hyperhive/hive-c0re/src/coordinator.rs

//! Runtime state + config shared between the host admin socket, the manager
//! socket, and the per-agent sockets: the broker, configured `agent_flake`,
//! and the map of registered agent sockets.

use std::collections::HashMap;
use std::path::{Path, PathBuf};
use std::sync::atomic::{AtomicU64, Ordering};
use std::sync::{Arc, Mutex};

use anyhow::{Context, Result};
use tokio::sync::{broadcast, watch};

use crate::agent_server::{self, AgentSocket};
use crate::approvals::Approvals;
use crate::broker::Broker;
use crate::container_view::{self, ContainerView};
use crate::dashboard_events::DashboardEvent;
use crate::operator_questions::OperatorQuestions;

/// Capacity of the dashboard event channel. Slow browser subscribers
/// (idle tab, throttled connection) drop frames past this — that's
/// fine, the seq dedupe makes a reconnect resync safe.
const DASHBOARD_CHANNEL: usize = 256;

const AGENT_RUNTIME_ROOT: &str = "/run/hyperhive/agents";
/// Manager-editable per-agent config repos. Bind-mounted RW into the manager
/// container as `/agents/<name>/`. Hive-c0re only writes to these on first
/// spawn (initial commit); after that it's manager-only.
const AGENT_STATE_ROOT: &str = "/var/lib/hyperhive/agents";
/// Hive-c0re-only authoritative per-agent config repos. Containers build from
/// these. Manager has no filesystem access; the only way to update is via
/// `request_apply_commit` + user approval.
const APPLIED_STATE_ROOT: &str = "/var/lib/hyperhive/applied";

pub struct Coordinator {
    pub broker: Arc<Broker>,
    pub approvals: Arc<Approvals>,
    pub questions: Arc<OperatorQuestions>,
    /// Scheduled-prompts queue. One sqlite connection,
    /// internal mutex; the worker drains due rows and the manager
    /// handlers insert / cancel through the same handle.
    pub scheduled_prompts: Arc<crate::scheduled_prompts::ScheduledPrompts>,
    /// Full build-log capture. `lifecycle::run` /
    /// `lifecycle::prebuild_toplevel` `start()` a row per attempt,
    /// pipe every stdout/stderr line into it, and `finish()` it on
    /// child exit. Dashboard reads it via `list_recent_for_agent` /
    /// `get_full` for the per-card chip + side-panel viewer. See
    /// `build_logs.rs` for retention.
    pub build_logs: Arc<crate::build_logs::BuildLogs>,
    /// URL of the hyperhive flake (no fragment). Inlined into per-agent
    /// `flake.nix` files as `inputs.hyperhive.url`.
    pub hyperhive_flake: String,
    /// Store-path URL of the nixpkgs to wire into the meta flake as
    /// `inputs.nixpkgs.url`. Populated by `--nixpkgs-flake` (set by the
    /// NixOS module to `"path:${pkgs.path}"` so the meta flake always
    /// tracks the same nixpkgs the host evaluated with — which is the
    /// host's nixpkgs when `inputs.hyperhive.inputs.nixpkgs.follows =
    /// "nixpkgs"` is set in the host flake). Empty string = legacy
    /// `follows = "hyperhive/nixpkgs"` behaviour.
    pub nixpkgs_flake: String,
    /// Store-path URL for `nixpkgs-unstable` to wire as a top-level meta
    /// flake input. Hyperhive's `inputs.nixpkgs-unstable` then follows it.
    /// Set via `--nixpkgs-unstable-flake` from `hive-c0re.nix`. Empty string
    /// falls back to the legacy `follows = "hyperhive/nixpkgs-unstable"`.
    pub nixpkgs_unstable_flake: String,
    /// TCP port the host's hive-c0re dashboard listens on. Inlined into
    /// each per-agent flake so the agent's web UI can build the right
    /// rebuild-button URL pointing back at the dashboard.
    pub dashboard_port: u16,
    /// Operator pronouns (free text) — `she/her` by default, set via
    /// the NixOS module option `services.hive-c0re.operatorPronouns`.
    /// Reaches each container as the `HIVE_OPERATOR_PRONOUNS` env var
    /// (injected into systemd.services.<harness>.environment by the
    /// meta flake); the harness substitutes it into the agent /
    /// manager system prompt at boot.
    pub operator_pronouns: String,
    /// Per-model context-window sizes in tokens. Set via the host-level
    /// `services.hive-c0re.contextWindowTokens` NixOS option; injected
    /// into each container as `HIVE_CONTEXT_WINDOW_TOKENS_<KEY_UPPER>`
    /// by the meta flake renderer. The harness uses these to derive
    /// compaction / auto-reset watermarks and exposes the active value
    /// on `/api/state` as `context_window_tokens`.
    pub context_window_tokens: std::collections::HashMap<String, u64>,
    /// Per-agent systemd `CPUQuota=` value (e.g. `"200%"`). Written into
    /// the `container@h-<name>.service.d/` drop-in on every spawn/rebuild.
    pub agent_cpu_quota: String,
    /// Per-agent systemd `MemoryMax=` value (e.g. `"4G"`). Same drop-in.
    pub agent_memory_max: String,
    agents: Mutex<HashMap<String, AgentSocket>>,
    /// Agents whose lifecycle action (currently just spawn) is in flight.
    /// Read by the dashboard to render a spinner; cleared when the action
    /// resolves (success or failure).
    transient: Mutex<HashMap<String, TransientState>>,
    /// Tombstone for transients that have JUST been cleared. The
    /// crash watcher polls every 10s and would race the
    /// drop-clears-immediately path of `TransientGuard`: an operator
    /// kill / restart sets `Stopping` → runs `nixos-container stop` →
    /// drop clears the transient → poll fires next tick and sees the
    /// container missing-from-running with no active transient →
    /// spurious "container stopped without an operator action"
    /// message.
    ///
    /// `clear_transient` stamps the cleared kind here with an
    /// `Instant`; `recent_transient_within(grace)` returns the set of
    /// agents whose tombstone is still inside the grace window. Crash
    /// watcher consults both this and the active map before declaring
    /// a stop deliberate.
    recent_transient: Mutex<HashMap<String, (TransientKind, std::time::Instant)>>,
    /// Unified wire-facing event channel feeding the dashboard SSE
    /// stream. Carries broker messages (mirrored from `broker.subscribe`
    /// by the forwarder task in `main.rs`) and dashboard-only mutation
    /// events (approval added/resolved, question added/answered, etc.).
    /// Snapshot endpoints capture `event_seq` before reading state so
    /// the client can dedupe its buffered live traffic against the
    /// snapshot.
    dashboard_events: broadcast::Sender<DashboardEvent>,
    event_seq: AtomicU64,
    /// Count of dashboard-triggered `meta-update` runs currently in
    /// flight. `post_meta_update` returns 200 immediately and does the
    /// multi-minute `nix flake update` + agent-rebuild ripple in a
    /// background task, so without this the META INPUTS panel showed
    /// no sign anything was happening. Held via
    /// `MetaUpdateGuard`; a count > 0 surfaces on `/api/state` as
    /// `meta_update_running` and via the `MetaUpdateRunning` event.
    meta_updates_active: AtomicU64,
    /// Last container snapshot seen by `rescan_containers_and_emit`,
    /// keyed by `ContainerView.name`. The rescan diffs a fresh
    /// `container_view::build_all` against this map and emits one
    /// `ContainerStateChanged` per added/changed row and one
    /// `ContainerRemoved` per disappeared row. Async — guarded by a
    /// tokio mutex so the rescan can `await` `lifecycle::list` /
    /// `is_running` without blocking other coordinator paths.
    last_containers: tokio::sync::Mutex<HashMap<String, ContainerView>>,
    /// Global rebuild queue. Every long-running container/meta op
    /// (rebuild, meta-update, first-spawn) goes through this queue so
    /// hive-c0re runs at most one at a time and the dashboard can
    /// render a single ordered view of pending + running work. See
    /// `rebuild_queue.rs` for the dedup rules + history retention.
    pub rebuild_queue: Arc<crate::rebuild_queue::RebuildQueue>,
    /// Shutdown signal broadcast to all background tasks. Sending
    /// `true` asks every loop to exit after its current work item.
    /// Use `shutdown_rx()` to subscribe; `request_shutdown()` to fire.
    shutdown_tx: watch::Sender<bool>,
}

/// Hive-wide configuration that lifecycle and meta operations need.
/// Extracted from `Coordinator` so callers can pass a single struct
/// instead of repeating the same 6 arguments everywhere.
///
/// Cloned from `Coordinator` via [`Coordinator::hive_env`]. All fields
/// are cheap to clone (small strings + small map); lifecycle ops are
/// infrequent enough that the copy cost is irrelevant.
#[derive(Clone, Debug)]
pub struct HiveEnv {
    pub hyperhive_flake: String,
    pub nixpkgs_flake: String,
    pub nixpkgs_unstable_flake: String,
    pub dashboard_port: u16,
    pub operator_pronouns: String,
    pub context_window_tokens: std::collections::HashMap<String, u64>,
    /// Per-agent systemd `CPUQuota=` value (e.g. `"200%"`).
    pub agent_cpu_quota: String,
    /// Per-agent systemd `MemoryMax=` value (e.g. `"4G"`).
    pub agent_memory_max: String,
}

/// Per-agent filesystem paths that lifecycle operations write to.
/// Assembled from `Coordinator`'s static path helpers so callers
/// don't repeat the same `Coordinator::agent_*_dir(name)` calls.
#[derive(Clone, Debug)]
pub struct AgentPaths {
    /// Runtime socket dir (tmpfs, recreated per boot).
    pub agent_dir: PathBuf,
    /// Manager-editable proposed config repo.
    pub proposed_dir: PathBuf,
    /// Hive-c0re-authoritative applied config repo.
    pub applied_dir: PathBuf,
    /// Claude OAuth credentials (survives purge boundary).
    pub claude_dir: PathBuf,
    /// Agent durable notes + forge token (survives purge boundary).
    pub notes_dir: PathBuf,
}

/// Per-agent in-progress state that the dashboard surfaces between approve
/// click and container ready.
#[derive(Debug, Clone)]
pub struct TransientState {
    pub kind: TransientKind,
    pub since: std::time::Instant,
}

/// RAII handle returned by `Coordinator::transient_guard`. Cleared on
/// drop — including drop-via-cancellation, the path that bare
/// `set_transient` / `clear_transient` pairs leaked through. Holds an
/// `Arc<Coordinator>` so the guard is freely returnable / movable.
pub struct TransientGuard {
    coord: Arc<Coordinator>,
    name: String,
}

impl Drop for TransientGuard {
    fn drop(&mut self) {
        self.coord.clear_transient(&self.name);
    }
}

/// RAII guard for the `meta-update` in-progress flag, held for the
/// duration of a `run_meta_update` background task. Created by
/// `Coordinator::meta_update_guard`. Drop decrements the active-run
/// count; the count crossing back to 0 emits
/// `MetaUpdateRunning { running: false }`, so a concurrent pair of
/// updates only flips the dashboard flag once.
pub struct MetaUpdateGuard {
    coord: Arc<Coordinator>,
}

impl Drop for MetaUpdateGuard {
    fn drop(&mut self) {
        if self
            .coord
            .meta_updates_active
            .fetch_sub(1, Ordering::SeqCst)
            == 1
        {
            self.coord
                .emit_dashboard_event(DashboardEvent::MetaUpdateRunning {
                    seq: self.coord.next_seq(),
                    running: false,
                });
        }
    }
}

#[derive(Debug, Clone, Copy)]
pub enum TransientKind {
    /// `lifecycle::spawn` is running (nixos-container create + update + start).
    Spawning,
    /// `lifecycle::start` is running.
    Starting,
    /// `lifecycle::kill` is running.
    Stopping,
    /// `lifecycle::restart` is running.
    Restarting,
    /// `lifecycle::rebuild` is running (nixos-container update).
    Rebuilding,
    /// `actions::destroy` is running.
    Destroying,
}

impl TransientKind {
    /// Wire/UI label. Matches the strings the dashboard already
    /// renders in the transient spinner.
    pub fn as_str(self) -> &'static str {
        match self {
            TransientKind::Spawning => "spawning",
            TransientKind::Starting => "starting",
            TransientKind::Stopping => "stopping",
            TransientKind::Restarting => "restarting",
            TransientKind::Rebuilding => "rebuilding",
            TransientKind::Destroying => "destroying",
        }
    }
}

impl Coordinator {
    #[allow(
        clippy::too_many_arguments,
        reason = "constructor wiring host-level config (flakes, ports, pronouns, \
                  context-window + resource limits) into the coordinator; bundling \
                  into a struct would just move the same fields one level out"
    )]
    pub fn open(
        db_path: &Path,
        hyperhive_flake: String,
        nixpkgs_flake: String,
        nixpkgs_unstable_flake: String,
        dashboard_port: u16,
        operator_pronouns: String,
        context_window_tokens: std::collections::HashMap<String, u64>,
        agent_cpu_quota: String,
        agent_memory_max: String,
    ) -> Result<Self> {
        let broker = Broker::open(db_path).context("open broker")?;
        let approvals = Approvals::open(db_path).context("open approvals")?;
        let questions = OperatorQuestions::open(db_path).context("open operator_questions")?;
        let scheduled_prompts = crate::scheduled_prompts::ScheduledPrompts::open(db_path)
            .context("open scheduled_prompts")?;
        // BuildLogs wants a directory (it picks its own `build_logs.sqlite`
        // file under it); every other opener here takes the sibling
        // sqlite-file path itself. Derive the dir from `db_path`'s
        // parent so the two shapes line up.
        let build_logs_dir = db_path.parent().unwrap_or_else(|| Path::new("."));
        let build_logs = Arc::new(
            crate::build_logs::BuildLogs::open(build_logs_dir).context("open build_logs")?,
        );
        // Install the process-wide handle so `lifecycle::run` /
        // `lifecycle::prebuild_toplevel` can write without us having
        // to thread an `Arc<BuildLogs>` through every public entry
        // point in the lifecycle surface.
        crate::build_logs::install(build_logs.clone());
        let (dashboard_events, _) = broadcast::channel(DASHBOARD_CHANNEL);
        let (shutdown_tx, _) = watch::channel(false);
        Ok(Self {
            broker: Arc::new(broker),
            approvals: Arc::new(approvals),
            questions: Arc::new(questions),
            scheduled_prompts: Arc::new(scheduled_prompts),
            build_logs,
            hyperhive_flake,
            nixpkgs_flake,
            nixpkgs_unstable_flake,
            dashboard_port,
            operator_pronouns,
            context_window_tokens,
            agent_cpu_quota,
            agent_memory_max,
            agents: Mutex::new(HashMap::new()),
            transient: Mutex::new(HashMap::new()),
            recent_transient: Mutex::new(HashMap::new()),
            dashboard_events,
            event_seq: AtomicU64::new(0),
            meta_updates_active: AtomicU64::new(0),
            last_containers: tokio::sync::Mutex::new(HashMap::new()),
            rebuild_queue: Arc::new(crate::rebuild_queue::RebuildQueue::new()),
            shutdown_tx,
        })
    }

    /// Snapshot the hive-wide configuration fields as a [`HiveEnv`].
    /// Pass the result to `lifecycle::spawn` / `rebuild` / `meta::sync_agents`
    /// instead of threading the individual fields separately.
    #[must_use]
    pub fn hive_env(&self) -> HiveEnv {
        HiveEnv {
            hyperhive_flake: self.hyperhive_flake.clone(),
            nixpkgs_flake: self.nixpkgs_flake.clone(),
            nixpkgs_unstable_flake: self.nixpkgs_unstable_flake.clone(),
            dashboard_port: self.dashboard_port,
            operator_pronouns: self.operator_pronouns.clone(),
            context_window_tokens: self.context_window_tokens.clone(),
            agent_cpu_quota: self.agent_cpu_quota.clone(),
            agent_memory_max: self.agent_memory_max.clone(),
        }
    }

    /// Assemble the per-agent filesystem paths for `name`. The caller
    /// must supply `agent_dir` (from `ensure_runtime`) since that
    /// creates the tmpfs entry on first call. All other paths are
    /// derived statically from `name`.
    ///
    /// ```ignore
    /// let paths = Coordinator::agent_paths(name, coord.ensure_runtime(name)?);
    /// ```
    #[must_use]
    pub fn agent_paths(name: &str, agent_dir: PathBuf) -> AgentPaths {
        AgentPaths {
            agent_dir,
            proposed_dir: Self::agent_proposed_dir(name),
            applied_dir: Self::agent_applied_dir(name),
            claude_dir: Self::agent_claude_dir(name),
            notes_dir: Self::agent_notes_dir(name),
        }
    }

    /// Emit a `RebuildQueueChanged` snapshot event. Called from the
    /// queue mutation helpers (`enqueue` / `finish` / `cancel`-adjacent
    /// wrappers below) and the worker so every state transition
    /// surfaces on the dashboard without extra plumbing.
    pub fn emit_rebuild_queue_snapshot(self: &Arc<Self>) {
        let queue = self.rebuild_queue.snapshot();
        self.emit_dashboard_event(DashboardEvent::RebuildQueueChanged {
            seq: self.next_seq(),
            queue,
        });
    }

    /// Emit a `SchedulesChanged` snapshot event. Called from every
    /// schedule mutation site (operator API handlers + the worker
    /// after each tick that fires or rearms a row) so the dashboard's
    /// scheduled-prompts tab updates live without polling.
    pub fn emit_schedules_snapshot(self: &Arc<Self>) {
        let schedules = match self.scheduled_prompts.list() {
            Ok(rows) => rows
                .into_iter()
                .map(crate::manager_server::schedule_to_wire_public)
                .collect(),
            Err(e) => {
                tracing::warn!(error = ?e, "emit_schedules_snapshot: list failed");
                return;
            }
        };
        self.emit_dashboard_event(DashboardEvent::SchedulesChanged {
            seq: self.next_seq(),
            schedules,
        });
    }

    /// Emit a `RemindersChanged` snapshot event. Called from every
    /// reminder mutation site (agent `remind` calls, operator cancel /
    /// retry, and the scheduler after each delivery batch) so the
    /// dashboard's pending-reminders list stays live without polling.
    pub fn emit_reminders_snapshot(self: &Arc<Self>) {
        let reminders = match self.broker.list_pending_reminders() {
            Ok(rows) => rows,
            Err(e) => {
                tracing::warn!(error = ?e, "emit_reminders_snapshot: list failed");
                return;
            }
        };
        self.emit_dashboard_event(DashboardEvent::RemindersChanged {
            seq: self.next_seq(),
            reminders,
        });
    }

    /// Emit a `CapabilitiesChanged` snapshot event. Called from the
    /// rebuild-queue worker after a `PermChange` / Capabilities entry
    /// commits the JSON file, so the P3RM1SS10NS tab updates live.
    pub fn emit_capabilities_snapshot(self: &Arc<Self>) {
        use hive_sh4re::Capability;
        let caps = Capability::ALL.iter().map(|c| c.as_str()).collect();
        let descriptions = Capability::ALL
            .iter()
            .map(|c| (c.as_str(), c.description()))
            .collect();
        let assignments = crate::capabilities::read();
        self.emit_dashboard_event(DashboardEvent::CapabilitiesChanged {
            seq: self.next_seq(),
            caps,
            descriptions,
            assignments,
        });
    }

    /// Emit a `ToolGroupsChanged` snapshot event. Called from the
    /// rebuild-queue worker after a `PermChange` / `ToolGroups` entry
    /// commits the JSON file, so the P3RM1SS10NS tab updates live.
    pub fn emit_tool_groups_snapshot(self: &Arc<Self>) {
        use hive_sh4re::ToolGroup;
        let groups = ToolGroup::ALL.iter().map(|g| g.as_str()).collect();
        let descriptions = ToolGroup::ALL
            .iter()
            .map(|g| (g.as_str(), g.description()))
            .collect();
        let assignments = crate::tool_groups::read();
        self.emit_dashboard_event(DashboardEvent::ToolGroupsChanged {
            seq: self.next_seq(),
            groups,
            descriptions,
            assignments,
        });
    }

    /// Update the `step` label on a running queue entry and (if it
    /// actually changed) re-emit the queue snapshot so the dashboard
    /// renders the new phase. Returns `true` when the label was new
    /// and an emit fired, mostly for tracing/logging callers; safe to
    /// ignore. No-op when `id` is `None` (e.g. callers that aren't
    /// running from the queue worker) or when the row isn't `Running`.
    pub fn set_queue_step(self: &Arc<Self>, id: Option<u64>, step: &str) {
        let Some(id) = id else { return };
        if self.rebuild_queue.set_step(id, step) {
            self.emit_rebuild_queue_snapshot();
        }
    }

    /// Subscribe to the shutdown watch channel. Background tasks call
    /// this at spawn time and break their loop when the receiver
    /// transitions to `true` (via `Coordinator::request_shutdown`).
    /// A closed channel (i.e. the Coordinator was dropped) also
    /// signals tasks to exit.
    pub fn shutdown_rx(&self) -> watch::Receiver<bool> {
        self.shutdown_tx.subscribe()
    }

    /// Signal all background tasks to exit cleanly. The tasks break
    /// out of their poll loop after completing their current work item.
    /// Best-effort — does nothing if all receivers have already been
    /// dropped (e.g. process is already mid-shutdown).
    pub fn request_shutdown(&self) {
        let _ = self.shutdown_tx.send(true);
    }

    /// Subscribe to the unified dashboard event channel. Used by the
    /// `/dashboard/stream` SSE handler and by the broker-to-dashboard
    /// forwarder task.
    pub fn dashboard_subscribe(&self) -> broadcast::Receiver<DashboardEvent> {
        self.dashboard_events.subscribe()
    }

    /// Stamp the next sequence number. Each emission of a
    /// `DashboardEvent` should fill its `seq` with `next_seq()` so the
    /// frame the wire carries is the one the client uses to dedupe.
    pub fn next_seq(&self) -> u64 {
        self.event_seq.fetch_add(1, Ordering::SeqCst) + 1
    }

    /// Current high-water seq. Snapshot endpoints read this *before*
    /// gathering state so the (snapshot.seq, snapshot) pair satisfies:
    /// any frame with `seq > snapshot.seq` is post-snapshot. The seq
    /// captured here may grow during snapshot construction — clients
    /// may double-apply such events, which renderers must tolerate.
    pub fn current_seq(&self) -> u64 {
        self.event_seq.load(Ordering::SeqCst)
    }

    /// Broadcast a freshly-built `DashboardEvent` (caller fills `seq`
    /// via `next_seq()`). Returns silently when there are no
    /// subscribers — the dashboard channel is best-effort presentation
    /// plumbing, not a delivery guarantee.
    pub fn emit_dashboard_event(&self, event: DashboardEvent) {
        let _ = self.dashboard_events.send(event);
    }

    /// Mark a `meta-update` as in flight and return an RAII guard that
    /// clears it on drop (including drop-via-panic). The first
    /// concurrent run emits `MetaUpdateRunning { running: true }`; the
    /// last one to finish emits `running: false`. The dashboard's META
    /// INPUTS panel reads the flag to show a disabled "updating…"
    /// state while the lock bump + rebuild ripple runs.
    pub fn meta_update_guard(self: &Arc<Self>) -> MetaUpdateGuard {
        if self.meta_updates_active.fetch_add(1, Ordering::SeqCst) == 0 {
            self.emit_dashboard_event(DashboardEvent::MetaUpdateRunning {
                seq: self.next_seq(),
                running: true,
            });
        }
        MetaUpdateGuard {
            coord: Arc::clone(self),
        }
    }

    /// True while at least one dashboard-triggered `meta-update` is
    /// running. Surfaced on `/api/state` as `meta_update_running` so a
    /// client that cold-loads mid-update sees the in-progress state.
    pub fn meta_update_in_progress(&self) -> bool {
        self.meta_updates_active.load(Ordering::SeqCst) > 0
    }

    /// Emit `ApprovalAdded` immediately after the row is inserted in
    /// sqlite. Caller passes the diff text it already computed (or
    /// `None` for spawn approvals which carry no diff).
    pub fn emit_approval_added(
        &self,
        id: i64,
        agent: &str,
        approval_kind: &'static str,
        sha_short: Option<String>,
        diff: Option<String>,
        description: Option<String>,
    ) {
        self.emit_dashboard_event(DashboardEvent::ApprovalAdded {
            seq: self.next_seq(),
            id,
            agent: agent.to_owned(),
            approval_kind,
            sha_short,
            diff,
            description,
        });
    }

    /// Emit `ApprovalResolved` after `mark_approved` / `mark_denied` /
    /// `mark_failed` lands. `resolved_at` is stamped from the system
    /// clock here so call sites don't repeat the conversion; if you
    /// already have an authoritative timestamp from the db update,
    /// the tiny skew between "row updated" and "event emitted" is
    /// presentation-only and doesn't matter to clients.
    #[allow(clippy::too_many_arguments)]
    pub fn emit_approval_resolved(
        &self,
        id: i64,
        agent: &str,
        approval_kind: &'static str,
        sha_short: Option<String>,
        status: &'static str,
        note: Option<String>,
        description: Option<String>,
    ) {
        let resolved_at = std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .ok()
            .and_then(|d| i64::try_from(d.as_secs()).ok())
            .unwrap_or(0);
        self.emit_dashboard_event(DashboardEvent::ApprovalResolved {
            seq: self.next_seq(),
            id,
            agent: agent.to_owned(),
            approval_kind,
            sha_short,
            status,
            resolved_at,
            note,
            description,
        });
    }

    /// Emit `QuestionAdded` after a question is inserted. Fires for
    /// both operator-targeted (`target = None`) and peer-to-peer
    /// (`target = Some(agent)`) threads — the dashboard surfaces
    /// both, distinguishing visually + offering operator override.
    #[allow(clippy::too_many_arguments)]
    pub fn emit_question_added(
        &self,
        id: i64,
        asker: &str,
        question: &str,
        options: &[String],
        multi: bool,
        deadline_at: Option<i64>,
        target: Option<&str>,
    ) {
        let asked_at = std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .ok()
            .and_then(|d| i64::try_from(d.as_secs()).ok())
            .unwrap_or(0);
        let question_refs = crate::dashboard::scan_validated_paths(question);
        self.emit_dashboard_event(DashboardEvent::QuestionAdded {
            seq: self.next_seq(),
            id,
            asker: asker.to_owned(),
            question: question.to_owned(),
            options: options.to_vec(),
            multi,
            asked_at,
            deadline_at,
            target: target.map(str::to_owned),
            question_refs,
        });
    }

    /// Emit `QuestionResolved` when a question transitions to
    /// answered (operator answer, peer answer, operator override on
    /// a peer thread, operator cancel, or ttl watchdog). Both
    /// operator-targeted and peer threads fire so the dashboard's
    /// derived store can move the row from pending to history.
    pub fn emit_question_resolved(
        &self,
        id: i64,
        answer: &str,
        answerer: &str,
        cancelled: bool,
        target: Option<&str>,
    ) {
        let answered_at = std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .ok()
            .and_then(|d| i64::try_from(d.as_secs()).ok())
            .unwrap_or(0);
        let answer_refs = crate::dashboard::scan_validated_paths(answer);
        self.emit_dashboard_event(DashboardEvent::QuestionResolved {
            seq: self.next_seq(),
            id,
            answer: answer.to_owned(),
            answerer: answerer.to_owned(),
            answered_at,
            cancelled,
            target: target.map(str::to_owned),
            answer_refs,
        });
    }

    /// Rebuild the per-container snapshot, diff it against the last
    /// one cached on `self`, and emit one
    /// `DashboardEvent::ContainerStateChanged` per added/changed row
    /// and one `DashboardEvent::ContainerRemoved` per disappeared row.
    /// Call after any mutation that could affect what
    /// `nixos-container list` returns or what a row's
    /// `running` / `needs_update` / `needs_login` / `deployed_sha`
    /// resolves to — lifecycle ops, destroy, approve (post-spawn),
    /// rebuild, meta-update, and the crash-watcher's periodic poll.
    /// Cheap when nothing changed (one `nixos-container list` + a
    /// `HashMap` diff + zero emits).
    pub async fn rescan_containers_and_emit(self: &Arc<Self>) {
        let fresh = container_view::build_all(self).await;
        let mut last = self.last_containers.lock().await;
        let mut changed_or_new = Vec::new();
        let mut removed = Vec::new();
        // Diff into change vs. add.
        for view in &fresh {
            match last.get(&view.name) {
                Some(prev) if prev == view => {} // unchanged
                _ => changed_or_new.push(view.clone()),
            }
        }
        // Anything in `last` but not in `fresh` is gone.
        let fresh_names: std::collections::HashSet<&str> =
            fresh.iter().map(|c| c.name.as_str()).collect();
        for name in last.keys() {
            if !fresh_names.contains(name.as_str()) {
                removed.push(name.clone());
            }
        }
        // Rebuild the cache from the fresh snapshot.
        last.clear();
        for c in fresh {
            last.insert(c.name.clone(), c);
        }
        drop(last);
        for c in changed_or_new {
            self.emit_dashboard_event(DashboardEvent::ContainerStateChanged {
                seq: self.next_seq(),
                container: c,
            });
        }
        for name in removed {
            self.emit_dashboard_event(DashboardEvent::ContainerRemoved {
                seq: self.next_seq(),
                name,
            });
        }
    }

    /// Apply a topology reparent + fan the resulting notifications
    /// out to the three affected agents. On success, drops a
    /// one-line system message into the inbox of:
    ///
    /// 1. The **old parent** (if any) — `"{child} moved out of your
    ///    subtree to {new_parent_or_root}"`.
    /// 2. The **new parent** (if any) — `"{child} just moved into
    ///    your subtree (was previously under
    ///    {old_parent_or_root})"`.
    /// 3. The **moved agent** — `"your parent changed from
    ///    {old_parent_or_root} to {new_parent_or_root}"`.
    ///
    /// `_or_root` resolves to the literal string `"<root>"` when the
    /// slot is `None`, keeping the wording consistent with the
    /// `<parent>` sentinel's "root → operator" routing (see
    /// `docs/conventions.md::Recipient sentinels`). The
    /// notifications fire as ordinary broker messages with
    /// `from = hive_sh4re::SYSTEM_SENDER` so the dashboard renders
    /// them under the existing system-source styling.
    ///
    /// Idempotent: if `topology::set_parent` skipped the disk write
    /// (same-parent no-op), no messages fire. The `topology` module's
    /// validation (`apply_set_parent`: unknown agent, cycle, etc.)
    /// runs *before* any message is sent, so a refused move never
    /// notifies anyone.
    ///
    /// Also drives a `rescan_containers_and_emit` after the write so
    /// the dashboard tree re-renders without polling.
    pub async fn reparent_with_notify(
        self: &Arc<Self>,
        child: &str,
        new_parent: Option<&str>,
    ) -> std::result::Result<(), String> {
        // Snapshot the old parent BEFORE the write so the
        // notifications can describe both sides of the change.
        let topo_before = crate::topology::read();
        let old_parent = topo_before.get(child).cloned().flatten();

        // The disk write + git commit happen here under META_LOCK, so
        // the topology.json change is committed atomically and the
        // working tree is never left dirty between the write and the
        // next meta operation. Topology validation + idempotent
        // fast-path inside `set_parent` may short-circuit (same
        // parent → no-op). We mirror the same idempotent shape for
        // the notifications: if nothing changed, send nothing.
        crate::meta::commit_topology(child, new_parent).await?;

        let changed = old_parent.as_deref() != new_parent;
        if changed {
            let old_label = old_parent.as_deref().unwrap_or("<root>");
            let new_label = new_parent.unwrap_or("<root>");
            // System-source notifications. Best-effort: a failed broker
            // send is logged + ignored so a transient sqlite error
            // doesn't bubble out and unwind the topology write.
            if let Some(op) = old_parent.as_deref() {
                let _ = self.broker.send(&hive_sh4re::Message {
                    from: hive_sh4re::SYSTEM_SENDER.to_owned(),
                    to: op.to_owned(),
                    body: format!("{child} moved out of your subtree to {new_label}"),
                    in_reply_to: None,
                });
            }
            if let Some(np) = new_parent {
                let _ = self.broker.send(&hive_sh4re::Message {
                    from: hive_sh4re::SYSTEM_SENDER.to_owned(),
                    to: np.to_owned(),
                    body: format!(
                        "{child} just moved into your subtree (was previously under {old_label})"
                    ),
                    in_reply_to: None,
                });
            }
            // Coalesce: if a prior move notification is already pending in
            // the broker (agent was offline for multiple moves), update it
            // in-place so the agent sees "A to C" not "A to B" then "B to C".
            let _ = self
                .broker
                .send_coalescing_reparent(child, old_label, new_label);
        }

        // Rescan + diff-emit regardless of whether messages fired —
        // even an idempotent no-op might have happened concurrently
        // with another lifecycle event the dashboard cares about.
        self.rescan_containers_and_emit().await;
        Ok(())
    }

    /// Batch version of [`reparent_with_notify`]: applies all moves under a
    /// single `META_LOCK` acquisition (one git commit) then sends per-agent
    /// notifications for each move that actually changed topology.
    /// First validation failure aborts the whole batch with no disk writes.
    ///
    /// # Errors
    ///
    /// Propagates any error returned by [`crate::meta::bulk_commit_topology`]
    /// (validation failure or topology-file write error).
    pub async fn reparent_bulk_with_notify(
        self: &Arc<Self>,
        moves: &[(&str, Option<&str>)],
    ) -> std::result::Result<(), String> {
        if moves.is_empty() {
            return Ok(());
        }
        // bulk_commit_topology applies all set_parent calls under one lock
        // and returns (child, old_parent) for every move that changed.
        let changed = crate::meta::bulk_commit_topology(moves).await?;

        // Send per-agent notifications for each changed move.
        for (child, old_parent) in &changed {
            // Find the new parent from the moves slice.
            let new_parent = moves
                .iter()
                .find(|(c, _)| *c == child)
                .and_then(|(_, np)| *np);
            let old_label = old_parent.as_deref().unwrap_or("<root>");
            let new_label = new_parent.unwrap_or("<root>");
            if let Some(op) = old_parent.as_deref() {
                let _ = self.broker.send(&hive_sh4re::Message {
                    from: hive_sh4re::SYSTEM_SENDER.to_owned(),
                    to: op.to_owned(),
                    body: format!("{child} moved out of your subtree to {new_label}"),
                    in_reply_to: None,
                });
            }
            if let Some(np) = new_parent {
                let _ = self.broker.send(&hive_sh4re::Message {
                    from: hive_sh4re::SYSTEM_SENDER.to_owned(),
                    to: np.to_owned(),
                    body: format!(
                        "{child} just moved into your subtree (was previously under {old_label})"
                    ),
                    in_reply_to: None,
                });
            }
            let _ = self
                .broker
                .send_coalescing_reparent(child, old_label, new_label);
        }

        self.rescan_containers_and_emit().await;
        Ok(())
    }

    /// Read-only snapshot of the last cached container view. Used by
    /// `/api/state` to cold-load page-open clients without re-running
    /// `nixos-container list` themselves; the
    /// `rescan_containers_and_emit` calls keep this fresh.
    pub async fn containers_snapshot(&self) -> Vec<ContainerView> {
        let last = self.last_containers.lock().await;
        let mut out: Vec<ContainerView> = last.values().cloned().collect();
        out.sort_by(|a, b| a.name.cmp(&b.name));
        out
    }

    pub fn register_agent(self: &Arc<Self>, name: &str) -> Result<PathBuf> {
        // Idempotent: drop any existing listener so re-registration (e.g. on rebuild,
        // or after a hive-c0re restart cleared /run/hyperhive) gets a fresh socket.
        self.unregister_agent(name);
        let agent_dir = Self::agent_dir(name);
        std::fs::create_dir_all(&agent_dir)
            .with_context(|| format!("create agent dir {}", agent_dir.display()))?;
        let socket_path = Self::socket_path(name);
        // Hand the full Coordinator to the per-agent socket — it
        // needs broker + operator_questions to handle the agent-side
        // `ask` / `answer` tools, not just the broker.
        let socket = agent_server::start(name, &socket_path, self.clone())?;
        self.agents.lock().unwrap().insert(name.to_owned(), socket);
        Ok(agent_dir)
    }

    pub fn unregister_agent(&self, name: &str) {
        if let Some(socket) = self.agents.lock().unwrap().remove(name) {
            socket.handle.abort();
            let _ = std::fs::remove_file(&socket.path);
        }
    }
    pub fn list_agents(&self) -> Vec<String> {
        self.agents.lock().unwrap().keys().cloned().collect()
    }

    /// Mark an agent as in-progress (only one state per agent for now).
    ///
    /// Prefer `transient_guard` when possible — it auto-clears on drop
    /// even if the surrounding future is cancelled (HTTP request
    /// aborted, runtime shutdown mid-rebuild, panic between set and
    /// clear). The bare `set_transient` / `clear_transient` pair leaks
    /// the transient on any of those paths and the dashboard then
    /// shows the agent stuck in "rebuilding…" forever.
    pub fn set_transient(&self, name: &str, kind: TransientKind) {
        self.transient.lock().unwrap().insert(
            name.to_owned(),
            TransientState {
                kind,
                since: std::time::Instant::now(),
            },
        );
        // Live-update dashboards. `since_unix` is wall-clock so the
        // browser can tick "Ns spawning…" without polling. The
        // intra-process map keeps using `Instant` for monotonicity.
        let since_unix = std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .ok()
            .and_then(|d| i64::try_from(d.as_secs()).ok())
            .unwrap_or(0);
        self.emit_dashboard_event(DashboardEvent::TransientSet {
            seq: self.next_seq(),
            name: name.to_owned(),
            transient_kind: kind.as_str(),
            since_unix,
        });
    }

    pub fn clear_transient(&self, name: &str) {
        let removed = self.transient.lock().unwrap().remove(name);
        if let Some(state) = removed {
            // Stamp the tombstone so the crash watcher can still see
            // "operator kicked this off recently" on its next 10s poll
            // — without this, the clear-then-poll race produced a
            // spurious ContainerCrash on every operator stop/restart.
            // Old entries get reaped lazily on read so the map doesn't
            // grow unbounded.
            self.recent_transient
                .lock()
                .unwrap()
                .insert(name.to_owned(), (state.kind, std::time::Instant::now()));
            self.emit_dashboard_event(DashboardEvent::TransientCleared {
                seq: self.next_seq(),
                name: name.to_owned(),
            });
        }
    }

    /// Set of agents whose transient was cleared within the last
    /// `grace` seconds — i.e. agents the operator just acted on,
    /// whose stop the crash watcher should NOT classify as a crash.
    /// Lazily reaps entries older than `grace` so the map stays
    /// bounded by the active agent count.
    pub fn recent_transient_within(
        &self,
        grace: std::time::Duration,
    ) -> HashMap<String, TransientKind> {
        let now = std::time::Instant::now();
        let mut map = self.recent_transient.lock().unwrap();
        map.retain(|_, (_, ts)| now.duration_since(*ts) <= grace);
        map.iter()
            .map(|(k, (kind, _))| (k.clone(), *kind))
            .collect()
    }

    /// Set a transient state and return a guard that clears it on drop.
    /// Use this from any path where the surrounding future could be
    /// cancelled or panic between set and clear (HTTP handlers, spawned
    /// tasks). The guard's `Drop` runs even on task cancellation, so
    /// the dashboard's spinner can't get pinned forever.
    pub fn transient_guard(self: &Arc<Self>, name: &str, kind: TransientKind) -> TransientGuard {
        self.set_transient(name, kind);
        TransientGuard {
            coord: self.clone(),
            name: name.to_owned(),
        }
    }

    pub fn transient_snapshot(&self) -> HashMap<String, TransientState> {
        self.transient.lock().unwrap().clone()
    }

    /// Drop a system message into the given agent's inbox. Wakes the
    /// turn loop with a "you were just (re)started" hint — operator
    /// caused the transition, agent picks up where it left off
    /// (notes are in the bind-mounted state dir, last turn is in
    /// --continue's session). Best-effort; broker errors are logged
    /// but don't propagate.
    pub fn kick_agent(&self, name: &str, reason: &str) {
        // Sub-agents bind their state at /agents/<name>/state. The
        // manager has both /state (legacy mount) and /agents
        // bind-mounted, so /agents/<name>/state resolves there too —
        // use that uniformly so the wake message has one canonical
        // path that works everywhere.
        let body = format!(
            "{reason}\n\nYou were just (re)started by the operator. \
             If you were mid-task, check `/agents/{name}/state/` for \
             your notes and pick up where you left off. claude's \
             `--continue` session is intact, so prior context is \
             still in your window."
        );
        if let Err(e) = self.broker.send(&hive_sh4re::Message {
            from: hive_sh4re::SYSTEM_SENDER.to_owned(),
            to: name.to_owned(),
            body,
            in_reply_to: None,
        }) {
            tracing::warn!(error = ?e, %name, "kick_agent: broker.send failed");
        }
    }

    /// Push a `HelperEvent` into the manager's inbox. Encoded as JSON in
    /// `Message::body`; sender = `SYSTEM_SENDER`. The manager harness
    /// recognises the sender and parses the body. Best-effort: a serde or
    /// broker error is logged but does not propagate.
    pub fn notify_manager(&self, event: &hive_sh4re::HelperEvent) {
        self.notify_agent(hive_sh4re::MANAGER_AGENT, event);
    }

    /// Push a `HelperEvent` into an arbitrary agent's inbox. Encoded
    /// the same way as `notify_manager` (sender = `SYSTEM_SENDER`,
    /// body = JSON-encoded event). Used to route `QuestionAnswered`
    /// events back to the agent that called `ask`, `QuestionAsked`
    /// events to the target of a peer question, etc.
    pub fn notify_agent(&self, agent: &str, event: &hive_sh4re::HelperEvent) {
        self.notify_agent_from(hive_sh4re::SYSTEM_SENDER, agent, event);
    }

    /// Same as `notify_agent` but with an explicit sender. Use this
    /// when the event originates from a known agent or the operator
    /// (e.g. `QuestionAnswered` — the answerer should be the `from`,
    /// not `system`) so the recipient's terminal shows the right name.
    pub fn notify_agent_from(&self, from: &str, agent: &str, event: &hive_sh4re::HelperEvent) {
        let body = match serde_json::to_string(event) {
            Ok(s) => s,
            Err(e) => {
                tracing::warn!(error = ?e, "failed to encode helper event");
                return;
            }
        };
        if let Err(e) = self.broker.send(&hive_sh4re::Message {
            from: from.to_owned(),
            to: agent.to_owned(),
            body,
            in_reply_to: None,
        }) {
            tracing::warn!(error = ?e, target = %agent, "failed to push helper event");
        }
    }

    /// Deliver `body` to every currently-registered agent except the sender,
    /// appending the standard broadcast hint. Returns a list of per-agent
    /// error strings for any that failed (empty = all ok).
    pub fn broadcast_send(&self, from: &str, body: &str) -> Vec<String> {
        const HINT: &str =
            "\n\n⚠️ _hint: this was a broadcast and may not need any action from you_";
        let broadcast_body = format!("{body}{HINT}");
        let mut errors = Vec::new();
        for agent_name in self.list_agents() {
            if agent_name == from {
                continue;
            }
            if let Err(e) = self.broker.send(&hive_sh4re::Message {
                from: from.to_owned(),
                to: agent_name.clone(),
                body: broadcast_body.clone(),
                in_reply_to: None,
            }) {
                errors.push(format!("{agent_name}: {e}"));
            }
        }
        errors
    }

    pub fn agent_dir(name: &str) -> PathBuf {
        PathBuf::from(format!("{AGENT_RUNTIME_ROOT}/{name}"))
    }

    pub fn socket_path(name: &str) -> PathBuf {
        Self::agent_dir(name).join("mcp.sock")
    }

    /// Runtime dir for the manager. Uses the same per-agent subdir layout as
    /// sub-agents — the manager is just another agent under
    /// `AGENT_RUNTIME_ROOT` with its own subdirectory.
    pub fn manager_dir() -> PathBuf {
        Self::agent_dir(crate::lifecycle::MANAGER_NAME)
    }

    pub fn manager_socket_path() -> PathBuf {
        Self::socket_path(crate::lifecycle::MANAGER_NAME)
    }

    /// Ensure a runtime dir + (for sub-agents) per-agent socket exists. For
    /// the manager, `manager_server::start` owns the socket — just return
    /// the dir. For sub-agents this is `register_agent` (creates a fresh
    /// listener bound to `socket_path(name)`). Source directory of the
    /// `/run/hive/mcp.sock` bind that ends up in `set_nspawn_flags`.
    pub fn ensure_runtime(self: &Arc<Self>, name: &str) -> Result<PathBuf> {
        if name == crate::lifecycle::MANAGER_NAME {
            let dir = Self::agent_dir(name);
            std::fs::create_dir_all(&dir)
                .with_context(|| format!("create manager dir {}", dir.display()))?;
            return Ok(dir);
        }
        self.register_agent(name)
    }

    /// Per-agent state root (parent of `config/`, future `prompts/`, etc.).
    pub fn agent_state_root(name: &str) -> PathBuf {
        PathBuf::from(format!("{AGENT_STATE_ROOT}/{name}"))
    }

    /// Manager-editable proposed config repo. Bind-mounted into the manager
    /// container as `/agents/<name>/config/`.
    pub fn agent_proposed_dir(name: &str) -> PathBuf {
        Self::agent_state_root(name).join("config")
    }

    /// Per-agent Claude credentials dir. Bind-mounted RW into the agent
    /// container at `/root/.claude` so OAuth state survives container
    /// destroy/recreate. Each agent owns its own token lineage — sharing
    /// would break on the first refresh-token rotation.
    pub fn agent_claude_dir(name: &str) -> PathBuf {
        Self::agent_state_root(name).join("claude")
    }

    /// Per-agent durable knowledge dir. Bind-mounted RW into the agent
    /// container at `/agents/{name}/state`. Survives destroy/recreate.
    /// Agent-visible — claude is told to write long-lived notes here.
    pub fn agent_notes_dir(name: &str) -> PathBuf {
        Self::agent_state_root(name).join("state")
    }

    /// Per-agent harness-internal state dir. Bind-mounted RW into the
    /// agent container at `/agents/{name}/harness`. Holds sqlite dbs
    /// and config files owned by the harness (`hyperhive-events.sqlite`,
    /// `hyperhive-turn-stats.sqlite`, `hyperhive-model`) — kept separate
    /// from the agent-visible `state/` so claude's "my notes" view is
    /// uncluttered and the host vacuum has a clean sweep root.
    pub fn agent_harness_dir(name: &str) -> PathBuf {
        Self::agent_state_root(name).join("harness")
    }

    /// Authoritative applied config repo. Hive-c0re-only.
    pub fn agent_applied_dir(name: &str) -> PathBuf {
        PathBuf::from(format!("{APPLIED_STATE_ROOT}/{name}"))
    }

    /// Enumerate names that have a persistent state dir under
    /// `/var/lib/hyperhive/agents/` (i.e. config / claude creds /
    /// notes survive). Includes both currently-existing containers and
    /// destroyed-but-kept tombstones; callers filter the latter by
    /// subtracting `lifecycle::list()`.
    #[must_use]
    pub fn kept_state_names() -> Vec<String> {
        let Ok(rd) = std::fs::read_dir(AGENT_STATE_ROOT) else {
            return Vec::new();
        };
        let mut out: Vec<String> = rd
            .flatten()
            .filter(|e| e.file_type().is_ok_and(|t| t.is_dir()))
            .filter_map(|e| e.file_name().into_string().ok())
            .collect();
        out.sort();
        out
    }
}