import {
    assertPublicFilePayload,
    BANK_CONFIG_FILE,
    PrivateFileOperationError,
    isPrivateConfigPath
} from '../fleet/private-config.js';
import { packFileJson, unpackFileJson, referenceBlobs } from '../db/file-blobs.js';
import { pruneHistory } from '../retention.js';
import { recordAgentReceipt } from '../provisioning/agent-events.js';
import { EventEmitter } from 'node:events';
import { createHash, randomBytes, randomUUID, timingSafeEqual } from 'node:crypto';
import { isIP } from 'node:net';
import { db } from '../db/index.js';
import {
    successfulObservation,
    routineObservationSql,
    importantOperationSql,
    operationTargetSql,
    safeOperationTarget
} from './observations.js';
import { currentOperationSource } from './operation-context.js';
import { logResultMetadata } from './log-results.js';
import { parseHostInventory } from './request-context.js';
import { fleetSettings } from '../settings.js';
import { recordInstanceResources, validateInstanceResources } from './calibration.js';
import { validateTemperatures } from '../../host-temperatures.js';
import { recordTemperatures } from './temperatures.js';
import { refreshHostAvailability, scheduleAvailabilityRefresh } from './availability.js';
import { hostAgentLaneLabel, hostAgentLaneState } from '../../hosts.js';
import type {
    Host,
    HostDecommission,
    HostDeletion,
    HostInventory,
    HostMode,
    HostOperation,
    HostOperationFilter,
    HostOperationHistoryPage,
    HostOperationScope,
    HostOperationState
} from '../../hosts.js';

export const AGENT_PROTOCOL_VERSION = 1;
export const HEARTBEAT_MAX_AGE_MS = 90_000;
const now = () => new Date().toISOString();
const workEvents = new EventEmitter();
// Hold reply bodies only while a reader is awaiting this operation. No TTL cache or disk copy.
const logReaders = new Map<string, Set<{ received: boolean; result?: unknown }>>();
workEvents.setMaxListeners(0);
export function waitForHostWork(
    hostId: string,
    signal: AbortSignal,
    timeoutMs = 20_000
): Promise<void> {
    return new Promise((resolve) => {
        const done = () => {
            clearTimeout(timer);
            workEvents.off(hostId, done);
            signal.removeEventListener('abort', done);
            resolve();
        };
        const timer = setTimeout(done, timeoutMs);
        workEvents.on(hostId, done);
        signal.addEventListener('abort', done, { once: true });
        if (signal.aborted) done();
    });
}
const digest = (token: string) => createHash('sha256').update(token).digest('hex');
function database() {
    return db();
}
type HostRow = {
    id: string;
    name: string;
    hostname: string;
    mode: HostMode;
    port_min: number;
    port_max: number;
    bind_address: string;
    public_address: string;
    minimum_free_bytes: number;
    created_at: string;
    enrolled_at: string | null;
    last_heartbeat: string | null;
    inventory: string;
    credential_active: number;
};
const hostSql = `SELECT h.*, EXISTS(SELECT 1 FROM ec_host_credentials c WHERE c.host_id = h.id AND c.revoked_at IS NULL) AS credential_active FROM ec_hosts h`;
type DecommissionRow = {
    host_id: string;
    operation_id: string;
    token_hash: string;
    stage: HostDecommission['stage'];
    requested_at: string;
    updated_at: string;
    cleaned_at: string | null;
    error: string | null;
};
function decommissionRow(hostId: string): DecommissionRow | undefined {
    return database().prepare('SELECT * FROM ec_host_decommissions WHERE host_id=?').get(hostId) as
        DecommissionRow | undefined;
}
function presentDecommission(row: DecommissionRow | undefined): HostDecommission | null {
    return row
        ? {
              operationId: row.operation_id,
              stage: row.stage,
              requestedAt: row.requested_at,
              updatedAt: row.updated_at,
              error: row.error,
              retryable:
                  row.stage === 'failed' &&
                  getHostOperationStatus(row.operation_id)?.state === 'failed'
          }
        : null;
}
function hostFromRow(row: HostRow): Host {
    const enabling = database()
        .prepare('SELECT requested_at FROM ec_host_enable_requests WHERE host_id=?')
        .get(row.id) as { requested_at: string } | undefined;
    const inventory = parseHostInventory(row.id, row.inventory);
    const connected =
        !!row.credential_active &&
        !!row.last_heartbeat &&
        Date.now() - Date.parse(row.last_heartbeat) <= HEARTBEAT_MAX_AGE_MS;
    const reasons: string[] = [];
    if (!row.enrolled_at) reasons.push('Agent has not enrolled.');
    else if (!row.credential_active) reasons.push('Agent credential has been revoked.');
    if (!connected) reasons.push('Agent heartbeat is unavailable or stale.');
    if (connected)
        for (const lane of inventory.agentLanes ?? []) {
            const state = hostAgentLaneState(lane);
            if (state === 'stopped' || state === 'stalled')
                reasons.push(
                    `Agent ${hostAgentLaneLabel(lane.name).toLowerCase()} worker is ${state}. Check the host agent service.`
                );
        }
    if (inventory.protocolVersion !== AGENT_PROTOCOL_VERSION)
        reasons.push('A compatible agent protocol is required.');
    if (!inventory.dockerRunning) reasons.push('Docker is not ready.');
    if (!inventory.directoriesWritable) reasons.push('Managed directories are not writable.');
    if (
        typeof inventory.storageAvailable !== 'number' ||
        inventory.storageAvailable < row.minimum_free_bytes
    )
        reasons.push('Insufficient available game storage.');
    const infrastructureReady = reasons.length === 0;
    const runtimeReady = !!inventory.preparedRuntimeImages?.length;
    const libraryReady = !!inventory.libraries?.some((library) => library.state === 'ready');
    if (!runtimeReady) reasons.push('The Plutainer runtime image is not ready yet.');
    if (!libraryReady) reasons.push('No verified game-file library is available yet.');
    if (row.mode === 'draining') reasons.push('Host is draining; new deployments are blocked.');
    if (row.mode === 'disabled')
        reasons.push(
            enabling
                ? 'Host setup must refresh the runtime and verify both BO1 and BO2 game files before enabling.'
                : 'Host is disabled.'
        );
    const decommission = presentDecommission(decommissionRow(row.id));
    if (decommission)
        reasons.push(
            'Host deletion is in progress; waiting for confirmed cleanup and agent removal.'
        );
    return {
        id: row.id,
        name: row.name,
        hostname: row.hostname,
        mode: row.mode,
        portMin: row.port_min,
        portMax: row.port_max,
        bindAddress: row.bind_address,
        publicAddress: row.public_address,
        minimumFreeBytes: row.minimum_free_bytes,
        createdAt: row.created_at,
        lastHeartbeat: row.last_heartbeat,
        connected,
        connectionState: connected ? 'online' : 'offline',
        enablingSince: enabling?.requested_at ?? null,
        readiness: decommission
            ? 'deleting'
            : enabling
              ? 'preparing'
              : row.mode === 'draining'
                ? 'draining'
                : row.mode === 'disabled'
                  ? 'disabled'
                  : !row.enrolled_at
                    ? 'preparing'
                    : !infrastructureReady
                      ? 'degraded'
                      : !runtimeReady
                        ? 'needs-runtime'
                        : !libraryReady
                          ? 'needs-game-files'
                          : 'ready',
        readinessReasons: reasons,
        inventory,
        enrolled: !!row.enrolled_at,
        credentialActive: !!row.credential_active,
        decommission
    };
}
export function listHosts(): Host[] {
    return (
        database()
            .prepare(hostSql + ' WHERE h.deleted_at IS NULL ORDER BY h.name, h.id')
            .all() as HostRow[]
    ).map(hostFromRow);
}
export function getHost(id: string): Host | null {
    const row = database()
        .prepare(hostSql + ' WHERE h.id = ? AND h.deleted_at IS NULL')
        .get(id) as HostRow | undefined;
    return row ? hostFromRow(row) : null;
}
function requireHost(id: string): Host {
    const host = getHost(id);
    if (!host) throw new Error('Host was not found.');
    return host;
}

export class HostDeletionError extends Error {
    constructor(
        message: string,
        readonly status: 400 | 401 | 404 | 409,
        readonly blockers: string[] = []
    ) {
        super(message);
    }
}

/** Controller records can be removed only after all remote instance ownership is resolved. */
export function hostDeletionStatus(id: string): HostDeletion {
    const host = getHost(id);
    if (!host) throw new HostDeletionError('Host not found.', 404);
    if (host.decommission && !host.decommission.retryable) return { allowed: true, blockers: [] };
    const handle = database();
    const blockers: string[] = [];
    if (host.enrolled && !host.inventory.capabilities?.includes('host.decommission'))
        blockers.push(
            'Update this host agent before deleting it: generate an installer from Agent access, rerun it on this host, and wait for a fresh heartbeat.'
        );
    if (host.enrolled && !host.credentialActive)
        blockers.push(
            'Re-enroll this host so its agent can receive and complete the cleanup request.'
        );
    const instances = handle
        .prepare(
            'SELECT server FROM native_instances WHERE host_id=? AND retired_at IS NULL ORDER BY server'
        )
        .all(id) as { server: string }[];
    if (instances.length) {
        const names =
            instances
                .slice(0, 5)
                .map((instance) => instance.server)
                .join(', ') + (instances.length > 5 ? ', …' : '');
        blockers.push(
            `Remove the ${instances.length} server instance${instances.length === 1 ? '' : 's'} assigned to this host first (${names}). Queued and failed deployments also require removal.`
        );
    }
    const pinned = handle
        .prepare(
            `SELECT d.server FROM server_deployments d
        JOIN native_creation_intents q ON q.deployment_id=d.id
        LEFT JOIN native_provisioning n ON n.deployment_id=d.id
        WHERE d.action='create' AND d.server_deleted_at IS NULL
        AND d.state IN ('queued','waiting','running','awaiting-health','interrupted') AND n.deployment_id IS NULL
        AND json_extract(q.selection,'$.hostId')=? AND COALESCE(json_extract(q.selection,'$.automatic'),0)!=1
        ORDER BY d.server LIMIT 6`
        )
        .all(id) as { server: string }[];
    if (pinned.length) {
        const names =
            pinned
                .slice(0, 5)
                .map((job) => job.server)
                .join(', ') + (pinned.length > 5 ? ', …' : '');
        blockers.push(
            `Cancel the queued server launches pinned to this host before deleting it (${names}).`
        );
    }
    const ports = handle
        .prepare('SELECT COUNT(*) AS count FROM ec_host_ports WHERE host_id=?')
        .get(id) as { count: number };
    if (ports.count && !instances.length)
        blockers.push(
            `This host still has ${ports.count} reserved game port${ports.count === 1 ? '' : 's'}. Finish or reconcile the corresponding server removals first.`
        );
    // A pending command may have reached the agent before its acknowledgement.
    // Only commands that have never been delivered are safe to cancel locally.
    const operations = handle
        .prepare(
            `SELECT kind,state FROM ec_host_operations WHERE host_id=?
        AND (state IN ('accepted','running','unknown') OR (state='pending' AND last_delivered_at IS NOT NULL))
        ORDER BY created_at`
        )
        .all(id) as { kind: string; state: string }[];
    if (operations.length) {
        const work =
            operations
                .slice(0, 5)
                .map((operation) => `${operation.kind}: ${operation.state}`)
                .join(', ') + (operations.length > 5 ? ', …' : '');
        blockers.push(
            `${operations.length} delivered operation${operations.length === 1 ? ' is' : 's are'} unresolved (${work}). Let the agent reconnect and finish or reconcile this work before deleting the host.`
        );
    }
    return { allowed: blockers.length === 0, blockers };
}

/** Keep the host visible and authenticated until its independent cleanup worker proves removal. */
export function deleteHost(id: string): { deleted: boolean; operationId?: string } {
    const handle = database();
    return handle
        .transaction(() => {
            const host = getHost(id);
            if (!host) throw new HostDeletionError('Host not found.', 404);
            if (host.decommission && !host.decommission.retryable)
                return { deleted: false, operationId: host.decommission.operationId };
            const status = hostDeletionStatus(id);
            if (!status.allowed)
                throw new HostDeletionError(status.blockers.join(' '), 409, status.blockers);
            const timestamp = now();
            const reason =
                'Host deletion requested before this operation was delivered to the agent.';
            handle
                .prepare(
                    `INSERT INTO ec_host_operation_events(operation_id,state,created_at,error)
            SELECT id,'failed',?,? FROM ec_host_operations WHERE host_id=? AND state='pending' AND last_delivered_at IS NULL`
                )
                .run(timestamp, reason, id);
            handle
                .prepare(
                    "UPDATE ec_host_operations SET state='failed',error=?,updated_at=? WHERE host_id=? AND state='pending' AND last_delivered_at IS NULL"
                )
                .run(reason, timestamp, id);
            handle
                .prepare(
                    'UPDATE ec_host_enrollments SET consumed_at=? WHERE host_id=? AND consumed_at IS NULL'
                )
                .run(timestamp, id);
            if (!host.enrolled) {
                handle
                    .prepare(
                        "UPDATE ec_hosts SET deleted_at=?,mode='disabled' WHERE id=? AND deleted_at IS NULL"
                    )
                    .run(timestamp, id);
                return { deleted: true };
            }
            const operationId = randomUUID();
            const token = 'ec_cleanup_' + randomBytes(32).toString('base64url');
            const payload = {
                hostId: id,
                operationId,
                receiptToken: token,
                receiptUrl: `/api/agent/decommission/${operationId}`
            };
            handle
                .prepare(
                    "INSERT INTO ec_host_operations(id,host_id,kind,payload,state,created_at,updated_at,source) VALUES(?,?,'host.decommission',?,'pending',?,?,?)"
                )
                .run(
                    operationId,
                    id,
                    JSON.stringify(payload),
                    timestamp,
                    timestamp,
                    (currentOperationSource() ?? 'Controller').slice(0, 200)
                );
            handle
                .prepare(
                    "INSERT INTO ec_host_operation_events(operation_id,state,created_at) VALUES(?,'pending',?)"
                )
                .run(operationId, timestamp);
            handle
                .prepare(
                    `INSERT INTO ec_host_decommissions(host_id,operation_id,token_hash,requested_at,updated_at) VALUES(?,?,?,?,?)
            ON CONFLICT(host_id) DO UPDATE SET operation_id=excluded.operation_id,token_hash=excluded.token_hash,stage='queued',requested_at=excluded.requested_at,updated_at=excluded.updated_at,cleaned_at=NULL,error=NULL`
                )
                .run(id, operationId, digest(token), timestamp, timestamp);
            handle.prepare("UPDATE ec_hosts SET mode='draining' WHERE id=?").run(id);
            queueMicrotask(() => workEvents.emit(id));
            return { deleted: false, operationId };
        })
        .immediate();
}

export function receiveDecommissionReceipt(
    operationId: string,
    token: string,
    input: Record<string, unknown>
): { acknowledged: true } {
    if (!token || token.length > 200)
        throw new HostDeletionError('A valid cleanup receipt credential is required.', 401);
    return database()
        .transaction(() => {
            const row = database()
                .prepare('SELECT * FROM ec_host_decommissions WHERE operation_id=?')
                .get(operationId) as DecommissionRow | undefined;
            if (
                !row ||
                !timingSafeEqual(
                    Buffer.from(row.token_hash, 'hex'),
                    Buffer.from(digest(token), 'hex')
                )
            )
                throw new HostDeletionError('A valid cleanup receipt credential is required.', 401);
            if (!['cleaned', 'completed', 'failed'].includes(input.stage as string))
                throw new HostDeletionError('Invalid cleanup receipt stage.', 400);
            if (row.stage === 'completed') return { acknowledged: true as const };
            const operation = getHostOperationStatus(operationId)!;
            if (!['accepted', 'running', 'unknown'].includes(operation.state))
                throw new HostDeletionError('Cleanup has not been accepted by the host.', 409);
            const timestamp = now();
            if (input.stage === 'failed') {
                database()
                    .prepare(
                        "UPDATE ec_host_decommissions SET stage='failed',error=?,updated_at=? WHERE host_id=?"
                    )
                    .run(
                        typeof input.error === 'string'
                            ? input.error.slice(0, 2000)
                            : 'Host cleanup needs attention. The cleanup worker will retry.',
                        timestamp,
                        row.host_id
                    );
                return { acknowledged: true as const };
            }
            if (input.stage === 'cleaned') {
                database()
                    .prepare(
                        "UPDATE ec_host_decommissions SET stage='cleaned',cleaned_at=COALESCE(cleaned_at,?),error=NULL,updated_at=? WHERE host_id=?"
                    )
                    .run(timestamp, timestamp, row.host_id);
                return { acknowledged: true as const };
            }
            if (!row.cleaned_at)
                throw new HostDeletionError(
                    'The host must confirm file cleanup before confirming agent removal.',
                    409
                );
            database()
                .prepare(
                    "UPDATE ec_host_decommissions SET stage='completed',error=NULL,updated_at=? WHERE host_id=?"
                )
                .run(timestamp, row.host_id);
            database()
                .prepare(
                    "UPDATE ec_host_operations SET state='completed',result=?,error=NULL,updated_at=? WHERE id=?"
                )
                .run(
                    JSON.stringify({ filesRemoved: true, agentRemoved: true }),
                    timestamp,
                    operationId
                );
            database()
                .prepare(
                    "INSERT INTO ec_host_operation_events(operation_id,state,created_at) VALUES(?,'completed',?)"
                )
                .run(operationId, timestamp);
            database()
                .prepare(
                    'UPDATE ec_host_credentials SET revoked_at=? WHERE host_id=? AND revoked_at IS NULL'
                )
                .run(timestamp, row.host_id);
            database()
                .prepare(
                    'UPDATE ec_host_enrollments SET consumed_at=? WHERE host_id=? AND consumed_at IS NULL'
                )
                .run(timestamp, row.host_id);
            if (
                database()
                    .prepare(
                        "SELECT 1 FROM sqlite_master WHERE type='table' AND name='host_library_caches'"
                    )
                    .get()
            ) {
                database()
                    .prepare(
                        "UPDATE host_library_caches SET status='missing',bytes_downloaded=0,manifest_sha256=NULL,error=NULL,updated_at=? WHERE host_id=?"
                    )
                    .run(timestamp, row.host_id);
            }
            database()
                .prepare("UPDATE ec_hosts SET deleted_at=?,mode='disabled' WHERE id=?")
                .run(timestamp, row.host_id);
            return { acknowledged: true as const };
        })
        .immediate();
}
function textField(value: unknown, label: string, max = 200): string {
    if (
        typeof value !== 'string' ||
        !value.trim() ||
        value.length > max ||
        // eslint-disable-next-line no-control-regex -- Reject control characters in host text fields.
        /[\x00-\x1f]/.test(value)
    )
        throw new Error(`${label} must be a nonempty string up to ${max} characters.`);
    return value.trim();
}
function port(value: unknown): number {
    if (typeof value !== 'number' || !Number.isInteger(value) || value < 1 || value > 65535)
        throw new Error('Ports must be whole numbers between 1 and 65535.');
    return value;
}
export function createHost(input: Record<string, unknown>): Host {
    const id = randomUUID();
    const name = textField(input.name, 'Host name');
    const min = port(input.portMin ?? 28960);
    const max = port(input.portMax ?? 28980);
    if (max < min) throw new Error('The last game port must not precede the first.');
    const bind =
        input.bindAddress === undefined ? '0.0.0.0' : textField(input.bindAddress, 'Bind address');
    if (!isIP(bind)) throw new Error('Bind address must be an IPv4 or IPv6 address.');
    database()
        .prepare(
            'INSERT INTO ec_hosts(id,name,port_min,port_max,bind_address,created_at) VALUES(?,?,?,?,?,?)'
        )
        .run(id, name, min, max, bind, now());
    scheduleAvailabilityRefresh();
    return requireHost(id);
}
export function updateHost(id: string, input: Record<string, unknown>): Host {
    const host = requireHost(id);
    if (host.decommission)
        throw new Error('Host cleanup is in progress; its settings cannot change.');
    const name = input.name === undefined ? host.name : textField(input.name, 'Host name');
    let mode = input.mode ?? host.mode;
    if (!['active', 'draining', 'disabled'].includes(mode as string))
        throw new Error('Host mode must be active, draining, or disabled.');
    const min = port(input.portMin ?? host.portMin);
    const max = port(input.portMax ?? host.portMax);
    if (max < min) throw new Error('The last game port must not precede the first.');
    const bind =
        input.bindAddress === undefined
            ? host.bindAddress
            : textField(input.bindAddress, 'Bind address');
    if (!isIP(bind)) throw new Error('Bind address must be an IPv4 or IPv6 address.');
    const publicAddress =
        input.publicAddress === undefined
            ? host.publicAddress
            : input.publicAddress === ''
              ? ''
              : textField(input.publicAddress, 'Public address');
    const minimum = input.minimumFreeBytes ?? host.minimumFreeBytes;
    if (typeof minimum !== 'number' || !Number.isSafeInteger(minimum) || minimum < 0)
        throw new Error('Minimum free storage must be a nonnegative byte count.');
    database().transaction(() => {
        if (input.mode === 'active' && host.mode === 'draining')
            throw new Error('Wait for this host to finish draining before enabling it.');
        if (input.mode === 'active' && host.mode === 'disabled') {
            database()
                .prepare(
                    'INSERT OR IGNORE INTO ec_host_enable_requests(host_id,requested_at,operation_floor) VALUES(?,?,(SELECT COALESCE(MAX(rowid),0) FROM ec_host_operations))'
                )
                .run(id, now());
            mode = 'disabled';
        }
        if (input.mode === 'draining') {
            if (host.enablingSince)
                throw new Error('Wait for automatic host setup to finish before draining.');
            const incoming = database()
                .prepare(
                    `SELECT 1 FROM ec_host_migrations m JOIN server_deployments d ON d.id=m.deployment_id
                WHERE m.target_host_id=? AND d.state NOT IN ('done','warning') AND d.server_deleted_at IS NULL LIMIT 1`
                )
                .get(id);
            if (incoming)
                throw new Error(
                    'Wait for incoming instance migrations to finish before draining this host.'
                );
        }
        database()
            .prepare(
                'UPDATE ec_hosts SET name=?,mode=?,port_min=?,port_max=?,bind_address=?,public_address=?,minimum_free_bytes=? WHERE id=?'
            )
            .run(name, mode, min, max, bind, publicAddress, minimum, id);
    })();
    scheduleAvailabilityRefresh();
    return requireHost(id);
}

export function createEnrollment(
    hostId: string,
    ttlMs = 15 * 60_000
): { id: string; hostId: string; token: string; expiresAt: string } {
    const host = requireHost(hostId);
    if (host.decommission && !host.decommission.retryable)
        throw new Error('Host cleanup is in progress; enrollment is unavailable.');
    if (!Number.isInteger(ttlMs) || ttlMs <= 0 || ttlMs > 60 * 60_000)
        throw new Error('Enrollment lifetime must be at most one hour.');
    const token = 'ec_enroll_' + randomBytes(32).toString('base64url');
    const id = randomUUID();
    const expiresAt = new Date(Date.now() + ttlMs).toISOString();
    database().transaction(() => {
        database()
            .prepare(
                'UPDATE ec_host_enrollments SET consumed_at=? WHERE host_id=? AND consumed_at IS NULL'
            )
            .run(now(), hostId);
        database()
            .prepare(
                'INSERT INTO ec_host_enrollments(id,host_id,token_hash,created_at,expires_at) VALUES(?,?,?,?,?)'
            )
            .run(id, hostId, digest(token), now(), expiresAt);
    })();
    return { id, hostId, token, expiresAt };
}
function issueCredential(
    hostId: string,
    credential = 'ec_host_' + randomBytes(32).toString('base64url')
): string {
    database()
        .prepare(
            'INSERT INTO ec_host_credentials(id,host_id,token_hash,created_at) VALUES(?,?,?,?)'
        )
        .run(randomUUID(), hostId, digest(credential), now());
    return credential;
}
export function validateInventory(value: unknown): HostInventory {
    if (!value || typeof value !== 'object' || Array.isArray(value))
        throw new Error('Host inventory must be an object.');
    const inventory = value as HostInventory;
    if (JSON.stringify(inventory).length > 256_000) throw new Error('Host inventory is too large.');
    if (inventory.temperatures !== undefined)
        inventory.temperatures = validateTemperatures(inventory.temperatures);
    for (const key of ['hostname', 'agentVersion', 'os', 'architecture', 'cpu', 'dockerVersion']) {
        if (
            inventory[key] !== undefined &&
            (typeof inventory[key] !== 'string' || String(inventory[key]).length > 1000)
        )
            throw new Error(`Invalid inventory ${key}.`);
    }
    for (const key of [
        'cpuCount',
        'memoryTotal',
        'memoryAvailable',
        'storageTotal',
        'storageAvailable',
        'protocolVersion'
    ]) {
        if (
            inventory[key] !== undefined &&
            (typeof inventory[key] !== 'number' ||
                !Number.isSafeInteger(inventory[key]) ||
                Number(inventory[key]) < 0)
        )
            throw new Error(`Invalid inventory ${key}.`);
    }
    if (
        inventory.cpuUsagePercent !== undefined &&
        (typeof inventory.cpuUsagePercent !== 'number' ||
            !Number.isFinite(inventory.cpuUsagePercent) ||
            inventory.cpuUsagePercent < 0 ||
            inventory.cpuUsagePercent > 100)
    )
        throw new Error('Invalid inventory cpuUsagePercent.');
    validateInstanceResources(inventory);
    if (inventory.instanceStates !== undefined) {
        if (!Array.isArray(inventory.instanceStates) || inventory.instanceStates.length > 1000) {
            throw new Error('Invalid instance state inventory.');
        }
        // A malformed server observation must not discard the host heartbeat.
        inventory.instanceStates = inventory.instanceStates.filter(
            (state) =>
                state &&
                typeof state === 'object' &&
                typeof state.instanceId === 'string' &&
                /^[A-Za-z0-9][A-Za-z0-9_-]{0,127}$/.test(state.instanceId) &&
                Number.isSafeInteger(state.generation) &&
                state.generation >= 1 &&
                typeof state.state === 'string' &&
                /^[a-z-]{1,40}$/.test(state.state) &&
                typeof state.healthy === 'boolean' &&
                (!state.healthy || state.state === 'running') &&
                typeof state.observedAt === 'string' &&
                state.observedAt.length <= 40 &&
                Number.isFinite(Date.parse(state.observedAt))
        );
    }
    for (const key of ['dockerRunning', 'directoriesWritable'])
        if (inventory[key] !== undefined && typeof inventory[key] !== 'boolean')
            throw new Error(`Invalid inventory ${key}.`);
    for (const key of ['runtimeImages', 'preparedRuntimeImages'] as const) {
        const images = inventory[key];
        if (
            images !== undefined &&
            (!Array.isArray(images) || images.some((image) => typeof image !== 'string'))
        )
            throw new Error('Invalid runtime image inventory.');
    }
    if (
        inventory.capabilities !== undefined &&
        (!Array.isArray(inventory.capabilities) ||
            inventory.capabilities.length > 32 ||
            inventory.capabilities.some((value) => typeof value !== 'string' || value.length > 80))
    )
        throw new Error('Invalid agent capability inventory.');
    if (inventory.plutoniumCache !== undefined) {
        const cache = inventory.plutoniumCache;
        if (
            !cache ||
            typeof cache !== 'object' ||
            Array.isArray(cache) ||
            !Number.isSafeInteger(cache.revision) ||
            cache.revision < 1 ||
            !Number.isSafeInteger(cache.bytes) ||
            cache.bytes < 0
        )
            throw new Error('Invalid Plutonium cache inventory.');
        inventory.plutoniumCache = { revision: cache.revision, bytes: cache.bytes };
    }
    if (inventory.agentUpdate !== undefined) {
        const update = inventory.agentUpdate;
        const version = (value: unknown) =>
            typeof value === 'string' && value.length <= 80 && /^\d+\.\d+\.\d+$/.test(value);
        if (
            !update ||
            typeof update !== 'object' ||
            Array.isArray(update) ||
            typeof update.enabled !== 'boolean' ||
            !['current', 'checking', 'deferred', 'updating', 'updated', 'failed'].includes(
                update.state
            ) ||
            !version(update.currentVersion) ||
            (update.targetVersion !== undefined && !version(update.targetVersion)) ||
            (update.error !== undefined &&
                (typeof update.error !== 'string' || update.error.length > 2000)) ||
            (update.checkedAt !== undefined &&
                (typeof update.checkedAt !== 'string' ||
                    update.checkedAt.length > 80 ||
                    !Number.isFinite(Date.parse(update.checkedAt))))
        ) {
            throw new Error('Invalid agent update inventory.');
        }
        // Only expose display fields, never the local recovery journal or secrets.
        inventory.agentUpdate = {
            enabled: update.enabled,
            state: update.state,
            currentVersion: update.currentVersion,
            ...(update.targetVersion === undefined ? {} : { targetVersion: update.targetVersion }),
            ...(update.error === undefined ? {} : { error: update.error }),
            ...(update.checkedAt === undefined ? {} : { checkedAt: update.checkedAt })
        };
    }
    if (inventory.agentLanes !== undefined) {
        if (!Array.isArray(inventory.agentLanes) || inventory.agentLanes.length > 4)
            throw new Error('Invalid agent lane inventory.');
        // Keep valid lane diagnostics without discarding a host heartbeat over
        // one malformed sample. Do not persist thread details or raw errors.
        const names = new Set<string>();
        inventory.agentLanes = inventory.agentLanes
            .filter((lane) => {
                if (
                    !lane ||
                    !['health-1', 'health-2', 'read', 'write'].includes(lane.name) ||
                    names.has(lane.name) ||
                    typeof lane.alive !== 'boolean' ||
                    typeof lane.busy !== 'boolean' ||
                    typeof lane.pollAgeSeconds !== 'number' ||
                    !Number.isFinite(lane.pollAgeSeconds) ||
                    lane.pollAgeSeconds < 0 ||
                    (lane.lastPollAt !== null &&
                        (typeof lane.lastPollAt !== 'string' ||
                            lane.lastPollAt.length > 40 ||
                            !Number.isFinite(Date.parse(lane.lastPollAt))))
                )
                    return false;
                names.add(lane.name);
                return true;
            })
            .map(({ name, alive, busy, lastPollAt, pollAgeSeconds }) => ({
                name,
                alive,
                busy,
                lastPollAt,
                pollAgeSeconds
            }));
    }
    if (
        inventory.libraries !== undefined &&
        (!Array.isArray(inventory.libraries) ||
            inventory.libraries.length > 2000 ||
            inventory.libraries.some(
                (library) =>
                    !library ||
                    typeof library !== 'object' ||
                    typeof library.id !== 'string' ||
                    !library.id ||
                    library.id.length > 200 ||
                    ![
                        'missing',
                        'downloading',
                        'verifying',
                        'ready',
                        'failed',
                        'outdated'
                    ].includes(library.state)
            ))
    )
        throw new Error('Invalid game library inventory.');
    return inventory;
}
export function enrollHost(
    token: unknown,
    rawInventory: unknown
): { hostId: string; credential: string; heartbeatSeconds: number } {
    if (typeof token !== 'string' || token.length > 200)
        throw new Error('Enrollment token is invalid or expired.');
    const inventory = validateInventory(rawInventory);
    return database().transaction(() => {
        const enrollment = database()
            .prepare(
                'SELECT id,host_id FROM ec_host_enrollments WHERE token_hash=? AND consumed_at IS NULL AND expires_at>?'
            )
            .get(digest(token), now()) as { id: string; host_id: string } | undefined;
        if (!enrollment) throw new Error('Enrollment token is invalid or expired.');
        const changed = database()
            .prepare(
                'UPDATE ec_host_enrollments SET consumed_at=? WHERE id=? AND consumed_at IS NULL'
            )
            .run(now(), enrollment.id);
        if (changed.changes !== 1) throw new Error('Enrollment token has already been consumed.');
        revokeCredentials(enrollment.host_id);
        const credential = issueCredential(enrollment.host_id);
        database()
            .prepare(
                'UPDATE ec_hosts SET enrolled_at=?,last_heartbeat=?,hostname=?,inventory=? WHERE id=?'
            )
            .run(
                now(),
                now(),
                inventory.hostname ?? '',
                JSON.stringify(inventory),
                enrollment.host_id
            );
        recordResources(enrollment.host_id, inventory, now());
        scheduleAvailabilityRefresh();
        return { hostId: enrollment.host_id, credential, heartbeatSeconds: 15 };
    })();
}
export function authenticateCredential(token: string): Host | null {
    if (!token || token.length > 200) return null;
    const row = database()
        .prepare(
            'SELECT id,host_id,last_used_at FROM ec_host_credentials WHERE token_hash=? AND revoked_at IS NULL'
        )
        .get(digest(token)) as
        { id: string; host_id: string; last_used_at: string | null } | undefined;
    if (!row) return null;
    const timestamp = Date.now();
    if (row.last_used_at === null || timestamp - Date.parse(row.last_used_at) >= 60_000) {
        database()
            .prepare(
                `UPDATE ec_host_credentials SET last_used_at=? WHERE id=? AND revoked_at IS NULL
            AND (last_used_at IS NULL OR last_used_at<=?)`
            )
            .run(
                new Date(timestamp).toISOString(),
                row.id,
                new Date(timestamp - 60_000).toISOString()
            );
    }
    return getHost(row.host_id);
}
export function revokeCredentials(hostId: string): void {
    const host = requireHost(hostId);
    if (host.decommission && !host.decommission.retryable)
        throw new Error('Host cleanup needs its credentials until removal is confirmed.');
    database()
        .prepare(
            'UPDATE ec_host_credentials SET revoked_at=? WHERE host_id=? AND revoked_at IS NULL'
        )
        .run(now(), hostId);
    scheduleAvailabilityRefresh();
}
export function rotateCredential(hostId: string, nextCredential?: string): string {
    requireHost(hostId);
    if (nextCredential !== undefined && !/^ec_host_[A-Za-z0-9_-]{43}$/.test(nextCredential))
        throw new Error('New credentials must contain 32 random bytes encoded as base64url.');
    return database().transaction(() => {
        if (nextCredential) {
            const existing = database()
                .prepare('SELECT host_id,revoked_at FROM ec_host_credentials WHERE token_hash=?')
                .get(digest(nextCredential)) as
                { host_id: string; revoked_at: string | null } | undefined;
            if (existing) {
                if (existing.host_id !== hostId || existing.revoked_at)
                    throw new Error('This credential cannot be reused.');
                // A lost rotation response is retried with the persisted replacement.
                // This acknowledges an active credential without authorizing another rotation.
                return nextCredential;
            }
        }
        const operation = database()
            .prepare(
                `SELECT id FROM ec_host_operations WHERE host_id=? AND kind='credentials.rotate'
                AND state IN ('pending','accepted','running','unknown') ORDER BY created_at,rowid LIMIT 1`
            )
            .get(hostId) as { id: string } | undefined;
        if (!operation)
            throw new Error('Credential rotation requires an open administrator request.');
        revokeCredentials(hostId);
        const credential = issueCredential(hostId, nextCredential);
        reportHostOperationStatus(hostId, operation.id, {
            state: 'completed',
            result: { rotated: true }
        });
        return credential;
    })();
}
export function heartbeat(hostId: string, value: unknown): Host {
    requireHost(hostId);
    const inventory = validateInventory(value);
    database().transaction(() => {
        const timestamp = now();
        database()
            .prepare('UPDATE ec_hosts SET last_heartbeat=?,hostname=?,inventory=? WHERE id=?')
            .run(timestamp, inventory.hostname ?? '', JSON.stringify(inventory), hostId);
        recordResources(hostId, inventory, timestamp);
    })();
    const host = requireHost(hostId);
    refreshHostAvailability(host);
    return host;
}

function recordResources(hostId: string, inventory: HostInventory, timestamp: string): void {
    recordInstanceResources(hostId, inventory, timestamp);
    recordTemperatures(hostId, inventory, timestamp);
    database()
        .prepare(
            `INSERT OR REPLACE INTO ec_host_resource_samples
        (host_id,sampled_at,cpu_count,cpu_usage_percent,memory_total,memory_available) VALUES(?,?,?,?,?,?)`
        )
        .run(
            hostId,
            timestamp,
            inventory.cpuCount ?? null,
            inventory.cpuUsagePercent ?? null,
            inventory.memoryTotal ?? null,
            inventory.memoryAvailable ?? null
        );
    if (fleetSettings().hostResourceKeepDays)
        database()
            .prepare('DELETE FROM ec_host_resource_samples WHERE host_id=? AND sampled_at<?')
            .run(
                hostId,
                new Date(
                    Date.parse(timestamp) - fleetSettings().hostResourceKeepDays * 86400_000
                ).toISOString()
            );
}
export function requireReadyHost(
    hostId: string,
    options: {
        libraryId?: string;
        requiredBytes?: number;
        image?: string;
        port?: number;
        bindAddress?: string;
        protocol?: 'udp' | 'tcp';
    } = {}
): Host {
    const host = requireHost(hostId);
    const reasons = [...host.readinessReasons];
    if (
        options.requiredBytes !== undefined &&
        (host.inventory.storageAvailable ?? 0) < options.requiredBytes + host.minimumFreeBytes
    )
        reasons.push('Insufficient storage for this deployment.');
    if (
        options.libraryId &&
        !host.inventory.libraries?.some(
            (library) => library.id === options.libraryId && library.state === 'ready'
        )
    )
        reasons.push('The selected game library is not ready on this host.');
    if (options.image && !host.inventory.preparedRuntimeImages?.includes(options.image))
        reasons.push('The selected runtime image is not prepared on this host.');
    if (
        options.port !== undefined &&
        !hostPortAvailable(hostId, options.port, options.bindAddress, options.protocol)
    )
        reasons.push('The selected host port is not available.');
    if (reasons.length) throw new Error(reasons.join(' '));
    return host;
}

export type OperationRow = {
    id: string;
    host_id: string;
    kind: string;
    instance_id: string | null;
    generation: number | null;
    payload: string;
    state: HostOperationState;
    result: string | null;
    error: string | null;
    created_at: string;
    updated_at: string;
};
export type OperationDeliveryRow = Omit<OperationRow, 'payload'>;
export type HostOperationStatus = Omit<HostOperation, 'payload'>;
const operationStatusColumns =
    'o.id,o.host_id,o.kind,o.instance_id,o.generation,o.state,o.result,o.error,o.created_at,o.updated_at';
const operationPayloadSql =
    'COALESCE((SELECT p.payload FROM ec_host_operation_payloads p WHERE p.operation_id=o.id),o.payload)';
const readOnlyOperationSql = `(o.kind IN ('host.inspect','instance.inspect','rcon.status-batch','files.read','files.list','files.stat','files.manifest','logs.read')
    OR (o.kind='rcon.execute' AND COALESCE(json_extract(${operationPayloadSql},'$.command') IN ('status','getstatus','version'),0)))`;
/** Optional cache downloads yield their write lane to deployments and host changes. */
export function shouldDeferPlutoniumPreparation(hostId: string): boolean {
    return !!database()
        .prepare(
            `SELECT 1 FROM ec_host_operations o WHERE o.host_id=?
        AND o.state IN ('pending','accepted','running','unknown') AND o.kind!='plutonium.prepare'
        AND NOT ${readOnlyOperationSql} LIMIT 1`
        )
        .get(hostId);
}
function operationStatusFromRow(row: Omit<OperationRow, 'payload'>): HostOperationStatus {
    return {
        id: row.id,
        hostId: row.host_id,
        kind: row.kind,
        instanceId: row.instance_id,
        generation: row.generation,
        state: row.state,
        result: row.result === null ? null : JSON.parse(row.result),
        error: row.error,
        createdAt: row.created_at,
        updatedAt: row.updated_at
    };
}
function operationFromRow(row: OperationRow): HostOperation {
    const status = operationStatusFromRow(row);
    return {
        ...status,
        result: unpackFileJson(status.result),
        payload: unpackFileJson(JSON.parse(row.payload))
    };
}
export function getHostOperation(id: string): HostOperation | null {
    const row = database()
        .prepare(
            `SELECT ${operationStatusColumns},${operationPayloadSql} AS payload FROM ec_host_operations o WHERE o.id=?`
        )
        .get(id) as OperationRow | undefined;
    return row ? operationFromRow(row) : null;
}
/** Polling and receipts need the outcome, never another copy of launch files. */
export function getHostOperationStatus(id: string): HostOperationStatus | null {
    const row = database()
        .prepare(
            'SELECT id,host_id,kind,instance_id,generation,state,result,error,created_at,updated_at FROM ec_host_operations WHERE id=?'
        )
        .get(id) as Omit<OperationRow, 'payload'> | undefined;
    return row ? operationStatusFromRow(row) : null;
}
export function listHostOperations(hostId: string, limit = 100, summary = false): HostOperation[] {
    const columns = summary
        ? `o.id,o.host_id,o.kind,o.instance_id,o.generation,o.state,o.error,o.created_at,o.updated_at,'{}' AS payload,NULL AS result`
        : `${operationStatusColumns},${operationPayloadSql} AS payload`;
    return (
        database()
            .prepare(
                `SELECT ${columns} FROM ec_host_operations o WHERE o.host_id=? AND o.history_expired_at IS NULL ORDER BY o.created_at DESC,o.rowid DESC LIMIT ?`
            )
            .all(hostId, Math.min(500, Math.max(1, limit))) as OperationRow[]
    ).map(operationFromRow);
}
/** Browse retained history without loading command payloads or credential-bearing results. */
export function listHostOperationHistory(
    page = 1,
    filter: HostOperationFilter = 'important',
    scope: HostOperationScope = {}
): HostOperationHistoryPage {
    const handle = database();
    const pageSize = 25;
    const conditions =
        filter === 'all'
            ? []
            : [filter === 'routine' ? 'o.routine=1' : `(${importantOperationSql})`];
    conditions.push('o.history_expired_at IS NULL');
    const parameters: string[] = [];
    if (scope.host) {
        conditions.push('o.host_id=?');
        parameters.push(scope.host);
    }
    if (scope.server) {
        conditions.push('o.server_name=?');
        parameters.push(scope.server);
    }
    if (scope.operation) {
        conditions.push('o.id=?');
        parameters.push(scope.operation);
    }
    const where = conditions.length ? `WHERE ${conditions.join(' AND ')}` : '';
    return handle.transaction((): HostOperationHistoryPage => {
        const countColumn = filter === 'all' ? 'total' : filter;
        // An exact operation seeks its unique ID instead of paging through history.
        const total = scope.operation
            ? ((
                  handle
                      .prepare(`SELECT 1 AS total FROM ec_host_operations o ${where}`)
                      .get(...parameters) as { total: number } | undefined
              )?.total ?? 0)
            : ((
                  handle
                      .prepare(
                          `SELECT ${countColumn} AS total FROM ec_host_operation_history_counts WHERE host_id=? AND server_name=?`
                      )
                      .get(scope.host ?? '', scope.server ?? '') as { total: number } | undefined
              )?.total ?? 0);
        const totalPages = Math.max(1, Math.ceil(total / pageSize));
        const currentPage = Math.min(totalPages, Number.isSafeInteger(page) && page > 0 ? page : 1);
        const operations = handle
            .prepare(
                `SELECT o.id,o.host_id AS hostId,h.name AS hostName,o.kind,
            o.instance_id AS instanceId,o.generation,o.state,
            CASE WHEN o.routine=1 AND o.state='completed' AND o.observation_success=0
                THEN COALESCE(NULLIF(o.error,''),'Observation reported a problem') ELSE o.error END AS error,
            o.created_at AS createdAt,o.updated_at AS updatedAt,o.routine,o.server_name AS serverName,o.target_path AS targetPath,o.source
            FROM ec_host_operations o LEFT JOIN ec_hosts h ON h.id=o.host_id AND h.deleted_at IS NULL
            ${where}
            ORDER BY o.created_at DESC,o.rowid DESC LIMIT ? OFFSET ?`
            )
            .all(
                ...parameters,
                pageSize,
                (currentPage - 1) * pageSize
            ) as HostOperationHistoryPage['operations'];
        return {
            operations: operations.map((operation) => ({
                ...operation,
                routine: !!operation.routine,
                targetPath: safeOperationTarget(operation.kind, operation.targetPath)
            })),
            filter,
            page: currentPage,
            pageSize,
            total,
            totalPages
        };
    })();
}

/** Bound each cleanup pass so retained history cannot stall monitoring or receipts. */
export function pruneHostObservations(): number {
    return pruneHistory('observation');
}
/** Heartbeats stop either launch generation at its next safe command boundary. */
export function pendingCreationCancellations(hostId: string): string[] {
    const rows = database()
        .prepare(
            `SELECT json_extract(payload,'$.createOperationId') AS creation_id,
        json_extract(payload,'$.recoveryRebuildOperationId') AS recovery_id FROM ec_host_operations
        WHERE host_id=? AND kind='instance.cancel-create' AND state IN ('pending','accepted','running','unknown')`
        )
        .all(hostId) as { creation_id: string; recovery_id: string | null }[];
    return rows.flatMap((row) =>
        row.recovery_id ? [row.creation_id, row.recovery_id] : [row.creation_id]
    );
}
type QueueHostOperationOptions = {
    instanceId?: string;
    generation?: number;
    idempotencyKey?: string;
    id?: string;
};
export function queueHostOperation(
    hostId: string,
    kind: string,
    payload: Record<string, unknown>,
    options: QueueHostOperationOptions = {}
): HostOperation {
    if (!payload || typeof payload !== 'object' || Array.isArray(payload))
        throw new Error('Operation payload must be an object.');
    const operation = enqueueHostOperation(hostId, kind, JSON.stringify(payload), options);
    return getHostOperation(operation.id)!;
}
/** Keep immutable launch bytes separate so receipts and delivery do not rewrite large payloads. */
export function queueHostOperationSerialized(
    hostId: string,
    kind: string,
    payload: Buffer,
    options: QueueHostOperationOptions = {},
    routingPayload: Record<string, unknown> = {}
): HostOperationStatus {
    if (!Buffer.isBuffer(payload) || payload[0] !== 123 || payload[payload.length - 1] !== 125)
        throw new Error('Serialized operation payload must be a JSON object.');
    if (!routingPayload || typeof routingPayload !== 'object' || Array.isArray(routingPayload))
        throw new Error('Operation routing payload must be an object.');
    return enqueueHostOperation(hostId, kind, payload, options, JSON.stringify(routingPayload));
}
function enqueueHostOperation(
    hostId: string,
    kind: string,
    payload: string | Buffer,
    options: QueueHostOperationOptions,
    routingPayload?: string
): HostOperationStatus {
    const host = requireHost(hostId);
    if (host.decommission)
        throw new Error('Host cleanup is in progress; new operations are blocked.');
    if (kind === 'host.decommission')
        throw new Error('Use the host deletion workflow to request cleanup.');
    if (!/^[a-z][a-z0-9_.-]{0,79}$/.test(kind)) throw new Error('Invalid operation kind.');
    if (
        options.generation !== undefined &&
        (!Number.isSafeInteger(options.generation) || options.generation < 1)
    )
        throw new Error('Instance generation must be a positive integer.');
    const operation = database().transaction(() => {
        if (options.idempotencyKey) {
            const existing = database()
                .prepare(
                    `SELECT o.id,o.kind,o.instance_id,o.generation,o.history_expired_at,o.request_hash,${operationPayloadSql}=CAST(? AS TEXT) AS same_payload
                FROM ec_host_operations o WHERE o.host_id=? AND o.idempotency_key=?`
                )
                .get(payload, hostId, options.idempotencyKey) as
                | {
                      id: string;
                      kind: string;
                      instance_id: string | null;
                      generation: number | null;
                      history_expired_at: string | null;
                      request_hash: string | null;
                      same_payload: number;
                  }
                | undefined;
            if (existing) {
                const samePayload = existing.request_hash
                    ? existing.request_hash === createHash('sha256').update(payload).digest('hex')
                    : !!existing.same_payload;
                if (
                    existing.kind !== kind ||
                    existing.instance_id !== (options.instanceId ?? null) ||
                    existing.generation !== (options.generation ?? null) ||
                    !samePayload
                )
                    throw new Error(
                        'Operation idempotency key is already associated with a different request.'
                    );
                return getHostOperationStatus(existing.id)!;
            }
        }
        if (['instance.create', 'create'].includes(kind)) requireReadyHost(hostId);
        if (
            host.mode === 'disabled' &&
            kind !== 'instance.cancel-create' &&
            !(
                host.enablingSince &&
                ['runtime.pull', 'library.download', 'plutonium.prepare', 'host.inspect'].includes(
                    kind
                )
            )
        )
            throw new Error('Host is disabled. Enable it before requesting operations.');
        const requestHash = createHash('sha256').update(payload).digest('hex');
        const parsedPayload = JSON.parse(payload.toString());
        assertPublicFilePayload(parsedPayload);
        const packed = packFileJson(parsedPayload);
        payload = JSON.stringify(packed.value);
        const id = options.id ?? randomUUID();
        const timestamp = now();
        const serverName = options.instanceId
            ? ((
                  database()
                      .prepare('SELECT server FROM native_instances WHERE id=?')
                      .get(options.instanceId) as { server: string } | undefined
              )?.server ?? null)
            : null;
        database()
            .prepare(
                `INSERT INTO ec_host_operations(id,host_id,kind,instance_id,generation,idempotency_key,payload,created_at,updated_at,source,server_name,request_hash)
            VALUES(?,?,?,?,?,?,CAST(? AS TEXT),?,?,?,?,?)`
            )
            .run(
                id,
                hostId,
                kind,
                options.instanceId ?? null,
                options.generation ?? null,
                options.idempotencyKey ?? null,
                routingPayload ?? payload,
                timestamp,
                timestamp,
                (currentOperationSource() ?? 'Controller').slice(0, 200),
                serverName,
                requestHash
            );
        referenceBlobs('operation', id, packed.hashes);
        if (routingPayload !== undefined)
            database()
                .prepare(
                    'INSERT INTO ec_host_operation_payloads(operation_id,payload) VALUES(?,CAST(? AS TEXT))'
                )
                .run(id, payload);
        database()
            .prepare(
                `UPDATE ec_host_operations AS o SET routine=CASE WHEN ${routineObservationSql} THEN 1 ELSE 0 END,
            target_path=${operationTargetSql} WHERE o.id=?`
            )
            .run(id);
        database()
            .prepare(
                'INSERT INTO ec_host_operation_events(operation_id,state,created_at) VALUES(?,?,?)'
            )
            .run(id, 'pending', timestamp);
        return getHostOperationStatus(id)!;
    })();
    queueMicrotask(() => workEvents.emit(hostId));
    return operation;
}
export function pendingHostOperations(
    hostId: string,
    lane: 'all' | 'read' | 'health' | 'write' = 'all'
): HostOperation[] {
    return pendingHostOperationRows(hostId, lane).map(operationFromRow);
}
type OperationLane = 'all' | 'read' | 'health' | 'write';
export function pendingHostOperationRows(
    hostId: string,
    lane?: OperationLane,
    includePayload?: true
): OperationRow[];
export function pendingHostOperationRows(
    hostId: string,
    lane: OperationLane,
    includePayload: false
): OperationDeliveryRow[];
/** Delivery snapshots retain status/results while large immutable payloads stay in SQLite. */
export function pendingHostOperationRows(
    hostId: string,
    lane: OperationLane = 'all',
    includePayload = true
): OperationDeliveryRow[] {
    const host = requireHost(hostId);
    if ((host.mode === 'disabled' && !host.enablingSince) || !host.connected) return [];
    // Older agents hold activity.lock across the entire delivered batch, including
    // observations. Filtering only the unsupported cleanup can keep the updater
    // busy indefinitely. Drain the old batch by withholding ALL further work;
    // heartbeats and receipts still flow, and the new capability releases this hold.
    // This must live in the controller so the fix also works before an agent update.
    if (
        database()
            .prepare(
                `SELECT 1 FROM ec_host_operations
        WHERE host_id=? AND kind='instance.cancel-create' AND state IN ('pending','accepted','running','unknown')
        AND (NOT ? OR (json_extract(payload,'$.recoveryRebuildOperationId') IS NOT NULL AND NOT ?)) LIMIT 1`
            )
            .get(
                hostId,
                Number(host.inventory.capabilities?.includes('instance.cancel-create') ?? false),
                Number(
                    host.inventory.capabilities?.includes('instance.unhealthy-recovery') ?? false
                )
            )
    )
        return [];
    // Accepted/running/unknown commands keep the same immutable ID. The agent
    // consults its durable journal before acknowledging or executing a replay.
    const healthOnly = `(kind IN ('instance.inspect','rcon.status-batch') OR (kind='rcon.execute' AND json_extract(${operationPayloadSql},'$.command') IN ('status','getstatus','version')))`;
    const healthLane = host.inventory.capabilities?.includes('operations.health-lane');
    const laneFilter =
        lane === 'all'
            ? ''
            : lane === 'health'
              ? ` AND ${healthOnly}`
              : ` AND ${lane === 'write' ? 'NOT ' : ''}${readOnlyOperationSql}${lane === 'read' && healthLane ? ` AND NOT ${healthOnly}` : ''}`;
    // Health never queues behind a delivered file batch. Keep background reads
    // in small batches to amortize delivery without handing out a long backlog.
    const limit = healthLane ? (lane === 'health' ? 1 : lane === 'read' ? 4 : 25) : 25;
    return database().transaction(() => {
        const columns = includePayload
            ? `${operationStatusColumns},${operationPayloadSql} AS payload`
            : operationStatusColumns;
        const rows = database()
            .prepare(
                `SELECT ${columns} FROM ec_host_operations o WHERE host_id=? AND state IN ('pending','accepted','running','unknown')
            ${laneFilter}
            ${host.mode === 'disabled' ? "AND kind IN ('runtime.pull','library.download','plutonium.prepare','host.inspect')" : ''}
            AND (? OR state != 'pending' OR kind NOT IN ('instance.create','create'))
            AND (kind!='instance.cancel-create' OR ?)
            AND NOT EXISTS (SELECT 1 FROM ec_host_operations cancellation WHERE cancellation.host_id=o.host_id
                AND cancellation.kind='instance.cancel-create' AND json_extract(cancellation.payload,'$.createOperationId')=o.id)
            AND NOT EXISTS (SELECT 1 FROM native_creation_cancellations cancellation
                JOIN native_provisioning creation ON creation.deployment_id=cancellation.creation_id
                WHERE creation.operation_id=o.id)
            ${lane === 'health' ? "AND (state NOT IN ('accepted','running') OR MAX(updated_at,COALESCE(last_delivered_at,'')) <= ?)" : ''}
            ORDER BY CASE WHEN kind='instance.cancel-create' THEN 0 WHEN kind='plutonium.prepare' THEN 2 ELSE 1 END,
                COALESCE(last_delivered_at,''),created_at,rowid LIMIT ${limit}`
            )
            // A short replay lease avoids handing the idle health lane its busy
            // sibling's work, but still recovers a lost receipt or agent restart.
            .all(
                hostId,
                Number(host.readiness === 'ready' || host.mode === 'draining'),
                Number(host.inventory.capabilities?.includes('instance.cancel-create') ?? false),
                ...(lane === 'health' ? [new Date(Date.now() - 30_000).toISOString()] : [])
            ) as OperationDeliveryRow[];
        const preparationLimit = fleetSettings().preparationConcurrency;
        const libraryKinds = ['library.download', 'library.import'];
        const preparing =
            preparationLimit && rows.some((operation) => libraryKinds.includes(operation.kind))
                ? new Set(
                      (
                          database()
                              .prepare(
                                  `SELECT DISTINCT host_id FROM ec_host_operations
                WHERE kind IN ('library.download','library.import') AND last_delivered_at IS NOT NULL
                AND state IN ('pending','accepted','running','unknown')`
                              )
                              .all() as { host_id: string }[]
                      ).map((row) => row.host_id)
                  )
                : new Set<string>();
        const admitted = rows.filter((operation) => {
            // Withhold unsafe legacy commands without breaking the entire delivery stream.
            if (operation.kind.startsWith('files.') || operation.kind === 'logs.read') {
                try {
                    getHostOperationPayload(hostId, operation.id);
                } catch (error) {
                    if (error instanceof PrivateFileOperationError) return false;
                    throw error;
                }
            }
            if (
                !libraryKinds.includes(operation.kind) ||
                preparing.has(hostId) ||
                !preparationLimit
            )
                return true;
            if (preparing.size >= preparationLimit) return false;
            preparing.add(hostId);
            return true;
        });
        const deliveredAt = now();
        for (const operation of admitted)
            database()
                .prepare('UPDATE ec_host_operations SET last_delivered_at=? WHERE id=?')
                .run(deliveredAt, operation.id);
        return admitted;
    })();
}
/** Payloads never change after enqueueing; fetch one delivery's UTF-8 bytes without decoding. */
export function getHostOperationPayload(hostId: string, id: string): Buffer {
    const row = database()
        .prepare(
            `SELECT CAST(${operationPayloadSql} AS BLOB) AS payload FROM ec_host_operations o WHERE o.id=? AND o.host_id=?`
        )
        .get(id, hostId) as { payload: Buffer } | undefined;
    if (!row) throw new Error('Host operation was not found for this host.');
    // Block old private-file commands before delivery to agents predating the guard.
    if (row.payload.includes(BANK_CONFIG_FILE))
        assertPublicFilePayload(JSON.parse(row.payload.toString()));
    if (
        !row.payload.includes('"contentSha256"') ||
        getHost(hostId)?.inventory.capabilities?.includes('files.blobs')
    )
        return row.payload;
    return Buffer.from(JSON.stringify(unpackFileJson(JSON.parse(row.payload.toString()))));
}
export function reportHostOperationStatus(
    hostId: string,
    id: string,
    input: { state: unknown; result?: unknown; error?: unknown }
): HostOperationStatus {
    let liveLogResult: { value: unknown } | undefined;
    const operation = database().transaction(() => {
        requireHost(hostId);
        const operation = getHostOperationStatus(id);
        if (!operation || operation.hostId !== hostId)
            throw new Error('Operation was not found for this host.');
        if (operation.kind === 'host.decommission' && input.state === 'completed')
            throw new Error('Host removal requires the cleanup worker completion receipt.');
        if (
            !['accepted', 'running', 'completed', 'failed', 'unknown'].includes(
                input.state as string
            )
        )
            throw new Error('Invalid operation state.');
        if (['completed', 'failed'].includes(operation.state)) return operation;
        const state = input.state as HostOperationState;
        if (operation.state === 'running' && state === 'accepted') return operation;
        const error =
            input.error === undefined || input.error === null
                ? null
                : String(input.error).slice(0, 4000);
        let result = input.result === undefined ? null : JSON.stringify(input.result);
        if (result !== null && Buffer.byteLength(result) > 128 * 1024 * 1024)
            throw new Error('Operation result exceeds the limit.');
        if (result !== null) {
            const target =
                operation.kind === 'files.read'
                    ? (database()
                          .prepare('SELECT target_path FROM ec_host_operations WHERE id=?')
                          .get(id) as { target_path: string | null })
                    : null;
            const packed = packFileJson(
                target?.target_path && isPrivateConfigPath(target.target_path)
                    ? { redacted: true }
                    : operation.kind === 'logs.read'
                      ? logResultMetadata(input.result)
                      : input.result
            );
            result = JSON.stringify(packed.value);
            referenceBlobs('operation-result', id, packed.hashes);
        }
        const observation =
            state === 'completed' &&
            !error &&
            successfulObservation(
                operation.kind,
                operation.kind === 'rcon.execute'
                    ? JSON.parse(getHostOperationPayload(hostId, id).toString('utf8'))
                    : {},
                input.result
            );
        database()
            .prepare(
                'UPDATE ec_host_operations SET state=?,result=?,error=?,updated_at=?,observation_success=? WHERE id=?'
            )
            .run(state, result, error, now(), Number(observation), id);
        if (operation.kind === 'logs.read' && state === 'completed')
            liveLogResult = { value: input.result ?? null };
        if (operation.kind === 'host.decommission') {
            if (state === 'failed')
                database()
                    .prepare(
                        "UPDATE ec_host_decommissions SET stage='failed',error=?,updated_at=? WHERE operation_id=?"
                    )
                    .run(
                        error ??
                            'The agent could not start cleanup. Repair the installation, then retry deletion.',
                        now(),
                        id
                    );
            else
                database()
                    .prepare(
                        "UPDATE ec_host_decommissions SET stage='running',updated_at=? WHERE operation_id=? AND stage IN ('queued','running')"
                    )
                    .run(now(), id);
        }
        if (operation.state !== state) {
            database()
                .prepare(
                    'INSERT INTO ec_host_operation_events(operation_id,state,created_at,error) VALUES(?,?,?,?)'
                )
                .run(id, state, now(), error);
            if (
                (operation.kind.startsWith('instance.') && operation.kind !== 'instance.inspect') ||
                operation.kind === 'files.stage'
            ) {
                recordAgentReceipt(id, state, now());
            }
        }
        return getHostOperationStatus(id)!;
    })();
    if (liveLogResult)
        for (const reader of logReaders.get(id) ?? []) {
            reader.received = true;
            reader.result = liveLogResult.value;
        }
    queueMicrotask(() => workEvents.emit(`operation:${id}`));
    return operation;
}
export function reportHostOperation(
    hostId: string,
    id: string,
    input: { state: unknown; result?: unknown; error?: unknown }
): HostOperation {
    reportHostOperationStatus(hostId, id, input);
    return getHostOperation(id)!;
}
export async function waitHostOperationStatus(
    id: string,
    timeoutMs = 30_000
): Promise<HostOperationStatus> {
    if (getHostOperationStatus(id)?.kind !== 'logs.read') return waitOperationStatus(id, timeoutMs);
    const reader: { received: boolean; result?: unknown } = { received: false };
    const readers = logReaders.get(id) ?? new Set();
    readers.add(reader);
    logReaders.set(id, readers);
    try {
        const operation = await waitOperationStatus(id, timeoutMs);
        if (operation.state !== 'completed') return operation;
        if (!reader.received)
            throw new Error('Log reply is no longer available. Request a new read.');
        return { ...operation, result: reader.result };
    } finally {
        readers.delete(reader);
        if (!readers.size) logReaders.delete(id);
    }
}
async function waitOperationStatus(id: string, timeoutMs: number): Promise<HostOperationStatus> {
    const deadline = Date.now() + timeoutMs;
    while (true) {
        const operation = getHostOperationStatus(id);
        if (!operation) throw new Error('Host operation was not found.');
        if (['completed', 'failed', 'unknown'].includes(operation.state)) return operation;
        if (Date.now() >= deadline) {
            // Delivery and expiry both claim the pending row transactionally.
            // Never cancel a delivered check or a command with side effects.
            const expired = database().transaction(() => {
                const timestamp = now();
                const error = 'Expired before delivery.';
                const result = database()
                    .prepare(
                        `UPDATE ec_host_operations SET state='failed',error=?,updated_at=?
                    WHERE id=? AND state='pending' AND last_delivered_at IS NULL
                    AND kind IN ('instance.inspect','rcon.status-batch')`
                    )
                    .run(error, timestamp, id);
                if (result.changes)
                    database()
                        .prepare(
                            'INSERT INTO ec_host_operation_events(operation_id,state,created_at,error) VALUES(?,?,?,?)'
                        )
                        .run(id, 'failed', timestamp, error);
                return result.changes > 0;
            })();
            if (expired) {
                queueMicrotask(() => workEvents.emit(`operation:${id}`));
                throw new Error(`Host operation ${id} expired before delivery.`);
            }
            throw new Error(
                `Host operation ${id} is awaiting acknowledgement; reconcile this operation ID before retrying.`
            );
        }
        await waitForHostWork(
            `operation:${id}`,
            new AbortController().signal,
            Math.min(1000, Math.max(1, deadline - Date.now()))
        );
    }
}
export async function waitHostOperation(id: string, timeoutMs = 30_000): Promise<HostOperation> {
    const status = await waitHostOperationStatus(id, timeoutMs);
    const operation = getHostOperation(id)!;
    return status.kind === 'logs.read' ? { ...operation, result: status.result } : operation;
}

export function hostPortAvailable(
    hostId: string,
    candidate: number,
    bindAddress?: string,
    protocol: 'udp' | 'tcp' = 'udp',
    instanceId?: string
): boolean {
    const host = requireHost(hostId);
    port(candidate);
    const bind = bindAddress ?? host.bindAddress;
    if (host.decommission) return false;
    if (candidate < host.portMin || candidate > host.portMax) return false;
    const rows = database()
        .prepare(
            'SELECT instance_id,bind_address FROM ec_host_ports WHERE host_id=? AND protocol=? AND port=?'
        )
        .all(hostId, protocol, candidate) as { instance_id: string; bind_address: string }[];
    return !rows.some(
        (row) =>
            row.instance_id !== instanceId &&
            (row.bind_address === bind ||
                ['0.0.0.0', '::'].includes(bind) ||
                ['0.0.0.0', '::'].includes(row.bind_address))
    );
}
export function nextHostPort(
    hostId: string,
    additionalPorts: number[] = [],
    bindAddress?: string,
    protocol: 'udp' | 'tcp' = 'udp'
): number | null {
    const host = requireHost(hostId);
    for (let candidate = host.portMin; candidate <= host.portMax; candidate++)
        if (
            !additionalPorts.includes(candidate) &&
            hostPortAvailable(hostId, candidate, bindAddress, protocol)
        )
            return candidate;
    return null;
}
export function reserveHostPort(
    hostId: string,
    instanceId: string,
    options: { port?: number; bindAddress?: string; protocol?: 'udp' | 'tcp' } = {}
): number {
    const host = requireHost(hostId);
    const bind = options.bindAddress ?? host.bindAddress;
    const protocol = options.protocol ?? 'udp';
    if (host.decommission)
        throw new Error('Host cleanup is in progress; new port reservations are blocked.');
    if (!isIP(bind)) throw new Error('Bind address must be an IP address.');
    if (!['udp', 'tcp'].includes(protocol)) throw new Error('Port protocol must be UDP or TCP.');
    if (!instanceId) throw new Error('An immutable instance ID is required.');
    return database().transaction(() => {
        const existing = database()
            .prepare(
                'SELECT port FROM ec_host_ports WHERE host_id=? AND instance_id=? AND bind_address=? AND protocol=?'
            )
            .get(hostId, instanceId, bind, protocol) as { port: number } | undefined;
        if (existing && (options.port === undefined || options.port === existing.port))
            return existing.port;
        const allocated = options.port ?? nextHostPort(hostId, [], bind, protocol);
        if (allocated === null || !hostPortAvailable(hostId, allocated, bind, protocol, instanceId))
            throw new Error('No available game port on the selected host.');
        database()
            .prepare(
                'INSERT INTO ec_host_ports(host_id,instance_id,bind_address,protocol,port,created_at) VALUES(?,?,?,?,?,?)'
            )
            .run(hostId, instanceId, bind, protocol, allocated, now());
        scheduleAvailabilityRefresh();
        return allocated;
    })();
}
export function releaseHostPorts(instanceId: string): void {
    database().prepare('DELETE FROM ec_host_ports WHERE instance_id=?').run(instanceId);
    scheduleAvailabilityRefresh();
}