speccoder_runtime/acp/

govern.rs

//! An external agent's calls under speccoder's policy: its permission
//! requests, and the file and terminal access speccoder offers it.
//!
//! Each call is decided as a native attempt's call is — the same
//! classification ([`Policy`]), the same objects, the same grants, the same
//! person through the same [`Approver`] — and recorded in the attempt's
//! tool-call log in the native shape, so `task approve`, the report and the
//! audit read it alike. A permission request names no stable tool, so it is
//! classified from its declared kind and arguments, never its title; one
//! that cannot be classified goes to a person. With nobody to ask, the
//! first call that needs a person ends the attempt `needs_approval`, saved
//! with that call for `speccoder task approve`.

use std::path::{Path, PathBuf};
use std::sync::{Arc, Mutex};

use serde_json::{Value, json};

use super::calls::ToolRequest;
use crate::approvals::{
    Answer, Approver, Decision as Said, PresentContext, Request, Scope, Who, present,
};
use crate::progress::{Event, Progress};
use crate::tools::WorkspaceTools;
use crate::tools::policy::{Decision, Object, Policy};

/// A command allowed to run: its argv, directory and environment.
pub type Command = (Vec<String>, PathBuf, Vec<(String, String)>);

/// The tool name a call speccoder cannot classify is recorded under.
pub const AGENT_CALL: &str = "agent_call";

/// One of the agent's permission options.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct PermissionOption {
    /// Its id.
    pub id: String,
    /// `allow_once`, `allow_always`, `reject_once`, `reject_always`.
    pub kind: String,
}

/// What a call came to.
#[derive(Debug, Clone, PartialEq)]
pub enum Verdict {
    /// It may run (checked again against `object` where it has one).
    Allow(Option<Object>),
    /// It is refused, and why.
    Deny(String),
    /// A person is needed and nobody can be asked (or the person stopped
    /// the task): the attempt ends.
    Stop,
}

/// Who decides for one attempt, and what they decided.
pub struct Governor {
    root: PathBuf,
    tools: WorkspaceTools,
    policy: Policy,
    approver: Option<Arc<dyn Approver>>,
    present: PresentContext,
    task: String,
    task_title: String,
    run: Option<String>,
    frozen_additions: bool,
    progress: Option<(String, Arc<dyn Progress>)>,
    /// Files copied from the checkout (`[worktree] include`).
    copied: Vec<String>,
    /// The agent (its preset id), whose own actions a grant names.
    agent: String,
    /// Milliseconds a person has spent deciding.
    asking: std::sync::atomic::AtomicU64,
    /// Since when a person is being asked now.
    asking_since: Mutex<Option<std::time::Instant>>,
    state: Mutex<State>,
}

impl std::fmt::Debug for Governor {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("Governor")
            .field("root", &self.root)
            .field("task", &self.task)
            .finish_non_exhaustive()
    }
}

#[derive(Debug, Default)]
struct State {
    /// Objects a person approved for one call each.
    once: Vec<Object>,
    /// Objects a person approved for the run or the task, with the scope.
    remembered: Vec<(Object, &'static str)>,
    /// Every decision and every call the agent reported, in order.
    log: Vec<Value>,
    /// The call waiting for a person nobody could ask.
    pending: Option<Value>,
    /// The agent's words since its last call (the claim a person sees).
    said: String,
    /// The attempt is ending: nothing more is allowed.
    stopped: bool,
    /// Prompts shown to a person.
    asked: u32,
    /// Permission requests answered, by the agent's call id.
    decided: std::collections::HashSet<String>,
    /// Of them, allowed.
    allowed: std::collections::HashSet<String>,
    /// The request being decided: its log entries carry its id.
    request: Option<String>,
    /// Calls the agent reported changing something without asking.
    unasked: u32,
}

/// What a [`Governor`] is built from.
pub struct Setup {
    /// The worktree (canonical).
    pub root: PathBuf,
    /// The attempt's tools (with the sandboxed runner).
    pub tools: WorkspaceTools,
    /// The attempt's policy, with the task's decisions.
    pub policy: Policy,
    /// Who answers a call that needs a person; `None` with `--no-prompt`.
    pub approver: Option<Arc<dyn Approver>>,
    /// What a person is shown about the sandbox.
    pub present: PresentContext,
    /// `feature/task`.
    pub task: String,
    /// The task's title.
    pub task_title: String,
    /// The run.
    pub run: Option<String>,
    /// `[tests] frozen = "additions"`.
    pub frozen_additions: bool,
    /// Objects approved for every task of this run.
    pub run_approved: Vec<Object>,
    /// Objects approved for one call each.
    pub approved_once: Vec<Object>,
    /// The task id and where its events go.
    pub progress: Option<(String, Arc<dyn Progress>)>,
    /// Files copied from the checkout (`[worktree] include`),
    /// worktree-relative.
    pub copied: Vec<String>,
    /// The agent (its preset id, or `acp`).
    pub agent: String,
}

/// A command line as an argv: split on ASCII whitespace when it is a plain
/// command, else given to `sh -c` whole — which a person decides, so a
/// shell's meaning (or a look-alike space) is never guessed.
#[must_use]
pub fn argv_of_line(line: &str) -> Vec<String> {
    const SHELL: &[char] = &[
        '|', '&', ';', '<', '>', '(', ')', '$', '`', '\\', '"', '\'', '*', '?', '[', ']', '{', '}',
        '~', '!', '#', '\n', '=',
    ];
    let line = line.trim_matches(|c: char| c.is_ascii_whitespace());
    let odd_space = line
        .chars()
        .any(|c| c.is_whitespace() && !c.is_ascii_whitespace());
    if line.contains(SHELL)
        || odd_space
        || line
            .chars()
            .any(|c| c.is_control() && !c.is_ascii_whitespace())
    {
        return vec!["sh".to_owned(), "-c".to_owned(), line.to_owned()];
    }
    line.split_ascii_whitespace().map(str::to_owned).collect()
}

/// A shell line of plain commands joined by `;`, `&&`, `||` or newlines:
/// its commands, each plain; `None` for anything else a shell would read.
#[must_use]
pub fn commands_of_line(line: &str) -> Option<Vec<Vec<String>>> {
    let mut parts = Vec::new();
    let mut rest = line.trim();
    while !rest.is_empty() {
        let at = ["&&", "||", ";", "\n"]
            .iter()
            .filter_map(|sep| rest.find(sep).map(|i| (i, sep.len())))
            .min();
        let (part, next) = match at {
            Some((i, n)) => (&rest[..i], &rest[i + n..]),
            None => (rest, ""),
        };
        let argv = argv_of_line(part);
        if argv.is_empty() {
            return None;
        }
        if argv.first().is_some_and(|p| p == "sh") && argv.get(1).is_some_and(|f| f == "-c") {
            return None;
        }
        parts.push(argv);
        rest = next.trim();
    }
    (!parts.is_empty()).then_some(parts)
}

/// A shell started with one line (`["/bin/zsh", "-lc", "…"]`, `sh -c …`):
/// that line.
fn shell_line(argv: &[String]) -> Option<&str> {
    let [shell, flag, line] = argv else {
        return None;
    };
    let name = shell.rsplit('/').next().unwrap_or(shell);
    (matches!(name, "sh" | "bash" | "zsh" | "dash")
        && matches!(flag.as_str(), "-c" | "-lc" | "-ic"))
    .then_some(line.as_str())
}

/// Programs a plain-read line may run, with the options they may take
/// (`N`: the option takes a number).
const READS: &[(&str, &[&str])] = &[
    ("cat", &["-n"]),
    ("head", &["-n N", "-c N"]),
    ("tail", &["-n N", "-c N"]),
    ("wc", &["-l", "-w", "-c", "-m"]),
];

/// Keys that hold a command, at any depth of a request's input.
const COMMAND_KEYS: &[&str] = &[
    "command", "commands", "cmd", "argv", "args", "script", "shell", "bash",
];

/// Keys that name a file, at any depth of a request's input.
const PATH_KEYS: &[&str] = &[
    "path",
    "paths",
    "file_path",
    "filePath",
    "fileName",
    "file",
    "files",
    "notebook_path",
    "destination",
    "new_path",
    "newPath",
    "old_path",
    "source",
    "target",
    "cwd",
    "workdir",
    "directory",
    "dir",
];

/// The input keys each kind of request may carry; any other key, or a
/// value of another shape, and a person decides.
fn known_keys(kind: &str) -> Option<&'static [&'static str]> {
    Some(match kind {
        "read" => &[
            "path",
            "paths",
            "file_path",
            "filePath",
            "fileName",
            "line",
            "limit",
            "offset",
            "start_line",
            "end_line",
        ],
        "search" => &[
            "pattern",
            "query",
            "path",
            "paths",
            "glob",
            "include",
            "file_path",
        ],
        "edit" => &[
            "path",
            "file_path",
            "filePath",
            "fileName",
            "old_string",
            "new_string",
            "replace_all",
            "content",
            "file_text",
            "diff",
            "edits",
        ],
        "delete" => &["path", "paths", "file_path", "filePath", "fileName"],
        "move" => &[
            "path",
            "file_path",
            "source",
            "destination",
            "new_path",
            "newPath",
            "target",
        ],
        "think" => &[
            "thought",
            "thoughts",
            "todos",
            "plan",
            "text",
            "description",
        ],
        _ => return None,
    })
}

/// Keys inside each of an edit's `edits[]`.
const EDIT_KEYS: &[&str] = &[
    "path",
    "file_path",
    "old_string",
    "new_string",
    "replace_all",
];

/// File names that are never read without a person, beyond the
/// policy's credentials: what commonly holds a credential.
const SECRET_NAMES: &[&str] = &[
    "**/.git-credentials",
    "**/*.tfstate*",
    "**/*credentials*",
    "**/*.p12",
    "**/*.pfx",
    "**/*.kdbx",
    "**/id_*",
    "**/.netrc",
    "**/.pgpass",
    "**/.npmrc",
    "**/.pypirc",
    "**/.dockercfg",
    "**/.docker/config.json",
    "**/kubeconfig",
    "**/.kube/config",
    "**/.htpasswd",
    "**/*secret*",
    "**/token",
    "**/*.token",
    "**/token.txt",
    "**/*.jks",
    "**/*.keystore",
    "**/deploy_key*",
];

fn secret_name(rel: &str) -> bool {
    static SET: std::sync::OnceLock<Option<globset::GlobSet>> = std::sync::OnceLock::new();
    SET.get_or_init(|| {
        let mut b = globset::GlobSetBuilder::new();
        for g in SECRET_NAMES {
            if let Ok(glob) = globset::GlobBuilder::new(g).case_insensitive(true).build() {
                b.add(glob);
            }
        }
        b.build().ok()
    })
    .as_ref()
    .is_none_or(|s| s.is_match(rel))
}

/// The one file a plain-read line (`cat src/lib.rs`, `head -n 5 x`) reads;
/// `None` for anything else — another program, another option, `--`, `-`,
/// several files.
#[must_use]
pub fn plain_read(argv: &[String]) -> Option<String> {
    let (program, args) = argv.split_first()?;
    let (_, options) = READS.iter().find(|(p, _)| p == program)?;
    let mut file = None;
    let mut words = args.iter();
    while let Some(a) = words.next() {
        if let Some(flag) = a.strip_prefix('-') {
            if options.contains(&a.as_str()) {
                continue;
            }
            // `-n 5`, `-n5`: the letter, then its number.
            let mut chars = flag.chars();
            let letter = chars.next()?;
            let rest: String = chars.collect();
            if !options.contains(&format!("-{letter} N").as_str()) {
                return None;
            }
            let number = if rest.is_empty() {
                words.next()?.clone()
            } else {
                rest
            };
            if number.is_empty() || !number.chars().all(|c| c.is_ascii_digit()) {
                return None;
            }
            continue;
        }
        if file.replace(a.clone()).is_some() {
            return None;
        }
    }
    file
}

/// The call kind of a person's "reads for this task".
pub const READS_GRANT: &str = "reads";

/// JSON with every object's keys sorted: one spelling for one value.
fn canonical(v: &Value) -> String {
    fn sorted(v: &Value) -> Value {
        match v {
            Value::Object(o) => {
                let mut keys: Vec<&String> = o.keys().collect();
                keys.sort();
                let mut out = serde_json::Map::new();
                for k in keys {
                    out.insert(k.clone(), sorted(&o[k]));
                }
                Value::Object(out)
            }
            Value::Array(a) => Value::Array(a.iter().map(sorted).collect()),
            other => other.clone(),
        }
    }
    sorted(v).to_string()
}

/// Whether an `execute` request carries only what a plain read needs:
/// its command (and Copilot's copy of it as `commands`), a working
/// directory that is the worktree, a timeout, a description.
fn execute_keeps_to(raw: &Value, argv: &[String]) -> bool {
    let Some(o) = raw.as_object() else {
        return false;
    };
    let line = argv.join(" ");
    o.iter().all(|(k, v)| match k.as_str() {
        "command" => true,
        "commands" => v.as_array().is_some_and(|a| {
            a.len() == 1
                && a[0].as_str().is_some_and(|c| {
                    c.split_ascii_whitespace().collect::<Vec<_>>().join(" ") == line
                })
        }),
        "cwd" | "working_directory" | "workdir" => {
            v.as_str().is_some_and(|c| c.is_empty() || c == ".")
        }
        "timeout" => v.is_u64(),
        "description" => v.is_string(),
        _ => false,
    })
}

/// Whether a file's text looks like it holds a credential: a private key,
/// a URL with a user and password, a well-known token prefix, or a
/// key/secret/password/token set to a value.
#[must_use]
pub fn holds_a_credential(text: &str) -> bool {
    static PATTERNS: std::sync::OnceLock<Option<regex::RegexSet>> = std::sync::OnceLock::new();
    PATTERNS
        .get_or_init(|| {
            regex::RegexSet::new([
                r"-----BEGIN [A-Z ]*PRIVATE KEY-----",
                r"[a-zA-Z][a-zA-Z0-9+.-]*://[^\s/:@]+:[^\s/@]+@",
                r"\bAKIA[0-9A-Z]{16}\b",
                r"\b(ghp|gho|ghu|ghs|ghr)_[A-Za-z0-9]{20,}",
                r"\bgithub_pat_[A-Za-z0-9_]{20,}",
                r"\bxox[abprs]-[A-Za-z0-9-]{10,}",
                r"\bsk-[A-Za-z0-9_-]{16,}",
                r#"(?i)(api[_-]?key|secret|passw(or)?d|token|private[_-]?key)["']?\s*[:=]\s*["']?[^\s"']{4,}"#,
            ])
            .ok()
        })
        .as_ref()
        .is_none_or(|set| set.is_match(text))
}

/// Why a command the agent runs itself needs a person.
pub const RUNS_ITSELF: &str = "the agent runs it itself, outside speccoder's sandbox";

/// What a permission request comes to.
#[derive(Debug, Clone, PartialEq)]
enum Judged {
    /// A plain read of this one file, covered by a person's "reads for
    /// this task" (its scope).
    Granted(String, &'static str),
    /// Nothing outside the turn (pure thinking).
    Think,
    /// Refused, whoever asks.
    Deny(String),
    /// A person decides; a decision covers exactly this object.
    Person(String, Object),
}

/// Every string a key of `keys` holds anywhere in `v`.
fn strings_at(v: &Value, keys: &[&str], out: &mut Vec<Value>) {
    match v {
        Value::Object(o) => {
            for (k, x) in o {
                if keys.contains(&k.as_str()) {
                    out.push(x.clone());
                }
                strings_at(x, keys, out);
            }
        }
        Value::Array(a) => a.iter().for_each(|x| strings_at(x, keys, out)),
        _ => {}
    }
}

/// A command a value holds: a line, or an argv.
fn command_of(v: &Value) -> Vec<Vec<String>> {
    match v {
        Value::String(line) => vec![argv_of_line(line)],
        Value::Array(a) if a.iter().all(Value::is_string) => {
            vec![
                a.iter()
                    .filter_map(|v| v.as_str().map(str::to_owned))
                    .collect(),
            ]
        }
        Value::Array(a) => a.iter().flat_map(command_of).collect(),
        // A command in a shape speccoder does not read: unreadable, never
        // dropped (a person sees it).
        other => vec![vec!["sh".to_owned(), "-c".to_owned(), other.to_string()]],
    }
}

/// Whether `raw` keeps to `kind`'s keys, each of the shape it should have.
fn keeps_to(kind: &str, raw: &Value) -> bool {
    let Some(keys) = known_keys(kind) else {
        return false;
    };
    let Some(o) = raw.as_object() else {
        return raw.is_null();
    };
    o.iter().all(|(k, v)| {
        keys.contains(&k.as_str())
            && match k.as_str() {
                "line" | "limit" | "offset" | "start_line" | "end_line" => v.is_u64(),
                "replace_all" => v.is_boolean(),
                "paths" => v.as_array().is_some_and(|a| a.iter().all(Value::is_string)),
                "todos" => v.is_array() || v.is_string(),
                "edits" => v.as_array().is_some_and(|a| {
                    a.iter().all(|e| {
                        e.as_object().is_some_and(|e| {
                            e.iter().all(|(k, v)| {
                                EDIT_KEYS.contains(&k.as_str())
                                    && (v.is_string() || (k == "replace_all" && v.is_boolean()))
                            })
                        })
                    })
                }),
                _ => v.is_string(),
            }
    })
}

impl Governor {
    /// The governor for one attempt.
    #[must_use]
    pub fn new(s: Setup) -> Self {
        let remembered = s
            .run_approved
            .into_iter()
            .map(|o| (o, "run-grant"))
            .collect();
        Self {
            root: s.root,
            tools: s.tools,
            policy: s.policy,
            approver: s.approver,
            present: s.present,
            task: s.task,
            task_title: s.task_title,
            run: s.run,
            frozen_additions: s.frozen_additions,
            progress: s.progress,
            copied: s.copied,
            agent: s.agent,
            asking: std::sync::atomic::AtomicU64::new(0),
            asking_since: Mutex::new(None),
            state: Mutex::new(State {
                once: s.approved_once,
                remembered,
                ..State::default()
            }),
        }
    }

    /// The worktree.
    #[must_use]
    pub fn root(&self) -> &Path {
        &self.root
    }

    /// The decisions and calls so far.
    #[must_use]
    pub fn log(&self) -> Vec<Value> {
        self.state.lock().map(|s| s.log.clone()).unwrap_or_default()
    }

    /// The call waiting for a person nobody could ask, if one is.
    #[must_use]
    pub fn pending(&self) -> Option<Value> {
        self.state.lock().ok().and_then(|s| s.pending.clone())
    }

    /// Whether the attempt is ending.
    #[must_use]
    pub fn stopped(&self) -> bool {
        self.state.lock().map_or(true, |s| s.stopped)
    }

    /// Prompts a person was shown.
    #[must_use]
    pub fn asked(&self) -> u32 {
        self.state.lock().map_or(0, |s| s.asked)
    }

    /// How long a person has spent deciding so far: the attempt's clock
    /// stands while they do.
    #[must_use]
    pub fn asking(&self) -> std::time::Duration {
        let done =
            std::time::Duration::from_millis(self.asking.load(std::sync::atomic::Ordering::SeqCst));
        let now = self
            .asking_since
            .lock()
            .ok()
            .and_then(|s| s.map(|t| t.elapsed()))
            .unwrap_or_default();
        done + now
    }

    /// The agent's words since its last call.
    pub fn said(&self, text: &str) {
        if let Ok(mut s) = self.state.lock() {
            s.said.push_str(text);
        }
    }

    /// The agent reported a call it makes: recorded beside the decisions,
    /// as the agent's own (`decision: "reported"`) — its claim, never
    /// evidence. Masked, its long values cut; one that changed something
    /// without a decision of speccoder's is counted ([`Governor::unasked`]).
    pub fn reported(&self, call: &ToolRequest) {
        let mut arguments = call.raw_input.clone().unwrap_or(Value::Null);
        cap(&mut arguments);
        crate::secrets::mask_json(&mut arguments);
        let ok = call.status.as_deref() == Some("completed");
        let mut held = Vec::new();
        strings_at(
            call.raw_input.as_ref().unwrap_or(&Value::Null),
            COMMAND_KEYS,
            &mut held,
        );
        let effect = matches!(
            call.kind.as_deref(),
            Some("edit" | "delete" | "move" | "execute")
        ) || !held.is_empty();
        let entry = json!({
            "tool": format!("agent:{}", call.kind.as_deref().unwrap_or("other")),
            "arguments": arguments,
            "title": crate::secrets::mask(&call.shown_title()),
            "decision": "reported",
            "ok": ok,
            "by": "agent",
            "call": call.id,
        });
        self.emit(&entry);
        let unasked = if let Ok(mut s) = self.state.lock() {
            s.said.clear();
            // Done without an allowed request: its own settings let it. A
            // failed one counts only when it never asked (a refusal fails).
            let failed = call.status.as_deref() == Some("failed");
            let new = effect
                && ((ok && !s.allowed.contains(&call.id))
                    || (failed && !s.decided.contains(&call.id)));
            if new {
                s.unasked += 1;
            }
            s.log.push(entry);
            new.then_some(s.unasked)
        } else {
            None
        };
        if let Some(calls) = unasked {
            self.event(Event::AgentUnasked {
                task: self.task_id(),
                calls,
            });
        }
    }

    /// Calls the agent reported changing something (an edit, a command)
    /// that never reached speccoder as a request: its own settings let it
    /// decide them.
    #[must_use]
    pub fn unasked(&self) -> u32 {
        self.state.lock().map_or(0, |s| s.unasked)
    }

    /// Ends the attempt: nothing more is allowed.
    pub fn stop(&self) {
        if let Ok(mut s) = self.state.lock() {
            s.stopped = true;
        }
    }

    /// A path the agent named, relative to the worktree as it resolves — a
    /// symlink followed, a relative path against the worktree; refused when
    /// it lands outside.
    fn rel(&self, path: &Path) -> Result<String, String> {
        let full = if path.is_relative() {
            self.root.join(path)
        } else {
            path.to_path_buf()
        };
        // Its nearest existing ancestor resolved (symlinks, `/tmp` and
        // `/private/tmp`), the rest as written — never `..`.
        let mut base = full.clone();
        let mut rest = Vec::new();
        while std::fs::symlink_metadata(&base).is_err() {
            match (
                base.file_name().map(std::ffi::OsStr::to_os_string),
                base.parent(),
            ) {
                (Some(name), Some(parent)) => {
                    rest.push(name);
                    base = parent.to_path_buf();
                }
                _ => break,
            }
        }
        let outside = || {
            format!(
                "`{}` is outside the worktree; an attempt works only inside it",
                path.display()
            )
        };
        let mut canonical = std::fs::canonicalize(&base).map_err(|_| outside())?;
        for name in rest.iter().rev() {
            if name == ".." {
                return Err(outside());
            }
            canonical.push(name);
        }
        let r = canonical
            .strip_prefix(&self.root)
            .map_err(|_| outside())?
            .to_string_lossy()
            .replace('\\', "/");
        Ok(if r.is_empty() { ".".to_owned() } else { r })
    }

    /// Whether a person's "reads for this task" covers the agent reading
    /// `rel` itself: one existing regular file inside the worktree, no
    /// symlink on its way, no other name for it (a hard link), under the
    /// read cap; never `.git/` or speccoder's own, never ignored by git (an
    /// error from git counts as ignored), never a credential by name or by
    /// content, never a file copied from your checkout, never one the
    /// secret masking would change — the agent's own read is not masked.
    fn plain_file(&self, rel: &str) -> bool {
        use std::os::unix::fs::MetadataExt as _;
        // Any letter case: on a case-insensitive file system `.ENV` is `.env`.
        let folded = rel.to_lowercase();
        if self.policy.protected().is_secret(rel)
            || self.policy.protected().is_secret(&folded)
            || secret_name(rel)
            || self.copied.iter().any(|c| c.eq_ignore_ascii_case(rel))
            || folded
                .split('/')
                .any(|part| part == ".git" || part.starts_with(".speccoder"))
        {
            return false;
        }
        let mut at = self.root.clone();
        for part in Path::new(rel).components() {
            at.push(part);
            match std::fs::symlink_metadata(&at) {
                Ok(m) if !m.file_type().is_symlink() => {}
                _ => return false,
            }
        }
        let Ok(m) = std::fs::symlink_metadata(&at) else {
            return false;
        };
        if !m.is_file() || m.nlink() != 1 || m.len() > crate::tools::READ_CAP as u64 {
            return false;
        }
        // 1: not ignored; 0 (ignored) or anything else (an error): no.
        let not_ignored = std::process::Command::new("git")
            .args(["check-ignore", "-q", "--"])
            .arg(rel)
            .current_dir(&self.root)
            .status()
            .is_ok_and(|s| s.code() == Some(1));
        if !not_ignored {
            return false;
        }
        std::fs::read(&at).is_ok_and(|b| {
            let text = String::from_utf8_lossy(&b);
            crate::secrets::mask(&text) == text && !holds_a_credential(&text)
        })
    }

    /// What a permission request comes to: only a plain read of one plain
    /// file is allowed without a person; a credential, a protected path or
    /// a place outside the worktree is refused; everything else is a
    /// person's, decided once for exactly what it names.
    fn judge(&self, call: &ToolRequest) -> Judged {
        let raw = call.raw_input.clone().unwrap_or(Value::Null);
        let kind = call.kind.as_deref().unwrap_or("other");
        // Every command, anywhere in it.
        let mut held = Vec::new();
        strings_at(&raw, COMMAND_KEYS, &mut held);
        let mut argvs: Vec<Vec<String>> = Vec::new();
        for v in &held {
            for argv in command_of(v) {
                match shell_line(&argv).and_then(commands_of_line) {
                    Some(parts) => argvs.extend(parts),
                    None => argvs.push(argv),
                }
            }
        }
        argvs.retain(|a| !a.is_empty());
        // Every path, anywhere in it, and its locations.
        let mut named = Vec::new();
        strings_at(&raw, PATH_KEYS, &mut named);
        let mut paths: Vec<PathBuf> = call.locations.clone();
        for v in &named {
            match v {
                Value::String(p) => paths.push(PathBuf::from(p)),
                Value::Array(a) => {
                    paths.extend(a.iter().filter_map(Value::as_str).map(PathBuf::from))
                }
                _ => {}
            }
        }
        if let Some(changes) = raw.get("changes").and_then(Value::as_object) {
            paths.extend(changes.keys().map(PathBuf::from));
        }
        let mut rels = Vec::new();
        for p in &paths {
            match self.rel(p) {
                Ok(r) => rels.push(r),
                Err(e) => return Judged::Deny(e),
            }
        }
        // A plain-read line's file is a path it names too.
        let reading = argvs.len() == 1 && plain_read(&argvs[0]).is_some();
        if reading && let Some(file) = plain_read(&argvs[0]) {
            match self.rel(Path::new(&file)) {
                Ok(r) => rels.push(r),
                Err(e) => return Judged::Deny(e),
            }
        }
        rels.sort();
        rels.dedup();
        let writes = matches!(kind, "edit" | "delete" | "move");
        for r in &rels {
            if self.policy.protected().is_secret(r)
                || self.policy.protected().is_secret(&r.to_lowercase())
            {
                return Judged::Deny(format!("`{r}` looks like a credential"));
            }
            if writes && let Some(class) = self.policy.write_protected(r) {
                return Judged::Deny(format!(
                    "`{r}` is protected: {}",
                    self.policy.protected().reason(class)
                ));
            }
        }
        // A grant covers exactly this request again: its kind, its whole
        // input and its locations — nothing normalised away.
        let exact = Object::Agent {
            agent: self.agent.clone(),
            call: kind.to_owned(),
            argvs: argvs.clone(),
            paths: rels.clone(),
            input: crate::integrity::sha256_hex(
                canonical(&json!([kind, raw, call.locations])).as_bytes(),
            ),
        };
        if kind == "fetch" {
            return Judged::Deny(
                "fetching from the network: an attempt's commands run without it".to_owned(),
            );
        }
        if kind == "switch_mode" {
            return Judged::Deny(
                "the agent is kept in the mode that asks before acting".to_owned(),
            );
        }
        if kind == "think" && argvs.is_empty() && keeps_to("think", &raw) {
            return Judged::Think;
        }
        // A read of one file: what a person may allow for the whole task.
        let read_shaped = match kind {
            "read" => argvs.is_empty() && keeps_to("read", &raw) && rels.len() == 1,
            "execute" => reading && rels.len() == 1 && execute_keeps_to(&raw, &argvs[0]),
            _ => false,
        };
        if read_shaped && self.plain_file(&rels[0]) {
            let reads = self.reads_object();
            if let Some(scope) = self.granted(&reads) {
                return Judged::Granted(rels[0].clone(), scope);
            }
            return Judged::Person(format!("the agent reads `{}` itself", rels[0]), reads);
        }
        let why = if !argvs.is_empty() || kind == "execute" {
            RUNS_ITSELF.to_owned()
        } else if !keeps_to(kind, &raw) {
            "speccoder does not know everything this call carries".to_owned()
        } else {
            match kind {
                "read" | "search" => "the agent reads files itself".to_owned(),
                "edit" | "delete" | "move" => format!("the agent changes files itself ({kind})"),
                _ => "no rule can tell what this call does".to_owned(),
            }
        };
        Judged::Person(why, exact)
    }

    /// The object of a person's "reads for this task".
    fn reads_object(&self) -> Object {
        Object::Agent {
            agent: self.agent.clone(),
            call: READS_GRANT.to_owned(),
            argvs: Vec::new(),
            paths: Vec::new(),
            input: String::new(),
        }
    }

    /// Answers a permission request: the agent's allow-once option when
    /// allowed (a plain read, or a person's yes), its reject option when
    /// not, `None` (cancelled) when the attempt ends here.
    pub fn permission(&self, call: &ToolRequest, options: &[PermissionOption]) -> Option<String> {
        let pick = |kinds: &[&str]| {
            kinds
                .iter()
                .find_map(|k| options.iter().find(|o| o.kind == *k))
                .map(|o| o.id.clone())
        };
        let reject = || pick(&["reject_once", "reject_always"]);
        if let Ok(mut s) = self.state.lock() {
            s.decided.insert(call.id.clone());
            s.request = Some(call.id.clone());
        }
        let args = call_args(call);
        let verdict = if self.stopped() {
            Verdict::Stop
        } else {
            match self.judge(call) {
                Judged::Granted(rel, scope) => {
                    self.record(json!({ "tool": "read_file", "arguments": { "path": rel }, "decision": "allow", "ok": true, "by": "person", "approved_by": "person", "scope": scope, "object": self.reads_object(), "rule": "your reads for this task" }));
                    Verdict::Allow(None)
                }
                Judged::Think => {
                    self.record(json!({ "tool": AGENT_CALL, "arguments": args, "decision": "allow", "by": "rule", "rule": "thinking" }));
                    Verdict::Allow(None)
                }
                Judged::Deny(reason) => {
                    self.record(json!({ "tool": AGENT_CALL, "arguments": args, "decision": "deny", "reason": reason, "by": "rule", "rule": "agent call" }));
                    Verdict::Deny(reason)
                }
                Judged::Person(reason, object) => self.person(&args, &reason, object),
            }
        };
        let answer = match &verdict {
            // Never an option the agent would remember: a later call must
            // reach speccoder again.
            Verdict::Allow(_) => pick(&["allow_once"]).or_else(|| {
                self.record(json!({ "tool": AGENT_CALL, "arguments": args, "decision": "deny", "reason": "the agent offered no allow-once option", "by": "rule", "rule": "agent options" }));
                reject()
            }),
            Verdict::Deny(_) => reject(),
            Verdict::Stop => None,
        };
        if answer.is_some()
            && answer == pick(&["allow_once"])
            && let Ok(mut s) = self.state.lock()
        {
            s.allowed.insert(call.id.clone());
        }
        self.settle_request(
            call,
            match (&verdict, &answer) {
                (Verdict::Allow(_), Some(a)) if Some(a) == pick(&["allow_once"]).as_ref() => {
                    "allow"
                }
                (Verdict::Stop, _) => "approval",
                _ => "deny",
            },
        );
        answer
    }

    /// Ends the request being decided, said as one line.
    fn settle_request(&self, call: &ToolRequest, decision: &str) {
        let request = self.state.lock().ok().and_then(|mut s| s.request.take());
        if request.is_some() {
            let target = crate::secrets::mask(&call.shown_title());
            self.emit(&json!({
                "tool": format!("agent:{}", call.kind.as_deref().unwrap_or("other")),
                "arguments": {},
                "title": target,
                "decision": decision,
                "ok": decision == "allow",
            }));
        }
    }

    /// A decision that could not be made (it failed): refused, and the
    /// request closed.
    pub fn abandon(&self, call: &ToolRequest) {
        self.record(json!({ "tool": AGENT_CALL, "arguments": call_args(call), "decision": "deny", "reason": "the decision failed", "by": "rule", "rule": "failure" }));
        self.settle_request(call, "deny");
    }

    /// A call that is a person's: their grant for exactly `object`, their
    /// rejection of it, or the question.
    fn person(&self, args: &Value, reason: &str, object: Object) -> Verdict {
        if let Some(r) = self.policy.rejection(&object) {
            let why = format!("a person rejected this: {}", r.reason);
            self.record(json!({ "tool": AGENT_CALL, "arguments": args, "decision": "deny", "reason": why, "object": object, "by": "person", "scope": "task-grant" }));
            return Verdict::Deny(why);
        }
        if let Some(scope) = self.granted(&object) {
            self.record(json!({ "tool": AGENT_CALL, "arguments": args, "decision": "allow", "ok": true, "object": object, "by": "person", "approved_by": "person", "scope": scope }));
            return Verdict::Allow(Some(object));
        }
        let mut request = self.request(AGENT_CALL, args, reason, Some(&object));
        // A read: "for this task" is every plain read of the task.
        if matches!(&object, Object::Agent { call, .. } if call == READS_GRANT) {
            request.kind = READS_GRANT.to_owned();
        }
        self.ask(AGENT_CALL, args, Some(object), reason, request)
    }

    /// The grant that covers `object` here: the task's (by the policy),
    /// one call's (used up), or the run's or one made in this attempt.
    fn granted(&self, object: &Object) -> Option<&'static str> {
        if self.policy.approved().iter().any(|a| a == object) {
            return Some("task-grant");
        }
        let mut s = self.state.lock().ok()?;
        if let Some(at) = s.once.iter().position(|r| r == object) {
            s.once.remove(at);
            return Some("once-grant");
        }
        s.remembered
            .iter()
            .find(|(r, _)| r == object)
            .map(|(_, scope)| *scope)
    }

    /// Decides one speccoder tool call as a native attempt would.
    pub fn decide(&self, tool: &str, args: &Value, call: Option<&ToolRequest>) -> Verdict {
        let _ = call;
        self.decide_as(tool, args)
    }

    /// [`Governor::decide`], for a call speccoder itself carries out
    /// (a file, a terminal command in its sandbox).
    fn decide_as(&self, tool: &str, args: &Value) -> Verdict {
        if self.stopped() {
            return Verdict::Deny("the attempt is ending".to_owned());
        }
        let mut decision = self.policy.base(tool, args);
        // `[tests] frozen = "additions"`: a write that keeps every line of
        // the frozen test is allowed.
        let mut additions_only = false;
        if self.frozen_additions
            && tool == "write_file"
            && matches!(&decision, Decision::Approval(r) if r.contains("frozen test"))
            && let (Some(path), Some(new)) = (args["path"].as_str(), args["content"].as_str())
            && let Ok(old) = std::fs::read_to_string(self.root.join(path))
            && crate::integrity::only_additions(&old, new)
        {
            decision = Decision::Allow;
            additions_only = true;
        }
        let mut object: Option<Object> = None;
        if matches!(decision, Decision::Approval(_)) {
            let resolved = self.tools.resolve(tool, args);
            if resolved["ok"] == true {
                object = serde_json::from_value(resolved["object"].clone()).ok();
                decision = self.policy.classify(tool, args, object.as_ref());
            } else {
                decision = Decision::Deny(
                    resolved["error"]
                        .as_str()
                        .unwrap_or("the call's object cannot be resolved")
                        .to_owned(),
                );
            }
        }
        let mut person: Option<Value> = None;
        if decision == Decision::Allow && object.is_some() {
            person = Some(
                json!({ "approved_by": "person", "scope": "task-grant", "grant": { "scope": "task", "run": self.run } }),
            );
        }
        if matches!(decision, Decision::Approval(_))
            && let Some(o) = &object
            && let Ok(mut s) = self.state.lock()
        {
            if let Some(at) = s.once.iter().position(|r| r == o) {
                s.once.remove(at);
                person = Some(
                    json!({ "approved_by": "person", "scope": "once-grant", "grant": { "scope": "once", "run": self.run } }),
                );
                decision = Decision::Allow;
            } else if let Some((_, scope)) = s.remembered.iter().find(|(r, _)| r == o) {
                person = Some(
                    json!({ "approved_by": "person", "scope": scope, "grant": { "scope": scope.trim_end_matches("-grant"), "run": self.run } }),
                );
                decision = Decision::Allow;
            }
        }
        decision = self.policy.settle(decision);
        match decision {
            Decision::Allow => {
                let mut entry =
                    json!({ "tool": tool, "arguments": args, "decision": "allow", "ok": true });
                if tool == "run_command" {
                    entry["executed_by"] = json!("speccoder");
                    entry["sandboxed"] = json!(true);
                }
                self.decided_by(&mut entry, object.as_ref(), person.as_ref(), tool, args);
                if additions_only {
                    entry["frozen_additions"] = json!(true);
                }
                self.record(entry);
                Verdict::Allow(object)
            }
            Decision::Deny(reason) => {
                let mut entry = json!({ "tool": tool, "arguments": args, "decision": "deny", "reason": reason });
                self.decided_by(&mut entry, object.as_ref(), person.as_ref(), tool, args);
                self.record(entry);
                Verdict::Deny(reason)
            }
            Decision::Approval(reason) => {
                let request = self.request(tool, args, &reason, object.as_ref());
                self.ask(tool, args, object, &reason, request)
            }
        }
    }

    /// Who decided an entry: a person (by a grant), or a rule.
    fn decided_by(
        &self,
        entry: &mut Value,
        object: Option<&Object>,
        person: Option<&Value>,
        tool: &str,
        args: &Value,
    ) {
        if let Some(o) = object {
            entry["object"] = json!(o);
        }
        match person.and_then(Value::as_object) {
            Some(p) => {
                entry["by"] = json!("person");
                if let Some(e) = entry.as_object_mut() {
                    e.extend(p.clone());
                }
            }
            None => {
                entry["by"] = json!("rule");
                entry["rule"] = json!(self.policy.rule(tool, args, object));
            }
        }
    }

    /// The question for a call that needs a person, as a native attempt
    /// builds it.
    fn request(&self, tool: &str, args: &Value, reason: &str, object: Option<&Object>) -> Request {
        let kind = crate::approvals::kind_of(tool, args);
        let risk = crate::approvals::risk(tool, reason);
        let said = self
            .state
            .lock()
            .map(|s| s.said.clone())
            .unwrap_or_default();
        let changed = object.and_then(|o| {
            self.policy
                .approved()
                .iter()
                .find_map(|earlier| o.changed_from(earlier))
        });
        Request {
            task: self.task.clone(),
            task_title: self.task_title.clone(),
            turn: 0,
            tool: tool.to_owned(),
            arguments: args.clone(),
            kind: kind.to_owned(),
            reason: reason.to_owned(),
            object: object.cloned(),
            changed,
            risk: risk.to_owned(),
            claim: crate::approvals::claim(&crate::secrets::mask(&said)),
            options: crate::approvals::options(risk, object.is_some(), false, kind, risk),
            run: self.run.clone(),
            ..Request::default()
        }
    }

    /// Asks a person, or ends the attempt with the call waiting.
    fn ask(
        &self,
        tool: &str,
        args: &Value,
        object: Option<Object>,
        reason: &str,
        mut request: Request,
    ) -> Verdict {
        self.event(Event::ApprovalRequested {
            task: self.task_id(),
            call: String::new(),
            tool: tool.to_owned(),
            what: format!("{tool} {}", crate::progress::target(tool, args))
                .chars()
                .filter(|c| !c.is_control())
                .take(60)
                .collect(),
            class: object
                .as_ref()
                .map(|o| o.class().as_str().to_owned())
                .unwrap_or_default(),
            object: object.as_ref().map(Object::short).unwrap_or_default(),
        });
        let Some(approver) = &self.approver else {
            return self.wait(tool, args, object, reason, request);
        };
        if let Ok(mut s) = self.state.lock() {
            s.asked += 1;
            request.asked = s.asked;
        }
        let context = PresentContext {
            root: Some(self.root.clone()),
            ..self.present.clone()
        };
        let began = std::time::Instant::now();
        if let Ok(mut s) = self.asking_since.lock() {
            *s = Some(began);
        }
        let answer: Answer = approver.ask(&present(&request, &context));
        self.asking.fetch_add(
            u64::try_from(began.elapsed().as_millis()).unwrap_or(u64::MAX),
            std::sync::atomic::Ordering::SeqCst,
        );
        if let Ok(mut s) = self.asking_since.lock() {
            *s = None;
        }
        // The attempt ended while the person decided (the agent left its
        // mode, the time was up): nothing is allowed any more.
        let answer = if self.stopped() && answer.decision == Said::Approve {
            Answer::reject("the attempt ended while you decided", answer.by)
        } else {
            answer
        };
        let by = answer.by.clone();
        let approver_v = serde_json::to_value(&by).unwrap_or(Value::Null);
        let operator = by.as_ref().map(Who::view);
        self.event(Event::ApprovalDecided {
            task: self.task_id(),
            call: String::new(),
            decision: if answer.decision == Said::Approve {
                "approve"
            } else {
                "reject"
            }
            .to_owned(),
            scope: (answer.decision == Said::Approve).then(|| answer.scope.name().to_owned()),
            by: by
                .as_ref()
                .map_or_else(|| "unknown".to_owned(), |w| w.name.clone()),
            how: by
                .as_ref()
                .map_or_else(|| "unknown".to_owned(), |w| w.basis.clone()),
            class: object
                .as_ref()
                .map(|o| o.class().as_str().to_owned())
                .unwrap_or_default(),
            object: object.as_ref().map(Object::short).unwrap_or_default(),
        });
        let mut entry =
            json!({ "tool": tool, "arguments": args, "reason": reason, "by": "person" });
        if let Some(o) = &object {
            entry["object"] = json!(o);
        }
        match answer.decision {
            Said::Approve => {
                entry["decision"] = json!("allow");
                entry["ok"] = json!(true);
                entry["approved_by"] = json!("person");
                entry["scope"] = json!(answer.scope.name());
                entry["note"] = json!(answer.note);
                entry["approver"] = approver_v;
                entry["operator"] = json!(operator);
                if answer.always {
                    entry["always"] = json!(true);
                }
                if let (Some(o), Scope::Task | Scope::Run) = (&object, answer.scope) {
                    entry["grant"] = json!({ "scope": answer.scope.name(), "run": self.run });
                    if let Ok(mut s) = self.state.lock() {
                        s.remembered.push((
                            o.clone(),
                            if answer.scope == Scope::Run {
                                "run-grant"
                            } else {
                                "task-grant"
                            },
                        ));
                    }
                }
                self.record(entry);
                Verdict::Allow(object)
            }
            Said::Reject => {
                let why = answer
                    .reason
                    .unwrap_or_else(|| "no reason given".to_owned());
                entry["decision"] = json!("deny");
                entry["rejected_by"] = json!("person");
                entry["approver"] = approver_v;
                entry["operator"] = json!(operator);
                entry["rejection"] = json!(why);
                self.record(entry);
                Verdict::Deny(format!("a person rejected this: {why}"))
            }
            // The task ends here; the call waits for `task approve`.
            Said::Stop => self.wait(tool, args, object, reason, request),
        }
    }

    /// The call waits for a person: the attempt ends `needs_approval`.
    fn wait(
        &self,
        tool: &str,
        args: &Value,
        object: Option<Object>,
        reason: &str,
        request: Request,
    ) -> Verdict {
        let mut entry =
            json!({ "tool": tool, "arguments": args, "decision": "approval", "reason": reason });
        if let Some(o) = &object {
            entry["object"] = json!(o);
        }
        self.record(entry);
        if let Ok(mut s) = self.state.lock() {
            if s.pending.is_none() {
                s.pending = Some(json!({
                    "tool": tool,
                    "arguments": args,
                    "reason": reason,
                    "object": object,
                    "run": self.run,
                    "request": request,
                }));
            }
            s.stopped = true;
        }
        Verdict::Stop
    }

    /// `fs/read_text_file`: a file in the worktree, read through the
    /// workspace tools (credentials refused, copied secrets masked).
    ///
    /// # Errors
    ///
    /// Why it is refused or cannot be read.
    pub async fn read_text_file(
        &self,
        path: &Path,
        line: Option<u32>,
        limit: Option<u32>,
    ) -> Result<String, String> {
        let rel = self.rel(path)?;
        let start = line.map(|l| l.max(1) as usize);
        let end = limit.map(|n| start.unwrap_or(1) + (n as usize).saturating_sub(1));
        let args = json!({ "path": rel, "start_line": start, "end_line": end });
        match self.decide("read_file", &json!({ "path": rel }), None) {
            Verdict::Allow(_) => {}
            Verdict::Deny(r) => return Err(format!("denied: {r}")),
            Verdict::Stop => return Err("the attempt is ending".to_owned()),
        }
        let out = self.tools.run("read_file", &args).await;
        if out["ok"] != true {
            return Err(out["error"].as_str().unwrap_or("not readable").to_owned());
        }
        if out["binary"] == true {
            return Err(format!("`{rel}` is not a text file"));
        }
        let mut content = out["content"].as_str().unwrap_or_default().to_owned();
        // The tool joins lines with `\n`; the file's last one is kept.
        if out["end_line"] == out["total_lines"]
            && out["truncated"] != true
            && std::fs::read(self.root.join(&rel)).is_ok_and(|b| b.ends_with(b"\n"))
        {
            content.push('\n');
        }
        Ok(content)
    }

    /// `fs/write_text_file`: a file in the worktree, written through the
    /// workspace tools (protected paths refused, frozen tests a person's).
    ///
    /// # Errors
    ///
    /// Why it is refused or cannot be written.
    pub async fn write_text_file(&self, path: &Path, content: &str) -> Result<(), String> {
        let rel = self.rel(path)?;
        let args = json!({ "path": rel, "content": content });
        let object = match self.decide("write_file", &args, None) {
            Verdict::Allow(o) => o,
            Verdict::Deny(r) => return Err(format!("denied: {r}")),
            Verdict::Stop => {
                return Err("the attempt is ending: this write waits for a person".to_owned());
            }
        };
        let mut call = args;
        if let Some(o) = object {
            call[crate::tools::EXPECT] = json!(o);
        }
        let out = self.tools.run("write_file", &call).await;
        if out["ok"] == true {
            Ok(())
        } else {
            Err(out["error"].as_str().unwrap_or("not written").to_owned())
        }
    }

    /// `terminal/create`: whether the command may run, and how — its argv,
    /// directory and scrubbed environment.
    ///
    /// # Errors
    ///
    /// Why it is refused.
    pub fn command(&self, argv: Vec<String>, cwd: Option<&Path>) -> Result<Command, String> {
        let mut args = json!({ "argv": argv });
        if let Some(c) = cwd {
            args["cwd"] = json!(self.rel(c)?);
        }
        let object = match self.decide("run_command", &args, None) {
            Verdict::Allow(o) => o,
            Verdict::Deny(r) => return Err(format!("denied: {r}")),
            Verdict::Stop => {
                return Err("the attempt is ending: this command waits for a person".to_owned());
            }
        };
        let dir = self.tools.command_cwd(args["cwd"].as_str()).map_err(|e| {
            e["error"]
                .as_str()
                .unwrap_or("no such directory")
                .to_owned()
        })?;
        // Decided on an object: it runs only as that object.
        if let Some(Object::Command { executable, .. }) = object {
            let now = self.tools.resolve("run_command", &args);
            if now["object"]["executable"] != json!(executable) {
                return Err(format!(
                    "the object changed since it was approved: {executable} → {}",
                    now["object"]["executable"]
                ));
            }
        }
        Ok((
            crate::tools::policy::argv_of(&args),
            dir,
            self.tools.command_env(None),
        ))
    }

    fn task_id(&self) -> String {
        self.task
            .rsplit('/')
            .next()
            .unwrap_or(&self.task)
            .to_owned()
    }

    fn event(&self, e: Event) {
        if let Some((_, p)) = &self.progress {
            p.event(&e);
        }
    }

    fn emit(&self, entry: &Value) {
        let mut entry = entry.clone();
        cap(&mut entry);
        crate::secrets::mask_json(&mut entry);
        let entry = &entry;
        if let Some((task, p)) = &self.progress {
            let tool = entry["tool"].as_str().unwrap_or_default();
            p.event(&Event::ToolCall {
                task: task.clone(),
                turn: 0,
                tool: tool.to_owned(),
                target: match entry["title"].as_str() {
                    Some(t) => crate::progress::target("", &json!({ "path": t })),
                    None => crate::progress::target(tool, &entry["arguments"]),
                },
                decision: entry["decision"].as_str().unwrap_or_default().to_owned(),
                ok: entry["ok"].as_bool(),
                tail: Vec::new(),
            });
        }
    }

    fn record(&self, mut entry: Value) {
        entry["via"] = json!("acp");
        // An action the agent takes itself: said so.
        if entry["object"]["kind"] == "agent" {
            entry["executed_by"] = json!("agent");
            entry["sandboxed"] = json!(false);
        }
        // What the agent sent is kept masked, and cut.
        cap(&mut entry);
        crate::secrets::mask_json(&mut entry);
        let Ok(mut s) = self.state.lock() else { return };
        // A permission request's decisions are said once, as one line.
        match &s.request {
            Some(id) => entry["request"] = json!(id),
            None => self.emit(&entry),
        }
        s.log.push(entry);
    }
}

/// What a person sees of a call no rule covers (masked, long values cut).
fn call_args(call: &ToolRequest) -> Value {
    let mut raw = call.raw_input.clone().unwrap_or(Value::Null);
    cap(&mut raw);
    let mut v = json!({
        "title": call.shown_title(),
        "kind": call.kind,
        "rawInput": raw,
        "locations": call.locations,
    });
    crate::secrets::mask_json(&mut v);
    v
}

/// The most of one string of an agent's reported input that is kept.
const KEPT: usize = 4096;

/// Cuts every string of `v` to [`KEPT`] bytes (a file's whole content is
/// not the report's to keep).
fn cap(v: &mut Value) {
    match v {
        Value::String(s) if s.len() > KEPT => {
            let mut at = KEPT;
            while !s.is_char_boundary(at) {
                at -= 1;
            }
            let n = s.len();
            s.truncate(at);
            s.push_str(&format!("… [{n} bytes]"));
        }
        Value::Array(a) => a.iter_mut().for_each(cap),
        Value::Object(o) => o.values_mut().for_each(cap),
        _ => {}
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    /// A worktree with a file, credentials, a copied file, a hard link and
    /// symlinks out of it.
    struct Tree {
        _d: tempfile::TempDir,
        _o: tempfile::TempDir,
        root: PathBuf,
        out: PathBuf,
    }

    fn tree() -> Tree {
        let d = tempfile::tempdir().unwrap_or_else(|e| panic!("{e}"));
        let o = tempfile::tempdir().unwrap_or_else(|e| panic!("{e}"));
        let root = std::fs::canonicalize(d.path()).unwrap_or_else(|e| panic!("{e}"));
        let out = std::fs::canonicalize(o.path()).unwrap_or_else(|e| panic!("{e}"));
        let w = |p: &str, t: &str| std::fs::write(root.join(p), t).unwrap_or_default();
        std::fs::create_dir_all(root.join("src")).unwrap_or_default();
        w("src/lib.rs", "x\n");
        w(".env", "TOKEN=abc\n");
        w("settings.local", "TOKEN=abc\n");
        w(".git-credentials", "https://u:p@example.com\n");
        w("terraform.tfstate", "{}\n");
        std::fs::write(out.join("credentials"), "secret\n").unwrap_or_default();
        std::fs::hard_link(out.join("credentials"), root.join("hard.txt")).unwrap_or_default();
        std::os::unix::fs::symlink(out.join("credentials"), root.join("notes.txt"))
            .unwrap_or_default();
        std::os::unix::fs::symlink(&out, root.join("docs")).unwrap_or_default();
        let _ = std::process::Command::new("git")
            .args(["init", "-q"])
            .current_dir(&root)
            .output();
        Tree {
            _d: d,
            _o: o,
            root,
            out,
        }
    }

    fn governor_with(root: &Path, run_approved: Vec<Object>) -> Governor {
        let argv = |s: &str| s.split(' ').map(str::to_owned).collect::<Vec<_>>();
        let policy = Policy::new(
            &[argv("cargo test"), argv("git diff")],
            &[argv("make deploy")],
        );
        let tools = WorkspaceTools::new(root, policy.clone()).unwrap_or_else(|e| panic!("{e}"));
        Governor::new(Setup {
            root: root.to_path_buf(),
            tools,
            policy,
            approver: None,
            present: PresentContext::default(),
            task: "f/T1".to_owned(),
            task_title: "t".to_owned(),
            run: None,
            frozen_additions: false,
            run_approved,
            approved_once: Vec::new(),
            progress: None,
            copied: vec!["settings.local".to_owned()],
            agent: "copilot".to_owned(),
        })
    }

    const OPTIONS: [(&str, &str); 2] = [("allow", "allow_once"), ("reject", "reject_once")];

    fn options() -> Vec<PermissionOption> {
        OPTIONS
            .iter()
            .map(|(id, kind)| PermissionOption {
                id: (*id).to_owned(),
                kind: (*kind).to_owned(),
            })
            .collect()
    }

    fn call(kind: &str, raw: Value, locations: Vec<PathBuf>) -> ToolRequest {
        ToolRequest {
            id: "c1".to_owned(),
            title: Some("Read file".to_owned()),
            kind: Some(kind.to_owned()),
            raw_input: Some(raw),
            locations,
            status: None,
        }
    }

    /// What the agent is answered for one request, by a fresh governor:
    /// `allow`, `reject`, or `None` (a person's, nobody to ask).
    fn answer(t: &Tree, kind: &str, raw: Value, locations: Vec<PathBuf>) -> Option<String> {
        governor_with(&t.root, Vec::new()).permission(&call(kind, raw, locations), &options())
    }

    fn allow() -> Option<String> {
        Some("allow".to_owned())
    }

    /// The person's "reads for this task", as a grant.
    fn reads(t: &Tree) -> Governor {
        let g = governor_with(&t.root, Vec::new());
        let r = g.reads_object();
        governor_with(&t.root, vec![r])
    }

    const PLAIN_READS: [(&str, &str); 5] = [
        ("execute", r#"{ "command": "cat src/lib.rs" }"#),
        ("execute", r#"{ "command": "cat\tsrc/lib.rs" }"#),
        ("execute", r#"{ "command": "head -n 5 src/lib.rs" }"#),
        (
            "execute",
            r#"{ "command": ["/bin/zsh", "-lc", "cat src/lib.rs"] }"#,
        ),
        ("read", r#"{ "path": "src/lib.rs", "line": 1, "limit": 5 }"#),
    ];

    #[test]
    fn nothing_the_agent_does_itself_is_allowed_without_a_person() {
        let t = tree();
        for (kind, raw) in PLAIN_READS {
            let raw: Value = serde_json::from_str(raw).unwrap_or_default();
            assert_eq!(answer(&t, kind, raw.clone(), vec![]), None, "{raw}");
        }
    }

    #[test]
    fn a_persons_reads_for_the_task_cover_plain_reads_of_plain_files_only() {
        let t = tree();
        for (kind, raw) in PLAIN_READS {
            let raw: Value = serde_json::from_str(raw).unwrap_or_default();
            assert_eq!(
                reads(&t).permission(&call(kind, raw.clone(), vec![]), &options()),
                allow(),
                "{raw}"
            );
        }
        let w = |p: &str, text: &str| {
            if let Some(dir) = Path::new(p).parent() {
                std::fs::create_dir_all(t.root.join(dir)).unwrap_or_default();
            }
            std::fs::write(t.root.join(p), text).unwrap_or_default();
        };
        w("deploy_key", "-----BEGIN OPENSSH PRIVATE KEY-----\nabc\n");
        w(
            "notes/key.pem.txt",
            "-----BEGIN RSA PRIVATE KEY-----\nabc\n",
        );
        w("config.ini", "password: hunter2hunter2\n");
        w(
            ".git/config",
            "[remote]\nurl = https://user:pass@example.com/r.git\n",
        );
        w(
            "conf/remote.txt",
            "url = https://user:pass@example.com/r.git\n",
        );
        w("secrets.yaml", "x: 1\n");
        w(".htpasswd", "admin:$apr1$abc$def\n");
        w("token.txt", "abcdefabcdefabcdef\n");
        w("ci.txt", "GH=ghp_ABCDEFGHIJKLMNOPQRSTUVWXYZ012345\n");
        w(".speccoder/x", "x\n");
        for file in [
            "deploy_key",
            "notes/key.pem.txt",
            "config.ini",
            ".git/config",
            "conf/remote.txt",
            "secrets.yaml",
            ".htpasswd",
            "token.txt",
            "ci.txt",
            ".speccoder/x",
            "settings.local",
            "hard.txt",
            "terraform.tfstate",
        ] {
            let raw = json!({ "command": format!("cat {file}") });
            assert_ne!(
                reads(&t).permission(&call("execute", raw, vec![]), &options()),
                allow(),
                "{file}"
            );
        }
        // A command in a request of another kind never takes the read path,
        // nor an execute with more than a plain read needs.
        for (kind, raw) in [
            ("edit", json!({ "command": "cat src/lib.rs" })),
            ("delete", json!({ "command": "cat src/lib.rs" })),
            ("move", json!({ "command": "cat src/lib.rs" })),
            ("other", json!({ "command": "cat src/lib.rs" })),
            ("think", json!({ "command": "cat src/lib.rs" })),
            (
                "switch_mode",
                json!({ "command": "cat src/lib.rs", "mode": "bypassPermissions" }),
            ),
            ("fetch", json!({ "command": "cat src/lib.rs" })),
            ("read", json!({ "command": "cat src/lib.rs" })),
            (
                "execute",
                json!({ "command": "cat lib.rs", "working_directory": "src" }),
            ),
            (
                "execute",
                json!({ "command": "cat src/lib.rs", "env": { "LD_PRELOAD": "x" } }),
            ),
            (
                "execute",
                json!({ "command": "cat src/lib.rs", "stdin": "x" }),
            ),
        ] {
            assert_ne!(
                reads(&t).permission(&call(kind, raw.clone(), vec![]), &options()),
                allow(),
                "{kind} {raw}"
            );
        }
    }

    /// A person who answers from a list, then no.
    #[derive(Debug)]
    struct Answers(Mutex<Vec<Answer>>);

    impl Approver for Answers {
        fn ask(&self, _: &crate::approvals::Presentation) -> Answer {
            let mut a = self
                .0
                .lock()
                .unwrap_or_else(std::sync::PoisonError::into_inner);
            if a.is_empty() {
                Answer::reject("no", None)
            } else {
                a.remove(0)
            }
        }
    }

    #[test]
    fn for_this_task_covers_exactly_that_request_again() {
        let t = tree();
        for (granted, same, other) in [
            (
                json!({ "command": "make a && make b" }),
                json!({ "command": "make a && make b" }),
                json!({ "command": "make a; make b" }),
            ),
            (
                json!({ "command": "make" }),
                json!({ "command": "make" }),
                json!({ "command": "make", "cwd": "src" }),
            ),
            (
                json!({ "command": "make" }),
                json!({ "command": "make" }),
                json!({ "command": "make", "env": { "A": "1" } }),
            ),
            (
                json!({ "path": "src/a", "destination": "src/b" }),
                json!({ "path": "src/a", "destination": "src/b" }),
                json!({ "path": "src/b", "destination": "src/a" }),
            ),
            (
                json!({ "file_path": "src/lib.rs", "content": "a" }),
                json!({ "file_path": "src/lib.rs", "content": "a" }),
                json!({ "file_path": "src/lib.rs", "content": "b" }),
            ),
        ] {
            let kind = if granted.get("command").is_some() {
                "execute"
            } else if granted.get("destination").is_some() {
                "move"
            } else {
                "edit"
            };
            let mut g = governor_with(&t.root, Vec::new());
            g.approver = Some(Arc::new(Answers(Mutex::new(vec![Answer::approve(
                Scope::Task,
                None,
                None,
            )]))));
            assert_eq!(
                g.permission(&call(kind, granted.clone(), vec![]), &options()),
                allow()
            );
            assert_eq!(
                g.permission(&call(kind, same, vec![]), &options()),
                allow(),
                "{granted}"
            );
            assert_eq!(
                g.permission(&call(kind, other.clone(), vec![]), &options()),
                Some("reject".to_owned()),
                "{other}"
            );
        }
    }

    #[test]
    fn a_request_naming_anything_outside_or_a_credential_is_refused() {
        let t = tree();
        let src = || vec![PathBuf::from("src/lib.rs")];
        let refused = Some("reject".to_owned());
        for (kind, raw, loc) in [
            ("read", json!({ "path": t.out.join("credentials") }), src()),
            (
                "edit",
                json!({ "file_path": t.out.join("x"), "content": "x" }),
                src(),
            ),
            (
                "move",
                json!({ "path": "src/lib.rs", "destination": t.out.join("lib.rs") }),
                vec![],
            ),
            (
                "edit",
                json!({ "edits": [{ "path": t.out.join("x"), "new_string": "x" }] }),
                src(),
            ),
            (
                "edit",
                json!({ "command": "ls", "file_path": t.out.join("x") }),
                vec![],
            ),
            ("edit", json!({ "file_path": "notes.txt" }), vec![]),
            ("read", json!({ "path": "notes.txt" }), vec![]),
            ("execute", json!({ "command": "cat notes.txt" }), vec![]),
            ("execute", json!({ "command": "cat .env" }), vec![]),
            ("execute", json!({ "command": "cat .ENV" }), vec![]),
            (
                "execute",
                json!({ "command": "cat src/lib.rs", "cwd": t.out }),
                vec![],
            ),
        ] {
            assert_eq!(answer(&t, kind, raw.clone(), loc), refused, "{kind} {raw}");
        }
    }

    #[test]
    fn a_grant_of_speccoders_own_calls_never_covers_the_agents_and_back() {
        let t = tree();
        // `make deploy` granted for the run, as a sandboxed command.
        let tools =
            WorkspaceTools::new(&t.root, Policy::default()).unwrap_or_else(|e| panic!("{e}"));
        let native: Object = serde_json::from_value(
            tools.resolve("run_command", &json!({ "argv": ["make", "deploy"] }))["object"].clone(),
        )
        .unwrap_or_else(|e| panic!("{e}"));
        let g = governor_with(&t.root, vec![native]);
        assert_eq!(
            g.permission(
                &call("execute", json!({ "command": "make deploy" }), vec![]),
                &options()
            ),
            None
        );
        // The agent's own action, granted by a person for the task: it
        // never lets speccoder's terminal run that command.
        let mut g = governor_with(&t.root, Vec::new());
        g.approver = Some(Arc::new(Answers(Mutex::new(vec![Answer::approve(
            Scope::Task,
            None,
            None,
        )]))));
        let lint = call("execute", json!({ "command": "make lint" }), vec![]);
        assert_eq!(g.permission(&lint, &options()), allow());
        assert_eq!(g.permission(&lint, &options()), allow());
        assert!(
            g.command(vec!["make".to_owned(), "lint".to_owned()], None)
                .is_err()
        );
    }

    #[test]
    fn a_refused_or_unasked_change_the_agent_made_counts_as_deciding_alone() {
        let t = tree();
        let g = governor_with(&t.root, Vec::new());
        let mut refused = call(
            "edit",
            json!({ "file_path": t.out.join("x"), "content": "x" }),
            vec![],
        );
        refused.id = "d1".to_owned();
        assert_eq!(
            g.permission(&refused, &options()),
            Some("reject".to_owned())
        );
        refused.status = Some("completed".to_owned());
        g.reported(&refused);
        let mut other = call("other", json!({ "command": "rm -rf x" }), vec![]);
        other.id = "u1".to_owned();
        other.status = Some("completed".to_owned());
        g.reported(&other);
        let mut failed = call("execute", json!({ "command": "rm -rf x" }), vec![]);
        failed.id = "u2".to_owned();
        failed.status = Some("failed".to_owned());
        g.reported(&failed);
        assert_eq!(g.unasked(), 3);
        // An allowed read is no such change, nor a refused one that failed.
        let g = reads(&t);
        let mut read = call("read", json!({ "path": "src/lib.rs" }), vec![]);
        read.id = "r1".to_owned();
        assert_eq!(g.permission(&read, &options()), allow());
        read.status = Some("completed".to_owned());
        g.reported(&read);
        refused.id = "d2".to_owned();
        refused.status = None;
        let _ = g.permission(&refused, &options());
        refused.status = Some("failed".to_owned());
        g.reported(&refused);
        assert_eq!(g.unasked(), 0);
    }

    /// A person who says yes — while the attempt ends meanwhile.
    #[derive(Debug)]
    struct YesTooLate(Arc<std::sync::OnceLock<Arc<Governor>>>);

    impl Approver for YesTooLate {
        fn ask(&self, _: &crate::approvals::Presentation) -> Answer {
            if let Some(g) = self.0.get() {
                g.stop();
            }
            Answer::approve(Scope::Task, None, None)
        }
    }

    #[test]
    fn a_yes_after_the_attempt_ended_allows_nothing() {
        let t = tree();
        let cell = Arc::new(std::sync::OnceLock::new());
        let mut g = governor_with(&t.root, Vec::new());
        g.approver = Some(Arc::new(YesTooLate(Arc::clone(&cell))));
        let g = Arc::new(g);
        let _ = cell.set(Arc::clone(&g));
        let c = call("execute", json!({ "command": "make lint" }), vec![]);
        assert_eq!(g.permission(&c, &options()), Some("reject".to_owned()));
    }

    #[test]
    fn what_the_governor_records_is_masked_and_cut() {
        let t = tree();
        crate::secrets::register("GOV_TOKEN", "tok-Zx81-secret-value-gov");
        let g = governor_with(&t.root, Vec::new());
        let big = format!("tok-Zx81-secret-value-gov{}", "x".repeat(10_000));
        let mut c = call(
            "edit",
            json!({ "file_path": "src/lib.rs", "content": big }),
            vec![],
        );
        c.title = Some("Write tok-Zx81-secret-value-gov".to_owned());
        let _ = g.permission(&c, &options());
        let log = serde_json::to_string(&g.log()).unwrap_or_default();
        assert!(!log.contains("tok-Zx81-secret-value-gov"), "{log}");
        assert!(log.len() < 9000, "{}", log.len());
    }

    #[test]
    fn a_plain_command_is_split_and_a_shell_line_is_left_to_sh() {
        assert_eq!(
            argv_of_line("cargo test -p core"),
            ["cargo", "test", "-p", "core"]
        );
        assert_eq!(argv_of_line("ls | grep x"), ["sh", "-c", "ls | grep x"]);
        assert_eq!(
            argv_of_line("git commit -m \"x\""),
            ["sh", "-c", "git commit -m \"x\""]
        );
        assert_eq!(argv_of_line("A=1 make"), ["sh", "-c", "A=1 make"]);
        assert_eq!(
            commands_of_line("cat src/lib.rs; ls && cargo test"),
            Some(vec![
                vec!["cat".to_owned(), "src/lib.rs".to_owned()],
                vec!["ls".to_owned()],
                vec!["cargo".to_owned(), "test".to_owned()],
            ])
        );
        assert_eq!(commands_of_line("cat a | grep b"), None);
        assert_eq!(commands_of_line("echo $(id)"), None);
    }
}