hara_native/core/

native.rs

fn os_values(operation: &str, values: Vec<Value>) -> Result<Value, String> {
    let operation = operation.strip_prefix("os/").unwrap_or(operation);
    let operation = operation
        .strip_prefix("std.native.OS/")
        .unwrap_or(operation);
    let process_operation = operation.strip_prefix("std.native.Process/");
    let operation = match process_operation.unwrap_or(operation) {
        "alive?" if process_operation.is_some() => "process-alive?",
        "write" if process_operation.is_some() => "process-write",
        "close-input" if process_operation.is_some() => "process-close-input",
        "stdout" if process_operation.is_some() => "process-stdout",
        "stderr" if process_operation.is_some() => "process-stderr",
        "stdout-stream" if process_operation.is_some() => "process-stdout-stream",
        "stderr-stream" if process_operation.is_some() => "process-stderr-stream",
        "wait" if process_operation.is_some() => "process-wait",
        "kill" if process_operation.is_some() => "process-kill",
        value => value,
    };
    match operation {
        "time-ms" => {
            if !values.is_empty() {
                return Err("os/time-ms expects no arguments".into());
            }
            return Ok(Value::Number(crate::clock::time_ms()));
        }
        "time-ns" => {
            if !values.is_empty() {
                return Err("os/time-ns expects no arguments".into());
            }
            return Ok(Value::Number(crate::clock::time_ns()));
        }
        "platform" => {
            if !values.is_empty() {
                return Err("os/platform expects no arguments".into());
            }
            let platform = if cfg!(target_os = "linux") {
                "linux"
            } else if cfg!(target_os = "macos") {
                "macos"
            } else if cfg!(target_os = "windows") {
                "windows"
            } else {
                "unknown"
            };
            return Ok(Value::Keyword(platform.into()));
        }
        "arch" => {
            if !values.is_empty() {
                return Err("os/arch expects no arguments".into());
            }
            let arch = match std::env::consts::ARCH {
                "x86_64" => "x86-64",
                value => value,
            };
            return Ok(Value::Keyword(arch.into()));
        }
        "cwd" => {
            if !values.is_empty() {
                return Err("os/cwd expects no arguments".into());
            }
            #[cfg(target_arch = "wasm32")]
            return Ok(Value::String("/".into()));
            #[cfg(not(target_arch = "wasm32"))]
            return std::env::current_dir()
                .map(|path| Value::String(path.to_string_lossy().into_owned()))
                .map_err(|error| format!("os/cwd failed: {error}"));
        }
        "env" => {
            if !values.is_empty() {
                return Err("os/env expects no arguments".into());
            }
            #[cfg(target_arch = "wasm32")]
            return Ok(Value::Map(PMap::new()));
            #[cfg(not(target_arch = "wasm32"))]
            return Ok(Value::Map(PMap::from_iter(
                std::env::vars().map(|(key, value)| (Value::String(key), Value::String(value))),
            )));
        }
        "getenv" => {
            if values.len() != 1 {
                return Err("os/getenv expects a name".into());
            }
            let Value::String(name) = &values[0] else {
                return Err("os/getenv expects a string".into());
            };
            #[cfg(target_arch = "wasm32")]
            {
                let _ = name;
                return Ok(Value::Nil);
            }
            #[cfg(not(target_arch = "wasm32"))]
            return Ok(std::env::var(name).map(Value::String).unwrap_or(Value::Nil));
        }
        "process?" => {
            if values.len() != 1 {
                return Err("os/process? expects one argument".into());
            }
            let value = values[0].clone();
            #[cfg(not(target_arch = "wasm32"))]
            return Ok(Value::Bool(crate::native_process::is_process(&value)));
            #[cfg(target_arch = "wasm32")]
            return Ok(Value::Bool(false));
        }
        _ => {}
    }
    require_process_access(&format!("os/{operation}"))?;
    #[cfg(target_arch = "wasm32")]
    return Err(format!("os/{operation} is unsupported on wasm"));
    #[cfg(not(target_arch = "wasm32"))]
    match operation {
        "spawn" => {
            if !(1..=2).contains(&values.len()) {
                return Err("os/spawn expects argv and optional options".into());
            }
            let argv = iterator_values(values[0].clone())?
                .into_iter()
                .map(|value| match value {
                    Value::String(value) => Ok(value),
                    _ => Err("os/spawn argv must contain strings".to_owned()),
                })
                .collect::<Result<Vec<_>, _>>()?;
            let mut cwd = None;
            let mut environment = Vec::new();
            if values.len() == 2 {
                let options = values[1].clone();
                for (key, value) in map_entries(&options)
                    .ok_or_else(|| "os/spawn options must be a map".to_owned())?
                {
                    match (key, value) {
                        (Value::Keyword(key), Value::String(value)) if key.as_str() == "cwd" => {
                            cwd = Some(value);
                        }
                        (Value::Keyword(key), value) if key.as_str() == "env" => {
                            for (name, value) in map_entries(&value)
                                .ok_or_else(|| "os/spawn :env must be a map".to_owned())?
                            {
                                let (Value::String(name), Value::String(value)) = (name, value)
                                else {
                                    return Err("os/spawn :env must contain string pairs".into());
                                };
                                environment.push((name, value));
                            }
                        }
                        _ => {}
                    }
                }
            }
            crate::native_process::spawn(&argv, cwd.as_deref(), &environment)
        }
        method @ ("process-alive?"
        | "process-close-input"
        | "process-stdout"
        | "process-stderr"
        | "process-wait"
        | "process-kill") => {
            if values.len() != 1 {
                return Err(format!("os/{method} expects a process"));
            }
            let process = values[0].clone();
            match method {
                "process-alive?" => crate::native_process::alive(&process).map(Value::Bool),
                "process-close-input" => {
                    crate::native_process::close_input(&process).map(|()| Value::Nil)
                }
                "process-stdout" => {
                    crate::native_process::promise(&process, "stdout").map(Value::Promise)
                }
                "process-stderr" => {
                    crate::native_process::promise(&process, "stderr").map(Value::Promise)
                }
                "process-wait" => {
                    crate::native_process::promise(&process, "wait").map(Value::Promise)
                }
                "process-kill" => crate::native_process::kill(&process).map(|()| process),
                _ => unreachable!(),
            }
        }
        method @ ("process-stdout-stream" | "process-stderr-stream") => {
            if values.len() != 1 {
                return Err(format!("os/{method} expects a process"));
            }
            let process = values[0].clone();
            let kind = if method == "process-stderr-stream" {
                "stderr"
            } else {
                "stdout"
            };
            let handle = crate::native_process::take_stream(&process, kind)?;
            Ok(host_stream(
                Rc::new(move || Ok(crate::native_process::stream_promise(handle, kind))),
                Rc::new(|| Ok(())),
            ))
        }
        "process-write" => {
            if values.len() != 2 {
                return Err("os/process-write expects a process and bytes".into());
            }
            let process = values[0].clone();
            let bytes = match &values[1] {
                Value::Bytes(value) => value.clone(),
                Value::ByteBuffer(value) => value.borrow().clone(),
                _ => return Err("os/process-write expects bytes".into()),
            };
            crate::native_process::write(&process, &bytes).map(|count| Value::Number(count as i64))
        }
        _ => Err(format!("unknown os operation: {operation}")),
    }
}

fn native_test_events() -> Value {
    Value::Vector(PVector::from_iter([
        Value::Keyword("test/run-started".into()),
        Value::Keyword("test/fact-started".into()),
        Value::Keyword("test/fact-completed".into()),
        Value::Keyword("test/run-completed".into()),
    ]))
}

fn native_test_runner(value: Value) -> Result<Value, String> {
    match value {
        Value::Keyword(runner) if matches!(runner.as_str(), "code.test" | "native") => {
            Ok(Value::Keyword(runner))
        }
        _ => Err("runtime test runner must be :code.test or :native".into()),
    }
}

fn native_test_active_runner() -> Result<Value, String> {
    ACTIVE_TEST_RUNNER
        .with(|runner| native_test_runner(Value::Keyword(runner.borrow().clone().into())))
}

fn native_test_config(runner: Value, options: Value) -> Result<Value, String> {
    if map_entries(&options).is_none() {
        return Err("std.native.Test/config options must be a map".into());
    }
    if map_value(&options, &Value::Keyword("runner".into())).is_some() {
        return Err("std.native.Test/config runner is owned by the runtime".into());
    }
    Ok(Value::Map(PMap::from_iter([
        (Value::Keyword("runner".into()), runner),
        (Value::Keyword("options".into()), options),
    ])))
}

fn native_test_context(desc: Value, actual: Value, expected: Value, failures: Value) -> Value {
    Value::Map(PMap::from_iter([
        (
            Value::Keyword("test".into()),
            Value::Map(PMap::from_iter([
                (Value::Keyword("desc".into()), desc.clone()),
                // `:name` remains an output alias while source packages move
                // their fact identity to `:desc`.
                (Value::Keyword("name".into()), desc),
                (Value::Keyword("actual".into()), actual),
                (Value::Keyword("expected".into()), expected),
            ])),
        ),
        (Value::Keyword("failures".into()), failures),
    ]))
}

fn native_test_failure(actual: Value, expected: Value) -> Value {
    Value::Map(PMap::from_iter([
        (
            Value::Keyword("failure/code".into()),
            Value::Keyword("test/not-equal".into()),
        ),
        (
            Value::Keyword("failure/path".into()),
            Value::Vector(PVector::new()),
        ),
        (
            Value::Keyword("failure/in".into()),
            Value::Vector(PVector::new()),
        ),
        (Value::Keyword("failure/actual".into()), actual),
        (Value::Keyword("failure/expected".into()), expected),
        (
            Value::Keyword("failure/message".into()),
            Value::String("values are not equal".into()),
        ),
        (
            Value::Keyword("failure/context".into()),
            Value::Map(PMap::new()),
        ),
        (
            Value::Keyword("failure/children".into()),
            Value::Vector(PVector::new()),
        ),
    ]))
}

fn native_test_compare(actual: Value, expected: Value) -> Result<Value, String> {
    let pass = actual == expected;
    let failures = if pass {
        Value::Vector(PVector::new())
    } else {
        Value::Vector(PVector::from_iter([native_test_failure(
            actual.clone(),
            expected.clone(),
        )]))
    };
    Ok(Value::Result(Rc::new(ResultValue::success(
        Value::Bool(pass),
        native_test_context(Value::Nil, actual, expected, failures),
    )?)))
}

fn native_test_result(
    desc: Value,
    actual: Value,
    expected: Value,
    comparison: Value,
) -> Result<Value, String> {
    let Value::Result(comparison) = comparison else {
        return Err("std.native.Test/result expects a comparison Result".into());
    };
    let failures = map_value(&comparison.context, &Value::Keyword("failures".into()))
        .cloned()
        .unwrap_or_else(|| Value::Vector(PVector::new()));
    Ok(Value::Result(Rc::new(comparison.with_context(
        native_test_context(desc, actual, expected, failures),
    )?)))
}

fn native_test_error(desc: Value, actual: Value, expected: Value, error: String) -> Value {
    Value::Result(Rc::new(
        ResultValue::error(
            caught_error(&error),
            native_test_context(desc, actual, expected, Value::Vector(PVector::new())),
        )
        .expect("native Test error context is a map"),
    ))
}

fn native_test_checked_result(desc: Value, metadata: Option<Value>, checked: Value) -> Value {
    let Value::Result(result) = checked else {
        return native_test_error(
            desc,
            Value::Nil,
            Value::Nil,
            "Test/check check function must return a Result".into(),
        );
    };
    let mut context =
        PMap::from_iter(map_entries(&result.context).expect("Result context is a map"));
    let test = map_value(&result.context, &Value::Keyword("test".into()))
        .cloned()
        .unwrap_or_else(|| Value::Map(PMap::new()));
    let mut test = PMap::from_iter(map_entries(&test).unwrap_or_default());
    test = test.assoc_value(Value::Keyword("desc".into()), desc.clone());
    test = test.assoc_value(Value::Keyword("name".into()), desc);
    context = context.assoc_value(Value::Keyword("test".into()), Value::Map(test));
    if let Some(metadata) = metadata {
        context = context.assoc_value(Value::Keyword("meta".into()), metadata);
    }
    Value::Result(Rc::new(
        result
            .with_context(Value::Map(context))
            .expect("native Test checked context is a map"),
    ))
}

fn native_test_lifecycle_error(phase: &str, error: String) -> Value {
    let desc = Value::String(format!("test {phase}"));
    let phase = Value::Keyword(phase.into());
    let Value::Result(result) = native_test_error(desc, Value::Nil, Value::Nil, error) else {
        unreachable!()
    };
    Value::Result(Rc::new(
        result
            .with_context(Value::Map(PMap::from_iter([(
                Value::Keyword("phase".into()),
                phase,
            )])))
            .expect("native Test lifecycle context is a map"),
    ))
}

fn native_test_lifecycle(lifecycle: &Value, phase: &str) -> Result<(), String> {
    let Some(function) = map_value(lifecycle, &Value::Keyword(phase.into())).cloned() else {
        return Ok(());
    };
    call_value(function, Vec::new())
        .and_then(native_test_await)
        .map(|_| ())
}

fn native_test_state() -> Result<crate::kernel::Namespace<Value>, String> {
    Ok(namespace_registry()?.find_or_create("std.native.Test.state"))
}

fn native_test_state_value(key: &str) -> Result<Value, String> {
    let state = native_test_state()?;
    Ok(state
        .resolve(&crate::lang::data::Symbol::parse(key))
        .map(|var| var.deref_value())
        .unwrap_or(Value::Nil))
}

fn native_test_set_state(key: &str, value: Value) -> Result<(), String> {
    native_test_state()?.intern(key, value);
    Ok(())
}

fn native_test_facts() -> Result<Vec<Value>, String> {
    match native_test_state_value("facts")? {
        Value::Vector(facts) => Ok(facts.iter().cloned().collect()),
        Value::Nil => Ok(Vec::new()),
        _ => Err("std.native.Test state facts must be a vector".into()),
    }
}

fn native_test_set_facts(facts: Vec<Value>) -> Result<(), String> {
    native_test_set_state("facts", Value::Vector(PVector::from_iter(facts)))
}

fn native_test_current_namespace() -> Result<String, String> {
    Ok(namespace_registry()?.current().name().as_str().to_owned())
}

fn native_test_description(value: &Value, operation: &str) -> Result<Value, String> {
    let desc = map_value(value, &Value::Keyword("desc".into())).cloned();
    let name = map_value(value, &Value::Keyword("name".into())).cloned();
    match (desc, name) {
        (Some(Value::String(desc)), Some(Value::String(name)))
            if !desc.is_empty() && desc == name =>
        {
            Ok(Value::String(desc))
        }
        (Some(Value::String(_)), Some(Value::String(_))) => Err(format!(
            "std.native.Test/{operation} :desc and legacy :name must agree"
        )),
        (Some(Value::String(desc)), None) | (None, Some(Value::String(desc)))
            if !desc.is_empty() =>
        {
            Ok(Value::String(desc))
        }
        (Some(_), _) | (_, Some(_)) => Err(format!(
            "std.native.Test/{operation} :desc must be a non-empty string"
        )),
        (None, None) => Err(format!("std.native.Test/{operation} requires :desc")),
    }
}

fn native_test_truthy(value: Option<&Value>) -> bool {
    !matches!(value, None | Some(Value::Nil) | Some(Value::Bool(false)))
}

fn native_test_metadata(value: &Value, namespace: &str, order: i64) -> Result<Value, String> {
    let metadata = map_value(value, &Value::Keyword("meta".into()))
        .cloned()
        .unwrap_or_else(|| Value::Map(PMap::new()));
    let Some(entries) = map_entries(&metadata) else {
        return Err("std.native.Test/register :meta must be a map".into());
    };
    let metadata = PMap::from_iter(entries)
        .assoc_value(
            Value::Keyword("test/namespace".into()),
            Value::String(namespace.into()),
        )
        .assoc_value(Value::Keyword("test/order".into()), Value::Number(order));
    Ok(Value::Map(metadata))
}

fn native_test_next_order() -> Result<i64, String> {
    let current = match native_test_state_value("order")? {
        Value::Number(value) if value >= 0 => value,
        Value::Nil => 0,
        _ => return Err("std.native.Test state order must be a non-negative number".into()),
    };
    let next = current + 1;
    native_test_set_state("order", Value::Number(next))?;
    Ok(next)
}

fn native_test_fact_value(
    namespace: String,
    desc: Value,
    metadata: Value,
    descriptor: &Value,
) -> Result<Value, String> {
    let function = map_value(descriptor, &Value::Keyword("function".into())).cloned();
    let test = map_value(descriptor, &Value::Keyword("test".into())).cloned();
    let expected = map_value(descriptor, &Value::Keyword("expected".into())).cloned();
    if function.is_some() && (test.is_some() || expected.is_some()) {
        return Err(
            "std.native.Test/register accepts either :function or :test with :expected".into(),
        );
    }
    if function.is_none() && (test.is_none() || expected.is_none()) {
        return Err(
            "std.native.Test/register requires :function or both :test and :expected".into(),
        );
    }
    let mut fields = vec![
        (Value::Keyword("namespace".into()), Value::String(namespace)),
        (Value::Keyword("desc".into()), desc.clone()),
        (Value::Keyword("name".into()), desc),
        (Value::Keyword("meta".into()), metadata),
    ];
    if let Some(function) = function {
        fields.push((Value::Keyword("function".into()), function));
    } else {
        fields.push((Value::Keyword("test".into()), test.expect("checked above")));
        fields.push((
            Value::Keyword("expected".into()),
            expected.expect("checked above"),
        ));
    }
    for key in ["before", "after"] {
        if let Some(value) = map_value(descriptor, &Value::Keyword(key.into())).cloned() {
            fields.push((Value::Keyword(key.into()), value));
        }
    }
    Ok(Value::Map(PMap::from_iter(fields)))
}

fn native_test_register(descriptor: Value) -> Result<Value, String> {
    if map_entries(&descriptor).is_none() {
        return Err("std.native.Test/register expects a fact map".into());
    }
    let namespace = native_test_current_namespace()?;
    let desc = native_test_description(&descriptor, "register")?;
    let order = native_test_next_order()?;
    let metadata = native_test_metadata(&descriptor, &namespace, order)?;
    let fact = native_test_fact_value(namespace.clone(), desc.clone(), metadata, &descriptor)?;
    let mut facts = native_test_facts()?;
    facts.retain(|candidate| {
        native_test_map_value(candidate, "namespace") != Some(Value::String(namespace.clone()))
            || native_test_map_value(candidate, "desc") != Some(desc.clone())
    });
    facts.push(fact.clone());
    native_test_set_facts(facts)?;
    Ok(fact)
}

fn native_test_check(
    cases: Value,
    check_function: Option<Value>,
    lifecycle: Option<Value>,
) -> Result<Value, String> {
    let cases = match cases {
        Value::Vector(cases) => cases.iter().cloned().collect::<Vec<_>>(),
        Value::Tuple(cases) => cases.iter().cloned().collect::<Vec<_>>(),
        _ => return Err("std.native.Test/check expects a vector of test cases".into()),
    };
    let mut results = Vec::new();
    let setup_ok = match &lifecycle {
        Some(lifecycle) => match native_test_lifecycle(lifecycle, "setup") {
            Ok(()) => true,
            Err(error) => {
                results.push(native_test_lifecycle_error("setup", error));
                false
            }
        },
        None => true,
    };
    if setup_ok {
        for (index, case) in cases.iter().enumerate() {
            let fallback_desc = Value::String(format!("invalid case {}", index + 1));
            let Some(entries) = map_entries(case) else {
                results.push(native_test_error(
                    fallback_desc,
                    Value::Nil,
                    Value::Nil,
                    "Test/check case must be a map".into(),
                ));
                continue;
            };
            let _ = entries;
            let desc = native_test_description(case, "check").unwrap_or(fallback_desc);
            let expected = map_value(case, &Value::Keyword("expected".into())).cloned();
            let test = map_value(case, &Value::Keyword("test".into())).cloned();
            let metadata = map_value(case, &Value::Keyword("meta".into())).cloned();
            let result = match (test, expected) {
                (Some(test), Some(expected)) => match &check_function {
                    Some(check) => match call_value(check.clone(), vec![test, expected])
                        .and_then(native_test_await)
                    {
                        Ok(checked) => native_test_checked_result(desc, metadata, checked),
                        Err(error) => {
                            let failed =
                                native_test_error(desc.clone(), Value::Nil, Value::Nil, error);
                            native_test_checked_result(desc, metadata, failed)
                        }
                    },
                    None => match call_value(test, Vec::new()).and_then(native_test_await) {
                        Ok(actual) => {
                            let comparison = native_test_compare(actual.clone(), expected.clone())?;
                            native_test_result(desc, actual, expected, comparison)?
                        }
                        Err(error) => native_test_error(desc, Value::Nil, expected, error),
                    },
                },
                (None, expected) => native_test_error(
                    desc,
                    Value::Nil,
                    expected.unwrap_or(Value::Nil),
                    "Test/check case requires :test".into(),
                ),
                (Some(_), None) => native_test_error(
                    desc,
                    Value::Nil,
                    Value::Nil,
                    "Test/check case requires :expected".into(),
                ),
            };
            results.push(result);
        }
    }
    if let Some(lifecycle) = &lifecycle {
        if let Err(error) = native_test_lifecycle(lifecycle, "teardown") {
            results.push(native_test_lifecycle_error("teardown", error));
        }
    }
    let output = Value::Vector(PVector::from_iter(results.clone()));
    let mut history = match native_test_state_value("results")? {
        Value::Vector(values) => values.iter().cloned().collect::<Vec<_>>(),
        Value::Nil => Vec::new(),
        _ => return Err("std.native.Test state results must be a vector".into()),
    };
    history.extend(results);
    native_test_set_state("results", Value::Vector(PVector::from_iter(history)))?;
    Ok(output)
}

fn native_test_result_passed(value: &Value) -> bool {
    matches!(
        value,
        Value::Result(result) if result.is_success() && matches!(result.data, Value::Bool(true))
    )
}

fn native_test_result_timed_out(value: &Value) -> bool {
    let Value::Result(result) = value else {
        return false;
    };
    result.is_timeout()
        || result
            .error
            .as_ref()
            .is_some_and(|error| error.message == "asynchronous test did not settle")
}

fn native_test_checks(value: Value, desc: Value) -> Vec<Value> {
    let values = match value {
        Value::Vector(values) => values.iter().cloned().collect(),
        Value::Tuple(values) => values.iter().cloned().collect(),
        Value::Result(_) => vec![value],
        value => {
            let context = native_test_context(
                desc,
                value,
                Value::Keyword("returned".into()),
                Value::Vector(PVector::new()),
            );
            return vec![Value::Result(Rc::new(
                ResultValue::success(Value::Bool(true), context)
                    .expect("native Test returned-value context is a map"),
            ))];
        }
    };
    values
        .into_iter()
        .map(|value| match value {
            Value::Result(_) => value,
            value => native_test_error(
                desc.clone(),
                value,
                Value::Keyword("Result".into()),
                "Test fact functions must return Results or a vector of Results".into(),
            ),
        })
        .collect()
}

fn native_test_fact_identity(fact: &Value) -> Result<Vec<(Value, Value)>, String> {
    let namespace = native_test_map_value(fact, "namespace")
        .ok_or_else(|| "std.native.Test fact is missing :namespace".to_owned())?;
    let desc = native_test_map_value(fact, "desc")
        .ok_or_else(|| "std.native.Test fact is missing :desc".to_owned())?;
    let metadata = native_test_map_value(fact, "meta")
        .ok_or_else(|| "std.native.Test fact is missing :meta".to_owned())?;
    Ok(vec![
        (Value::Keyword("namespace".into()), namespace),
        (Value::Keyword("desc".into()), desc.clone()),
        (Value::Keyword("name".into()), desc),
        (Value::Keyword("meta".into()), metadata),
    ])
}

fn native_test_hook(value: Option<Value>) -> Result<(), String> {
    let Some(function) = value else {
        return Ok(());
    };
    call_value(function, Vec::new())
        .and_then(native_test_await)
        .map(|_| ())
}

fn native_test_cancelled(fact: &Value, options: &Value) -> Result<bool, String> {
    let Some(value) = native_test_map_value(options, "cancelled") else {
        return Ok(false);
    };
    match value {
        Value::Bool(value) => Ok(value),
        Value::Nil => Ok(false),
        function => call_value(function, vec![fact.clone()])
            .and_then(native_test_await)
            .map(|value| native_test_truthy(Some(&value))),
    }
}

fn native_test_fact_checks(fact: &Value, options: &Value) -> Result<Vec<Value>, String> {
    let desc = native_test_map_value(fact, "desc")
        .ok_or_else(|| "std.native.Test fact is missing :desc".to_owned())?;
    if let Some(function) = native_test_map_value(fact, "function") {
        return call_value(function, vec![options.clone()])
            .and_then(native_test_await)
            .map(|value| native_test_checks(value, desc));
    }
    let test = native_test_map_value(fact, "test")
        .ok_or_else(|| "std.native.Test fact is missing :test".to_owned())?;
    let expected = native_test_map_value(fact, "expected")
        .ok_or_else(|| "std.native.Test fact is missing :expected".to_owned())?;
    native_test_check(
        Value::Vector(PVector::from_iter([Value::Map(PMap::from_iter([
            (Value::Keyword("desc".into()), desc),
            (Value::Keyword("test".into()), test),
            (Value::Keyword("expected".into()), expected),
        ]))])),
        None,
        None,
    )
    .and_then(|value| match value {
        Value::Vector(values) => Ok(values.iter().cloned().collect()),
        _ => unreachable!(),
    })
}

fn native_test_status(checks: &[Value]) -> &'static str {
    if checks.iter().any(native_test_result_timed_out) {
        "timeout"
    } else if checks
        .iter()
        .any(|value| matches!(value, Value::Result(result) if result.is_error()))
    {
        "error"
    } else if checks.iter().all(native_test_result_passed) {
        "passed"
    } else {
        "failed"
    }
}

fn native_test_fact_result(
    fact: &Value,
    status: &str,
    checks: Vec<Value>,
    error: Option<String>,
    elapsed: i64,
) -> Result<Value, String> {
    let mut fields = native_test_fact_identity(fact)?;
    fields.push((
        Value::Keyword("status".into()),
        Value::Keyword(status.into()),
    ));
    fields.push((
        Value::Keyword("checks".into()),
        Value::Vector(PVector::from_iter(checks)),
    ));
    fields.push((
        Value::Keyword("elapsed".into()),
        Value::Number(elapsed.max(0)),
    ));
    if let Some(error) = error {
        fields.push((Value::Keyword("error".into()), Value::String(error)));
    }
    Ok(Value::Map(PMap::from_iter(fields)))
}

fn native_test_run_fact(fact: Value, options: Value) -> Result<Value, String> {
    if map_entries(&fact).is_none() {
        return Err("std.native.Test/run-fact expects a fact map".into());
    }
    let started = crate::clock::time_ms();
    let metadata = native_test_map_value(&fact, "meta")
        .ok_or_else(|| "std.native.Test fact is missing :meta".to_owned())?;
    if native_test_truthy(native_test_map_value(&metadata, "skip").as_ref()) {
        return native_test_fact_result(&fact, "skipped", Vec::new(), None, 0);
    }
    if native_test_cancelled(&fact, &options)? {
        return native_test_fact_result(&fact, "cancelled", Vec::new(), None, 0);
    }

    let mut checks = Vec::new();
    let mut failure = None;
    for hook in [
        native_test_map_value(&options, "before-each"),
        native_test_map_value(&fact, "before"),
    ] {
        if let Err(error) = native_test_hook(hook) {
            failure = Some(error);
            break;
        }
    }
    if failure.is_none() {
        match native_test_fact_checks(&fact, &options) {
            Ok(output) => checks = output,
            Err(error) => failure = Some(error),
        }
    }
    for hook in [
        native_test_map_value(&fact, "after"),
        native_test_map_value(&options, "after-each"),
    ] {
        if let Err(error) = native_test_hook(hook) {
            failure.get_or_insert(error);
        }
    }
    let elapsed = crate::clock::time_ms() - started;
    match failure {
        Some(error) => native_test_fact_result(&fact, "error", checks, Some(error), elapsed),
        None => native_test_fact_result(&fact, native_test_status(&checks), checks, None, elapsed),
    }
}

fn native_test_summary(results: Vec<Value>) -> Result<Value, String> {
    let mut counts = [0_i64; 6];
    let mut check_total = 0_i64;
    let mut check_passed = 0_i64;
    let mut namespaces = HashSet::new();
    for result in &results {
        let status = native_test_map_value(result, "status")
            .ok_or_else(|| "std.native.Test summary result is missing :status".to_owned())?;
        let index = match status {
            Value::Keyword(status) => match status.as_str() {
                "passed" => 0,
                "failed" => 1,
                "error" => 2,
                "timeout" => 3,
                "skipped" => 4,
                "cancelled" => 5,
                value => {
                    return Err(format!(
                        "std.native.Test summary has unknown status :{value}"
                    ))
                }
            },
            _ => return Err("std.native.Test summary status must be a keyword".into()),
        };
        counts[index] += 1;
        if let Some(Value::String(namespace)) = native_test_map_value(result, "namespace") {
            namespaces.insert(namespace);
        }
        if let Some(Value::Vector(checks)) = native_test_map_value(result, "checks") {
            for check in checks.iter() {
                check_total += 1;
                if native_test_result_passed(check) {
                    check_passed += 1;
                }
            }
        }
    }
    let check_failed = check_total - check_passed;
    let status = if counts[1] + counts[2] + counts[3] == 0 {
        "passed"
    } else {
        "failed"
    };
    Ok(Value::Map(PMap::from_iter([
        (
            Value::Keyword("status".into()),
            Value::Keyword(status.into()),
        ),
        (
            Value::Keyword("counts".into()),
            Value::Map(PMap::from_iter([
                (Value::Keyword("passed".into()), Value::Number(counts[0])),
                (Value::Keyword("failed".into()), Value::Number(counts[1])),
                (Value::Keyword("error".into()), Value::Number(counts[2])),
                (Value::Keyword("timeout".into()), Value::Number(counts[3])),
                (Value::Keyword("skipped".into()), Value::Number(counts[4])),
                (Value::Keyword("cancelled".into()), Value::Number(counts[5])),
            ])),
        ),
        (
            Value::Keyword("check-counts".into()),
            Value::Map(PMap::from_iter([
                (Value::Keyword("total".into()), Value::Number(check_total)),
                (Value::Keyword("passed".into()), Value::Number(check_passed)),
                (Value::Keyword("failed".into()), Value::Number(check_failed)),
            ])),
        ),
        (
            Value::Keyword("files".into()),
            Value::Number(namespaces.len() as i64),
        ),
        (
            Value::Keyword("facts".into()),
            Value::Number(results.len() as i64),
        ),
        (Value::Keyword("checks".into()), Value::Number(check_total)),
        (Value::Keyword("passed".into()), Value::Number(check_passed)),
        (Value::Keyword("failed".into()), Value::Number(check_failed)),
        (Value::Keyword("throw".into()), Value::Number(counts[2])),
        (Value::Keyword("timeout".into()), Value::Number(counts[3])),
        (
            Value::Keyword("results".into()),
            Value::Vector(PVector::from_iter(results)),
        ),
    ])))
}

fn native_test_namespace(value: Value, operation: &str) -> Result<String, String> {
    match value {
        Value::String(value) => Ok(value),
        Value::Symbol(value) => Ok(value.as_str().to_owned()),
        _ => Err(format!(
            "std.native.Test/{operation} namespace must be a string or symbol"
        )),
    }
}

fn native_test_run(options: Value) -> Result<Value, String> {
    if map_entries(&options).is_none() {
        return Err(
            "std.native.Test/run expects an optional options map; use Test/check for cases".into(),
        );
    }
    let namespace = match native_test_map_value(&options, "namespace") {
        Some(value) => native_test_namespace(value, "run")?,
        None => native_test_current_namespace()?,
    };
    let facts = native_test_facts()?
        .into_iter()
        .filter(|fact| {
            native_test_map_value(fact, "namespace") == Some(Value::String(namespace.clone()))
        })
        .collect::<Vec<_>>();
    let checks = match native_test_state_value("results")? {
        Value::Vector(values) => values.iter().cloned().collect::<Vec<_>>(),
        Value::Nil => Vec::new(),
        _ => return Err("std.native.Test state results must be a vector".into()),
    };
    let mut results = checks
        .into_iter()
        .enumerate()
        .map(|(index, check)| {
            let desc = match &check {
                Value::Result(result) => map_value(&result.context, &Value::Keyword("desc".into()))
                    .cloned()
                    .unwrap_or_else(|| Value::String(format!("test check {}", index + 1))),
                _ => Value::String(format!("test check {}", index + 1)),
            };
            let fact = Value::Map(PMap::from_iter([
                (
                    Value::Keyword("namespace".into()),
                    Value::String(namespace.clone()),
                ),
                (Value::Keyword("desc".into()), desc.clone()),
                (Value::Keyword("name".into()), desc),
                (Value::Keyword("meta".into()), Value::Map(PMap::new())),
            ]));
            native_test_fact_result(
                &fact,
                native_test_status(&[check.clone()]),
                vec![check],
                None,
                0,
            )
        })
        .collect::<Result<Vec<_>, _>>()?;
    let mut suite_error = None;
    if let Err(error) = native_test_hook(native_test_map_value(&options, "before-all")) {
        suite_error = Some(error);
    }
    if suite_error.is_none() {
        let mut fail_fast = false;
        for fact in facts {
            if fail_fast {
                results.push(native_test_fact_result(
                    &fact,
                    "cancelled",
                    Vec::new(),
                    None,
                    0,
                )?);
                continue;
            }
            let result = native_test_run_fact(fact, options.clone())?;
            fail_fast = native_test_truthy(native_test_map_value(&options, "fail-fast").as_ref())
                && matches!(
                    native_test_map_value(&result, "status"),
                    Some(Value::Keyword(status)) if matches!(status.as_str(), "failed" | "error" | "timeout")
                );
            results.push(result);
        }
    } else {
        let synthetic = Value::Map(PMap::from_iter([
            (
                Value::Keyword("namespace".into()),
                Value::String(namespace.clone()),
            ),
            (
                Value::Keyword("desc".into()),
                Value::String("test before-all".into()),
            ),
            (
                Value::Keyword("name".into()),
                Value::String("test before-all".into()),
            ),
            (Value::Keyword("meta".into()), Value::Map(PMap::new())),
        ]));
        results.push(native_test_fact_result(
            &synthetic,
            "error",
            Vec::new(),
            suite_error,
            0,
        )?);
    }
    if let Err(error) = native_test_hook(native_test_map_value(&options, "after-all")) {
        let synthetic = Value::Map(PMap::from_iter([
            (Value::Keyword("namespace".into()), Value::String(namespace)),
            (
                Value::Keyword("desc".into()),
                Value::String("test after-all".into()),
            ),
            (
                Value::Keyword("name".into()),
                Value::String("test after-all".into()),
            ),
            (Value::Keyword("meta".into()), Value::Map(PMap::new())),
        ]));
        results.push(native_test_fact_result(
            &synthetic,
            "error",
            Vec::new(),
            Some(error),
            0,
        )?);
    }
    let summary = native_test_summary(results)?;
    native_test_set_state("last-run", summary.clone())?;
    Ok(summary)
}

fn native_test_lookup(namespace: &str, desc: &Value) -> Result<Value, String> {
    Ok(native_test_facts()?
        .into_iter()
        .find(|fact| {
            native_test_map_value(fact, "namespace") == Some(Value::String(namespace.into()))
                && native_test_map_value(fact, "desc") == Some(desc.clone())
        })
        .unwrap_or(Value::Nil))
}

fn native_test_desc_argument(value: Value, operation: &str) -> Result<Value, String> {
    match value {
        Value::String(value) if !value.is_empty() => Ok(Value::String(value)),
        _ => Err(format!(
            "std.native.Test/{operation} description must be a non-empty string"
        )),
    }
}

fn native_test_reset() -> Result<Value, String> {
    native_test_set_state("facts", Value::Vector(PVector::new()))?;
    native_test_set_state("results", Value::Vector(PVector::new()))?;
    native_test_set_state("order", Value::Number(0))?;
    native_test_set_state("last-run", Value::Nil)?;
    Ok(Value::Nil)
}

fn native_test_await(value: Value) -> Result<Value, String> {
    match value {
        Value::Promise(promise) => match promise.wait_state() {
            PromiseState::Fulfilled(value) => Ok(value),
            PromiseState::Rejected(error) => Err(promise_rejection_error(error)),
            PromiseState::Pending => Err("asynchronous test did not settle".into()),
        },
        value => Ok(value),
    }
}

fn native_test_require_result(value: Value, operation: &str) -> Result<Rc<ResultValue>, String> {
    match value {
        Value::Result(result) => Ok(result),
        _ => Err(format!("std.native.Test/{operation} expects a Result")),
    }
}

fn native_test_context_value(result: &ResultValue, key: &str) -> Value {
    native_test_map_value(&result.context, key).unwrap_or(Value::Nil)
}

fn native_test_map_value(value: &Value, key: &str) -> Option<Value> {
    map_entries(value)?
        .into_iter()
        .find_map(|(candidate, value)| {
            matches!(candidate, Value::Keyword(keyword) if keyword.as_str() == key).then_some(value)
        })
}

fn native_test_detail(result: &ResultValue, key: &str) -> Value {
    let test = native_test_context_value(result, "test");
    native_test_map_value(&test, key).unwrap_or(Value::Nil)
}

fn native_test_failure_shape(value: &Value) -> bool {
    let Some(_) = map_entries(value) else {
        return false;
    };
    let keyword = |key: &str| matches!(native_test_map_value(value, key), Some(Value::Keyword(_)));
    let vector = |key: &str| {
        matches!(
            native_test_map_value(value, key),
            Some(Value::Vector(_) | Value::Tuple(_))
        )
    };
    let string = |key: &str| matches!(native_test_map_value(value, key), Some(Value::String(_)));
    let map = |key: &str| {
        native_test_map_value(value, key).is_some_and(|value| map_entries(&value).is_some())
    };
    let children_valid = match native_test_map_value(value, "failure/children") {
        Some(Value::Vector(children)) => children.iter().all(native_test_failure_shape),
        Some(Value::Tuple(children)) => children.iter().all(native_test_failure_shape),
        _ => false,
    };
    keyword("failure/code")
        && vector("failure/path")
        && vector("failure/in")
        && native_test_map_value(value, "failure/actual").is_some()
        && native_test_map_value(value, "failure/expected").is_some()
        && string("failure/message")
        && map("failure/context")
        && vector("failure/children")
        && children_valid
}

fn native_test_failure_leaves(value: &Value, leaves: &mut Vec<Value>) {
    if !native_test_failure_shape(value) {
        return;
    }
    match native_test_map_value(value, "failure/children") {
        Some(Value::Vector(children)) => {
            if children.is_empty() {
                leaves.push(value.clone());
            } else {
                for child in children.iter() {
                    native_test_failure_leaves(child, leaves);
                }
            }
        }
        Some(Value::Tuple(children)) => {
            if children.is_empty() {
                leaves.push(value.clone());
            } else {
                for child in children.iter() {
                    native_test_failure_leaves(child, leaves);
                }
            }
        }
        _ => {}
    }
}

fn native_test_failures(result: &ResultValue) -> Value {
    match native_test_context_value(result, "failures") {
        Value::Vector(failures) => Value::Vector(failures),
        Value::Tuple(failures) => Value::Vector(PVector::from_iter(failures.iter().cloned())),
        _ => Value::Vector(PVector::new()),
    }
}

fn native_test_failure_seq(result: &ResultValue) -> Value {
    let mut leaves = Vec::new();
    if let Value::Vector(failures) = native_test_failures(result) {
        for failure in failures.iter() {
            native_test_failure_leaves(failure, &mut leaves);
        }
    }
    Value::Vector(PVector::from_iter(leaves))
}

fn native_test_values(operation: &str, values: Vec<Value>) -> Result<Value, String> {
    let operation = operation
        .strip_prefix("std.native.Test/")
        .unwrap_or(operation);
    match operation {
        "events" => {
            if !values.is_empty() {
                return Err("std.native.Test/events expects no arguments".into());
            }
            Ok(native_test_events())
        }
        "catalog" => {
            if !values.is_empty() {
                return Err("std.native.Test/catalog expects no arguments".into());
            }
            Ok(Value::Map(PMap::from_iter([
                (
                    Value::Keyword("runners".into()),
                    Value::Vector(PVector::from_iter([
                        Value::Keyword("code.test".into()),
                        Value::Keyword("native".into()),
                    ])),
                ),
                (
                    Value::Keyword("default".into()),
                    Value::Keyword("code.test".into()),
                ),
                (
                    Value::Keyword("runner".into()),
                    native_test_active_runner()?,
                ),
                (
                    Value::Keyword("context".into()),
                    Value::Keyword("test".into()),
                ),
                (Value::Keyword("events".into()), native_test_events()),
            ])))
        }
        "config" => {
            if values.len() > 1 {
                return Err("std.native.Test/config expects optional options".into());
            }
            let options = if values.is_empty() {
                Value::Map(PMap::new())
            } else {
                values[0].clone()
            };
            native_test_config(native_test_active_runner()?, options)
        }
        "context" => {
            if values.len() > 1 {
                return Err("std.native.Test/context expects an optional config".into());
            }
            let config = if values.is_empty() {
                native_test_config(native_test_active_runner()?, Value::Map(PMap::new()))?
            } else {
                let value = values[0].clone();
                let Some(runner) = map_value(&value, &Value::Keyword("runner".into())).cloned()
                else {
                    return Err("std.native.Test/context expects a Test/config map".into());
                };
                let runner = native_test_runner(runner)?;
                if runner != native_test_active_runner()? {
                    return Err(
                        "std.native.Test/context config runner does not match the runtime".into(),
                    );
                }
                value
            };
            Ok(Value::Pointer(PPointer::new(
                "test".into(),
                PMap::from_iter([
                    (Value::Keyword("id".into()), Value::Keyword("test".into())),
                    (Value::Keyword("config".into()), config),
                ]),
            )))
        }
        "compare" => {
            if values.len() != 2 {
                return Err("std.native.Test/compare expects actual and expected".into());
            }
            native_test_compare(values[0].clone(), values[1].clone())
        }
        "result" => {
            if values.len() != 4 {
                return Err(
                    "std.native.Test/result expects name, actual, expected, and comparison Result"
                        .into(),
                );
            }
            let name = values[0].clone();
            let actual = values[1].clone();
            let expected = values[2].clone();
            let comparison = values[3].clone();
            native_test_result(name, actual, expected, comparison)
        }
        "check" => {
            if values.is_empty() || values.len() > 3 {
                return Err(
                    "std.native.Test/check expects cases, an optional check function, and an optional lifecycle map".into(),
                );
            }
            let cases = values[0].clone();
            let second = if values.len() >= 2 {
                Some(values[1].clone())
            } else {
                None
            };
            let third = if values.len() == 3 {
                Some(values[2].clone())
            } else {
                None
            };
            let (check_function, lifecycle) = match (second, third) {
                (Some(check), Some(lifecycle)) => (Some(check), Some(lifecycle)),
                (Some(value), None) if map_entries(&value).is_some() => (None, Some(value)),
                (check, None) => (check, None),
                (None, Some(_)) => unreachable!(),
            };
            if lifecycle
                .as_ref()
                .is_some_and(|value| map_entries(value).is_none())
            {
                return Err("std.native.Test/check lifecycle must be a map".into());
            }
            native_test_check(cases, check_function, lifecycle)
        }
        "register" => match values.as_slice() {
            [fact] => native_test_register(fact.clone()),
            _ => Err("std.native.Test/register expects one fact map".into()),
        },
        "facts" => {
            if values.len() > 1 {
                return Err("std.native.Test/facts expects an optional namespace".into());
            }
            let namespace = match values.as_slice() {
                [] => native_test_current_namespace()?,
                [namespace] => native_test_namespace(namespace.clone(), "facts")?,
                _ => unreachable!(),
            };
            Ok(Value::Vector(PVector::from_iter(
                native_test_facts()?.into_iter().filter(|fact| {
                    native_test_map_value(fact, "namespace")
                        == Some(Value::String(namespace.clone()))
                }),
            )))
        }
        "get" => {
            let (namespace, desc) = match values.as_slice() {
                [desc] => (
                    native_test_current_namespace()?,
                    native_test_desc_argument(desc.clone(), "get")?,
                ),
                [namespace, desc] => (
                    native_test_namespace(namespace.clone(), "get")?,
                    native_test_desc_argument(desc.clone(), "get")?,
                ),
                _ => {
                    return Err(
                        "std.native.Test/get expects a description and optional namespace".into(),
                    )
                }
            };
            native_test_lookup(&namespace, &desc)
        }
        "remove" => {
            let (namespace, desc) = match values.as_slice() {
                [desc] => (
                    native_test_current_namespace()?,
                    native_test_desc_argument(desc.clone(), "remove")?,
                ),
                [namespace, desc] => (
                    native_test_namespace(namespace.clone(), "remove")?,
                    native_test_desc_argument(desc.clone(), "remove")?,
                ),
                _ => {
                    return Err(
                        "std.native.Test/remove expects a description and optional namespace"
                            .into(),
                    )
                }
            };
            let removed = native_test_lookup(&namespace, &desc)?;
            let mut facts = native_test_facts()?;
            facts.retain(|fact| {
                native_test_map_value(fact, "namespace") != Some(Value::String(namespace.clone()))
                    || native_test_map_value(fact, "desc") != Some(desc.clone())
            });
            native_test_set_facts(facts)?;
            Ok(removed)
        }
        "purge" => {
            if values.len() > 1 {
                return Err("std.native.Test/purge expects an optional namespace".into());
            }
            let namespace = match values.as_slice() {
                [] => native_test_current_namespace()?,
                [namespace] => native_test_namespace(namespace.clone(), "purge")?,
                _ => unreachable!(),
            };
            let facts = native_test_facts()?;
            let removed = facts
                .iter()
                .filter(|fact| {
                    native_test_map_value(fact, "namespace")
                        == Some(Value::String(namespace.clone()))
                })
                .cloned()
                .collect::<Vec<_>>();
            native_test_set_facts(
                facts
                    .into_iter()
                    .filter(|fact| {
                        native_test_map_value(fact, "namespace")
                            != Some(Value::String(namespace.clone()))
                    })
                    .collect(),
            )?;
            Ok(Value::Vector(PVector::from_iter(removed)))
        }
        "reset" => {
            if !values.is_empty() {
                return Err("std.native.Test/reset expects no arguments".into());
            }
            native_test_reset()
        }
        "run-fact" => {
            let (fact, options) = match values.as_slice() {
                [fact] => (fact.clone(), Value::Map(PMap::new())),
                [fact, options] if map_entries(options).is_some() => {
                    (fact.clone(), options.clone())
                }
                [_, _] => return Err("std.native.Test/run-fact options must be a map".into()),
                _ => return Err(
                    "std.native.Test/run-fact expects a fact or description and optional options"
                        .into(),
                ),
            };
            let fact = if map_entries(&fact).is_some() {
                fact
            } else {
                let desc = native_test_desc_argument(fact, "run-fact")?;
                let namespace = native_test_current_namespace()?;
                let fact = native_test_lookup(&namespace, &desc)?;
                if matches!(fact, Value::Nil) {
                    return Err(format!(
                        "std.native.Test/run-fact fact not found: {}",
                        desc.display()
                    ));
                }
                fact
            };
            native_test_run_fact(fact, options)
        }
        "run" => {
            if values.len() > 1 {
                return Err(
                    "std.native.Test/run expects an optional options map; use Test/check for cases"
                        .into(),
                );
            }
            let options = values
                .into_iter()
                .next()
                .unwrap_or_else(|| Value::Map(PMap::new()));
            native_test_run(options)
        }
        "summary" => match values.as_slice() {
            [Value::Vector(results)] => native_test_summary(results.iter().cloned().collect()),
            [Value::Tuple(results)] => native_test_summary(results.iter().cloned().collect()),
            [_] => Err("std.native.Test/summary expects a vector of fact results".into()),
            _ => Err("std.native.Test/summary expects one vector of fact results".into()),
        },
        "passed?" => {
            if values.len() != 1 {
                return Err("std.native.Test/passed? expects one result".into());
            }
            let result = native_test_require_result(values[0].clone(), "passed?")?;
            Ok(Value::Bool(
                result.is_success() && matches!(result.data, Value::Bool(true)),
            ))
        }
        "actual" | "expected" | "failures" | "failure-seq" | "failure-count" => {
            if values.len() != 1 {
                return Err(format!("std.native.Test/{operation} expects one Result"));
            }
            let result = native_test_require_result(values[0].clone(), operation)?;
            Ok(match operation {
                "actual" => native_test_detail(&result, "actual"),
                "expected" => native_test_detail(&result, "expected"),
                "failures" => native_test_failures(&result),
                "failure-seq" => native_test_failure_seq(&result),
                "failure-count" => match native_test_failure_seq(&result) {
                    Value::Vector(values) => Value::Number(values.len() as i64),
                    _ => unreachable!(),
                },
                _ => unreachable!(),
            })
        }
        "failure" => {
            if values.len() != 2 {
                return Err("std.native.Test/failure expects a Result and index".into());
            }
            let result = native_test_require_result(values[0].clone(), "failure")?;
            let index = match &values[1] {
                Value::Number(index) if *index >= 0 => *index as usize,
                _ => {
                    return Err(
                        "std.native.Test/failure index must be a non-negative integer".into(),
                    )
                }
            };
            match native_test_failure_seq(&result) {
                Value::Vector(values) => Ok(values.get(index).cloned().unwrap_or(Value::Nil)),
                _ => unreachable!(),
            }
        }
        "failure?" => {
            if values.len() != 1 {
                return Err("std.native.Test/failure? expects one value".into());
            }
            Ok(Value::Bool(native_test_failure_shape(&values[0])))
        }
        _ => Err(format!("unknown std.native.Test operation: {operation}")),
    }
}

struct NativeCommandRequest {
    app: u64,
    request: crate::command::Request,
    context: Value,
}

struct NativeCommandSnapshot {
    app: u64,
    snapshot: crate::command::Snapshot<Value>,
}

struct NativeCommandState {
    next_app: u64,
    next_request: u64,
    next_snapshot: u64,
    apps: HashMap<u64, crate::command::App<Value>>,
    requests: HashMap<u64, NativeCommandRequest>,
    snapshots: HashMap<u64, NativeCommandSnapshot>,
}

impl Default for NativeCommandState {
    fn default() -> Self {
        Self {
            next_app: 1,
            next_request: 1,
            next_snapshot: 1,
            apps: HashMap::new(),
            requests: HashMap::new(),
            snapshots: HashMap::new(),
        }
    }
}

thread_local! {
    static NATIVE_COMMAND_STATE: RefCell<NativeCommandState> = RefCell::new(NativeCommandState::default());
}

fn native_command_keyword(name: &str) -> Value {
    Value::Keyword(Keyword::from(name))
}

fn native_command_map(entries: impl IntoIterator<Item = (Value, Value)>) -> Value {
    Value::Map(PMap::from_iter(entries))
}

fn native_command_pointer(
    context: &str,
    entries: impl IntoIterator<Item = (Value, Value)>,
) -> Value {
    Value::Pointer(PPointer::new(
        Keyword::from(context),
        PMap::from_iter(entries),
    ))
}

fn native_command_handle(value: &Value, context: &str, operation: &str) -> Result<u64, String> {
    let Value::Pointer(pointer) = value else {
        return Err(format!(
            "std.native.Command/{operation} expects a {context} handle"
        ));
    };
    if pointer.context().as_str() != context {
        return Err(format!(
            "std.native.Command/{operation} expects a {context} handle"
        ));
    }
    match pointer.get(&native_command_keyword("id")) {
        Some(Value::Number(id)) if *id > 0 => Ok(*id as u64),
        _ => Err(format!(
            "std.native.Command/{operation} received an invalid {context} handle"
        )),
    }
}

fn native_command_app(value: &Value, operation: &str) -> Result<u64, String> {
    native_command_handle(value, "command/app", operation)
}

fn native_command_route(
    value: &Value,
    app: u64,
    operation: &str,
) -> Result<crate::command::RouteHandle, String> {
    let route = native_command_handle(value, "command/route", operation)?;
    let Value::Pointer(pointer) = value else {
        unreachable!()
    };
    match pointer.get(&native_command_keyword("app")) {
        Some(Value::Number(candidate)) if *candidate == app as i64 => {
            Ok(crate::command::RouteHandle::from_id(route))
        }
        _ => Err(format!(
            "std.native.Command/{operation} route belongs to a different application"
        )),
    }
}

fn native_command_config_argument(
    value: &Value,
    operation: &str,
) -> Result<crate::command::AppConfig, String> {
    let Some(entries) = map_entries(value) else {
        return Err(format!(
            "std.native.Command/{operation} expects a config map"
        ));
    };
    let config = Value::Map(PMap::from_iter(entries));
    let id = match map_value(&config, &native_command_keyword("id")) {
        Some(Value::Symbol(id)) if !id.as_str().is_empty() => id.as_str().to_owned(),
        _ => {
            return Err(format!(
                "std.native.Command/{operation} config :id must be a symbol"
            ))
        }
    };
    let desc = match map_value(&config, &native_command_keyword("desc")) {
        Some(Value::String(desc)) if !desc.trim().is_empty() => desc.clone(),
        _ => {
            return Err(format!(
                "std.native.Command/{operation} config :desc must be a non-empty string"
            ))
        }
    };
    Ok(crate::command::AppConfig { id, desc })
}

fn native_command_vector(
    value: &Value,
    operation: &str,
    field: &str,
) -> Result<Vec<Value>, String> {
    match value {
        Value::Vector(values) => Ok(values.iter().cloned().collect()),
        Value::Tuple(values) => Ok(values.iter().cloned().collect()),
        _ => Err(format!(
            "std.native.Command/{operation} {field} must be a vector"
        )),
    }
}

fn native_command_string(value: &Value, operation: &str, field: &str) -> Result<String, String> {
    match value {
        Value::String(value) => Ok(value.clone()),
        _ => Err(format!(
            "std.native.Command/{operation} {field} must be a string"
        )),
    }
}

fn native_command_strings(
    value: &Value,
    operation: &str,
    field: &str,
) -> Result<Vec<String>, String> {
    native_command_vector(value, operation, field)?
        .into_iter()
        .map(|value| native_command_string(&value, operation, field))
        .collect()
}

fn native_command_keyword_argument(
    value: &Value,
    operation: &str,
    field: &str,
) -> Result<String, String> {
    match value {
        Value::Keyword(value) if !value.as_str().is_empty() => Ok(value.as_str().to_owned()),
        _ => Err(format!(
            "std.native.Command/{operation} {field} must be a keyword"
        )),
    }
}

fn native_command_boolean(
    value: Option<&Value>,
    operation: &str,
    field: &str,
    fallback: bool,
) -> Result<bool, String> {
    match value {
        None | Some(Value::Nil) => Ok(fallback),
        Some(Value::Bool(value)) => Ok(*value),
        _ => Err(format!(
            "std.native.Command/{operation} {field} must be a boolean"
        )),
    }
}

fn native_command_option(
    value: Value,
    operation: &str,
) -> Result<crate::command::OptionSpec, String> {
    let Some(entries) = map_entries(&value) else {
        return Err(format!(
            "std.native.Command/{operation} :options entries must be maps"
        ));
    };
    let value = Value::Map(PMap::from_iter(entries));
    let id = native_command_keyword_argument(
        map_value(&value, &native_command_keyword("id"))
            .ok_or_else(|| format!("std.native.Command/{operation} option :id is required"))?,
        operation,
        "option :id",
    )?;
    let long = match map_value(&value, &native_command_keyword("long")) {
        None | Some(Value::Nil) => None,
        Some(value) => Some(native_command_string(value, operation, "option :long")?),
    };
    let short = match map_value(&value, &native_command_keyword("short")) {
        None | Some(Value::Nil) => None,
        Some(Value::String(value)) if value.chars().count() == 1 => value.chars().next(),
        _ => {
            return Err(format!(
                "std.native.Command/{operation} option :short must be one character"
            ))
        }
    };
    let kind = match map_value(&value, &native_command_keyword("type")) {
        Some(Value::Keyword(kind)) if kind.as_str() == "boolean" => {
            crate::command::OptionKind::Boolean
        }
        Some(Value::Keyword(kind)) if kind.as_str() == "string" => {
            crate::command::OptionKind::String
        }
        _ => {
            return Err(format!(
                "std.native.Command/{operation} option :type must be :boolean or :string"
            ))
        }
    };
    let many = native_command_boolean(
        map_value(&value, &native_command_keyword("many?")),
        operation,
        "option :many?",
        false,
    )?;
    let default = match map_value(&value, &native_command_keyword("default")) {
        None | Some(Value::Nil) => None,
        Some(Value::Bool(value)) => Some(crate::command::ParsedValue::Boolean(*value)),
        Some(Value::String(value)) => Some(crate::command::ParsedValue::String(value.clone())),
        Some(value) => Some(crate::command::ParsedValue::Strings(
            native_command_strings(value, operation, "option :default")?,
        )),
    };
    Ok(crate::command::OptionSpec {
        id,
        long,
        short,
        kind,
        many,
        default,
    })
}

fn native_command_argument(
    value: Value,
    operation: &str,
) -> Result<crate::command::ArgumentSpec, String> {
    let Some(entries) = map_entries(&value) else {
        return Err(format!(
            "std.native.Command/{operation} :arguments entries must be maps"
        ));
    };
    let value = Value::Map(PMap::from_iter(entries));
    Ok(crate::command::ArgumentSpec {
        id: native_command_keyword_argument(
            map_value(&value, &native_command_keyword("id")).ok_or_else(|| {
                format!("std.native.Command/{operation} argument :id is required")
            })?,
            operation,
            "argument :id",
        )?,
        required: native_command_boolean(
            map_value(&value, &native_command_keyword("required?")),
            operation,
            "argument :required?",
            true,
        )?,
        many: native_command_boolean(
            map_value(&value, &native_command_keyword("many?")),
            operation,
            "argument :many?",
            false,
        )?,
    })
}

fn native_command_route_argument(
    value: Value,
    operation: &str,
) -> Result<crate::command::Route<Value>, String> {
    let Some(entries) = map_entries(&value) else {
        return Err(format!(
            "std.native.Command/{operation} expects a route map"
        ));
    };
    let value = Value::Map(PMap::from_iter(entries));
    let path = native_command_strings(
        map_value(&value, &native_command_keyword("path"))
            .ok_or_else(|| format!("std.native.Command/{operation} route :path is required"))?,
        operation,
        "route :path",
    )?;
    let aliases = match map_value(&value, &native_command_keyword("aliases")) {
        None | Some(Value::Nil) => Vec::new(),
        Some(value) => native_command_vector(value, operation, "route :aliases")?
            .into_iter()
            .map(|alias| native_command_strings(&alias, operation, "route :aliases"))
            .collect::<Result<Vec<_>, _>>()?,
    };
    let options = match map_value(&value, &native_command_keyword("options")) {
        None | Some(Value::Nil) => Vec::new(),
        Some(value) => native_command_vector(value, operation, "route :options")?
            .into_iter()
            .map(|value| native_command_option(value, operation))
            .collect::<Result<Vec<_>, _>>()?,
    };
    let arguments = match map_value(&value, &native_command_keyword("arguments")) {
        None | Some(Value::Nil) => Vec::new(),
        Some(value) => native_command_vector(value, operation, "route :arguments")?
            .into_iter()
            .map(|value| native_command_argument(value, operation))
            .collect::<Result<Vec<_>, _>>()?,
    };
    let handler = match map_value(&value, &native_command_keyword("handler")) {
        Some(Value::Function(function)) => Value::Function(function.clone()),
        _ => {
            return Err(format!(
                "std.native.Command/{operation} route :handler must be a function"
            ))
        }
    };
    Ok(crate::command::Route {
        spec: crate::command::RouteSpec {
            id: native_command_keyword_argument(
                map_value(&value, &native_command_keyword("id")).ok_or_else(|| {
                    format!("std.native.Command/{operation} route :id is required")
                })?,
                operation,
                "route :id",
            )?,
            path,
            aliases,
            desc: native_command_string(
                map_value(&value, &native_command_keyword("desc")).ok_or_else(|| {
                    format!("std.native.Command/{operation} route :desc is required")
                })?,
                operation,
                "route :desc",
            )?,
            options,
            arguments,
            passthrough: native_command_boolean(
                map_value(&value, &native_command_keyword("passthrough?")),
                operation,
                "route :passthrough?",
                false,
            )?,
        },
        handler,
    })
}

fn native_command_parsed_value(value: &crate::command::ParsedValue) -> Value {
    match value {
        crate::command::ParsedValue::Boolean(value) => Value::Bool(*value),
        crate::command::ParsedValue::String(value) => Value::String(value.clone()),
        crate::command::ParsedValue::Strings(values) => Value::Vector(PVector::from_iter(
            values.iter().cloned().map(Value::String),
        )),
    }
}

fn native_command_spec_value(spec: &crate::command::RouteSpec) -> Value {
    native_command_map([
        (
            native_command_keyword("id"),
            native_command_keyword(&spec.id),
        ),
        (
            native_command_keyword("path"),
            Value::Vector(PVector::from_iter(
                spec.path.iter().cloned().map(Value::String),
            )),
        ),
        (
            native_command_keyword("aliases"),
            Value::Vector(PVector::from_iter(spec.aliases.iter().map(|alias| {
                Value::Vector(PVector::from_iter(alias.iter().cloned().map(Value::String)))
            }))),
        ),
        (
            native_command_keyword("desc"),
            Value::String(spec.desc.clone()),
        ),
        (
            native_command_keyword("passthrough?"),
            Value::Bool(spec.passthrough),
        ),
        (
            native_command_keyword("options"),
            Value::Vector(PVector::from_iter(spec.options.iter().map(|option| {
                let mut entries = vec![
                    (
                        native_command_keyword("id"),
                        native_command_keyword(&option.id),
                    ),
                    (
                        native_command_keyword("long"),
                        Value::String(option.long_name()),
                    ),
                    (
                        native_command_keyword("short"),
                        option
                            .short
                            .map(|short| Value::String(short.into()))
                            .unwrap_or(Value::Nil),
                    ),
                    (
                        native_command_keyword("type"),
                        native_command_keyword(match option.kind {
                            crate::command::OptionKind::Boolean => "boolean",
                            crate::command::OptionKind::String => "string",
                        }),
                    ),
                    (native_command_keyword("many?"), Value::Bool(option.many)),
                ];
                if let Some(default) = &option.default {
                    entries.push((
                        native_command_keyword("default"),
                        native_command_parsed_value(default),
                    ));
                }
                native_command_map(entries)
            }))),
        ),
        (
            native_command_keyword("arguments"),
            Value::Vector(PVector::from_iter(spec.arguments.iter().map(|argument| {
                native_command_map([
                    (
                        native_command_keyword("id"),
                        native_command_keyword(&argument.id),
                    ),
                    (
                        native_command_keyword("required?"),
                        Value::Bool(argument.required),
                    ),
                    (native_command_keyword("many?"), Value::Bool(argument.many)),
                ])
            }))),
        ),
    ])
}

fn native_command_invocation(
    value: Value,
    operation: &str,
) -> Result<(Vec<String>, Value), String> {
    let Some(entries) = map_entries(&value) else {
        return Err(format!(
            "std.native.Command/{operation} expects an invocation map"
        ));
    };
    let value = Value::Map(PMap::from_iter(entries));
    let argv = native_command_strings(
        map_value(&value, &native_command_keyword("argv")).ok_or_else(|| {
            format!("std.native.Command/{operation} invocation :argv is required")
        })?,
        operation,
        "invocation :argv",
    )?;
    let context = map_value(&value, &native_command_keyword("context"))
        .cloned()
        .unwrap_or_else(|| Value::Map(PMap::new()));
    if map_entries(&context).is_none() {
        return Err(format!(
            "std.native.Command/{operation} invocation :context must be a map"
        ));
    }
    Ok((argv, context))
}

fn native_command_request_value(
    request_id: u64,
    request: &crate::command::Request,
    context: Value,
) -> Value {
    native_command_map([
        (
            native_command_keyword("app/id"),
            Value::Symbol(Symbol::parse(&request.app_id)),
        ),
        (
            native_command_keyword("route/id"),
            native_command_keyword(&request.route_id),
        ),
        (
            native_command_keyword("route/path"),
            Value::Vector(PVector::from_iter(
                request.route_path.iter().cloned().map(Value::String),
            )),
        ),
        (
            native_command_keyword("argv"),
            Value::Vector(PVector::from_iter(
                request.argv.iter().cloned().map(Value::String),
            )),
        ),
        (
            native_command_keyword("arguments"),
            native_command_map(request.arguments.iter().map(|(key, value)| {
                (
                    native_command_keyword(key),
                    native_command_parsed_value(value),
                )
            })),
        ),
        (
            native_command_keyword("options"),
            native_command_map(request.options.iter().map(|(key, value)| {
                (
                    native_command_keyword(key),
                    native_command_parsed_value(value),
                )
            })),
        ),
        (native_command_keyword("context"), context),
        (
            native_command_keyword("command/request"),
            native_command_pointer(
                "command/request",
                [(
                    native_command_keyword("id"),
                    Value::Number(request_id as i64),
                )],
            ),
        ),
    ])
}

fn native_command_response_value(response: crate::command::Response) -> Value {
    native_command_map([
        (
            native_command_keyword("stdout"),
            Value::String(response.stdout),
        ),
        (
            native_command_keyword("stderr"),
            Value::String(response.stderr),
        ),
        (native_command_keyword("exit"), Value::Number(response.exit)),
    ])
}

fn native_command_response_argument(
    value: Value,
    operation: &str,
) -> Result<crate::command::Response, String> {
    let Some(entries) = map_entries(&value) else {
        return Err(format!(
            "std.native.Command/{operation} handler must return a response map"
        ));
    };
    if entries.len() != 3 {
        return Err(format!(
            "std.native.Command/{operation} response must contain only :stdout, :stderr, and :exit"
        ));
    }
    let value = Value::Map(PMap::from_iter(entries));
    let stdout = native_command_string(
        map_value(&value, &native_command_keyword("stdout")).ok_or_else(|| {
            format!("std.native.Command/{operation} response :stdout is required")
        })?,
        operation,
        "response :stdout",
    )?;
    let stderr = native_command_string(
        map_value(&value, &native_command_keyword("stderr")).ok_or_else(|| {
            format!("std.native.Command/{operation} response :stderr is required")
        })?,
        operation,
        "response :stderr",
    )?;
    let exit = match map_value(&value, &native_command_keyword("exit")) {
        Some(Value::Number(value)) => *value,
        _ => {
            return Err(format!(
                "std.native.Command/{operation} response :exit must be an integer"
            ))
        }
    };
    crate::command::Response {
        stdout,
        stderr,
        exit,
    }
    .checked()
    .map_err(|error| error.to_string())
}

fn native_command_parse(app: u64, invocation: Value, operation: &str) -> Result<Value, String> {
    let (argv, context) = native_command_invocation(invocation, operation)?;
    NATIVE_COMMAND_STATE.with(|state| {
        let mut state = state.borrow_mut();
        let request = state
            .apps
            .get(&app)
            .ok_or_else(|| format!("std.native.Command/{operation} application was not found"))?
            .parse(argv)
            .map_err(|error| error.to_string())?;
        let request_id = state.next_request;
        state.next_request += 1;
        state.requests.insert(
            request_id,
            NativeCommandRequest {
                app,
                request: request.clone(),
                context: context.clone(),
            },
        );
        Ok(native_command_request_value(request_id, &request, context))
    })
}

fn native_command_request_id(value: &Value, operation: &str) -> Result<u64, String> {
    let Some(request) = map_value(value, &native_command_keyword("command/request")) else {
        return Err(format!(
            "std.native.Command/{operation} expects a Command/parse request"
        ));
    };
    native_command_handle(request, "command/request", operation)
}

fn native_command_dispatch(
    app: u64,
    request_value: Value,
    operation: &str,
) -> Result<Value, String> {
    let request_id = native_command_request_id(&request_value, operation)?;
    let (handler, request, context) = NATIVE_COMMAND_STATE.with(|state| {
        let state = state.borrow();
        let stored = state
            .requests
            .get(&request_id)
            .ok_or_else(|| format!("std.native.Command/{operation} request was not found"))?;
        if stored.app != app {
            return Err(format!(
                "std.native.Command/{operation} request belongs to a different application"
            ));
        }
        let application = state
            .apps
            .get(&app)
            .ok_or_else(|| format!("std.native.Command/{operation} application was not found"))?;
        let handler = application
            .handler(&stored.request)
            .map_err(|error| error.to_string())?
            .clone();
        Ok::<_, String>((handler, stored.request.clone(), stored.context.clone()))
    })?;
    let output = call_value(
        handler,
        vec![native_command_request_value(request_id, &request, context)],
    )?;
    native_command_response_argument(output, operation).map(native_command_response_value)
}

fn native_command_values(operation: &str, values: Vec<Value>) -> Result<Value, String> {
    let operation = operation
        .strip_prefix("std.native.Command/")
        .unwrap_or(operation);
    match operation {
        "create" => match values.as_slice() {
            [config] => {
                let config = native_command_config_argument(config, operation)?;
                NATIVE_COMMAND_STATE.with(|state| {
                    let mut state = state.borrow_mut();
                    let id = state.next_app;
                    state.next_app += 1;
                    state.apps.insert(
                        id,
                        crate::command::App::create(config).map_err(|error| error.to_string())?,
                    );
                    Ok(native_command_pointer(
                        "command/app",
                        [(native_command_keyword("id"), Value::Number(id as i64))],
                    ))
                })
            }
            _ => Err("std.native.Command/create expects one config map".into()),
        },
        "config" => match values.as_slice() {
            [app] => {
                let app = native_command_app(app, operation)?;
                NATIVE_COMMAND_STATE.with(|state| {
                    let state = state.borrow();
                    let config = state
                        .apps
                        .get(&app)
                        .ok_or_else(|| {
                            "std.native.Command/config application was not found".to_owned()
                        })?
                        .config();
                    Ok(native_command_map([
                        (
                            native_command_keyword("id"),
                            Value::Symbol(Symbol::parse(&config.id)),
                        ),
                        (native_command_keyword("desc"), Value::String(config.desc)),
                    ]))
                })
            }
            _ => Err("std.native.Command/config expects one application".into()),
        },
        "install" => match values.as_slice() {
            [app, route] => {
                let app = native_command_app(app, operation)?;
                let route = native_command_route_argument(route.clone(), operation)?;
                NATIVE_COMMAND_STATE.with(|state| {
                    let mut state = state.borrow_mut();
                    let handle = state
                        .apps
                        .get_mut(&app)
                        .ok_or_else(|| {
                            "std.native.Command/install application was not found".to_owned()
                        })?
                        .install(route)
                        .map_err(|error| error.to_string())?;
                    Ok(native_command_pointer(
                        "command/route",
                        [
                            (
                                native_command_keyword("id"),
                                Value::Number(handle.id() as i64),
                            ),
                            (native_command_keyword("app"), Value::Number(app as i64)),
                        ],
                    ))
                })
            }
            _ => Err("std.native.Command/install expects an application and route map".into()),
        },
        "uninstall" => match values.as_slice() {
            [app, route] => {
                let app = native_command_app(app, operation)?;
                let route = native_command_route(route, app, operation)?;
                NATIVE_COMMAND_STATE.with(|state| {
                    state
                        .borrow_mut()
                        .apps
                        .get_mut(&app)
                        .ok_or_else(|| {
                            "std.native.Command/uninstall application was not found".to_owned()
                        })?
                        .uninstall(route)
                        .map(Value::Bool)
                        .map_err(|error| error.to_string())
                })
            }
            _ => Err("std.native.Command/uninstall expects an application and route handle".into()),
        },
        "routes" => match values.as_slice() {
            [app] => {
                let app = native_command_app(app, operation)?;
                NATIVE_COMMAND_STATE.with(|state| {
                    state
                        .borrow()
                        .apps
                        .get(&app)
                        .ok_or_else(|| {
                            "std.native.Command/routes application was not found".to_owned()
                        })?
                        .routes()
                        .map(|routes| {
                            Value::Vector(PVector::from_iter(
                                routes.iter().map(native_command_spec_value),
                            ))
                        })
                        .map_err(|error| error.to_string())
                })
            }
            _ => Err("std.native.Command/routes expects one application".into()),
        },
        "snapshot" => match values.as_slice() {
            [app] => {
                let app = native_command_app(app, operation)?;
                NATIVE_COMMAND_STATE.with(|state| {
                    let mut state = state.borrow_mut();
                    let snapshot = state
                        .apps
                        .get(&app)
                        .ok_or_else(|| {
                            "std.native.Command/snapshot application was not found".to_owned()
                        })?
                        .snapshot()
                        .map_err(|error| error.to_string())?;
                    let id = state.next_snapshot;
                    state.next_snapshot += 1;
                    state
                        .snapshots
                        .insert(id, NativeCommandSnapshot { app, snapshot });
                    Ok(native_command_pointer(
                        "command/snapshot",
                        [
                            (native_command_keyword("id"), Value::Number(id as i64)),
                            (native_command_keyword("app"), Value::Number(app as i64)),
                        ],
                    ))
                })
            }
            _ => Err("std.native.Command/snapshot expects one application".into()),
        },
        "restore" => match values.as_slice() {
            [app, snapshot] => {
                let app = native_command_app(app, operation)?;
                let snapshot_id = native_command_handle(snapshot, "command/snapshot", operation)?;
                NATIVE_COMMAND_STATE.with(|state| {
                    let mut state = state.borrow_mut();
                    let snapshot = state
                        .snapshots
                        .get(&snapshot_id)
                        .ok_or_else(|| "std.native.Command/restore snapshot was not found".to_owned())?;
                    if snapshot.app != app {
                        return Err("std.native.Command/restore snapshot belongs to a different application".into());
                    }
                    let snapshot = snapshot.snapshot.clone();
                    state
                        .apps
                        .get_mut(&app)
                        .ok_or_else(|| "std.native.Command/restore application was not found".to_owned())?
                        .restore(snapshot)
                        .map_err(|error| error.to_string())?;
                    Ok(values[0].clone())
                })
            }
            _ => Err("std.native.Command/restore expects an application and snapshot".into()),
        },
        "reset" => match values.as_slice() {
            [app] => {
                let app = native_command_app(app, operation)?;
                NATIVE_COMMAND_STATE.with(|state| {
                    let mut state = state.borrow_mut();
                    state
                        .apps
                        .get_mut(&app)
                        .ok_or_else(|| {
                            "std.native.Command/reset application was not found".to_owned()
                        })?
                        .reset()
                        .map_err(|error| error.to_string())?;
                    state.requests.retain(|_, request| request.app != app);
                    Ok(values[0].clone())
                })
            }
            _ => Err("std.native.Command/reset expects one application".into()),
        },
        "closed?" => match values.as_slice() {
            [app] => {
                let app = native_command_app(app, operation)?;
                NATIVE_COMMAND_STATE.with(|state| {
                    state
                        .borrow()
                        .apps
                        .get(&app)
                        .map(|app| Value::Bool(app.closed()))
                        .ok_or_else(|| {
                            "std.native.Command/closed? application was not found".to_owned()
                        })
                })
            }
            _ => Err("std.native.Command/closed? expects one application".into()),
        },
        "close" => match values.as_slice() {
            [app] => {
                let app = native_command_app(app, operation)?;
                NATIVE_COMMAND_STATE.with(|state| {
                    let mut state = state.borrow_mut();
                    state
                        .apps
                        .get_mut(&app)
                        .ok_or_else(|| {
                            "std.native.Command/close application was not found".to_owned()
                        })?
                        .close();
                    state.requests.retain(|_, request| request.app != app);
                    Ok(Value::Nil)
                })
            }
            _ => Err("std.native.Command/close expects one application".into()),
        },
        "parse" => match values.as_slice() {
            [app, invocation] => native_command_parse(
                native_command_app(app, operation)?,
                invocation.clone(),
                operation,
            ),
            _ => Err("std.native.Command/parse expects an application and invocation map".into()),
        },
        "dispatch" => match values.as_slice() {
            [app, request] => native_command_dispatch(
                native_command_app(app, operation)?,
                request.clone(),
                operation,
            ),
            _ => {
                Err("std.native.Command/dispatch expects an application and parsed request".into())
            }
        },
        "run" => match values.as_slice() {
            [app, invocation] => {
                let app = native_command_app(app, operation)?;
                match native_command_parse(app, invocation.clone(), operation) {
                    Ok(request) => match native_command_dispatch(app, request, operation) {
                        Ok(response) => Ok(response),
                        Err(error) => Ok(native_command_response_value(
                            crate::command::Response::failure(1, error),
                        )),
                    },
                    Err(error) => Ok(native_command_response_value(
                        crate::command::Response::failure(2, error),
                    )),
                }
            }
            _ => Err("std.native.Command/run expects an application and invocation map".into()),
        },
        _ => Err(format!("unknown std.native.Command operation: {operation}")),
    }
}

fn native_regex_values(operation: &str, values: Vec<Value>) -> Result<Value, String> {
    let operation = operation
        .strip_prefix("std.native.RegExp/")
        .unwrap_or(operation);
    match operation {
        "compile" => {
            if values.len() != 1 {
                return Err("std.native.RegExp/compile expects one string".into());
            }
            let pattern = match &values[0] {
                Value::String(pattern) => pattern.clone(),
                _ => return Err("std.native.RegExp/compile expects one string".into()),
            };
            regex::Regex::new(&pattern).map_err(|error| format!("invalid regexp: {error}"))?;
            Ok(Value::Regex(pattern))
        }
        "pattern" => {
            if values.len() != 1 {
                return Err("std.native.RegExp/pattern expects one regexp".into());
            }
            match &values[0] {
                Value::Regex(pattern) => Ok(Value::String(pattern.clone())),
                _ => Err("std.native.RegExp/pattern expects one regexp".into()),
            }
        }
        "find?" => {
            if values.len() != 2 {
                return Err("std.native.RegExp/find? expects a regexp and string".into());
            }
            let pattern = match &values[0] {
                Value::Regex(pattern) => pattern.clone(),
                _ => return Err("std.native.RegExp/find? expects a regexp and string".into()),
            };
            let input = match &values[1] {
                Value::String(input) => input.clone(),
                _ => return Err("std.native.RegExp/find? expects a regexp and string".into()),
            };
            let regexp =
                regex::Regex::new(&pattern).map_err(|error| format!("invalid regexp: {error}"))?;
            Ok(Value::Bool(regexp.is_match(&input)))
        }
        "find" => {
            if values.len() != 2 {
                return Err("std.native.RegExp/find expects a regexp and string".into());
            }
            let pattern = match &values[0] {
                Value::Regex(pattern) => pattern.clone(),
                _ => return Err("std.native.RegExp/find expects a regexp and string".into()),
            };
            let input = match &values[1] {
                Value::String(input) => input.clone(),
                _ => return Err("std.native.RegExp/find expects a regexp and string".into()),
            };
            let regexp =
                regex::Regex::new(&pattern).map_err(|error| format!("invalid regexp: {error}"))?;
            Ok(regexp
                .find(&input)
                .map(|matched| Value::String(matched.as_str().to_owned()))
                .unwrap_or(Value::Nil))
        }
        "matches" => {
            if values.len() != 2 {
                return Err("std.native.RegExp/matches expects a regexp and string".into());
            }
            let pattern = match &values[0] {
                Value::Regex(pattern) => pattern.clone(),
                _ => return Err("std.native.RegExp/matches expects a regexp and string".into()),
            };
            let input = match &values[1] {
                Value::String(input) => input.clone(),
                _ => return Err("std.native.RegExp/matches expects a regexp and string".into()),
            };
            let anchored = format!(r"\A(?:{pattern})\z");
            let regexp =
                regex::Regex::new(&anchored).map_err(|error| format!("invalid regexp: {error}"))?;
            Ok(Value::Bool(regexp.is_match(&input)))
        }
        "replace" => {
            if values.len() != 3 {
                return Err(
                    "std.native.RegExp/replace expects a regexp, string, and replacement".into(),
                );
            }
            let pattern = match &values[0] {
                Value::Regex(pattern) => pattern.clone(),
                _ => {
                    return Err(
                        "std.native.RegExp/replace expects a regexp, string, and replacement"
                            .into(),
                    )
                }
            };
            let input = match &values[1] {
                Value::String(input) => input.clone(),
                _ => {
                    return Err(
                        "std.native.RegExp/replace expects a regexp, string, and replacement"
                            .into(),
                    )
                }
            };
            let replacement = match &values[2] {
                Value::String(replacement) => replacement.clone(),
                _ => {
                    return Err(
                        "std.native.RegExp/replace expects a regexp, string, and replacement"
                            .into(),
                    )
                }
            };
            let regexp =
                regex::Regex::new(&pattern).map_err(|error| format!("invalid regexp: {error}"))?;
            let replacement = native_regexp_replacement(&replacement, regexp.captures_len());
            Ok(Value::String(
                regexp
                    .replace_all(&input, replacement.as_str())
                    .into_owned(),
            ))
        }
        "split" => {
            if values.len() != 2 {
                return Err("std.native.RegExp/split expects a regexp and string".into());
            }
            let pattern = match &values[0] {
                Value::Regex(pattern) => pattern.clone(),
                _ => return Err("std.native.RegExp/split expects a regexp and string".into()),
            };
            let input = match &values[1] {
                Value::String(input) => input.clone(),
                _ => return Err("std.native.RegExp/split expects a regexp and string".into()),
            };
            if input.is_empty() {
                return Ok(Value::Nil);
            }
            if pattern.is_empty() {
                return Ok(Value::Vector(PVector::from_iter(
                    input
                        .chars()
                        .map(|character| Value::String(character.to_string())),
                )));
            }
            let regexp =
                regex::Regex::new(&pattern).map_err(|error| format!("invalid regexp: {error}"))?;
            Ok(Value::Vector(PVector::from_iter(
                regexp
                    .split(&input)
                    .map(|part| Value::String(part.to_owned())),
            )))
        }
        _ => Err(format!("unknown std.native.RegExp operation: {operation}")),
    }
}

/// Converts Hara's numbered `$1` capture syntax to the unambiguous form used
/// by Rust's regex engine. A following digit extends the capture number only
/// when that group exists, matching Java/Clojure replacement semantics.
fn native_regexp_replacement(replacement: &str, capture_count: usize) -> String {
    let mut output = String::with_capacity(replacement.len());
    let mut characters = replacement.chars().peekable();

    while let Some(character) = characters.next() {
        if character != '$' {
            output.push(character);
            continue;
        }

        let Some(first) = characters.peek().and_then(|value| value.to_digit(10)) else {
            output.push('$');
            continue;
        };
        let mut capture = first as usize;
        if capture >= capture_count {
            output.push('$');
            continue;
        }
        characters.next();

        while let Some(next) = characters.peek().and_then(|value| value.to_digit(10)) {
            let Some(candidate) = capture
                .checked_mul(10)
                .and_then(|value| value.checked_add(next as usize))
            else {
                break;
            };
            if candidate >= capture_count {
                break;
            }
            capture = candidate;
            characters.next();
        }

        output.push_str("${");
        output.push_str(&capture.to_string());
        output.push('}');
    }

    output
}

fn file_error(operation: &str, error: FileError) -> String {
    let method = operation
        .strip_prefix("std.native.File/")
        .unwrap_or(operation);
    format!("file/{method} failed: file/{}", error.code())
}

fn socket_error(operation: &str, error: SocketError) -> String {
    format!("{operation} failed: socket/{}", error.code())
}

fn active_file_provider() -> Option<Rc<dyn FileProvider>> {
    ACTIVE_FILE_PROVIDER.with(|active| active.borrow().clone())
}

fn rejected_file_effect(
    operation: &str,
    path: &str,
    target: Option<&str>,
    error: FileError,
) -> Value {
    let promise = Promise::new();
    promise.reject_value(crate::file::file_error_value(
        operation, path, target, &error,
    ));
    Value::Promise(promise)
}

fn file_effect(
    operation: &str,
    path: &str,
    target: Option<&str>,
    invoke: impl FnOnce(&dyn FileProvider) -> Result<Promise, FileError>,
) -> Value {
    let Some(provider) = active_file_provider() else {
        return rejected_file_effect(operation, path, target, FileError::Denied);
    };
    match invoke(provider.as_ref()) {
        Ok(promise) => Value::Promise(promise),
        Err(error) => rejected_file_effect(operation, path, target, error),
    }
}

fn file_option(options: &Value, name: &str) -> Option<Value> {
    let key = Value::Keyword(name.into());
    map_entries(options)?
        .into_iter()
        .find_map(|(candidate, value)| (candidate == key).then_some(value))
}

fn file_options_value(value: Value, operation: &str) -> Result<Value, String> {
    match value {
        Value::Nil => Ok(Value::Map(PMap::new())),
        value if map_entries(&value).is_some() => Ok(value),
        _ => Err(format!("{operation} options must be a map")),
    }
}

fn file_bool_option(
    options: &Value,
    name: &str,
    default: bool,
    operation: &str,
) -> Result<bool, String> {
    match file_option(options, name) {
        None => Ok(default),
        Some(Value::Bool(value)) => Ok(value),
        Some(_) => Err(format!("{operation} :{name} must be boolean")),
    }
}

fn file_string_option(
    options: &Value,
    name: &str,
    default: &str,
    operation: &str,
) -> Result<String, String> {
    match file_option(options, name) {
        None => Ok(default.into()),
        Some(Value::String(value)) => Ok(value),
        Some(_) => Err(format!("{operation} :{name} must be a string")),
    }
}

fn file_write_options(options: &Value) -> Result<WriteOptions, String> {
    let mode = match file_option(options, "mode") {
        None => WriteMode::Create,
        Some(Value::Keyword(value)) if value.as_str() == "create" => WriteMode::Create,
        Some(Value::Keyword(value)) if value.as_str() == "replace" => WriteMode::Replace,
        Some(Value::Keyword(value)) if value.as_str() == "append" => WriteMode::Append,
        Some(_) => {
            return Err("std.native.File/write :mode must be :create, :replace, or :append".into())
        }
    };
    Ok(WriteOptions {
        mode,
        parents: file_bool_option(options, "parents?", false, "std.native.File/write")?,
    })
}

fn file_mkdir_options(options: &Value) -> Result<MkdirOptions, String> {
    Ok(MkdirOptions {
        parents: file_bool_option(options, "parents?", true, "std.native.File/mkdir")?,
        exists_ok: file_bool_option(options, "exists-ok?", true, "std.native.File/mkdir")?,
    })
}

fn file_delete_options(options: &Value) -> Result<DeleteOptions, String> {
    Ok(DeleteOptions {
        missing_ok: file_bool_option(options, "missing-ok?", false, "std.native.File/delete")?,
    })
}

fn file_copy_options(options: &Value) -> Result<CopyOptions, String> {
    Ok(CopyOptions {
        replace: file_bool_option(options, "replace?", false, "std.native.File/copy")?,
        parents: file_bool_option(options, "parents?", false, "std.native.File/copy")?,
        preserve_modified: file_bool_option(
            options,
            "preserve-modified?",
            false,
            "std.native.File/copy",
        )?,
    })
}

fn file_move_options(options: &Value) -> Result<MoveOptions, String> {
    Ok(MoveOptions {
        replace: file_bool_option(options, "replace?", false, "std.native.File/move")?,
        parents: file_bool_option(options, "parents?", false, "std.native.File/move")?,
        atomic: file_bool_option(options, "atomic?", false, "std.native.File/move")?,
    })
}

fn file_values(operation: &str, values: Vec<Value>) -> Result<Value, String> {
    let effect_operation = operation
        .strip_prefix("std.native.File/")
        .map(|method| format!("file/{method}"))
        .unwrap_or_else(|| operation.to_owned());
    match operation {
        "std.native.File/join" | "std.native.File/resolve" => {
            if values.len() != 2 {
                return Err(format!("{operation} expects a base and path"));
            }
            let Value::String(base) = &values[0] else {
                return Err(format!("{operation} expects a base and path"));
            };
            let Value::String(path) = &values[1] else {
                return Err(format!("{operation} expects a base and path"));
            };
            let result = if operation == "std.native.File/join" {
                crate::file::logical_join(&base, &path)
            } else {
                crate::file::logical_resolve(&base, &path)
            };
            result
                .map(Value::String)
                .map_err(|error| file_error(operation, error))
        }
        "std.native.File/parent" => {
            if values.len() != 1 {
                return Err("std.native.File/parent expects a path".into());
            }
            let Value::String(path) = &values[0] else {
                return Err("std.native.File/parent expects a path".into());
            };
            crate::file::logical_parent(path)
                .map(|parent| parent.map(Value::String).unwrap_or(Value::Nil))
                .map_err(|error| file_error(operation, error))
        }
        "std.native.File/read"
        | "std.native.File/exists?"
        | "std.native.File/stat"
        | "std.native.File/entries"
        | "std.native.File/list"
        | "std.native.File/walk" => {
            if values.len() != 1 {
                return Err(format!("{operation} expects a path"));
            }
            let Value::String(path) = &values[0] else {
                return Err(format!("{operation} expects a path"));
            };
            Ok(file_effect(
                &effect_operation,
                &path,
                None,
                |provider| match operation {
                    "std.native.File/read" => provider.read(&path),
                    "std.native.File/exists?" => provider.exists(&path),
                    "std.native.File/stat" => provider.stat(&path),
                    "std.native.File/entries" => provider.entries(&path),
                    "std.native.File/list" => provider.list(&path),
                    "std.native.File/walk" => provider.walk(&path),
                    _ => unreachable!(),
                },
            ))
        }
        "std.native.File/write" => {
            if !(2..=3).contains(&values.len()) {
                return Err(
                    "std.native.File/write expects a path, bytes, and optional options".into(),
                );
            }
            let Value::String(path) = &values[0] else {
                return Err("std.native.File/write expects a path and bytes".into());
            };
            let bytes = match &values[1] {
                Value::Bytes(value) => value.clone(),
                Value::ByteBuffer(value) => value.borrow().clone(),
                _ => return Err("std.native.File/write expects a path and bytes".into()),
            };
            let options = if values.len() == 3 {
                file_options_value(values[2].clone(), operation)?
            } else {
                Value::Map(PMap::new())
            };
            let options = file_write_options(&options)?;
            Ok(file_effect(&effect_operation, &path, None, |provider| {
                provider.write_with_options(&path, bytes, options)
            }))
        }
        "std.native.File/mkdir" => {
            if !(1..=2).contains(&values.len()) {
                return Err("std.native.File/mkdir expects a path and optional options".into());
            }
            let Value::String(path) = &values[0] else {
                return Err("std.native.File/mkdir expects a path".into());
            };
            let options = if values.len() == 2 {
                file_options_value(values[1].clone(), operation)?
            } else {
                Value::Map(PMap::new())
            };
            let options = file_mkdir_options(&options)?;
            Ok(file_effect(&effect_operation, &path, None, |provider| {
                provider.mkdir_with_options(&path, options)
            }))
        }
        "std.native.File/delete" => {
            if !(1..=2).contains(&values.len()) {
                return Err("std.native.File/delete expects a path and optional options".into());
            }
            let Value::String(path) = &values[0] else {
                return Err("std.native.File/delete expects a path".into());
            };
            let options = if values.len() == 2 {
                file_options_value(values[1].clone(), operation)?
            } else {
                Value::Map(PMap::new())
            };
            let options = file_delete_options(&options)?;
            Ok(file_effect(&effect_operation, &path, None, |provider| {
                provider.delete_with_options(&path, options)
            }))
        }
        "std.native.File/copy" | "std.native.File/move" => {
            if !(2..=3).contains(&values.len()) {
                return Err(format!(
                    "{operation} expects source, target, and optional options"
                ));
            }
            let Value::String(source) = &values[0] else {
                return Err(format!("{operation} expects source and target paths"));
            };
            let Value::String(target) = &values[1] else {
                return Err(format!("{operation} expects source and target paths"));
            };
            let options = if values.len() == 3 {
                file_options_value(values[2].clone(), operation)?
            } else {
                Value::Map(PMap::new())
            };
            Ok(if operation == "std.native.File/copy" {
                let options = file_copy_options(&options)?;
                file_effect(&effect_operation, &source, Some(&target), |provider| {
                    provider.copy(&source, &target, options)
                })
            } else {
                let options = file_move_options(&options)?;
                file_effect(&effect_operation, &source, Some(&target), |provider| {
                    provider.move_entry(&source, &target, options)
                })
            })
        }
        "std.native.File/temp-file" | "std.native.File/temp-directory" => {
            if !(1..=2).contains(&values.len()) {
                return Err(format!("{operation} expects a parent and optional options"));
            }
            let Value::String(parent) = &values[0] else {
                return Err(format!("{operation} expects a parent path"));
            };
            let options = if values.len() == 2 {
                file_options_value(values[1].clone(), operation)?
            } else {
                Value::Map(PMap::new())
            };
            Ok(if operation == "std.native.File/temp-file" {
                let options = TempFileOptions {
                    prefix: file_string_option(&options, "prefix", "tmp", operation)?,
                    suffix: file_string_option(&options, "suffix", "", operation)?,
                };
                file_effect(&effect_operation, &parent, None, |provider| {
                    provider.temp_file(&parent, options)
                })
            } else {
                let options = TempDirectoryOptions {
                    prefix: file_string_option(&options, "prefix", "tmp", operation)?,
                };
                file_effect(&effect_operation, &parent, None, |provider| {
                    provider.temp_directory(&parent, options)
                })
            })
        }
        _ => Err(format!("unknown std.native.File operation: {operation}")),
    }
}

fn socket_values(operation: &str, values: Vec<Value>) -> Result<Value, String> {
    let operation = operation
        .strip_prefix("std.native.Socket/")
        .unwrap_or(operation);
    match operation {
        "receive-stream" | "socket/receive-stream" => {
            if values.len() != 1 {
                return Err(format!("Socket/{operation} expects a socket connection"));
            }
            let socket = socket_handle(&values[0], &format!("Socket/{operation}"))?;
            let events = socket_provider(operation)?
                .events(socket)
                .map_err(|e| socket_error(operation, e))?;
            Ok(host_stream(
                Rc::new(move || socket_receive_promise(events)),
                Rc::new(|| Ok(())),
            ))
        }
        "socket/connect" => {
            if values.len() != 4 {
                return Err("socket/connect expects a host, port, options, and callback".into());
            }
            let host = match &values[0] {
                Value::String(value) => value.clone(),
                _ => {
                    return Err("socket/connect expects a host, port, options, and callback".into())
                }
            };
            let port = value_u16_integer(&values[1], "socket/connect", false)?;
            let _options = &values[2];
            let callback = match &values[3] {
                Value::Function(value) => value.clone(),
                _ => return Err("socket/connect expects a callback".into()),
            };
            let callback = Rc::new(move |event| {
                let arguments = match event {
                    SocketEvent::Connected(handle) => {
                        vec![Value::Nil, Value::Number(handle as i64)]
                    }
                    SocketEvent::Failed(_, error) => vec![Value::String(error), Value::Nil],
                    SocketEvent::Data(_, _) | SocketEvent::Closed(_) => return,
                };
                let _ = call_function(&callback, arguments);
            });
            socket_provider(operation)?
                .connect(&host, port, callback)
                .map(|handle| Value::Number(handle as i64))
                .map_err(|error| socket_error(operation, error))
        }
        "socket/listen" => {
            if values.len() != 4 {
                return Err("socket/listen expects a host, port, options, and callback".into());
            }
            let host = match &values[0] {
                Value::String(value) => value.clone(),
                _ => return Err("socket/listen expects a host string".into()),
            };
            let port = value_u16_integer(&values[1], "socket/listen", true)?;
            let _options = &values[2];
            let callback = match &values[3] {
                Value::Function(value) => value.clone(),
                _ => return Err("socket/listen expects a callback".into()),
            };
            let callback = Rc::new(move |event| {
                let _ = call_function(&callback, vec![socket_server_event_value(event)]);
            });
            socket_provider(operation)?
                .listen(&host, port, callback)
                .map(|handle| Value::Number(handle as i64))
                .map_err(|error| socket_error(operation, error))
        }
        "socket/endpoint" => {
            if values.len() != 1 {
                return Err("socket/endpoint expects a server".into());
            }
            let server = socket_handle(&values[0], "socket/endpoint")?;
            socket_provider(operation)?
                .endpoint(server)
                .map(|(host, port)| {
                    Value::Map(PMap::from_iter([
                        (Value::Keyword("host".into()), Value::String(host)),
                        (Value::Keyword("port".into()), Value::Number(port as i64)),
                    ]))
                })
                .map_err(|error| socket_error(operation, error))
        }
        "socket/events" => {
            if values.len() != 2 {
                return Err("socket/events expects a socket handle and options".into());
            }
            let handle = socket_handle(&values[0], "socket/events")?;
            let _options = &values[1];
            socket_provider(operation)?
                .events(handle)
                .map(|stream| Value::Number(stream as i64))
                .map_err(|error| socket_error(operation, error))
        }
        "socket/next" => {
            if values.len() != 1 {
                return Err("socket/next expects a socket stream".into());
            }
            let stream = socket_handle(&values[0], "socket/next")?;
            socket_provider(operation)?
                .next(stream)
                .map(Value::Promise)
                .map_err(|error| socket_error(operation, error))
        }
        "socket/send" => {
            if values.len() != 2 {
                return Err("socket/send expects a socket connection and bytes".into());
            }
            let socket = socket_handle(&values[0], "socket/send")?;
            let bytes = match &values[1] {
                Value::Bytes(value) => value.clone(),
                Value::ByteBuffer(value) => value.borrow().clone(),
                _ => return Err("socket/send expects a socket connection and bytes".into()),
            };
            socket_provider(operation)?
                .send(socket, &bytes)
                .map(|count| Value::Number(count as i64))
                .map_err(|error| socket_error(operation, error))
        }
        "socket/close" => {
            if values.len() != 1 {
                return Err("socket/close expects a socket connection".into());
            }
            let socket = socket_handle(&values[0], "socket/close")?;
            socket_provider(operation)?
                .close(socket)
                .map(|()| Value::Nil)
                .map_err(|error| socket_error(operation, error))
        }
        _ => Err(format!("unknown std.native.Socket operation: {operation}")),
    }
}

fn socket_receive_promise(stream: SocketHandle) -> Result<Promise, String> {
    let source = socket_provider("Socket/receive-stream")?
        .next(stream)
        .map_err(|e| socket_error("Socket/receive-stream", e))?;
    let output = Promise::new();
    let settled = output.clone();
    source.on_settle(Rc::new(move |result| match result {
        PromiseState::Rejected(error) => {
            settled.reject_rejection(error);
        }
        PromiseState::Pending => {}
        PromiseState::Fulfilled(event) => {
            let entries = map_entries(&event).unwrap_or_default();
            let kind = entries.iter().find_map(|(k, v)| {
                if matches!(k, Value::Keyword(key) if key.as_str() == "type") {
                    Some(v.clone())
                } else {
                    None
                }
            });
            match kind {
                Some(Value::Keyword(kind)) if kind.as_str() == "data" => {
                    let bytes = entries
                        .into_iter()
                        .find_map(|(k, v)| {
                            if matches!(k, Value::Keyword(key) if key.as_str() == "bytes") {
                                Some(v)
                            } else {
                                None
                            }
                        })
                        .unwrap_or(Value::Nil);
                    settled.resolve(bytes);
                }
                Some(Value::Keyword(kind)) if kind.as_str() == "close" => {
                    settled.resolve(Value::Nil);
                }
                Some(Value::Keyword(kind)) if kind.as_str() == "error" => {
                    settled.reject("socket receive failed");
                }
                _ => {
                    settled.reject("Socket/receive-stream received an invalid event");
                }
            }
        }
    }));
    let poll = source.clone();
    output.set_poller(Rc::new(move || {
        poll.state();
    }));
    let wait = source.clone();
    output.set_waiter(Rc::new(move || {
        wait.wait_state();
    }));
    Ok(output)
}

fn socket_handle(value: &Value, operation: &str) -> Result<SocketHandle, String> {
    value_u64_integer(value, operation)
        .map(|value| value as SocketHandle)
        .map_err(|_| format!("{operation} expects a socket handle"))
}

fn native_host_values(operation: &str, values: Vec<Value>) -> Result<Value, String> {
    let method = operation
        .strip_prefix("std.native.Host/")
        .unwrap_or(operation);
    let (service, target, arguments) = match method {
        "call" => {
            if values.len() != 3 {
                return Err(
                    "std.native.Host/call expects service, method, and an argument vector".into(),
                );
            }
            let service = match &values[0] {
                Value::String(value) => value.clone(),
                _ => return Err("std.native.Host/call service must be a string".into()),
            };
            let target = match &values[1] {
                Value::String(value) => value.clone(),
                _ => return Err("std.native.Host/call method must be a string".into()),
            };
            let arguments = match &values[2] {
                Value::Vector(values) => values.iter().cloned().collect(),
                Value::Tuple(values) => values.iter().cloned().collect(),
                _ => return Err("std.native.Host/call arguments must be a vector".into()),
            };
            (service, target, arguments)
        }
        "describe" | "capabilities" => {
            if !values.is_empty() {
                return Err(format!("std.native.Host/{method} expects no arguments"));
            }
            ("host".into(), method.into(), Vec::new())
        }
        "capability?" => {
            if values.len() != 1 {
                return Err("std.native.Host/capability? expects one capability".into());
            }
            ("host".into(), "capability?".into(), vec![values[0].clone()])
        }
        _ => return Err(format!("unknown std.native.Host method: {method}")),
    };
    HOST_CALL_HANDLER.with(|active| {
        let Some(handler) = active.borrow().as_ref().cloned() else {
            let promise = Promise::new();
            promise.reject_value(host_error(
                "host/unavailable",
                "Host capability provider is unavailable",
            ));
            return Ok(Value::Promise(promise));
        };
        handler(service, target, arguments)
    })
}

pub(crate) fn namespace_identifier(value: Value, operation: &str) -> Result<String, String> {
    match value {
        Value::Symbol(name) if name.get_namespace().is_none() => Ok(name.as_str().to_owned()),
        Value::String(name) => Ok(name),
        Value::Namespace(namespace) => Ok(namespace.name().as_str().to_owned()),
        _ => Err(format!(
            "{operation} expects an unqualified namespace symbol, string, or Namespace"
        )),
    }
}

fn namespace_descriptor(registry: &NamespaceRegistry<Value>, name: &str) -> Value {
    let state = registry
        .load_state(name)
        .or_else(|| registry.find(name).map(|_| NamespaceLoadState::Loaded))
        .map(NamespaceLoadState::as_str)
        .unwrap_or("unknown");
    let package = package_catalog().coordinate_for_namespace(name);
    let origin = if name.starts_with("std.native") {
        "embedded"
    } else if package.is_some() {
        "package"
    } else if registry.find(name).is_some() {
        "runtime"
    } else {
        "registered"
    };
    let mut fields = vec![
        (
            Value::Keyword("namespace/name".into()),
            Value::Symbol(Symbol::parse(name)),
        ),
        (
            Value::Keyword("namespace/state".into()),
            Value::Keyword(state.into()),
        ),
        (
            Value::Keyword("namespace/role".into()),
            Value::Keyword(
                registry
                    .find(name)
                    .map(|namespace| namespace.role())
                    .unwrap_or_else(|| "standard".into())
                    .into(),
            ),
        ),
        (
            Value::Keyword("namespace/revision".into()),
            Value::Number(registry.module_revision(name) as i64),
        ),
        (
            Value::Keyword("namespace/origin".into()),
            Value::Keyword(origin.into()),
        ),
    ];
    if let Some(package) = package {
        fields.push((
            Value::Keyword("namespace/package".into()),
            Value::String(package),
        ));
    }
    Value::OrderedMap(Box::new(POrderedMap::from_iter(fields)))
}

fn native_runtime_values(
    operation: &str,
    values: Vec<Value>,
    env: &mut HashMap<String, Value>,
) -> Result<Value, String> {
    let method = operation
        .strip_prefix("std.native.Runtime/")
        .unwrap_or(operation);
    let registry = namespace_registry()?;
    match method {
        "ns-publics" => {
            let namespace = match values.as_slice() {
                [Value::Symbol(name)] if name.get_namespace().is_none() => name.as_str().to_owned(),
                [Value::String(name)] => name.clone(),
                [Value::Namespace(namespace)] => namespace.name().as_str().to_owned(),
                _ => {
                    return Err(
                        "std.native.Runtime/ns-publics expects a namespace symbol or string".into(),
                    )
                }
            };
            let target = registry
                .find(&namespace)
                .ok_or_else(|| format!("No such namespace: {namespace}"))?;
            let mut mappings = target.mappings();
            mappings.retain(|(_, var)| var.symbol().get_namespace() == Some(namespace.as_str()));
            mappings.sort_by(|(left, _), (right, _)| left.as_str().cmp(right.as_str()));
            Ok(Value::OrderedMap(Box::new(POrderedMap::from_iter(
                mappings.into_iter().map(|(name, var)| {
                    (
                        Value::Symbol(Symbol::create(None, name.as_str())),
                        Value::Var(var),
                    )
                }),
            ))))
        }
        "ns-aliases" => {
            let name = match values.as_slice() {
                [value] => namespace_identifier(value.clone(), "std.native.Runtime/ns-aliases")?,
                _ => return Err("std.native.Runtime/ns-aliases expects one namespace".into()),
            };
            let target = registry
                .find(&name)
                .ok_or_else(|| format!("No such namespace: {name}"))?;
            let mut aliases = target.aliases();
            aliases.sort_by(|(left, _), (right, _)| left.as_str().cmp(right.as_str()));
            Ok(Value::OrderedMap(Box::new(POrderedMap::from_iter(
                aliases.into_iter().map(|(alias, namespace)| {
                    (Value::Symbol(alias), Value::Namespace(Rc::new(namespace)))
                }),
            ))))
        }
        "ns-find" => {
            if values.len() != 1 {
                return Err("std.native.Runtime/ns-find expects one namespace".into());
            }
            let name = namespace_identifier(values[0].clone(), "std.native.Runtime/ns-find")?;
            Ok(registry
                .find(&name)
                .map(|namespace| Value::Namespace(Rc::new(namespace)))
                .unwrap_or(Value::Nil))
        }
        "ns-create" => match values.as_slice() {
            [Value::Symbol(name)] if name.get_namespace().is_none() => {
                let namespace = registry.find_or_create(name.as_str());
                Ok(Value::Namespace(Rc::new(namespace)))
            }
            _ => Err("std.native.Runtime/ns-create expects an unqualified symbol".into()),
        },
        "ns-name" => match values.as_slice() {
            [Value::Namespace(namespace)] => Ok(Value::Symbol(namespace.name().clone())),
            [Value::Symbol(name)]
                if name.get_namespace().is_none()
                    && namespace_registry()?.find(name.as_str()).is_some() =>
            {
                Ok(Value::Symbol(name.clone()))
            }
            _ => Err("std.native.Runtime/ns-name expects a namespace".into()),
        },
        "current" => {
            if !values.is_empty() {
                return Err("std.native.Runtime/current expects no arguments".into());
            }
            Ok(Value::Symbol(registry.current().name().clone()))
        }
        "snapshot" => {
            if !values.is_empty() {
                return Err("std.native.Runtime/snapshot expects no arguments".into());
            }
            let namespaces = registry
                .known_names()
                .into_iter()
                .map(|name| namespace_descriptor(&registry, name.as_str()))
                .collect::<Vec<_>>();
            Ok(Value::OrderedMap(Box::new(POrderedMap::from_iter([
                (
                    Value::Keyword("env/current".into()),
                    Value::Symbol(registry.current().name().clone()),
                ),
                (
                    Value::Keyword("env/namespaces".into()),
                    Value::Vector(PVector::from(namespaces)),
                ),
            ]))))
        }
        "namespaces" => {
            if !values.is_empty() {
                return Err("std.native.Runtime/namespaces expects no arguments".into());
            }
            Ok(Value::Vector(PVector::from(
                registry
                    .known_names()
                    .into_iter()
                    .map(|name| namespace_descriptor(&registry, name.as_str()))
                    .collect::<Vec<_>>(),
            )))
        }
        "namespace" => {
            if values.len() != 1 {
                return Err("std.native.Runtime/namespace expects one namespace".into());
            }
            let name = namespace_identifier(values[0].clone(), operation)?;
            if registry.load_state(&name).is_none() && registry.find(&name).is_none() {
                Ok(Value::Nil)
            } else {
                Ok(namespace_descriptor(&registry, &name))
            }
        }
        "module" => {
            if values.len() != 1 {
                return Err("std.native.Runtime/module expects one module path".into());
            }
            let requested = match &values[0] {
                Value::String(path) => path.clone(),
                Value::Symbol(name) => name.as_str().to_owned(),
                _ => {
                    return Err(
                        "std.native.Runtime/module expects a path string or namespace symbol"
                            .into(),
                    )
                }
            };
            let source = requested.strip_prefix("classpath:").unwrap_or(&requested);
            let namespace = if source.ends_with(".hal") || source.ends_with(".hrl") {
                source
                    .trim_end_matches(".hal")
                    .trim_end_matches(".hrl")
                    .trim_start_matches("./")
                    .replace('/', ".")
            } else {
                source.to_owned()
            };
            let revision = registry.module_revision(&namespace);
            if revision == 0
                && registry.load_state(&namespace).is_none()
                && registry.find(&namespace).is_none()
            {
                return Ok(Value::Nil);
            }
            let dependencies = registry
                .module_dependencies(&namespace)
                .into_iter()
                .map(|dependency| {
                    Value::String(format!("{}.hal", dependency.as_str().replace('.', "/")))
                })
                .collect::<Vec<_>>();
            Ok(Value::OrderedMap(Box::new(POrderedMap::from_iter([
                (
                    Value::Keyword("module/path".into()),
                    Value::String(requested),
                ),
                (
                    Value::Keyword("module/namespace".into()),
                    Value::Symbol(Symbol::parse(&namespace)),
                ),
                (
                    Value::Keyword("module/revision".into()),
                    Value::Number(revision as i64),
                ),
                (
                    Value::Keyword("module/dependencies".into()),
                    Value::Vector(PVector::from(dependencies)),
                ),
            ]))))
        }
        "vars" => {
            if values.len() > 1 {
                return Err("std.native.Runtime/vars expects zero or one namespace".into());
            }
            let name = if values.is_empty() {
                registry.current().name().as_str().to_owned()
            } else {
                namespace_identifier(values[0].clone(), operation)?
            };
            let namespace = registry
                .find(&name)
                .ok_or_else(|| format!("namespace/not-found: {name}"))?;
            let mut mappings = namespace.mappings();
            mappings.retain(|(_, var)| var.symbol().get_namespace() == Some(name.as_str()));
            mappings.sort_by(|(left, _), (right, _)| left.as_str().cmp(right.as_str()));
            Ok(Value::OrderedMap(Box::new(POrderedMap::from_iter(
                mappings.into_iter().map(|(symbol, var)| {
                    (
                        Value::Symbol(Symbol::create(None, symbol.as_str())),
                        Value::Var(var),
                    )
                }),
            ))))
        }
        "eval" => {
            if values.len() != 1 {
                return Err("std.native.Runtime/eval expects one form".into());
            }
            let mut environment = crate::core::current_namespace_environment()?;
            let result = eval_value(values[0].clone(), &mut environment);
            crate::core::save_namespace_environment(&registry, &mut environment);
            result
        }
        "load-string" => {
            let [Value::String(source)] = values.as_slice() else {
                return Err("std.native.Runtime/load-string expects one string".into());
            };
            #[cfg(all(feature = "direct-native", not(target_arch = "wasm32")))]
            if direct_native_execution() {
                return eval_direct_native_source(source);
            }
            eval_value_text(source, env)
        }
        "var-sym" => {
            let [Value::Var(var)] = values.as_slice() else {
                return Err("std.native.Runtime/var-sym expects one Var".into());
            };
            Ok(Value::Symbol(var.symbol().clone()))
        }
        "macroexpand-1" => {
            if values.len() != 1 {
                return Err("std.native.Runtime/macroexpand-1 expects one form".into());
            }
            let form = value_to_form(&values[0])?;
            let mut environment = current_namespace_environment()?;
            form_to_value(&macroexpand_once(&form, &mut environment)?)
        }
        "gensym" => {
            let prefix = match values.as_slice() {
                [] => "G__".to_owned(),
                [Value::String(prefix)] => prefix.clone(),
                [value] => {
                    return Err(format!(
                        "gensym expects a string prefix, got {}",
                        portable_type_name(value)
                    ))
                }
                _ => return Err("gensym expects zero or one arguments".into()),
            };
            Ok(Value::Symbol(Symbol::from(gensym(&prefix))))
        }
        "eval-in" => {
            if values.len() != 2 {
                return Err("std.native.Runtime/eval-in expects namespace and forms".into());
            }
            let target = namespace_identifier(values[0].clone(), operation)?;
            if registry.find(&target).is_none() {
                return Err(format!(
                    "std.native.Runtime/eval-in requires an existing namespace: {target}"
                ));
            }
            let forms = iterator_values(values[1].clone())?
                .into_iter()
                .map(|value| value_to_form(&value))
                .collect::<Result<Vec<_>, _>>()?;
            let previous = registry.current().name().as_str().to_owned();
            select_namespace_environment(&registry, env, &target);
            #[cfg(all(feature = "direct-native", not(target_arch = "wasm32")))]
            let result = if direct_native_execution() {
                let source = if forms.is_empty() {
                    "nil".to_owned()
                } else {
                    Form::List(
                        std::iter::once(Form::Symbol("do".into()))
                            .chain(forms.iter().cloned())
                            .collect(),
                    )
                    .to_string()
                };
                eval_direct_native_source(&source)
            } else {
                let mut result = Value::Nil;
                for form in &forms {
                    result = eval(form, env)?;
                }
                Ok(result)
            };
            #[cfg(not(all(feature = "direct-native", not(target_arch = "wasm32"))))]
            let result = {
                let mut result = Value::Nil;
                for form in &forms {
                    result = eval(form, env)?;
                }
                Ok(result)
            };
            select_namespace_environment(&registry, env, &previous);
            result
        }
        "alias-state" => {
            if values.len() != 1 && values.len() != 2 {
                return Err(
                    "std.native.Runtime/alias-state expects alias or namespace and alias".into(),
                );
            }
            let (owner, alias_value) = if values.len() == 2 {
                (
                    namespace_identifier(values[0].clone(), operation)?,
                    &values[1],
                )
            } else {
                (registry.current().name().as_str().to_owned(), &values[0])
            };
            let Value::Symbol(alias) = alias_value else {
                return Err(
                    "std.native.Runtime/alias-state expects an unqualified alias symbol".into(),
                );
            };
            if alias.get_namespace().is_some() {
                return Err(
                    "std.native.Runtime/alias-state expects an unqualified alias symbol".into(),
                );
            }
            let Some(namespace) = registry.find(&owner) else {
                return Ok(Value::Nil);
            };
            // Global aliases are resolver-visible even when the owning namespace
            // has not materialized a local alias entry. Report the same target
            // and lifecycle state that qualified symbol resolution observes.
            let target = namespace
                .lazy_target(alias.as_str())
                .or_else(|| {
                    namespace
                        .aliases()
                        .into_iter()
                        .find(|(name, _)| name == alias)
                        .map(|(_, target)| target.name().clone())
                })
                .or_else(|| {
                    registry
                        .global_aliases()
                        .into_iter()
                        .find(|(name, _)| name == alias)
                        .map(|(_, target)| target)
                });
            let Some(target) = target else {
                return Ok(Value::Nil);
            };
            let state = registry
                .load_state(target.as_str())
                .or_else(|| {
                    registry
                        .find(target.as_str())
                        .map(|_| NamespaceLoadState::Loaded)
                })
                .map(NamespaceLoadState::as_str)
                .unwrap_or("unknown");
            Ok(Value::Map(PMap::from_iter([
                (Value::Keyword("alias".into()), Value::Symbol(alias.clone())),
                (Value::Keyword("target".into()), Value::Symbol(target)),
                (Value::Keyword("state".into()), Value::Keyword(state.into())),
            ])))
        }
        "intern-var" => {
            if values.len() != 3 && values.len() != 4 {
                return Err(
                    "std.native.Runtime/intern-var expects namespace, symbol, Var, and optional metadata"
                        .into(),
                );
            }
            let target = namespace_identifier(values[0].clone(), operation)?;
            let Value::Symbol(name) = &values[1] else {
                return Err(
                    "std.native.Runtime/intern-var expects an unqualified target symbol".into(),
                );
            };
            if name.get_namespace().is_some() {
                return Err(
                    "std.native.Runtime/intern-var expects an unqualified target symbol".into(),
                );
            }
            let Value::Var(source) = &values[2] else {
                return Err("std.native.Runtime/intern-var expects a source Var".into());
            };
            let mut metadata = source.metadata();
            if let Some(extension) = values.get(3) {
                let Some(entries) = map_entries(extension) else {
                    return Err(
                        "std.native.Runtime/intern-var metadata extension must be a map".into(),
                    );
                };
                for (key, value) in entries {
                    metadata.extra.insert(key.display(), value.display());
                }
            }
            let value = source.deref_value();
            if let Value::Function(function) = &value {
                if function.is_macro {
                    ACTIVE_MACROS.with(|active| {
                        if let Some(macros) = active.borrow().as_ref() {
                            macros.borrow_mut().insert(
                                (target.clone(), name.as_str().to_owned()),
                                function.clone(),
                            );
                        }
                    });
                }
            }
            Ok(Value::Var(
                registry.find_or_create(&target).intern_with_metadata(
                    name.as_str(),
                    value,
                    metadata,
                ),
            ))
        }
        _ => Err(format!("unknown std.native.Runtime method: {method}")),
    }
}

#[cfg(all(feature = "direct-native", not(target_arch = "wasm32")))]
fn eval_direct_native_source(source: &str) -> Result<Value, String> {
    let context = DirectNativeContext::capture();
    let forms = crate::kernel::read_forms(source).map_err(|error| error.to_string())?;
    let has_namespace_form = forms.iter().any(|form| {
        matches!(
            form_without_metadata(&form.form),
            Form::List(items)
                if matches!(items.first(), Some(Form::Symbol(operator)) if operator == "ns" || operator == "ns+")
        )
    });
    let config = if has_namespace_form {
        crate::vm::source_namespace_config(&forms).map_err(|error| error.to_string())?
    } else {
        crate::kernel::GeneratedNamespaceConfig::defaults()
    };
    let namespaces = context.namespaces.clone();
    let program = context
        .with(|| {
            without_direct_native_execution(|| {
                crate::vm::compile_source_with_config_allow_unbound_globals(
                    source,
                    &namespaces,
                    config,
                )
            })
        })
        .map_err(|error| error.to_string())?;
    let mut program = program;
    if program.namespace.is_none() {
        program.namespace = Some(context.namespace.clone());
    }
    let engine = crate::direct_native::NativeEngine::new();
    // `context.with` already installs the captured providers, namespace, and
    // multimethod map. Calling the convenience entry point here would wrap
    // the same map in a second context and restore an old snapshot over any
    // declarations made by the nested program.
    let result = context.with(|| engine.execute_blocking(Rc::new(program)));
    // Nested Runtime/eval calls execute with a captured multimethod map. Carry
    // declarations made there back into the enclosing native frame so a later
    // form in the same frame can install methods or invoke the new multifn.
    let nested_multimethods = context.multimethods.borrow().clone();
    ACTIVE_MULTIMETHODS.with(|active| {
        active.borrow_mut().extend(nested_multimethods);
    });
    result.map(|report| report.value)
}

fn eval_value(value: Value, env: &mut HashMap<String, Value>) -> Result<Value, String> {
    #[cfg(all(feature = "direct-native", not(target_arch = "wasm32")))]
    if direct_native_execution() {
        return eval_direct_native_source(&value_to_form(&value)?.to_string());
    }
    eval(&value_to_form(&value)?, env)
}

fn native_package_values(
    operation: &str,
    arguments: Vec<Value>,
    env: &mut HashMap<String, Value>,
) -> Result<Value, String> {
    let method = operation
        .strip_prefix("std.native.Package/")
        .unwrap_or(operation);
    if matches!(
        method,
        "build" | "inspect" | "seal" | "inspect-seal" | "verify-seal" | "distribute"
    ) {
        return native_package_artifact_values(method, arguments);
    }
    if method == "read" {
        if arguments.len() != 2 {
            return Err(
                "std.native.Package/read expects an exact descriptor and relative path".into(),
            );
        }
        let Value::OrderedMap(_) = &arguments[0] else {
            return Err("std.native.Package/read expects an exact package descriptor".into());
        };
        let Value::String(relative) = &arguments[1] else {
            return Err("std.native.Package/read expects a relative path string".into());
        };
        return package_catalog()
            .read(&arguments[0], relative)
            .map(Value::Bytes);
    }
    let expected = match method {
        "catalog" => 0..=0,
        "find" | "ensure" | "load" | "state" => 1..=1,
        "unload" => 1..=2,
        _ => return Err(format!("unknown std.native.Package method: {method}")),
    };
    if !expected.contains(&arguments.len()) {
        return Err(format!(
            "std.native.Package/{method} expects {} arguments",
            expected.start()
        ));
    }
    let catalog = package_catalog();
    if method == "catalog" {
        return Ok(catalog.catalog_value());
    }
    let target = match arguments.first() {
        Some(Value::Symbol(value)) => value.as_str().to_owned(),
        Some(Value::String(value)) => value.clone(),
        Some(Value::Keyword(value)) => value.as_str().to_owned(),
        Some(value @ Value::OrderedMap(_)) if method == "ensure" || method == "unload" => {
            package_descriptor_coordinate(value).ok_or_else(|| {
                format!("std.native.Package/{method} descriptor requires :package/coordinate")
            })?
        }
        _ => {
            return Err(format!(
                "std.native.Package/{method} expects a namespace, coordinate, or exact descriptor"
            ))
        }
    };
    let found = catalog.find(&target);
    if method == "find" {
        return Ok(found.map(|(_, value)| value).unwrap_or(Value::Nil));
    }
    let Some((coordinate, descriptor)) = found else {
        if method == "state" {
            return Ok(Value::Nil);
        }
        return Err(format!("package/not-locked: {target}"));
    };
    if method == "state" {
        return Ok(Value::Keyword(
            catalog
                .state(&coordinate)
                .unwrap_or_else(|| "available".into())
                .into(),
        ));
    }
    if method == "load" {
        if catalog.coordinate_for_namespace(&target).as_deref() != Some(&coordinate) {
            return Err("std.native.Package/load expects a locked namespace".into());
        }
        if catalog.state(&coordinate).as_deref() != Some("ready") {
            return Err(format!(
                "package/not-ready: {coordinate}; call Package/ensure first"
            ));
        }
        let registry = namespace_registry()?;
        require_namespace(&registry, env, &target)?;
        return Ok(Value::Symbol(Symbol::parse(&target)));
    }
    if method == "ensure" {
        if catalog.state(&coordinate).as_deref() == Some("ready") {
            let promise = Promise::new();
            promise.resolve(descriptor);
            return Ok(Value::Promise(promise));
        }
        if let Some(pending) = catalog.pending(&coordinate) {
            return Ok(Value::Promise(pending));
        }
    } else if catalog.state(&coordinate).as_deref() == Some("available") {
        let promise = Promise::new();
        promise.resolve(Value::Vector(PVector::new()));
        return Ok(Value::Promise(promise));
    } else if catalog.pending(&coordinate).is_some() {
        return Err(format!("package/busy: {coordinate}"));
    }
    if method == "unload" {
        if let Some(options) = arguments.get(1) {
            if map_entries(options).is_none() {
                return Err("std.native.Package/unload options must be a map".into());
            }
            if let Some(value) = map_value(options, &Value::Keyword("cascade".into())) {
                if !matches!(value, Value::Bool(_)) {
                    return Err("std.native.Package/unload :cascade must be boolean".into());
                }
            }
        }
    }
    let previous_state = catalog
        .state(&coordinate)
        .unwrap_or_else(|| "available".into());
    catalog.set_state(
        &coordinate,
        if method == "ensure" {
            "ensuring"
        } else {
            "unloading"
        },
    );
    HOST_CALL_HANDLER.with(|active| {
        let Some(handler) = active.borrow().as_ref().cloned() else {
            let promise = Promise::new();
            promise.reject_value(host_error(
                "package/unsupported",
                "Package capability provider is unavailable",
            ));
            catalog.set_state(
                &coordinate,
                if method == "ensure" {
                    "failed"
                } else {
                    &previous_state
                },
            );
            return Ok(Value::Promise(promise));
        };
        let mut provider_arguments = vec![descriptor];
        provider_arguments.extend(arguments.iter().skip(1).cloned());
        let result = handler("package".into(), method.into(), provider_arguments);
        if let Ok(Value::Promise(promise)) = &result {
            let state = catalog.clone();
            let coordinate = coordinate.clone();
            let operation = method.to_owned();
            let rollback = previous_state.clone();
            state.set_pending(&coordinate, Some(promise.clone()));
            promise.on_settle(Rc::new(move |settlement| {
                let next = match (&operation[..], settlement) {
                    ("ensure", PromiseState::Fulfilled(_)) => "ready",
                    ("ensure", _) => "failed",
                    ("unload", PromiseState::Fulfilled(_)) => "available",
                    ("unload", _) => rollback.as_str(),
                    _ => rollback.as_str(),
                };
                state.set_state(&coordinate, next);
                state.set_pending(&coordinate, None);
            }));
        } else if result.is_ok() {
            catalog.set_state(
                &coordinate,
                if method == "ensure" {
                    "ready"
                } else {
                    "available"
                },
            );
        } else {
            catalog.set_state(
                &coordinate,
                if method == "ensure" {
                    "failed"
                } else {
                    &previous_state
                },
            );
        }
        result
    })
}

#[cfg(not(target_arch = "wasm32"))]
fn native_package_artifact_values(method: &str, arguments: Vec<Value>) -> Result<Value, String> {
    match method {
        "build" => {
            if !(1..=4).contains(&arguments.len()) {
                return Err(
                    "std.native.Package/build expects input and up to three options".into(),
                );
            }
            let input =
                package_string_argument(&arguments, 0, "std.native.Package/build")?.to_owned();
            let output =
                package_optional_string_argument(&arguments, 1, "std.native.Package/build")?
                    .map(str::to_owned);
            let package =
                package_optional_string_argument(&arguments, 2, "std.native.Package/build")?
                    .map(str::to_owned);
            let profile =
                package_optional_string_argument(&arguments, 3, "std.native.Package/build")?
                    .map(str::to_owned);
            let built = std::thread::Builder::new()
                .name("hara-package-build".into())
                .stack_size(crate::package::BUILD_THREAD_STACK_SIZE)
                .spawn(move || {
                    crate::package::build_path_with_package(
                        std::path::Path::new(&input),
                        output.as_deref().map(std::path::Path::new),
                        package.as_deref(),
                        profile.as_deref().map(std::path::Path::new),
                    )
                })
                .map_err(|error| format!("std.native.Package/build thread failed: {error}"))?
                .join()
                .map_err(|_| "std.native.Package/build thread panicked".to_owned())??;
            Ok(Value::String(built.to_string_lossy().into_owned()))
        }
        "inspect" => {
            if arguments.len() != 1 {
                return Err("std.native.Package/inspect expects one archive path".into());
            }
            Ok(Value::String(crate::package::inspect_path(
                std::path::Path::new(package_string_argument(
                    &arguments,
                    0,
                    "std.native.Package/inspect",
                )?),
            )?))
        }
        "seal" => {
            if arguments.len() != 1 {
                return Err("std.native.Package/seal expects one descriptor map".into());
            }
            let manifest = crate::distribution::seal(&sealed_package_spec(&arguments[0])?)?;
            Ok(sealed_manifest_value(&manifest))
        }
        "distribute" => {
            if arguments.len() != 1 {
                return Err("std.native.Package/distribute expects one descriptor map".into());
            }
            let spec = distribution_build_spec(&arguments[0])?;
            let manifest = if spec.replace {
                crate::distribution::build_replace(&spec.project, &spec.host, &spec.output)?
            } else {
                crate::distribution::build(&spec.project, &spec.host, &spec.output)?
            };
            Ok(distribution_manifest_value(&manifest))
        }
        "inspect-seal" | "verify-seal" => {
            if arguments.len() != 1 {
                return Err(format!(
                    "std.native.Package/{method} expects one executable path"
                ));
            }
            let path = std::path::Path::new(package_string_argument(
                &arguments,
                0,
                &format!("std.native.Package/{method}"),
            )?);
            let found = if method == "inspect-seal" {
                crate::distribution::inspect_sealed(path)?
            } else {
                crate::distribution::verify_sealed(path)?
            };
            Ok(found
                .as_ref()
                .map(sealed_manifest_value)
                .unwrap_or(Value::Nil))
        }
        _ => unreachable!("caller restricts native package artifact methods"),
    }
}

#[cfg(target_arch = "wasm32")]
fn native_package_artifact_values(method: &str, _arguments: Vec<Value>) -> Result<Value, String> {
    Err(format!(
        "package/unsupported: Package/{method} is unavailable on wasm"
    ))
}

#[cfg(not(target_arch = "wasm32"))]
fn sealed_package_spec(value: &Value) -> Result<crate::distribution::SealSpec, String> {
    let entries = map_entries(value)
        .ok_or_else(|| "std.native.Package/seal expects one descriptor map".to_owned())?;
    let descriptor = Value::OrderedMap(Box::new(POrderedMap::from_iter(entries)));
    let required_string = |key: &str| match map_value(&descriptor, &Value::Keyword(key.into())) {
        Some(Value::String(value)) if !value.is_empty() => Ok(value.clone()),
        Some(_) => Err(format!(
            "std.native.Package/seal :{key} must be a non-empty string"
        )),
        None => Err(format!("std.native.Package/seal is missing :{key}")),
    };
    let entry = match map_value(&descriptor, &Value::Keyword("entry".into())) {
        Some(Value::Symbol(value)) => value.as_str().to_owned(),
        Some(_) => return Err("std.native.Package/seal :entry must be a symbol".into()),
        None => return Err("std.native.Package/seal is missing :entry".into()),
    };
    let host = match map_value(&descriptor, &Value::Keyword("host".into())) {
        Some(Value::String(value)) if !value.is_empty() => std::path::PathBuf::from(value),
        Some(_) => return Err("std.native.Package/seal :host must be a non-empty string".into()),
        None => std::env::current_exe()
            .map_err(|error| format!("cannot determine current native executable: {error}"))?,
    };
    let archives = match map_value(&descriptor, &Value::Keyword("archives".into())) {
        Some(value) => iterator_values(value.clone())?,
        None => return Err("std.native.Package/seal is missing :archives".into()),
    }
    .into_iter()
    .map(|archive| {
        let archive_entries = map_entries(&archive)
            .ok_or_else(|| "std.native.Package/seal archives must be maps".to_owned())?;
        let archive = Value::OrderedMap(Box::new(POrderedMap::from_iter(archive_entries)));
        let path = match map_value(&archive, &Value::Keyword("path".into())) {
            Some(Value::String(value)) if !value.is_empty() => std::path::PathBuf::from(value),
            Some(_) => {
                return Err(
                    "std.native.Package/seal archive :path must be a non-empty string".into(),
                )
            }
            None => return Err("std.native.Package/seal archive is missing :path".into()),
        };
        let primary = match map_value(&archive, &Value::Keyword("primary".into())) {
            Some(Value::Bool(value)) => *value,
            Some(_) => {
                return Err("std.native.Package/seal archive :primary must be boolean".into())
            }
            None => false,
        };
        Ok(crate::distribution::SealArchive { path, primary })
    })
    .collect::<Result<Vec<_>, String>>()?;
    Ok(crate::distribution::SealSpec {
        host,
        output: std::path::PathBuf::from(required_string("output")?),
        entry,
        archives,
    })
}

#[cfg(not(target_arch = "wasm32"))]
struct DistributionBuildSpec {
    project: std::path::PathBuf,
    host: std::path::PathBuf,
    output: std::path::PathBuf,
    replace: bool,
}

#[cfg(not(target_arch = "wasm32"))]
fn distribution_build_spec(value: &Value) -> Result<DistributionBuildSpec, String> {
    let entries = map_entries(value)
        .ok_or_else(|| "std.native.Package/distribute expects one descriptor map".to_owned())?;
    let descriptor = Value::OrderedMap(Box::new(POrderedMap::from_iter(entries)));
    let required_string = |key: &str| match map_value(&descriptor, &Value::Keyword(key.into())) {
        Some(Value::String(value)) if !value.is_empty() => Ok(value),
        Some(_) => Err(format!(
            "std.native.Package/distribute :{key} must be a non-empty string"
        )),
        None => Err(format!("std.native.Package/distribute is missing :{key}")),
    };
    let replace = match map_value(&descriptor, &Value::Keyword("replace?".into())) {
        Some(Value::Bool(value)) => *value,
        Some(_) => return Err("std.native.Package/distribute :replace? must be boolean".into()),
        None => false,
    };
    Ok(DistributionBuildSpec {
        project: std::path::PathBuf::from(required_string("project")?),
        host: std::path::PathBuf::from(required_string("host")?),
        output: std::path::PathBuf::from(required_string("output")?),
        replace,
    })
}

#[cfg(not(target_arch = "wasm32"))]
fn sealed_manifest_value(manifest: &crate::distribution::SealedManifest) -> Value {
    let archives: Vec<Value> = manifest
        .archives
        .iter()
        .map(|archive| {
            Value::OrderedMap(Box::new(POrderedMap::from_iter([
                (
                    Value::Keyword("identity".into()),
                    Value::String(archive.identity.clone()),
                ),
                (
                    Value::Keyword("version".into()),
                    Value::String(archive.version.clone()),
                ),
                (
                    Value::Keyword("sha256".into()),
                    Value::String(archive.sha256.clone()),
                ),
                (
                    Value::Keyword("offset".into()),
                    Value::Number(i64::try_from(archive.offset).unwrap_or(i64::MAX)),
                ),
                (
                    Value::Keyword("length".into()),
                    Value::Number(i64::try_from(archive.length).unwrap_or(i64::MAX)),
                ),
                (
                    Value::Keyword("primary".into()),
                    Value::Bool(archive.primary),
                ),
            ])))
        })
        .collect();
    Value::OrderedMap(Box::new(POrderedMap::from_iter([
        (
            Value::Keyword("executable/format".into()),
            Value::String(crate::distribution::SEALED_FORMAT.into()),
        ),
        (
            Value::Keyword("entry".into()),
            Value::Symbol(Symbol::parse(&manifest.entry)),
        ),
        (
            Value::Keyword("archives".into()),
            Value::Vector(PVector::from(archives)),
        ),
        (
            Value::Keyword("host/sha256".into()),
            Value::String(manifest.host_sha256.clone()),
        ),
        (
            Value::Keyword("payload/sha256".into()),
            Value::String(manifest.payload_sha256.clone()),
        ),
    ])))
}

#[cfg(not(target_arch = "wasm32"))]
fn distribution_manifest_value(manifest: &crate::distribution::Manifest) -> Value {
    Value::OrderedMap(Box::new(POrderedMap::from_iter([
        (
            Value::Keyword("distribution/format".into()),
            Value::String(crate::distribution::FORMAT.into()),
        ),
        (
            Value::Keyword("launcher".into()),
            Value::String(manifest.launcher.clone()),
        ),
        (
            Value::Keyword("entry".into()),
            Value::Symbol(Symbol::parse(&manifest.entry)),
        ),
        (
            Value::Keyword("archive".into()),
            Value::String(manifest.archive.to_string_lossy().into_owned()),
        ),
        (
            Value::Keyword("archive/sha256".into()),
            Value::String(manifest.archive_sha256.clone()),
        ),
        (
            Value::Keyword("source/identity".into()),
            Value::String(manifest.source_identity.clone()),
        ),
        (
            Value::Keyword("source/version".into()),
            Value::String(manifest.source_version.clone()),
        ),
        (
            Value::Keyword("native/version".into()),
            Value::String(manifest.native_version.clone()),
        ),
        (
            Value::Keyword("native/sha256".into()),
            Value::String(manifest.native_sha256.clone()),
        ),
    ])))
}

#[cfg(not(target_arch = "wasm32"))]
fn package_string_argument<'a>(
    arguments: &'a [Value],
    index: usize,
    operation: &str,
) -> Result<&'a str, String> {
    match arguments.get(index) {
        Some(Value::String(value)) => Ok(value),
        _ => Err(format!(
            "{operation} expects a string argument at position {index}"
        )),
    }
}

#[cfg(not(target_arch = "wasm32"))]
fn package_optional_string_argument<'a>(
    arguments: &'a [Value],
    index: usize,
    operation: &str,
) -> Result<Option<&'a str>, String> {
    match arguments.get(index) {
        None | Some(Value::Nil) => Ok(None),
        Some(Value::String(value)) => Ok(Some(value)),
        _ => Err(format!(
            "{operation} expects an optional string at position {index}"
        )),
    }
}

/// Invokes the active host capability provider with already-evaluated VM
/// values. This is the bytecode boundary for `std.native.Host/call`; the VM
/// remains unaware of timers, sockets, or any other concrete host operation.
pub fn call_host_value(service: Value, target: Value, arguments: Value) -> Result<Value, String> {
    let service = match service {
        Value::String(value) => value,
        _ => return Err("std.native.Host/call service must be a string".into()),
    };
    let target = match target {
        Value::String(value) => value,
        _ => return Err("std.native.Host/call method must be a string".into()),
    };
    let arguments = match arguments {
        Value::Vector(values) => values.iter().cloned().collect(),
        Value::Tuple(values) => values.iter().cloned().collect(),
        _ => return Err("std.native.Host/call arguments must be a vector".into()),
    };
    if !native_capability_granted("host-call") {
        return Ok(native_capability_denied_promise(
            "Host",
            "call",
            "host-call",
        ));
    }
    HOST_CALL_HANDLER.with(|active| {
        let Some(handler) = active.borrow().as_ref().cloned() else {
            let promise = Promise::new();
            promise.reject_value(host_error(
                "host/unavailable",
                "Host capability provider is unavailable",
            ));
            return Ok(Value::Promise(promise));
        };
        handler(service, target, arguments)
    })
}

fn host_error(code: &str, message: &str) -> Value {
    Value::ExceptionInfo(Rc::new(ExceptionInfo {
        message: message.into(),
        data: Box::new(Value::Map(
            vec![
                (
                    Value::Keyword("ex/code".into()),
                    Value::Keyword(code.into()),
                ),
                (
                    Value::Keyword("ex/class".into()),
                    Value::Keyword("ex.class/host".into()),
                ),
            ]
            .into_iter()
            .collect(),
        )),
        cause: None,
        provenance: Rc::new(RefCell::new(Default::default())),
    }))
}
/// Installs the explicit host-call boundary for one evaluation.
pub fn with_host_calls<R>(
    handler: Rc<dyn Fn(String, String, Vec<Value>) -> Result<Value, String>>,
    operation: impl FnOnce() -> R,
) -> R {
    HOST_CALL_HANDLER.with(|active| {
        let previous = active.replace(Some(handler));
        let result = operation();
        active.replace(previous);
        result
    })
}

/// Runs an evaluation with a source provider used to satisfy `require` loads.
pub fn with_namespace_source<R>(
    provider: Rc<dyn Fn(&str) -> Option<NamespaceResource>>,
    action: impl FnOnce() -> R,
) -> R {
    NAMESPACE_SOURCE_PROVIDER.with(|active| {
        let previous = active.borrow_mut().replace(provider);
        let result = action();
        *active.borrow_mut() = previous;
        result
    })
}

/// Installs the direct-native namespace loader for one runtime evaluation.
/// The ordinary source/bytecode loader remains the default; this hook lets a
/// Runtime replace only the execution of a materialized namespace while the
/// shared namespace transaction, dependency tracking, and rollback logic stay
/// in one place.
#[cfg(all(feature = "direct-native", not(target_arch = "wasm32")))]
pub(crate) fn with_direct_native_namespace_loader<R>(
    loader: Rc<dyn Fn(&str, NamespaceResource, &mut HashMap<String, Value>) -> Result<(), String>>,
    action: impl FnOnce() -> R,
) -> R {
    ACTIVE_DIRECT_NATIVE_NAMESPACE_LOADER.with(|active| {
        let previous = active.borrow_mut().replace(loader);
        let result = action();
        *active.borrow_mut() = previous;
        result
    })
}

/// Marks the duration of generated direct-native code. Native helpers may
/// still call one another during this scope, but any attempt to invoke the
/// tree evaluator through a helper is rejected at the shared boundary.
#[cfg(all(feature = "direct-native", not(target_arch = "wasm32")))]
pub(crate) fn with_direct_native_execution<R>(action: impl FnOnce() -> R) -> R {
    ACTIVE_DIRECT_NATIVE_EXECUTION.with(|active| {
        let previous = active.replace(true);
        let result = action();
        active.set(previous);
        result
    })
}

/// Temporarily leaves the generated-code execution scope while compiling a
/// nested program. Macro expansion and namespace configuration are
/// compilation-time compatibility seams; they may use the tree evaluator,
/// but the validated program must re-enter the direct guard before execution.
#[cfg(all(feature = "direct-native", not(target_arch = "wasm32")))]
pub(crate) fn without_direct_native_execution<R>(action: impl FnOnce() -> R) -> R {
    ACTIVE_DIRECT_NATIVE_EXECUTION.with(|active| {
        let previous = active.replace(false);
        let result = action();
        active.set(previous);
        result
    })
}

#[cfg(all(feature = "direct-native", not(target_arch = "wasm32")))]
fn direct_native_namespace_loader(
) -> Option<Rc<dyn Fn(&str, NamespaceResource, &mut HashMap<String, Value>) -> Result<(), String>>>
{
    ACTIVE_DIRECT_NATIVE_NAMESPACE_LOADER.with(|active| active.borrow().clone())
}

#[cfg(all(feature = "direct-native", not(target_arch = "wasm32")))]
pub(crate) fn direct_native_execution() -> bool {
    ACTIVE_DIRECT_NATIVE_EXECUTION.with(Cell::get)
}

/// Runtime state captured when a VM closure crosses the synchronous machine
/// boundary. The no-op shape keeps ordinary VM and wasm builds free of
/// direct-native dependencies while native callbacks and resumptions can
/// restore providers, namespace selection, protocols, and the evaluator
/// guard on native builds.
#[derive(Clone, Default)]
pub(crate) struct NativeCallbackContext {
    #[cfg(all(feature = "direct-native", not(target_arch = "wasm32")))]
    scope: Option<crate::direct_native::NativeExecutionScope>,
    #[cfg(all(feature = "direct-native", not(target_arch = "wasm32")))]
    context: Option<DirectNativeContext>,
}

impl NativeCallbackContext {
    pub(crate) fn capture() -> Self {
        #[cfg(all(feature = "direct-native", not(target_arch = "wasm32")))]
        {
            let scope = crate::direct_native::capture_execution_scope();
            let context = scope.as_ref().map(|_| DirectNativeContext::capture());
            return Self { scope, context };
        }
        #[cfg(not(all(feature = "direct-native", not(target_arch = "wasm32"))))]
        {
            Self::default()
        }
    }

    pub(crate) fn with<R>(&self, action: impl FnOnce() -> R) -> R {
        #[cfg(all(feature = "direct-native", not(target_arch = "wasm32")))]
        {
            return crate::direct_native::with_captured_context(
                self.scope.as_ref(),
                self.context.as_ref(),
                action,
            );
        }
        #[cfg(not(all(feature = "direct-native", not(target_arch = "wasm32"))))]
        {
            action()
        }
    }
}