-threaded (no GIL)
    // Internal constant used for sysconfigdata_name
    pub const ABIFLAGS: &str = "t";
    #[pyattr(name = "api_version")]
    const API_VERSION: u32 = 0x0; // what C api?
    #[pyattr(name = "copyright")]
    const COPYRIGHT: &str = "Copyright (c) 2019 RustPython Team";
    #[pyattr(name = "float_repr_style")]
    const FLOAT_REPR_STYLE: &str = "short";
    #[pyattr(name = "_framework")]
    const FRAMEWORK: &str = "";
    #[pyattr(name = "hexversion")]
    const HEXVERSION: usize = version::VERSION_HEX;
    #[pyattr(name = "maxsize")]
    pub(crate) const MAXSIZE: isize = isize::MAX;
    #[pyattr(name = "maxunicode")]
    const MAXUNICODE: u32 = core::char::MAX as u32;
    #[pyattr(name = "platform")]
    pub const PLATFORM: &str = {
        cfg_if::cfg_if! {
            if #[cfg(target_os = "linux")] {
                "linux"
            } else if #[cfg(target_os = "android")] {
                "android"
            } else if #[cfg(target_os = "macos")] {
                "darwin"
            } else if #[cfg(target_os = "ios")] {
                "ios"
            } else if #[cfg(windows)] {
                "win32"
            } else if #[cfg(target_os = "wasi")] {
                "wasi"
            } else {
                "unknown"
            }
        }
    };
    #[pyattr(name = "ps1")]
    const PS1: &str = ">>>>> ";
    #[pyattr(name = "ps2")]
    const PS2: &str = "..... ";

    #[cfg(windows)]
    #[pyattr(name = "_vpath")]
    const VPATH: Option<&'static str> = None; // TODO: actual VPATH value

    #[cfg(windows)]
    #[pyattr(name = "dllhandle")]
    const DLLHANDLE: usize = 0;

    #[pyattr]
    fn prefix(vm: &VirtualMachine) -> String {
        vm.state.config.paths.prefix.clone()
    }
    #[pyattr]
    fn base_prefix(vm: &VirtualMachine) -> String {
        vm.state.config.paths.base_prefix.clone()
    }
    #[pyattr]
    fn exec_prefix(vm: &VirtualMachine) -> String {
        vm.state.config.paths.exec_prefix.clone()
    }
    #[pyattr]
    fn base_exec_prefix(vm: &VirtualMachine) -> String {
        vm.state.config.paths.base_exec_prefix.clone()
    }
    #[pyattr]
    fn platlibdir(_vm: &VirtualMachine) -> &'static str {
        option_env!("RUSTPYTHON_PLATLIBDIR").unwrap_or("lib")
    }
    #[pyattr]
    fn _stdlib_dir(vm: &VirtualMachine) -> PyObjectRef {
        vm.state.config.paths.stdlib_dir.clone().to_pyobject(vm)
    }

    // alphabetical order with segments of pyattr and others

    #[pyattr]
    fn argv(vm: &VirtualMachine) -> Vec<PyObjectRef> {
        vm.state
            .config
            .settings
            .argv
            .iter()
            .map(|arg| vm.ctx.new_str(arg.clone()).into())
            .collect()
    }

    #[pyattr]
    fn builtin_module_names(vm: &VirtualMachine) -> PyTupleRef {
        let mut module_names: Vec<String> =
            vm.state.module_defs.keys().map(|&s| s.to_owned()).collect();
        module_names.push("sys".to_owned());
        module_names.push("builtins".to_owned());

        module_names.sort();
        vm.ctx.new_tuple(
            module_names
                .into_iter()
                .map(|n| vm.ctx.new_str(n).into())
                .collect(),
        )
    }

    // List from cpython/Python/stdlib_module_names.h
    const STDLIB_MODULE_NAMES: &[&str] = &[
        "__future__",
        "_abc",
        "_aix_support",
        "_android_support",
        "_apple_support",
        "_ast",
        "_asyncio",
        "_bisect",
        "_blake2",
        "_bz2",
        "_codecs",
        "_codecs_cn",
        "_codecs_hk",
        "_codecs_iso2022",
        "_codecs_jp",
        "_codecs_kr",
        "_codecs_tw",
        "_collections",
        "_collections_abc",
        "_colorize",
        "_compat_pickle",
        "_compression",
        "_contextvars",
        "_csv",
        "_ctypes",
        "_curses",
        "_curses_panel",
        "_datetime",
        "_dbm",
        "_decimal",
        "_elementtree",
        "_frozen_importlib",
        "_frozen_importlib_external",
        "_functools",
        "_gdbm",
        "_hashlib",
        "_heapq",
        "_imp",
        "_interpchannels",
        "_interpqueues",
        "_interpreters",
        "_io",
        "_ios_support",
        "_json",
        "_locale",
        "_lsprof",
        "_lzma",
        "_markupbase",
        "_md5",
        "_multibytecodec",
        "_multiprocessing",
        "_opcode",
        "_opcode_metadata",
        "_operator",
        "_osx_support",
        "_overlapped",
        "_pickle",
        "_posixshmem",
        "_posixsubprocess",
        "_py_abc",
        "_pydatetime",
        "_pydecimal",
        "_pyio",
        "_pylong",
        "_pyrepl",
        "_queue",
        "_random",
        "_scproxy",
        "_sha1",
        "_sha2",
        "_sha3",
        "_signal",
        "_sitebuiltins",
        "_socket",
        "_sqlite3",
        "_sre",
        "_ssl",
        "_stat",
        "_statistics",
        "_string",
        "_strptime",
        "_struct",
        "_suggestions",
        "_symtable",
        "_sysconfig",
        "_thread",
        "_threading_local",
        "_tkinter",
        "_tokenize",
        "_tracemalloc",
        "_typing",
        "_uuid",
        "_warnings",
        "_weakref",
        "_weakrefset",
        "_winapi",
        "_wmi",
        "_zoneinfo",
        "abc",
        "antigravity",
        "argparse",
        "array",
        "ast",
        "asyncio",
        "atexit",
        "base64",
        "bdb",
        "binascii",
        "bisect",
        "builtins",
        "bz2",
        "cProfile",
        "calendar",
        "cmath",
        "cmd",
        "code",
        "codecs",
        "codeop",
        "collections",
        "colorsys",
        "compileall",
        "concurrent",
        "configparser",
        "contextlib",
        "contextvars",
        "copy",
        "copyreg",
        "csv",
        "ctypes",
        "curses",
        "dataclasses",
        "datetime",
        "dbm",
        "decimal",
        "difflib",
        "dis",
        "doctest",
        "email",
        "encodings",
        "ensurepip",
        "enum",
        "errno",
        "faulthandler",
        "fcntl",
        "filecmp",
        "fileinput",
        "fnmatch",
        "fractions",
        "ftplib",
        "functools",
        "gc",
        "genericpath",
        "getopt",
        "getpass",
        "gettext",
        "glob",
        "graphlib",
        "grp",
        "gzip",
        "hashlib",
        "heapq",
        "hmac",
        "html",
        "http",
        "idlelib",
        "imaplib",
        "importlib",
        "inspect",
        "io",
        "ipaddress",
        "itertools",
        "json",
        "keyword",
        "linecache",
        "locale",
        "logging",
        "lzma",
        "mailbox",
        "marshal",
        "math",
        "mimetypes",
        "mmap",
        "modulefinder",
        "msvcrt",
        "multiprocessing",
        "netrc",
        "nt",
        "ntpath",
        "nturl2path",
        "numbers",
        "opcode",
        "operator",
        "optparse",
        "os",
        "pathlib",
        "pdb",
        "pickle",
        "pickletools",
        "pkgutil",
        "platform",
        "plistlib",
        "poplib",
        "posix",
        "posixpath",
        "pprint",
        "profile",
        "pstats",
        "pty",
        "pwd",
        "py_compile",
        "pyclbr",
        "pydoc",
        "pydoc_data",
        "pyexpat",
        "queue",
        "quopri",
        "random",
        "re",
        "readline",
        "reprlib",
        "resource",
        "rlcompleter",
        "runpy",
        "sched",
        "secrets",
        "select",
        "selectors",
        "shelve",
        "shlex",
        "shutil",
        "signal",
        "site",
        "smtplib",
        "socket",
        "socketserver",
        "sqlite3",
        "sre_compile",
        "sre_constants",
        "sre_parse",
        "ssl",
        "stat",
        "statistics",
        "string",
        "stringprep",
        "struct",
        "subprocess",
        "symtable",
        "sys",
        "sysconfig",
        "syslog",
        "tabnanny",
        "tarfile",
        "tempfile",
        "termios",
        "textwrap",
        "this",
        "threading",
        "time",
        "timeit",
        "tkinter",
        "token",
        "tokenize",
        "tomllib",
        "trace",
        "traceback",
        "tracemalloc",
        "tty",
        "turtle",
        "turtledemo",
        "types",
        "typing",
        "unicodedata",
        "unittest",
        "urllib",
        "uuid",
        "venv",
        "warnings",
        "wave",
        "weakref",
        "webbrowser",
        "winreg",
        "winsound",
        "wsgiref",
        "xml",
        "xmlrpc",
        "zipapp",
        "zipfile",
        "zipimport",
        "zlib",
        "zoneinfo",
    ];

    #[pyattr(once)]
    fn stdlib_module_names(vm: &VirtualMachine) -> PyObjectRef {
        let names = STDLIB_MODULE_NAMES
            .iter()
            .map(|&n| vm.ctx.new_str(n).into());
        PyFrozenSet::from_iter(vm, names)
            .expect("Creating stdlib_module_names frozen set must succeed")
            .to_pyobject(vm)
    }

    #[pyattr]
    fn byteorder(vm: &VirtualMachine) -> PyStrRef {
        // https://doc.rust-lang.org/reference/conditional-compilation.html#target_endian
        vm.ctx
            .intern_str(if cfg!(target_endian = "little") {
                "little"
            } else if cfg!(target_endian = "big") {
                "big"
            } else {
                "unknown"
            })
            .to_owned()
    }

    #[pyattr]
    fn _base_executable(vm: &VirtualMachine) -> String {
        vm.state.config.paths.base_executable.clone()
    }

    #[pyattr]
    fn dont_write_bytecode(vm: &VirtualMachine) -> bool {
        !vm.state.config.settings.write_bytecode
    }

    #[pyattr]
    fn executable(vm: &VirtualMachine) -> String {
        vm.state.config.paths.executable.clone()
    }

    #[pyattr]
    fn _git(vm: &VirtualMachine) -> PyTupleRef {
        vm.new_tuple((
            ascii!("RustPython"),
            version::get_git_identifier(),
            version::get_git_revision(),
        ))
    }

    #[pyattr]
    fn implementation(vm: &VirtualMachine) -> PyRef<PyNamespace> {
        const NAME: &str = "rustpython";

        let cache_tag = format!("{NAME}-{}{}", version::MAJOR, version::MINOR);
        let ctx = &vm.ctx;
        py_namespace!(vm, {
            "name" => ctx.new_str(NAME),
            "cache_tag" => ctx.new_str(cache_tag),
            "_multiarch" => ctx.new_str(multiarch()),
            "version" => version_info(vm),
            "hexversion" => ctx.new_int(version::VERSION_HEX),
            "supports_isolated_interpreters" => ctx.new_bool(false),
        })
    }

    #[pyattr]
    const fn meta_path(_vm: &VirtualMachine) -> Vec<PyObjectRef> {
        Vec::new()
    }

    #[pyattr]
    fn orig_argv(vm: &VirtualMachine) -> Vec<PyObjectRef> {
        env::args().map(|arg| vm.ctx.new_str(arg).into()).collect()
    }

    #[pyattr]
    fn path(vm: &VirtualMachine) -> Vec<PyObjectRef> {
        vm.state
            .config
            .paths
            .module_search_paths
            .iter()
            .map(|path| vm.ctx.new_str(path.clone()).into())
            .collect()
    }

    #[pyattr]
    const fn path_hooks(_vm: &VirtualMachine) -> Vec<PyObjectRef> {
        Vec::new()
    }

    #[pyattr]
    fn path_importer_cache(vm: &VirtualMachine) -> PyDictRef {
        vm.ctx.new_dict()
    }

    #[pyattr]
    fn pycache_prefix(vm: &VirtualMachine) -> PyObjectRef {
        vm.ctx.none()
    }

    #[pyattr]
    fn version(_vm: &VirtualMachine) -> String {
        version::get_version()
    }

    #[cfg(windows)]
    #[pyattr]
    fn winver(_vm: &VirtualMachine) -> String {
        // Note: This is Python DLL version in CPython, but we arbitrary fill it for compatibility
        version::get_winver_number()
    }

    #[pyattr]
    fn _xoptions(vm: &VirtualMachine) -> PyDictRef {
        let ctx = &vm.ctx;
        let xopts = ctx.new_dict();
        for (key, value) in &vm.state.config.settings.xoptions {
            let value = value.as_ref().map_or_else(
                || ctx.new_bool(true).into(),
                |s| ctx.new_str(s.clone()).into(),
            );
            xopts.set_item(&**key, value, vm).unwrap();
        }
        xopts
    }

    #[pyattr]
    fn warnoptions(vm: &VirtualMachine) -> Vec<PyObjectRef> {
        vm.state
            .config
            .settings
            .warnoptions
            .iter()
            .map(|s| vm.ctx.new_str(s.clone()).into())
            .collect()
    }

    #[cfg(feature = "rustpython-compiler")]
    #[pyfunction]
    fn _baserepl(vm: &VirtualMachine) -> PyResult<()> {
        // read stdin to end
        let stdin = std::io::stdin();
        let mut handle = stdin.lock();
        let mut source = String::new();
        handle
            .read_to_string(&mut source)
            .map_err(|e| vm.new_os_error(format!("Error reading from stdin: {e}")))?;
        vm.compile(&source, crate::compiler::Mode::Single, "<stdin>".to_owned())
            .map_err(|e| vm.new_os_error(format!("Error running stdin: {e}")))?;
        Ok(())
    }

    #[pyfunction]
    fn audit(_args: FuncArgs) {
        // TODO: sys.audit implementation
    }

    #[pyfunction]
    const fn _is_gil_enabled() -> bool {
        false // RustPython has no GIL (like free-threaded Python)
    }

    /// Return True if remote debugging is enabled, False otherwise.
    #[pyfunction]
    const fn is_remote_debug_enabled() -> bool {
        false // RustPython does not support remote debugging
    }

    #[pyfunction]
    fn exit(code: OptionalArg<PyObjectRef>, vm: &VirtualMachine) -> PyResult {
        let status = code.unwrap_or_none(vm);
        let args = if let Some(status_tuple) = status.downcast_ref::<PyTuple>() {
            status_tuple.as_slice().to_vec()
        } else {
            vec![status]
        };
        let exc = vm.invoke_exception(vm.ctx.exceptions.system_exit.to_owned(), args)?;
        Err(exc)
    }

    #[pyfunction]
    fn call_tracing(func: PyObjectRef, args: PyTupleRef, vm: &VirtualMachine) -> PyResult {
        // CPython temporarily enables tracing state around this call.
        // RustPython does not currently model the full C-level tracing toggles,
        // but call semantics (func(*args)) are matched.
        func.call(PosArgs::new(args.as_slice().to_vec()), vm)
    }

    #[pyfunction]
    fn exception(vm: &VirtualMachine) -> Option<PyBaseExceptionRef> {
        vm.topmost_exception()
    }

    #[pyfunction(name = "__displayhook__")]
    #[pyfunction]
    fn displayhook(obj: PyObjectRef, vm: &VirtualMachine) -> PyResult<()> {
        // Save non-None values as "_"
        if vm.is_none(&obj) {
            return Ok(());
        }
        // set to none to avoid recursion while printing
        vm.builtins.set_attr("_", vm.ctx.none(), vm)?;
        // TODO: catch encoding errors
        let repr = obj.repr(vm)?.into();
        builtins::print(PosArgs::new(vec![repr]), Default::default(), vm)?;
        vm.builtins.set_attr("_", obj, vm)?;
        Ok(())
    }

    #[pyfunction(name = "__excepthook__")]
    #[pyfunction]
    fn excepthook(
        exc_type: PyObjectRef,
        exc_val: PyObjectRef,
        exc_tb: PyObjectRef,
        vm: &VirtualMachine,
    ) -> PyResult<()> {
        let stderr = super::get_stderr(vm)?;
        match vm.normalize_exception(exc_type.clone(), exc_val.clone(), exc_tb) {
            Ok(exc) => {
                // PyErr_Display: try traceback._print_exception_bltin first
                if let Ok(tb_mod) = vm.import("traceback", 0)
                    && let Ok(print_exc_builtin) = tb_mod.get_attr("_print_exception_bltin", vm)
                    && print_exc_builtin
                        .call((exc.as_object().to_owned(),), vm)
                        .is_ok()
                {
                    return Ok(());
                }
                // Fallback to Rust-level exception printing
                vm.write_exception(&mut crate::py_io::PyWriter(stderr, vm), &exc)
            }
            Err(_) => {
                let type_name = exc_val.class().name();
                let msg = format!(
                    "TypeError: print_exception(): Exception expected for value, {type_name} found\n"
                );
                use crate::py_io::Write;
                write!(&mut crate::py_io::PyWriter(stderr, vm), "{msg}")?;
                Ok(())
            }
        }
    }

    #[pyfunction(name = "__breakpointhook__")]
    #[pyfunction]
    pub fn breakpointhook(args: FuncArgs, vm: &VirtualMachine) -> PyResult {
        let env_var = std::env::var("PYTHONBREAKPOINT")
            .and_then(|env_var| {
                if env_var.is_empty() {
                    Err(VarError::NotPresent)
                } else {
                    Ok(env_var)
                }
            })
            .unwrap_or_else(|_| "pdb.set_trace".to_owned());

        if env_var.eq("0") {
            return Ok(vm.ctx.none());
        };

        let print_unimportable_module_warn = || {
            warn(
                vm.ctx.exceptions.runtime_warning,
                format!("Ignoring unimportable $PYTHONBREAKPOINT: \"{env_var}\"",),
                0,
                vm,
            )
            .unwrap();
            Ok(vm.ctx.none())
        };

        let last = match env_var.rsplit_once('.') {
            Some((_, last)) => last,
            None if !env_var.is_empty() => env_var.as_str(),
            _ => return print_unimportable_module_warn(),
        };

        let (module_path, attr_name) = if last == env_var {
            ("builtins", env_var.as_str())
        } else {
            (&env_var[..(env_var.len() - last.len() - 1)], last)
        };

        let module = match vm.import(&vm.ctx.new_str(module_path), 0) {
            Ok(module) => module,
            Err(_) => {
                return print_unimportable_module_warn();
            }
        };

        match vm.get_attribute_opt(module, &vm.ctx.new_str(attr_name)) {
            Ok(Some(hook)) => hook.as_ref().call(args, vm),
            _ => print_unimportable_module_warn(),
        }
    }

    #[pyfunction]
    fn exc_info(vm: &VirtualMachine) -> (PyObjectRef, PyObjectRef, PyObjectRef) {
        match vm.topmost_exception() {
            Some(exception) => vm.split_exception(exception),
            None => (vm.ctx.none(), vm.ctx.none(), vm.ctx.none()),
        }
    }

    #[pyattr]
    fn flags(vm: &VirtualMachine) -> PyTupleRef {
        PyFlags::from_data(FlagsData::from_settings(&vm.state.config.settings), vm)
    }

    #[pyattr]
    fn float_info(vm: &VirtualMachine) -> PyTupleRef {
        PyFloatInfo::from_data(FloatInfoData::INFO, vm)
    }

    #[pyfunction]
    const fn getdefaultencoding() -> &'static str {
        crate::codecs::DEFAULT_ENCODING
    }

    #[pyfunction]
    fn getrefcount(obj: PyObjectRef) -> usize {
        obj.strong_count()
    }

    #[pyfunction]
    fn getrecursionlimit(vm: &VirtualMachine) -> usize {
        vm.recursion_limit.get()
    }

    #[derive(FromArgs)]
    struct GetsizeofArgs {
        obj: PyObjectRef,
        #[pyarg(any, optional)]
        default: Option<PyObjectRef>,
    }

    #[pyfunction]
    fn getsizeof(args: GetsizeofArgs, vm: &VirtualMachine) -> PyResult {
        let sizeof = || -> PyResult<usize> {
            let res = vm.call_special_method(&args.obj, identifier!(vm, __sizeof__), ())?;
            let res = res.try_index(vm)?.try_to_primitive::<usize>(vm)?;
            Ok(res + core::mem::size_of::<PyObject>())
        };
        sizeof()
            .map(|x| vm.ctx.new_int(x).into())
            .or_else(|err| args.default.ok_or(err))
    }

    #[pyfunction]
    fn getfilesystemencoding(vm: &VirtualMachine) -> PyStrRef {
        vm.fs_encoding().to_owned()
    }

    #[pyfunction]
    fn getfilesystemencodeerrors(vm: &VirtualMachine) -> PyUtf8StrRef {
        vm.fs_encode_errors().to_owned()
    }

    #[pyfunction]
    fn getprofile(vm: &VirtualMachine) -> PyObjectRef {
        vm.profile_func.borrow().clone()
    }

    #[pyfunction]
    fn _getframe(offset: OptionalArg<usize>, vm: &VirtualMachine) -> PyResult<FrameRef> {
        let offset = offset.into_option().unwrap_or(0);
        let frames = vm.frames.borrow();
        if offset >= frames.len() {
            return Err(vm.new_value_error("call stack is not deep enough"));
        }
        let idx = frames.len() - offset - 1;
        // SAFETY: the FrameRef is alive on the call stack while it's in the Vec
        let py: &crate::Py<Frame> = unsafe { frames[idx].as_ref() };
        Ok(py.to_owned())
    }

    #[pyfunction]
    fn _getframemodulename(depth: OptionalArg<usize>, vm: &VirtualMachine) -> PyResult {
        let depth = depth.into_option().unwrap_or(0);

        // Get the frame at the specified depth
        let func_obj = {
            let frames = vm.frames.borrow();
            if depth >= frames.len() {
                return Ok(vm.ctx.none());
            }
            let idx = frames.len() - depth - 1;
            // SAFETY: the FrameRef is alive on the call stack while it's in the Vec
            let frame: &crate::Py<Frame> = unsafe { frames[idx].as_ref() };
            frame.func_obj.clone()
        };

        // If the frame has a function object, return its __module__ attribute
        if let Some(func_obj) = func_obj {
            match func_obj.get_attr(identifier!(vm, __module__), vm) {
                Ok(module) => Ok(module),
                Err(_) => {
                    // CPython clears the error and returns None
                    Ok(vm.ctx.none())
                }
            }
        } else {
            Ok(vm.ctx.none())
        }
    }

    /// Return a dictionary mapping each thread's identifier to the topmost stack frame
    /// currently active in that thread at the time the function is called.
    #[cfg(feature = "threading")]
    #[pyfunction]
    fn _current_frames(vm: &VirtualMachine) -> PyResult<PyDictRef> {
        use crate::AsObject;
        use crate::stdlib::_thread::get_all_current_frames;

        let frames = get_all_current_frames(vm);
        let dict = vm.ctx.new_dict();

        for (thread_id, frame) in frames {
            let key = vm.ctx.new_int(thread_id);
            dict.set_item(key.as_object(), frame.into(), vm)?;
        }

        Ok(dict)
    }

    /// Return a dictionary mapping each thread's identifier to its currently
    /// active exception, or None if no exception is active.
    #[cfg(feature = "threading")]
    #[pyfunction]
    fn _current_exceptions(vm: &VirtualMachine) -> PyResult<PyDictRef> {
        use crate::AsObject;
        use crate::vm::thread::get_all_current_exceptions;

        let dict = vm.ctx.new_dict();
        for (thread_id, exc) in get_all_current_exceptions(vm) {
            let key = vm.ctx.new_int(thread_id);
            let value = exc.map_or_else(|| vm.ctx.none(), |e| e.into());
            dict.set_item(key.as_object(), value, vm)?;
        }

        Ok(dict)
    }

    #[cfg(not(feature = "threading"))]
    #[pyfunction]
    fn _current_exceptions(vm: &VirtualMachine) -> PyResult<PyDictRef> {
        let dict = vm.ctx.new_dict();
        let key = vm.ctx.new_int(0);
        dict.set_item(key.as_object(), vm.topmost_exception().to_pyobject(vm), vm)?;
        Ok(dict)
    }

    /// Stub for non-threading builds - returns empty dict
    #[cfg(not(feature = "threading"))]
    #[pyfunction]
    fn _current_frames(vm: &VirtualMachine) -> PyResult<PyDictRef> {
        Ok(vm.ctx.new_dict())
    }

    #[pyfunction]
    fn gettrace(vm: &VirtualMachine) -> PyObjectRef {
        vm.trace_func.borrow().clone()
    }

    #[cfg(windows)]
    fn get_kernel32_version() -> std::io::Result<(u32, u32, u32)> {
        use crate::common::windows::ToWideString;
        unsafe {
            // Create a wide string for "kernel32.dll"
            let module_name: Vec<u16> = std::ffi::OsStr::new("kernel32.dll").to_wide_with_nul();
            let h_kernel32 = GetModuleHandleW(module_name.as_ptr());
            if h_kernel32.is_null() {
                return Err(std::io::Error::last_os_error());
            }

            // Prepare a buffer for the module file path
            let mut kernel32_path = [0u16; MAX_PATH as usize];
            let len = GetModuleFileNameW(
                h_kernel32,
                kernel32_path.as_mut_ptr(),
                kernel32_path.len() as u32,
            );
            if len == 0 {
                return Err(std::io::Error::last_os_error());
            }

            // Get the size of the version information block
            let ver_block_size =
                GetFileVersionInfoSizeW(kernel32_path.as_ptr(), core::ptr::null_mut());
            if ver_block_size == 0 {
                return Err(std::io::Error::last_os_error());
            }

            // Allocate a buffer to hold the version information
            let mut ver_block = vec![0u8; ver_block_size as usize];
            if GetFileVersionInfoW(
                kernel32_path.as_ptr(),
                0,
                ver_block_size,
                ver_block.as_mut_ptr() as *mut _,
            ) == 0
            {
                return Err(std::io::Error::last_os_error());
            }

            // Prepare an empty sub-block string (L"") as required by VerQueryValueW
            let sub_block: Vec<u16> = std::ffi::OsStr::new("").to_wide_with_nul();

            let mut ffi_ptr: *mut VS_FIXEDFILEINFO = core::ptr::null_mut();
            let mut ffi_len: u32 = 0;
            if VerQueryValueW(
                ver_block.as_ptr() as *const _,
                sub_block.as_ptr(),
                &mut ffi_ptr as *mut *mut VS_FIXEDFILEINFO as *mut *mut _,
                &mut ffi_len as *mut u32,
            ) == 0
                || ffi_ptr.is_null()
            {
                return Err(std::io::Error::last_os_error());
            }

            // Extract the version numbers from the VS_FIXEDFILEINFO structure.
            let ffi = *ffi_ptr;
            let real_major = (ffi.dwProductVersionMS >> 16) & 0xFFFF;
            let real_minor = ffi.dwProductVersionMS & 0xFFFF;
            let real_build = (ffi.dwProductVersionLS >> 16) & 0xFFFF;

            Ok((real_major, real_minor, real_build))
        }
    }

    #[cfg(windows)]
    #[pyfunction]
    fn getwindowsversion(vm: &VirtualMachine) -> PyResult<crate::builtins::tuple::PyTupleRef> {
        use std::ffi::OsString;
        use std::os::windows::ffi::OsStringExt;
        use windows_sys::Win32::System::SystemInformation::{
            GetVersionExW, OSVERSIONINFOEXW, OSVERSIONINFOW,
        };

        let mut version: OSVERSIONINFOEXW = unsafe { core::mem::zeroed() };
        version.dwOSVersionInfoSize = core::mem::size_of::<OSVERSIONINFOEXW>() as u32;
        let result = unsafe {
            let os_vi = &mut version as *mut OSVERSIONINFOEXW as *mut OSVERSIONINFOW;
            // SAFETY: GetVersionExW accepts a pointer of OSVERSIONINFOW, but windows-sys crate's type currently doesn't allow to do so.
            // https://docs.microsoft.com/en-us/windows/win32/api/sysinfoapi/nf-sysinfoapi-getversionexw#parameters
            GetVersionExW(os_vi)
        };

        if result == 0 {
            return Err(vm.new_os_error("failed to get windows version".to_owned()));
        }

        let service_pack = {
            let (last, _) = version
                .szCSDVersion
                .iter()
                .take_while(|&x| x != &0)
                .enumerate()
                .last()
                .unwrap_or((0, &0));
            let sp = OsString::from_wide(&version.szCSDVersion[..last]);
            sp.into_string()
                .map_err(|_| vm.new_os_error("service pack is not ASCII".to_owned()))?
        };
        let real_version = get_kernel32_version().map_err(|e| vm.new_os_error(e.to_string()))?;
        let winver = WindowsVersionData {
            major: real_version.0,
            minor: real_version.1,
            build: real_version.2,
            platform: version.dwPlatformId,
            service_pack,
            service_pack_major: version.wServicePackMajor,
            service_pack_minor: version.wServicePackMinor,
            suite_mask: version.wSuiteMask,
            product_type: version.wProductType,
            platform_version: (real_version.0, real_version.1, real_version.2), // TODO Provide accurate version, like CPython impl
        };
        Ok(PyWindowsVersion::from_data(winver, vm))
    }

    fn _unraisablehook(unraisable: UnraisableHookArgsData, vm: &VirtualMachine) -> PyResult<()> {
        use super::PyStderr;

        let stderr = PyStderr(vm);
        if !vm.is_none(&unraisable.object) {
            if !vm.is_none(&unraisable.err_msg) {
                write!(stderr, "{}: ", unraisable.err_msg.str(vm)?);
            } else {
                write!(stderr, "Exception ignored in: ");
            }
            // exception in del will be ignored but printed
            let repr = &unraisable.object.repr(vm);
            let str = match repr {
                Ok(v) => v.to_string(),
                Err(_) => format!(
                    "<object {} repr() failed>",
                    unraisable.object.class().name()
                ),
            };
            writeln!(stderr, "{str}");
        } else if !vm.is_none(&unraisable.err_msg) {
            writeln!(stderr, "{}:", unraisable.err_msg.str(vm)?);
        }

        // Print traceback (using actual exc_traceback, not current stack)
        if !vm.is_none(&unraisable.exc_traceback) {
            let tb_module = vm.import("traceback", 0)?;
            let print_tb = tb_module.get_attr("print_tb", vm)?;
            let stderr_obj = super::get_stderr(vm)?;
            let kwargs: KwArgs = [("file".to_string(), stderr_obj)].into_iter().collect();
            let _ = print_tb.call(
                FuncArgs::new(vec![unraisable.exc_traceback.clone()], kwargs),
                vm,
            );
        }

        // Check exc_type
        if vm.is_none(unraisable.exc_type.as_object()) {
            return Ok(());
        }
        assert!(
            unraisable
                .exc_type
                .fast_issubclass(vm.ctx.exceptions.base_exception_type)
        );

        // Print module name (if not builtins or __main__)
        let module_name = unraisable.exc_type.__module__(vm);
        if let Ok(module_str) = module_name.downcast::<PyStr>() {
            let module = module_str.as_wtf8();
            if module != "builtins" && module != "__main__" {
                write!(stderr, "{}.", module);
            }
        } else {
            write!(stderr, "<unknown>.");
        }

        // Print qualname
        let qualname = unraisable.exc_type.__qualname__(vm);
        if let Ok(qualname_str) = qualname.downcast::<PyStr>() {
            write!(stderr, "{}", qualname_str.as_wtf8());
        } else {
            write!(stderr, "{}", unraisable.exc_type.name());
        }

        // Print exception value
        if !vm.is_none(&unraisable.exc_value) {
            write!(stderr, ": ");
            if let Ok(str) = unraisable.exc_value.str(vm) {
                write!(stderr, "{}", str.as_wtf8());
            } else {
                write!(stderr, "<exception str() failed>");
            }
        }
        writeln!(stderr);

        // Flush stderr
        if let Ok(stderr_obj) = super::get_stderr(vm)
            && let Ok(flush) = stderr_obj.get_attr("flush", vm)
        {
            let _ = flush.call((), vm);
        }

        Ok(())
    }

    #[pyattr]
    #[pyfunction(name = "__unraisablehook__")]
    fn unraisablehook(unraisable: UnraisableHookArgsData, vm: &VirtualMachine) {
        if let Err(e) = _unraisablehook(unraisable, vm) {
            let stderr = super::PyStderr(vm);
            writeln!(
                stderr,
                "{}",
                e.as_object()
                    .repr(vm)
                    .unwrap_or_else(|_| vm.ctx.empty_str.to_owned())
            );
        }
    }

    #[pyattr]
    fn hash_info(vm: &VirtualMachine) -> PyTupleRef {
        PyHashInfo::from_data(HashInfoData::INFO, vm)
    }

    #[pyfunction]
    fn intern(s: PyRefExact<PyStr>, vm: &VirtualMachine) -> PyRef<PyStr> {
        vm.ctx.intern_str(s).to_owned()
    }

    #[pyattr]
    fn int_info(vm: &VirtualMachine) -> PyTupleRef {
        PyIntInfo::from_data(IntInfoData::INFO, vm)
    }

    #[pyfunction]
    fn get_int_max_str_digits(vm: &VirtualMachine) -> usize {
        vm.state.int_max_str_digits.load()
    }

    #[pyfunction]
    fn set_int_max_str_digits(maxdigits: usize, vm: &VirtualMachine) -> PyResult<()> {
        let threshold = IntInfoData::INFO.str_digits_check_threshold;
        if maxdigits == 0 || maxdigits >= threshold {
            vm.state.int_max_str_digits.store(maxdigits);
            Ok(())
        } else {
            let error = format!("maxdigits must be 0 or larger than {threshold:?}");
            Err(vm.new_value_error(error))
        }
    }

    #[pyfunction]
    fn is_finalizing(vm: &VirtualMachine) -> bool {
        vm.state.finalizing.load(Ordering::Acquire)
    }

    #[pyfunction]
    fn setprofile(profilefunc: PyObjectRef, vm: &VirtualMachine) {
        vm.profile_func.replace(profilefunc);
        update_use_tracing(vm);
    }

    #[pyfunction]
    fn setrecursionlimit(recursion_limit: i32, vm: &VirtualMachine) -> PyResult<()> {
        let recursion_limit = recursion_limit
            .to_usize()
            .filter(|&u| u >= 1)
            .ok_or_else(|| {
                vm.new_value_error("recursion limit must be greater than or equal to one")
            })?;
        let recursion_depth = vm.current_recursion_depth();

        if recursion_limit > recursion_depth {
            vm.recursion_limit.set(recursion_limit);
            Ok(())
        } else {
            Err(vm.new_recursion_error(format!(
                "cannot set the recursion limit to {recursion_limit} at the recursion depth {recursion_depth}: the limit is too low"
            )))
        }
    }

    #[pyfunction]
    fn settrace(tracefunc: PyObjectRef, vm: &VirtualMachine) {
        vm.trace_func.replace(tracefunc);
        update_use_tracing(vm);
    }

    #[pyfunction]
    fn _settraceallthreads(tracefunc: PyObjectRef, vm: &VirtualMachine) {
        let func = (!vm.is_none(&tracefunc)).then(|| tracefunc.clone());
        *vm.state.global_trace_func.lock() = func;
        vm.trace_func.replace(tracefunc);
        update_use_tracing(vm);
    }

    #[pyfunction]
    fn _setprofileallthreads(profilefunc: PyObjectRef, vm: &VirtualMachine) {
        let func = (!vm.is_none(&profilefunc)).then(|| profilefunc.clone());
        *vm.state.global_profile_func.lock() = func;
        vm.profile_func.replace(profilefunc);
        update_use_tracing(vm);
    }

    #[cfg(feature = "threading")]
    #[pyattr]
    fn thread_info(vm: &VirtualMachine) -> PyTupleRef {
        PyThreadInfo::from_data(ThreadInfoData::INFO, vm)
    }

    #[pyattr]
    fn version_info(vm: &VirtualMachine) -> PyTupleRef {
        PyVersionInfo::from_data(VersionInfoData::VERSION, vm)
    }

    fn update_use_tracing(vm: &VirtualMachine) {
        let trace_is_none = vm.is_none(&vm.trace_func.borrow());
        let profile_is_none = vm.is_none(&vm.profile_func.borrow());
        let tracing = !(trace_is_none && profile_is_none);
        vm.use_tracing.set(tracing);
    }

    #[pyfunction]
    fn set_coroutine_origin_tracking_depth(depth: i32, vm: &VirtualMachine) -> PyResult<()> {
        if depth < 0 {
            return Err(vm.new_value_error("depth must be >= 0"));
        }
        crate::vm::thread::COROUTINE_ORIGIN_TRACKING_DEPTH.set(depth as u32);
        Ok(())
    }

    #[pyfunction]
    fn get_coroutine_origin_tracking_depth() -> i32 {
        crate::vm::thread::COROUTINE_ORIGIN_TRACKING_DEPTH.get() as i32
    }

    #[pyfunction]
    fn _clear_type_descriptors(type_obj: PyTypeRef, vm: &VirtualMachine) -> PyResult<()> {
        use crate::types::PyTypeFlags;

        // Check if type is immutable
        if type_obj.slots.flags.has_feature(PyTypeFlags::IMMUTABLETYPE) {
            return Err(vm.new_type_error("argument is immutable"));
        }

        let mut attributes = type_obj.attributes.write();

        // Remove __dict__ descriptor if present
        attributes.swap_remove(identifier!(vm, __dict__));

        // Remove __weakref__ descriptor if present
        attributes.swap_remove(identifier!(vm, __weakref__));

        drop(attributes);

        // Update slots to notify subclasses and recalculate cached values
        type_obj.update_slot::<true>(identifier!(vm, __dict__), &vm.ctx);
        type_obj.update_slot::<true>(identifier!(vm, __weakref__), &vm.ctx);

        Ok(())
    }

    #[pyfunction]
    fn getswitchinterval(vm: &VirtualMachine) -> f64 {
        // Return the stored switch interval
        vm.state.switch_interval.load()
    }

    // TODO: vm.state.switch_interval is currently not used anywhere in the VM
    #[pyfunction]
    fn setswitchinterval(interval: f64, vm: &VirtualMachine) -> PyResult<()> {
        // Validate the interval parameter like CPython does
        if interval <= 0.0 {
            return Err(vm.new_value_error("switch interval must be strictly positive"));
        }

        // Store the switch interval value
        vm.state.switch_interval.store(interval);
        Ok(())
    }

    #[derive(FromArgs)]
    struct SetAsyncgenHooksArgs {
        #[pyarg(any, optional)]
        firstiter: OptionalArg<Option<PyObjectRef>>,
        #[pyarg(any, optional)]
        finalizer: OptionalArg<Option<PyObjectRef>>,
    }

    #[pyfunction]
    fn set_asyncgen_hooks(args: SetAsyncgenHooksArgs, vm: &VirtualMachine) -> PyResult<()> {
        if let Some(Some(finalizer)) = args.finalizer.as_option()
            && !finalizer.is_callable()
        {
            return Err(vm.new_type_error(format!(
                "callable finalizer expected, got {:.50}",
                finalizer.class().name()
            )));
        }

        if let Some(Some(firstiter)) = args.firstiter.as_option()
            && !firstiter.is_callable()
        {
            return Err(vm.new_type_error(format!(
                "callable firstiter expected, got {:.50}",
                firstiter.class().name()
            )));
        }

        if let Some(finalizer) = args.finalizer.into_option() {
            *vm.async_gen_finalizer.borrow_mut() = finalizer;
        }
        if let Some(firstiter) = args.firstiter.into_option() {
            *vm.async_gen_firstiter.borrow_mut() = firstiter;
        }

        Ok(())
    }

    #[pystruct_sequence_data]
    pub(super) struct AsyncgenHooksData {
        firstiter: PyObjectRef,
        finalizer: PyObjectRef,
    }

    #[pyattr]
    #[pystruct_sequence(name = "asyncgen_hooks", data = "AsyncgenHooksData")]
    pub(super) struct PyAsyncgenHooks;

    #[pyclass(with(PyStructSequence))]
    impl PyAsyncgenHooks {}

    #[pyfunction]
    fn get_asyncgen_hooks(vm: &VirtualMachine) -> AsyncgenHooksData {
        AsyncgenHooksData {
            firstiter: vm.async_gen_firstiter.borrow().clone().to_pyobject(vm),
            finalizer: vm.async_gen_finalizer.borrow().clone().to_pyobject(vm),
        }
    }

    /// sys.flags
    ///
    /// Flags provided through command line arguments or environment vars.
    #[derive(Debug)]
    #[pystruct_sequence_data]
    pub(super) struct FlagsData {
        /// -d
        debug: u8,
        /// -i
        inspect: u8,
        /// -i
        interactive: u8,
        /// -O or -OO
        optimize: u8,
        /// -B
        dont_write_bytecode: u8,
        /// -s
        no_user_site: u8,
        /// -S
        no_site: u8,
        /// -E
        ignore_environment: u8,
        /// -v
        verbose: u8,
        /// -b
        bytes_warning: u64,
        /// -q
        quiet: u8,
        /// -R
        hash_randomization: u8,
        /// -I
        isolated: u8,
        /// -X dev
        dev_mode: bool,
        /// -X utf8
        utf8_mode: u8,
        /// -X int_max_str_digits=number
        int_max_str_digits: i64,
        /// -P, `PYTHONSAFEPATH`
        safe_path: bool,
        /// -X warn_default_encoding, PYTHONWARNDEFAULTENCODING
        warn_default_encoding: u8,
    }

    impl FlagsData {
        const fn from_settings(settings: &Settings) -> Self {
            Self {
                debug: settings.debug,
                inspect: settings.inspect as u8,
                interactive: settings.interactive as u8,
                optimize: settings.optimize,
                dont_write_bytecode: (!settings.write_bytecode) as u8,
                no_user_site: (!settings.user_site_directory) as u8,
                no_site: (!settings.import_site) as u8,
                ignore_environment: settings.ignore_environment as u8,
                verbose: settings.verbose,
                bytes_warning: settings.bytes_warning,
                quiet: settings.quiet as u8,
                hash_randomization: settings.hash_seed.is_none() as u8,
                isolated: settings.isolated as u8,
                dev_mode: settings.dev_mode,
                utf8_mode: if settings.utf8_mode < 0 {
                    1
                } else {
                    settings.utf8_mode as u8
                },
                int_max_str_digits: settings.int_max_str_digits,
                safe_path: settings.safe_path,
                warn_default_encoding: settings.warn_default_encoding as u8,
            }
        }
    }

    #[pystruct_sequence(name = "flags", data = "FlagsData", no_attr)]
    pub(super) struct PyFlags;

    #[pyclass(with(PyStructSequence))]
    impl PyFlags {
        #[pyslot]
        fn slot_new(_cls: PyTypeRef, _args: FuncArgs, vm: &VirtualMachine) -> PyResult {
            Err(vm.new_type_error("cannot create 'sys.flags' instances"))
        }

        #[pygetset]
        fn context_aware_warnings(&self, vm: &VirtualMachine) -> bool {
            vm.state.config.settings.context_aware_warnings
        }

        #[pygetset]
        fn thread_inherit_context(&self, vm: &VirtualMachine) -> bool {
            vm.state.config.settings.thread_inherit_context
        }
    }

    #[cfg(feature = "threading")]
    #[pystruct_sequence_data]
    pub(super) struct ThreadInfoData {
        name: Option<&'static str>,
        lock: Option<&'static str>,
        version: Option<&'static str>,
    }

    #[cfg(feature = "threading")]
    impl ThreadInfoData {
        const INFO: Self = Self {
            name: crate::stdlib::_thread::_thread::PYTHREAD_NAME,
            // As I know, there's only way to use lock as "Mutex" in Rust
            // with satisfying python document spec.
            lock: Some("mutex+cond"),
            version: None,
        };
    }

    #[cfg(feature = "threading")]
    #[pystruct_sequence(name = "thread_info", data = "ThreadInfoData", no_attr)]
    pub(super) struct PyThreadInfo;

    #[cfg(feature = "threading")]
    #[pyclass(with(PyStructSequence))]
    impl PyThreadInfo {}

    #[pystruct_sequence_data]
    pub(super) struct FloatInfoData {
        max: f64,
        max_exp: i32,
        max_10_exp: i32,
        min: f64,
        min_exp: i32,
        min_10_exp: i32,
        dig: u32,
        mant_dig: u32,
        epsilon: f64,
        radix: u32,
        rounds: i32,
    }

    impl FloatInfoData {
        const INFO: Self = Self {
            max: f64::MAX,
            max_exp: f64::MAX_EXP,
            max_10_exp: f64::MAX_10_EXP,
            min: f64::MIN_POSITIVE,
            min_exp: f64::MIN_EXP,
            min_10_exp: f64::MIN_10_EXP,
            dig: f64::DIGITS,
            mant_dig: f64::MANTISSA_DIGITS,
            epsilon: f64::EPSILON,
            radix: f64::RADIX,
            rounds: 1, // FE_TONEAREST
        };
    }

    #[pystruct_sequence(name = "float_info", data = "FloatInfoData", no_attr)]
    pub(super) struct PyFloatInfo;

    #[pyclass(with(PyStructSequence))]
    impl PyFloatInfo {}

    #[pystruct_sequence_data]
    pub(super) struct HashInfoData {
        width: usize,
        modulus: PyUHash,
        inf: PyHash,
        nan: PyHash,
        imag: PyHash,
        algorithm: &'static str,
        hash_bits: usize,
        seed_bits: usize,
        cutoff: usize,
    }

    impl HashInfoData {
        const INFO: Self = {
            use rustpython_common::hash::*;
            Self {
                width: core::mem::size_of::<PyHash>() * 8,
                modulus: MODULUS,
                inf: INF,
                nan: NAN,
                imag: IMAG,
                algorithm: ALGO,
                hash_bits: HASH_BITS,
                seed_bits: SEED_BITS,
                cutoff: 0, // no small string optimizations
            }
        };
    }

    #[pystruct_sequence(name = "hash_info", data = "HashInfoData", no_attr)]
    pub(super) struct PyHashInfo;

    #[pyclass(with(PyStructSequence))]
    impl PyHashInfo {}

    #[pystruct_sequence_data]
    pub(super) struct IntInfoData {
        bits_per_digit: usize,
        sizeof_digit: usize,
        default_max_str_digits: usize,
        str_digits_check_threshold: usize,
    }

    impl IntInfoData {
        const INFO: Self = Self {
            bits_per_digit: 30, //?
            sizeof_digit: core::mem::size_of::<u32>(),
            default_max_str_digits: 4300,
            str_digits_check_threshold: 640,
        };
    }

    #[pystruct_sequence(name = "int_info", data = "IntInfoData", no_attr)]
    pub(super) struct PyIntInfo;

    #[pyclass(with(PyStructSequence))]
    impl PyIntInfo {}

    #[derive(Default, Debug)]
    #[pystruct_sequence_data]
    pub struct VersionInfoData {
        major: usize,
        minor: usize,
        micro: usize,
        releaselevel: &'static str,
        serial: usize,
    }

    impl VersionInfoData {
        pub const VERSION: Self = Self {
            major: version::MAJOR,
            minor: version::MINOR,
            micro: version::MICRO,
            releaselevel: version::RELEASELEVEL,
            serial: version::SERIAL,
        };
    }

    #[pystruct_sequence(name = "version_info", data = "VersionInfoData", no_attr)]
    pub struct PyVersionInfo;

    #[pyclass(with(PyStructSequence))]
    impl PyVersionInfo {
        #[pyslot]
        fn slot_new(
            _cls: crate::builtins::type_::PyTypeRef,
            _args: crate::function::FuncArgs,
            vm: &crate::VirtualMachine,
        ) -> crate::PyResult {
            Err(vm.new_type_error("cannot create 'sys.version_info' instances"))
        }
    }

    #[cfg(windows)]
    #[derive(Default, Debug)]
    #[pystruct_sequence_data]
    pub(super) struct WindowsVersionData {
        major: u32,
        minor: u32,
        build: u32,
        platform: u32,
        service_pack: String,
        #[pystruct_sequence(skip)]
        service_pack_major: u16,
        #[pystruct_sequence(skip)]
        service_pack_minor: u16,
        #[pystruct_sequence(skip)]
        suite_mask: u16,
        #[pystruct_sequence(skip)]
        product_type: u8,
        #[pystruct_sequence(skip)]
        platform_version: (u32, u32, u32),
    }

    #[cfg(windows)]
    #[pystruct_sequence(name = "getwindowsversion", data = "WindowsVersionData", no_attr)]
    pub(super) struct PyWindowsVersion;

    #[cfg(windows)]
    #[pyclass(with(PyStructSequence))]
    impl PyWindowsVersion {}

    #[derive(Debug)]
    #[pystruct_sequence_data(try_from_object)]
    pub struct UnraisableHookArgsData {
        pub exc_type: PyTypeRef,
        pub exc_value: PyObjectRef,
        pub exc_traceback: PyObjectRef,
        pub err_msg: PyObjectRef,
        pub object: PyObjectRef,
    }

    #[pystruct_sequence(name = "UnraisableHookArgs", data = "UnraisableHookArgsData", no_attr)]
    pub struct PyUnraisableHookArgs;

    #[pyclass(with(PyStructSequence))]
    impl PyUnraisableHookArgs {}
}

pub(crate) fn init_module(vm: &VirtualMachine, module: &Py<PyModule>, builtins: &Py<PyModule>) {
    module.__init_methods(vm).unwrap();
    sys::module_exec(vm, module).unwrap();

    let modules = vm.ctx.new_dict();
    modules
        .set_item("sys", module.to_owned().into(), vm)
        .unwrap();
    modules
        .set_item("builtins", builtins.to_owned().into(), vm)
        .unwrap();

    // Create sys._jit submodule
    let jit_def = sys_jit::module_def(&vm.ctx);
    let jit_module = jit_def.create_module(vm).unwrap();

    extend_module!(vm, module, {
        "__doc__" => sys::DOC.to_owned().to_pyobject(vm),
        "modules" => modules,
        "_jit" => jit_module,
    });
}

pub(crate) fn set_bootstrap_stderr(vm: &VirtualMachine) -> PyResult<()> {
    let stderr = sys::BootstrapStderr.into_ref(&vm.ctx);
    let stderr_obj: crate::PyObjectRef = stderr.into();
    vm.sys_module.set_attr("stderr", stderr_obj.clone(), vm)?;
    vm.sys_module.set_attr("__stderr__", stderr_obj, vm)?;
    Ok(())
}

/// Similar to PySys_WriteStderr in CPython.
///
/// # Usage
///
/// ```rust,ignore
/// writeln!(sys::PyStderr(vm), "foo bar baz :)");
/// ```
///
/// Unlike writing to a `std::io::Write` with the `write[ln]!()` macro, there's no error condition here;
/// this is intended to be a replacement for the `eprint[ln]!()` macro, so `write!()`-ing to PyStderr just
/// returns `()`.
pub struct PyStderr<'vm>(pub &'vm VirtualMachine);

impl PyStderr<'_> {
    pub fn write_fmt(&self, args: core::fmt::Arguments<'_>) {
        use crate::py_io::Write;

        let vm = self.0;
        if let Ok(stderr) = get_stderr(vm) {
            let mut stderr = crate::py_io::PyWriter(stderr, vm);
            if let Ok(()) = stderr.write_fmt(args) {
                return;
            }
        }
        eprint!("{args}")
    }
}

pub fn get_stdin(vm: &VirtualMachine) -> PyResult {
    vm.sys_module
        .get_attr("stdin", vm)
        .map_err(|_| vm.new_runtime_error("lost sys.stdin"))
}
pub fn get_stdout(vm: &VirtualMachine) -> PyResult {
    vm.sys_module
        .get_attr("stdout", vm)
        .map_err(|_| vm.new_runtime_error("lost sys.stdout"))
}
pub fn get_stderr(vm: &VirtualMachine) -> PyResult {
    vm.sys_module
        .get_attr("stderr", vm)
        .map_err(|_| vm.new_runtime_error("lost sys.stderr"))
}

pub(crate) fn sysconfigdata_name() -> String {
    format!(
        "_sysconfigdata_{}_{}_{}",
        sys::ABIFLAGS,
        sys::PLATFORM,
        sys::multiarch()
    )
}
