#!/usr/bin/env node

import fs from 'node:fs';
import path from 'node:path';
import process from 'node:process';
import crypto from 'node:crypto';

const ROOT_DIR = path.resolve(import.meta.dirname, '..');
const DEFAULT_STATE_PATH = path.join(ROOT_DIR, 'memory', 'watchdog-state.json');
const DEFAULT_EVIDENCE_DIR = path.join(ROOT_DIR, 'state', 'long-task-watchdog');
const DEFAULT_EVENT_DIR = path.join(ROOT_DIR, 'state', 'long-task-watchdog-events');
const DEFAULT_NOTIFICATION_DIR = path.join(ROOT_DIR, 'state', 'operator-notify-queue');

function parseArgs(argv) {
  const args = {
    compact: false,
    state: DEFAULT_STATE_PATH,
    now: null,
    evidenceDir: DEFAULT_EVIDENCE_DIR,
    eventDir: DEFAULT_EVENT_DIR,
    notificationDir: DEFAULT_NOTIFICATION_DIR,
    writeState: false,
    help: false,
  };

  for (let i = 0; i < argv.length; i += 1) {
    const token = argv[i];
    if (token === '--compact') {
      args.compact = true;
      continue;
    }
    if (token === '--write-state') {
      args.writeState = true;
      continue;
    }
    if (token === '--help' || token === '-h') {
      args.help = true;
      continue;
    }
    if (token === '--state') {
      args.state = argv[i + 1] ?? args.state;
      i += 1;
      continue;
    }
    if (token.startsWith('--state=')) {
      args.state = token.slice('--state='.length) || args.state;
      continue;
    }
    if (token === '--now') {
      args.now = argv[i + 1] ?? null;
      i += 1;
      continue;
    }
    if (token.startsWith('--now=')) {
      args.now = token.slice('--now='.length) || null;
      continue;
    }
    if (token === '--evidence-dir') {
      args.evidenceDir = argv[i + 1] ?? args.evidenceDir;
      i += 1;
      continue;
    }
    if (token.startsWith('--evidence-dir=')) {
      args.evidenceDir = token.slice('--evidence-dir='.length) || args.evidenceDir;
      continue;
    }
    if (token === '--event-dir') {
      args.eventDir = argv[i + 1] ?? args.eventDir;
      i += 1;
      continue;
    }
    if (token.startsWith('--event-dir=')) {
      args.eventDir = token.slice('--event-dir='.length) || args.eventDir;
      continue;
    }
    if (token === '--notification-dir') {
      args.notificationDir = argv[i + 1] ?? args.notificationDir;
      i += 1;
      continue;
    }
    if (token.startsWith('--notification-dir=')) {
      args.notificationDir = token.slice('--notification-dir='.length) || args.notificationDir;
      continue;
    }
  }

  return args;
}

function printHelp() {
  process.stdout.write([
    'Usage: node scripts/long_task_watchdog.mjs [--compact] [--write-state] [--state <path>] [--now <iso>] [--evidence-dir <path>] [--event-dir <path>] [--notification-dir <path>]',
    '',
    'Minimal file-backed long-task watchdog runner with operator-notification queue output.',
  ].join('\n') + '\n');
}

function parseJsonFile(filePath) {
  const raw = fs.readFileSync(filePath, 'utf8');
  return JSON.parse(raw);
}

function parseTime(value) {
  if (typeof value !== 'string' || value.length === 0) return null;
  const timestamp = Date.parse(value);
  return Number.isNaN(timestamp) ? null : timestamp;
}

function toIso(value) {
  return new Date(value).toISOString();
}

function toSafeName(value) {
  return String(value || 'watchdog')
    .replace(/[^a-zA-Z0-9._-]+/g, '-')
    .replace(/^-+|-+$/g, '')
    .slice(0, 80) || 'watchdog';
}

function makeEventId(prefix) {
  return `${prefix}_${crypto.randomUUID()}`;
}

function evaluateWatchdog(watchdog, nowMs) {
  const intervalMinutes = Number.isFinite(watchdog?.intervalMinutes)
    ? watchdog.intervalMinutes
    : Number.parseInt(String(watchdog?.intervalMinutes ?? '0'), 10);
  const intervalMs = intervalMinutes > 0 ? intervalMinutes * 60 * 1000 : 0;
  const milestoneMs = parseTime(watchdog?.lastMilestoneAt);
  const lastAlertMs = parseTime(watchdog?.lastAlertAt);
  const active = watchdog?.status === 'active';

  if (!active) {
    return {
      id: watchdog?.id ?? null,
      active: false,
      overdue: false,
      action: 'skip_inactive',
      reason: 'watchdog is not active',
    };
  }

  if (!intervalMs || milestoneMs === null) {
    return {
      id: watchdog?.id ?? null,
      active: true,
      overdue: false,
      action: 'invalid_contract',
      reason: 'intervalMinutes or lastMilestoneAt is missing/invalid',
    };
  }

  const dueAtMs = milestoneMs + intervalMs;
  const overdue = nowMs >= dueAtMs;

  if (!overdue) {
    return {
      id: watchdog?.id ?? null,
      active: true,
      overdue: false,
      action: 'within_interval',
      reason: 'last milestone is still within interval',
      dueAt: toIso(dueAtMs),
      minutesOverdue: 0,
    };
  }

  const lastAlertStillFresh = lastAlertMs !== null && lastAlertMs >= dueAtMs;
  if (lastAlertStillFresh) {
    return {
      id: watchdog?.id ?? null,
      active: true,
      overdue: true,
      action: 'already_alerted_this_interval',
      reason: 'lastAlertAt already covers current overdue interval',
      dueAt: toIso(dueAtMs),
      minutesOverdue: Math.floor((nowMs - dueAtMs) / 60000),
    };
  }

  return {
    id: watchdog?.id ?? null,
    active: true,
    overdue: true,
    action: 'emit_external_evidence',
    reason: 'active watchdog is overdue and has not been externally evidenced for this interval',
    dueAt: toIso(dueAtMs),
    minutesOverdue: Math.floor((nowMs - dueAtMs) / 60000),
  };
}

function ensureDir(dirPath) {
  fs.mkdirSync(dirPath, { recursive: true });
}

function writeJsonFile(dirPath, fileName, payload) {
  ensureDir(dirPath);
  const filePath = path.join(dirPath, fileName);
  fs.writeFileSync(filePath, `${JSON.stringify(payload, null, 2)}\n`, 'utf8');
  return filePath;
}

function buildBaseRefs(evidencePath) {
  return [
    {
      kind: 'runtime_artifact',
      path: evidencePath,
      label: 'watchdog_evidence',
    },
  ];
}

function writeEvidence(evidenceDir, watchdog, evaluation, nowIso) {
  const fileName = `${nowIso.replace(/[:]/g, '').replace(/\.\d{3}Z$/, 'Z')}-${toSafeName(watchdog.id)}.json`;
  const payload = {
    generatedAt: nowIso,
    tool: 'long_task_watchdog',
    watchdog: {
      id: watchdog.id,
      task: watchdog.task,
      ownerSession: watchdog.ownerSession ?? null,
      ownerSessionKey: watchdog.ownerSessionKey ?? null,
      reportChannel: watchdog.reportChannel ?? watchdog.channel ?? null,
      reportTarget: watchdog.reportTarget ?? watchdog.target ?? null,
      intervalMinutes: watchdog.intervalMinutes,
      lastMilestoneAt: watchdog.lastMilestoneAt ?? null,
      lastAlertAt: watchdog.lastAlertAt ?? null,
    },
    evaluation,
    nextExpectedExternalAction: [
      'nudge owner session',
      'report owner-visible checkpoint',
      'or respawn / inspect locally if owner appears stalled',
    ],
  };
  return writeJsonFile(evidenceDir, fileName, payload);
}

function buildWatchdogEvent(watchdog, evaluation, nowIso, evidencePath) {
  const eventId = makeEventId('evt');
  return {
    event_id: eventId,
    event_type: 'watchdog_fired',
    runtime: 'openclaw',
    adapter_version: '1.1.0',
    agent_id: watchdog.ownerSessionKey ?? watchdog.ownerAgentId ?? 'agent:unknown',
    task_id: watchdog.id,
    correlation_id: `watchdog:${watchdog.id}`,
    timestamp: nowIso,
    payload: {
      watchdog_type: 'long_task_overdue',
      trigger_reason: evaluation.reason,
      triggered_at: nowIso,
      policy_id: 'long-task-watchdog-overdue-v1',
      severity: 'critical',
      due_at: evaluation.dueAt ?? null,
      minutes_overdue: evaluation.minutesOverdue ?? null,
    },
    evidence_refs: buildBaseRefs(evidencePath),
    operator_context: {
      channel: watchdog.reportChannel ?? watchdog.channel ?? null,
      operator_id: watchdog.reportTarget ?? watchdog.target ?? null,
      reporting_mode: 'watchdog',
      silent_task: true,
      watchdog_policy_id: 'long-task-watchdog-overdue-v1',
    },
  };
}

function writeEvent(eventDir, watchdog, nowIso, event) {
  const fileName = `${nowIso.replace(/[:]/g, '').replace(/\.\d{3}Z$/, 'Z')}-${toSafeName(watchdog.id)}-watchdog-fired.json`;
  return writeJsonFile(eventDir, fileName, event);
}

function buildNotificationMessage(watchdog, evaluation, nowIso) {
  const lines = [
    '【Watchdog 逾時告警】',
    `task: ${watchdog.task ?? watchdog.id ?? 'unknown-task'}`,
    `watchdog: ${watchdog.id ?? 'unknown-watchdog'}`,
    `dueAt: ${evaluation.dueAt ?? 'unknown'}`,
    `minutesOverdue: ${evaluation.minutesOverdue ?? 'unknown'}`,
    `lastMilestoneAt: ${watchdog.lastMilestoneAt ?? 'unknown'}`,
    `triggeredAt: ${nowIso}`,
    `ownerSessionKey: ${watchdog.ownerSessionKey ?? watchdog.ownerSession ?? 'unknown'}`,
    'requiredAction: 請立即對 owner/operator 發出可見更新，或檢查/重派 stalled task。',
  ];
  return lines.join('\n');
}

function buildNotificationQueueItem(watchdog, evaluation, nowIso, evidencePath, eventPath, eventId) {
  const notificationId = makeEventId('notify');
  const channel = watchdog.reportChannel ?? watchdog.channel ?? null;
  const target = watchdog.reportTarget ?? watchdog.target ?? null;
  return {
    notification_id: notificationId,
    kind: 'notify_operator',
    status: 'pending',
    created_at: nowIso,
    source_tool: 'long_task_watchdog',
    severity: 'critical',
    operator_notice: {
      required: true,
      channel,
      target,
      urgency: 'critical',
      message: buildNotificationMessage(watchdog, evaluation, nowIso),
      must_reference: ['watchdog_fired', 'forced_operator_update'],
    },
    dispatch_hint: {
      tool: 'message.send',
      channel,
      target,
      message: buildNotificationMessage(watchdog, evaluation, nowIso),
    },
    governance: {
      task_id: watchdog.id,
      correlation_id: `watchdog:${watchdog.id}`,
      trigger_event_id: eventId,
      trigger_event_type: 'watchdog_fired',
      decision: 'force_checkpoint',
      policy_id: 'long-task-watchdog-overdue-v1',
      reason: evaluation.reason,
    },
    evidence_refs: [
      ...buildBaseRefs(evidencePath),
      {
        kind: 'runtime_artifact',
        path: eventPath,
        label: 'watchdog_event',
      },
    ],
    blocked_gap: channel && target
      ? null
      : 'watchdog state does not define reportChannel/reportTarget, so dispatcher target is incomplete',
  };
}

function writeNotificationQueueItem(notificationDir, watchdog, nowIso, queueItem) {
  const fileName = `${nowIso.replace(/[:]/g, '').replace(/\.\d{3}Z$/, 'Z')}-${toSafeName(watchdog.id)}-notify-operator.json`;
  return writeJsonFile(notificationDir, fileName, queueItem);
}

function main() {
  const args = parseArgs(process.argv.slice(2));
  if (args.help) {
    printHelp();
    process.exit(0);
  }

  const nowMs = args.now ? parseTime(args.now) : Date.now();
  if (nowMs === null) {
    process.stderr.write('Invalid --now value\n');
    process.exit(1);
  }
  const nowIso = toIso(nowMs);

  const state = parseJsonFile(args.state);
  const watchdogs = Array.isArray(state.watchdogs) ? state.watchdogs : [];
  const evaluations = watchdogs.map((watchdog) => ({
    watchdogId: watchdog?.id ?? null,
    ...evaluateWatchdog(watchdog, nowMs),
  }));

  const evidenceWrites = [];
  const eventWrites = [];
  const notificationWrites = [];
  const nextWatchdogs = watchdogs.map((watchdog, index) => {
    const evaluation = evaluations[index];
    if (evaluation.action !== 'emit_external_evidence') {
      return watchdog;
    }
    const evidencePath = writeEvidence(args.evidenceDir, watchdog, evaluation, nowIso);
    evidenceWrites.push({ watchdogId: watchdog.id, path: evidencePath });

    const event = buildWatchdogEvent(watchdog, evaluation, nowIso, evidencePath);
    const eventPath = writeEvent(args.eventDir, watchdog, nowIso, event);
    eventWrites.push({ watchdogId: watchdog.id, path: eventPath, eventId: event.event_id, eventType: event.event_type });

    const notification = buildNotificationQueueItem(watchdog, evaluation, nowIso, evidencePath, eventPath, event.event_id);
    const notificationPath = writeNotificationQueueItem(args.notificationDir, watchdog, nowIso, notification);
    notificationWrites.push({
      watchdogId: watchdog.id,
      path: notificationPath,
      notificationId: notification.notification_id,
      channel: notification.operator_notice.channel,
      target: notification.operator_notice.target,
      dispatchReady: notification.blocked_gap === null,
      blockedGap: notification.blocked_gap,
    });

    return {
      ...watchdog,
      lastAlertAt: nowIso,
      lastObservedActivityAt: watchdog.lastObservedActivityAt ?? watchdog.lastMilestoneAt ?? null,
      lastNudgeAt: nowIso,
    };
  });

  if (args.writeState) {
    const nextState = {
      ...state,
      watchdogs: nextWatchdogs,
    };
    fs.writeFileSync(args.state, `${JSON.stringify(nextState, null, 2)}\n`, 'utf8');
  }

  const response = {
    ok: true,
    tool: 'long_task_watchdog',
    version: 'mvp-v2',
    statePath: path.resolve(args.state),
    evidenceDir: path.resolve(args.evidenceDir),
    eventDir: path.resolve(args.eventDir),
    notificationDir: path.resolve(args.notificationDir),
    now: nowIso,
    writeState: args.writeState,
    result: {
      activeCount: watchdogs.filter((item) => item?.status === 'active').length,
      overdueCount: evaluations.filter((item) => item.overdue === true).length,
      emittedCount: evidenceWrites.length,
      eventCount: eventWrites.length,
      notificationCount: notificationWrites.length,
      evaluations,
      evidenceWrites,
      eventWrites,
      notificationWrites,
    },
  };

  process.stdout.write(`${JSON.stringify(response, null, args.compact ? 0 : 2)}\n`);
}

main();