openlatch-client 0.1.6

pub mod heal;
pub mod request;

use std::path::{Path, PathBuf};

use tokio::sync::mpsc;

use crate::cloud::tamper::{FieldDelta, TamperCloudEventKind, TamperEvent};
use crate::cloud::CloudEvent;
use crate::core::hook_state::diff::diff_entry_fields;
use crate::core::hook_state::hmac::verify_entry_hmac;
use crate::core::hook_state::key::HmacKeyStore;
use crate::core::hook_state::marker::{classify_marker, MarkerShape};
use crate::core::hook_state::{hash_settings_path, HookStateFile, StateEntry};
use crate::core::logging::tamper_log::TamperLogger;
use crate::core::telemetry::{self, Event};
use crate::hooks::jsonc;

use heal::HealManager;
use request::ReconcileRequest;

/// The canonical agent type string for the current build. Kept as a constant
/// so detection events and heal events always agree on wire format.
const AGENT_TYPE: &str = "claude-code";

/// The OS string stamped on tamper CloudEvents. Matches the same vocabulary
/// used for hook CloudEvents (`linux` / `macos` / `windows`) so the platform
/// can aggregate across both channels.
fn current_os() -> &'static str {
    if cfg!(target_os = "macos") {
        "macos"
    } else if cfg!(target_os = "windows") {
        "windows"
    } else {
        "linux"
    }
}

/// Shared sinks the reconciler uses to publish tamper-detection events.
///
/// Grouped into a single struct so construction sites can pass `None` when
/// running outside a full daemon (e.g. `run_startup_reconcile`). Each field
/// is independently optional: telemetry may be off while local JSONL and
/// cloud forwarding are on, etc.
#[derive(Clone, Default)]
pub struct TamperSinks {
    pub logger: Option<TamperLogger>,
    pub cloud_tx: Option<mpsc::Sender<CloudEvent>>,
    pub agent_id: String,
    pub client_version: String,
}

/// Result of checking a single tracked hook entry against its recorded
/// HMAC. The `Drifted` variant names *why* so callers can route, heal, and
/// report without re-deriving the reason.
#[derive(Debug, Clone)]
enum DriftOutcome {
    Healthy,
    Drifted {
        method: &'static str,
        deltas: Vec<FieldDelta>,
    },
}

pub struct Reconciler {
    rx: mpsc::Receiver<ReconcileRequest>,
    settings_path: PathBuf,
    openlatch_dir: PathBuf,
    port: u16,
    token_file_path: PathBuf,
    heal_manager: HealManager,
    sinks: TamperSinks,
}

impl Reconciler {
    pub fn new(
        rx: mpsc::Receiver<ReconcileRequest>,
        settings_path: PathBuf,
        openlatch_dir: PathBuf,
        port: u16,
        token_file_path: PathBuf,
    ) -> Self {
        Self::new_with_sinks(
            rx,
            settings_path,
            openlatch_dir,
            port,
            token_file_path,
            TamperSinks::default(),
        )
    }

    pub fn new_with_sinks(
        rx: mpsc::Receiver<ReconcileRequest>,
        settings_path: PathBuf,
        openlatch_dir: PathBuf,
        port: u16,
        token_file_path: PathBuf,
        sinks: TamperSinks,
    ) -> Self {
        Self {
            rx,
            settings_path,
            openlatch_dir,
            port,
            token_file_path,
            heal_manager: HealManager::new(),
            sinks,
        }
    }

    pub async fn run(mut self) {
        tracing::info!("reconciler started");

        while let Some(req) = self.rx.recv().await {
            match req {
                ReconcileRequest::Shutdown => {
                    tracing::info!("reconciler shutting down");
                    break;
                }
                ReconcileRequest::Fs | ReconcileRequest::Poll => {
                    self.reconcile().await;
                }
            }
        }
    }

    pub fn reconcile_sync(&mut self) {
        let rt = tokio::runtime::Handle::try_current();
        if rt.is_ok() {
            self.do_reconcile();
        }
    }

    async fn reconcile(&mut self) {
        self.do_reconcile();
    }

    fn do_reconcile(&mut self) {
        let raw = match std::fs::read_to_string(&self.settings_path) {
            Ok(c) => c,
            Err(e) => {
                tracing::debug!(error = %e, "reconciler: cannot read settings.json");
                return;
            }
        };

        let state = match HookStateFile::load(&self.openlatch_dir) {
            Ok(Some(s)) => s,
            Ok(None) => {
                tracing::debug!("reconciler: no state file yet, skipping verification");
                return;
            }
            Err(e) => {
                tracing::warn!(error = %e, "reconciler: cannot load state file");
                return;
            }
        };

        let hmac_key = match HmacKeyStore::new(&self.openlatch_dir).load_or_create() {
            Ok(k) => k,
            Err(e) => {
                tracing::warn!(error = %e, "reconciler: cannot load HMAC key");
                return;
            }
        };

        let parsed = match jsonc::parse_settings_value(&raw) {
            Ok(v) => v,
            Err(e) => {
                tracing::warn!(error = %e, "reconciler: cannot parse settings.json");
                return;
            }
        };

        let hooks_obj = match parsed.get("hooks").and_then(|h| h.as_object()) {
            Some(h) => h,
            None => {
                if !state.entries.is_empty() {
                    tracing::warn!(
                        "reconciler: hooks object missing from settings.json — will heal"
                    );
                    let _ = self.try_heal();
                }
                return;
            }
        };

        let settings_path_hash = hash_settings_path(&self.settings_path);

        // Phase 1: detect and emit tamper_detected events. Hold onto them so
        // the healed follow-up can carry matching metadata + related_event_id.
        let mut pending_detections: Vec<(StateEntry, TamperEvent)> = Vec::new();
        let mut drift_results: Vec<(String, bool)> = Vec::new();

        for state_entry in &state.entries {
            if self.heal_manager.tracker(&state_entry.id).is_circuit_open() {
                drift_results.push((state_entry.id.clone(), false));
                continue;
            }

            let outcome = check_entry_drift(
                &state_entry.hook_event,
                &state_entry.id,
                hooks_obj,
                &hmac_key,
                self.port,
            );

            let drifted = matches!(outcome, DriftOutcome::Drifted { .. });
            drift_results.push((state_entry.id.clone(), drifted));

            if let DriftOutcome::Drifted { method, deltas } = outcome {
                let event = TamperEvent::new(
                    state_entry.id.clone(),
                    AGENT_TYPE.to_string(),
                    settings_path_hash.clone(),
                    state_entry.hook_event.clone(),
                    method.to_string(),
                )
                .with_field_deltas(deltas);

                self.publish_detected(&event);
                pending_detections.push((state_entry.clone(), event));
            }
        }

        // Phase 2: heal and emit tamper_healed events per pending detection.
        let mut any_drift = false;
        for (entry_id, drifted) in &drift_results {
            let tracker = self.heal_manager.tracker(entry_id);
            if *drifted {
                tracker.mark_drifted();
                any_drift = true;
            } else {
                tracker.mark_healthy();
            }
        }

        if any_drift {
            for (entry_id, _) in &drift_results {
                let tracker = self.heal_manager.tracker(entry_id);
                if tracker.should_heal() {
                    tracker.record_heal_attempt();
                }
            }

            let heal_ok = self.try_heal().is_ok();

            for (entry_id, _) in &drift_results {
                let tracker = self.heal_manager.tracker(entry_id);
                if matches!(tracker.state, heal::HealState::Healing) {
                    if heal_ok {
                        tracker.record_heal_success();
                    } else {
                        tracker.record_heal_failure();
                    }
                }
            }

            for (state_entry, detected) in &pending_detections {
                let tracker = self.heal_manager.tracker(&state_entry.id);
                let (outcome_str, circuit_str) = heal_outcome_strings(tracker, heal_ok);
                let healed =
                    TamperEvent::new_healed(detected, outcome_str, tracker.attempt, circuit_str);
                self.publish_healed(&state_entry.hook_event, &healed);
            }
        }
    }

    fn publish_detected(&self, event: &TamperEvent) {
        if let Some(logger) = &self.sinks.logger {
            logger.log(event.clone());
        }
        if let Some(tx) = &self.sinks.cloud_tx {
            let ce = event.to_cloud_event(
                &self.sinks.agent_id,
                &self.sinks.client_version,
                current_os(),
                TamperCloudEventKind::Detected,
            );
            let _ = tx.try_send(ce);
        }
        telemetry::capture_global(Event::tamper_detected(
            &event.tamper.detection_method,
            &event.tamper.agent_type,
        ));
    }

    fn publish_healed(&self, _hook_event: &str, event: &TamperEvent) {
        if let Some(logger) = &self.sinks.logger {
            logger.log(event.clone());
        }
        if let Some(tx) = &self.sinks.cloud_tx {
            let ce = event.to_cloud_event(
                &self.sinks.agent_id,
                &self.sinks.client_version,
                current_os(),
                TamperCloudEventKind::Healed,
            );
            let _ = tx.try_send(ce);
        }
        telemetry::capture_global(Event::tamper_healed(
            &event.tamper.detection_method,
            &event.tamper.agent_type,
            &event.tamper.heal.outcome,
            event.tamper.heal.attempt,
        ));
    }

    fn try_heal(&self) -> Result<(), ()> {
        let token = match std::fs::read_to_string(&self.token_file_path) {
            Ok(t) => t.trim().to_string(),
            Err(e) => {
                tracing::warn!(error = %e, "reconciler: cannot read daemon token for heal");
                return Err(());
            }
        };

        match crate::hooks::detect_agent() {
            Ok(agent) => match crate::hooks::install_hooks(&agent, self.port, &token) {
                Ok(result) => {
                    tracing::warn!(
                        hooks_reinstalled = result.entries.len(),
                        "reconciler: hooks healed via reinstall"
                    );
                    Ok(())
                }
                Err(e) => {
                    tracing::warn!(error = %e, "reconciler: heal failed");
                    Err(())
                }
            },
            Err(e) => {
                tracing::debug!(error = %e, "reconciler: cannot detect agent for heal");
                Err(())
            }
        }
    }

    pub fn open_circuits(&self) -> Vec<&str> {
        self.heal_manager.open_circuits()
    }
}

/// Translate a per-entry heal tracker state into the `outcome` + `circuit`
/// strings that appear in the OCSF `HealOutcome`. Kept as a free function
/// so the reconciler body stays readable and so unit tests can cover the
/// mapping in isolation.
fn heal_outcome_strings(
    tracker: &heal::EntryHealTracker,
    heal_ok: bool,
) -> (&'static str, &'static str) {
    use heal::HealState;
    match tracker.state {
        HealState::CircuitOpen { .. } => ("circuit_open", "open"),
        HealState::Healthy => (if heal_ok { "succeeded" } else { "failed" }, "closed"),
        HealState::Backoff { .. } | HealState::Drifted | HealState::Healing => {
            if heal_ok {
                ("succeeded", "closed")
            } else {
                ("failed", "closed")
            }
        }
    }
}

fn check_entry_drift(
    hook_event: &str,
    entry_id: &str,
    hooks_obj: &serde_json::Map<String, serde_json::Value>,
    hmac_key: &[u8],
    port: u16,
) -> DriftOutcome {
    let event_arr = match hooks_obj.get(hook_event).and_then(|a| a.as_array()) {
        Some(a) => a,
        None => {
            tracing::warn!(
                hook_event = %hook_event,
                detection_method = "entry_deleted",
                "reconciler: hook event array missing"
            );
            return DriftOutcome::Drifted {
                method: "entry_deleted",
                deltas: Vec::new(),
            };
        }
    };

    let openlatch_entry = event_arr.iter().find(|entry| {
        matches!(
            classify_marker(entry),
            MarkerShape::Legacy | MarkerShape::Current(_)
        )
    });

    match openlatch_entry {
        None => {
            tracing::warn!(
                hook_event = %hook_event,
                detection_method = "marker_missing",
                "reconciler: openlatch entry missing from hook array"
            );
            DriftOutcome::Drifted {
                method: "marker_missing",
                deltas: Vec::new(),
            }
        }
        Some(entry) => match classify_marker(entry) {
            MarkerShape::Legacy => {
                tracing::info!(
                    code = crate::error::ERR_LEGACY_MARKER_DETECTED,
                    hook_event = %hook_event,
                    detection_method = "legacy_marker_upgrade",
                    "reconciler: legacy boolean marker found — upgrading"
                );
                DriftOutcome::Drifted {
                    method: "legacy_marker_upgrade",
                    deltas: Vec::new(),
                }
            }
            MarkerShape::Current(ref marker) => {
                let hmac = match &marker.hmac {
                    Some(h) => h,
                    None => {
                        return DriftOutcome::Drifted {
                            method: "marker_missing",
                            deltas: Vec::new(),
                        };
                    }
                };
                match verify_entry_hmac(entry, hmac, hmac_key) {
                    Ok(true) => DriftOutcome::Healthy,
                    Ok(false) => {
                        tracing::warn!(
                            hook_event = %hook_event,
                            entry_id = %entry_id,
                            detection_method = "hmac_mismatch",
                            "reconciler: HMAC verification failed — entry tampered"
                        );
                        let deltas = compute_field_deltas(hook_event, port, marker, entry);
                        DriftOutcome::Drifted {
                            method: "hmac_mismatch",
                            deltas,
                        }
                    }
                    Err(_) => DriftOutcome::Drifted {
                        method: "hmac_mismatch",
                        deltas: Vec::new(),
                    },
                }
            }
            MarkerShape::Missing => DriftOutcome::Drifted {
                method: "marker_missing",
                deltas: Vec::new(),
            },
        },
    }
}

/// Rebuild the expected hook entry using the same install-time builder and
/// diff it against the observed entry. Emits field paths only; any failure
/// falls through to an empty delta vec so the detection event still fires.
fn compute_field_deltas(
    hook_event: &str,
    port: u16,
    marker: &crate::core::hook_state::marker::OpenlatchMarker,
    observed: &serde_json::Value,
) -> Vec<FieldDelta> {
    const TOKEN_ENV_VAR: &str = "OPENLATCH_TOKEN";
    let hook_bin = crate::hooks::resolve_hook_binary_path();
    let mut expected = crate::hooks::claude_code::build_hook_entry(
        hook_event,
        port,
        TOKEN_ENV_VAR,
        &hook_bin,
        marker,
    );

    // build_hook_entry does not embed the marker itself — it's added separately
    // by install_hooks. We inject the same marker here so the non-marker fields
    // (hooks, matcher, timeout) are what the diff focuses on.
    if let Ok(marker_value) = serde_json::to_value(marker) {
        expected["_openlatch"] = marker_value;
    }

    diff_entry_fields(&expected, observed)
}

pub fn run_startup_reconcile(settings_path: &Path, openlatch_dir: &Path, port: u16) {
    let token_file = openlatch_dir.join("daemon.token");
    let mut r = Reconciler {
        rx: mpsc::channel(1).1,
        settings_path: settings_path.to_path_buf(),
        openlatch_dir: openlatch_dir.to_path_buf(),
        port,
        token_file_path: token_file,
        heal_manager: HealManager::new(),
        sinks: TamperSinks::default(),
    };
    r.do_reconcile();
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::core::hook_state::hmac::compute_entry_hmac;
    use crate::core::hook_state::marker::OpenlatchMarker;
    use heal::{EntryHealTracker, HealState};

    #[test]
    fn heal_outcome_strings_when_healthy_and_ok() {
        let t = EntryHealTracker::new();
        assert_eq!(heal_outcome_strings(&t, true), ("succeeded", "closed"));
    }

    #[test]
    fn heal_outcome_strings_when_failed() {
        let mut t = EntryHealTracker::new();
        t.mark_drifted();
        t.record_heal_attempt();
        t.record_heal_failure();
        let (outcome, circuit) = heal_outcome_strings(&t, false);
        assert_eq!(outcome, "failed");
        assert_eq!(circuit, "closed");
    }

    #[test]
    fn heal_outcome_strings_when_circuit_open() {
        let mut t = EntryHealTracker::new();
        for _ in 0..5 {
            t.mark_drifted();
            t.record_heal_attempt();
            t.record_heal_success();
            t.mark_drifted();
        }
        assert!(matches!(t.state, HealState::CircuitOpen { .. }));
        assert_eq!(heal_outcome_strings(&t, false), ("circuit_open", "open"));
    }

    #[test]
    fn current_os_returns_a_known_string() {
        let os = current_os();
        assert!(matches!(os, "linux" | "macos" | "windows"));
    }

    /// Construct a well-formed hook entry with a computed HMAC, using a
    /// fixed test key. Mirrors the shape `install_hooks` produces.
    fn make_signed_entry(hook_event: &str, entry_id: &str, key: &[u8]) -> serde_json::Value {
        let marker_no_hmac = OpenlatchMarker::new(entry_id.to_string());
        let mut entry = crate::hooks::claude_code::build_hook_entry(
            hook_event,
            7443,
            "OPENLATCH_TOKEN",
            std::path::Path::new("/opt/openlatch/bin/openlatch-hook"),
            &marker_no_hmac,
        );
        entry["_openlatch"] = serde_json::to_value(&marker_no_hmac).unwrap();
        let hmac = compute_entry_hmac(&entry, key).unwrap();
        let marker = marker_no_hmac.with_hmac(hmac);
        entry["_openlatch"] = serde_json::to_value(&marker).unwrap();
        entry
    }

    fn build_hooks_obj(hook_event: &str, entry: serde_json::Value) -> serde_json::Value {
        serde_json::json!({ hook_event: [entry] })
    }

    #[test]
    fn check_entry_drift_healthy_when_hmac_matches() {
        let key = vec![0x42; 32];
        let entry = make_signed_entry("PreToolUse", "entry-a", &key);
        let hooks = build_hooks_obj("PreToolUse", entry);
        let outcome = check_entry_drift(
            "PreToolUse",
            "entry-a",
            hooks.as_object().unwrap(),
            &key,
            7443,
        );
        assert!(matches!(outcome, DriftOutcome::Healthy));
    }

    #[test]
    fn check_entry_drift_hmac_mismatch_populates_deltas() {
        let key = vec![0x42; 32];
        let mut entry = make_signed_entry("PreToolUse", "entry-a", &key);
        // Tamper a non-marker field — the HMAC is computed over the
        // pre-tamper value, so verification must fail.
        entry["timeout"] = serde_json::json!(999);
        let hooks = build_hooks_obj("PreToolUse", entry);
        let outcome = check_entry_drift(
            "PreToolUse",
            "entry-a",
            hooks.as_object().unwrap(),
            &key,
            7443,
        );
        match outcome {
            DriftOutcome::Drifted { method, deltas } => {
                assert_eq!(method, "hmac_mismatch");
                assert!(
                    deltas.iter().any(|d| d.field == "timeout"),
                    "expected timeout delta, got {deltas:?}"
                );
            }
            _ => panic!("expected Drifted, got {outcome:?}"),
        }
    }

    #[test]
    fn check_entry_drift_reports_entry_deleted_when_event_array_missing() {
        let key = vec![0x42; 32];
        let hooks = serde_json::json!({});
        let outcome = check_entry_drift(
            "PreToolUse",
            "entry-a",
            hooks.as_object().unwrap(),
            &key,
            7443,
        );
        match outcome {
            DriftOutcome::Drifted { method, deltas } => {
                assert_eq!(method, "entry_deleted");
                assert!(deltas.is_empty());
            }
            _ => panic!("expected Drifted"),
        }
    }

    #[test]
    fn check_entry_drift_reports_marker_missing_when_entry_absent() {
        let key = vec![0x42; 32];
        // Event array present but no entry has an _openlatch marker.
        let hooks = serde_json::json!({
            "PreToolUse": [{"matcher": "", "hooks": [{"type": "command", "command": "other"}]}]
        });
        let outcome = check_entry_drift(
            "PreToolUse",
            "entry-a",
            hooks.as_object().unwrap(),
            &key,
            7443,
        );
        match outcome {
            DriftOutcome::Drifted { method, .. } => assert_eq!(method, "marker_missing"),
            _ => panic!("expected Drifted"),
        }
    }

    #[test]
    fn check_entry_drift_reports_legacy_marker_upgrade() {
        let key = vec![0x42; 32];
        let hooks = serde_json::json!({
            "PreToolUse": [{"_openlatch": true, "matcher": "", "hooks": []}]
        });
        let outcome = check_entry_drift(
            "PreToolUse",
            "entry-a",
            hooks.as_object().unwrap(),
            &key,
            7443,
        );
        match outcome {
            DriftOutcome::Drifted { method, .. } => assert_eq!(method, "legacy_marker_upgrade"),
            _ => panic!("expected Drifted"),
        }
    }

    #[tokio::test]
    async fn publish_detected_fans_out_to_cloud_tx() {
        // Construct a reconciler in its loneliest possible form — no watcher,
        // no poll, no heal manager activity. The only thing we exercise is
        // the sink dispatch.
        let (_in_tx, in_rx) = mpsc::channel(1);
        let (cloud_tx, mut cloud_rx) = mpsc::channel(16);
        let tmp = tempfile::tempdir().unwrap();
        let (logger, _handle) =
            crate::core::logging::tamper_log::TamperLogger::new(tmp.path().to_path_buf());

        let reconciler = Reconciler::new_with_sinks(
            in_rx,
            tmp.path().join("settings.json"),
            tmp.path().to_path_buf(),
            7443,
            tmp.path().join("daemon.token"),
            TamperSinks {
                logger: Some(logger),
                cloud_tx: Some(cloud_tx),
                agent_id: "agt_test".into(),
                client_version: "0.0.1-test".into(),
            },
        );

        let event = TamperEvent::new(
            "entry-a".into(),
            "claude-code".into(),
            "sha256:abc".into(),
            "PreToolUse".into(),
            "hmac_mismatch".into(),
        );
        reconciler.publish_detected(&event);

        let ce = cloud_rx.try_recv().expect("cloud channel received event");
        assert_eq!(
            ce.envelope["type"].as_str(),
            Some("ai.openlatch.security.tamper_detected")
        );
        assert_eq!(ce.agent_id, "agt_test");
    }

    #[tokio::test]
    async fn publish_healed_links_to_detection_event_id() {
        let (_in_tx, in_rx) = mpsc::channel(1);
        let (cloud_tx, mut cloud_rx) = mpsc::channel(16);
        let tmp = tempfile::tempdir().unwrap();
        let (logger, _handle) =
            crate::core::logging::tamper_log::TamperLogger::new(tmp.path().to_path_buf());

        let reconciler = Reconciler::new_with_sinks(
            in_rx,
            tmp.path().join("settings.json"),
            tmp.path().to_path_buf(),
            7443,
            tmp.path().join("daemon.token"),
            TamperSinks {
                logger: Some(logger),
                cloud_tx: Some(cloud_tx),
                agent_id: "agt_test".into(),
                client_version: "0.0.1-test".into(),
            },
        );

        let detected = TamperEvent::new(
            "entry-a".into(),
            "claude-code".into(),
            "sha256:abc".into(),
            "PreToolUse".into(),
            "hmac_mismatch".into(),
        );
        let healed = TamperEvent::new_healed(&detected, "succeeded", 1, "closed");
        reconciler.publish_healed("PreToolUse", &healed);

        let ce = cloud_rx.try_recv().expect("cloud channel received event");
        assert_eq!(
            ce.envelope["type"].as_str(),
            Some("ai.openlatch.security.tamper_healed")
        );
        assert_eq!(
            ce.envelope["data"]["tamper"]["related_event_id"].as_str(),
            Some(detected.tamper.event_id.as_str())
        );
    }
}