import fs from 'fs';
import path from 'path';

import {
  ASSISTANT_NAME,
  IDLE_TIMEOUT,
  POLL_INTERVAL,
  SERVICE_AGENT_TYPE,
  STATUS_CHANNEL_ID,
  STATUS_UPDATE_INTERVAL,
  TIMEZONE,
  TRIGGER_PATTERN,
  USAGE_UPDATE_INTERVAL,
} from './config.js';
import './channels/index.js';
import {
  getChannelFactory,
  getRegisteredChannelNames,
} from './channels/registry.js';
import { AvailableGroup, writeGroupsSnapshot } from './agent-runner.js';
import {
  purgeDashboardChannel,
  startStatusDashboard,
  startUsageDashboard,
} from './dashboard.js';
import {
  deleteSession,
  getAllRegisteredGroups,
  getAllSessions,
  getRouterState,
  initDatabase,
  setRegisteredGroup,
  setRouterState,
  setSession,
  storeChatMetadata,
  storeMessage,
} from './db.js';
import { GroupQueue } from './group-queue.js';
import { resolveGroupFolderPath } from './group-folder.js';
import { startIpcWatcher } from './ipc.js';
import {
  createMessageRuntime,
  getAvailableGroups as getAvailableGroupsForRegisteredGroups,
} from './message-runtime.js';
import { findChannel, formatOutbound } from './router.js';
import {
  isSenderAllowed,
  loadSenderAllowlist,
  shouldDropMessage,
} from './sender-allowlist.js';
import { startSchedulerLoop } from './task-scheduler.js';
import { Channel, NewMessage, RegisteredGroup } from './types.js';
import { logger } from './logger.js';

// Re-export for backwards compatibility during refactor
export { escapeXml, formatMessages } from './router.js';

let lastTimestamp = '';
let sessions: Record<string, string> = {};
let registeredGroups: Record<string, RegisteredGroup> = {};
let lastAgentTimestamp: Record<string, string> = {};

const channels: Channel[] = [];
const queue = new GroupQueue();
const messageRuntime = createMessageRuntime({
  assistantName: ASSISTANT_NAME,
  idleTimeout: IDLE_TIMEOUT,
  pollInterval: POLL_INTERVAL,
  timezone: TIMEZONE,
  triggerPattern: TRIGGER_PATTERN,
  channels,
  queue,
  getRegisteredGroups: () => registeredGroups,
  getSessions: () => sessions,
  getLastTimestamp: () => lastTimestamp,
  setLastTimestamp: (timestamp) => {
    lastTimestamp = timestamp;
  },
  getLastAgentTimestamps: () => lastAgentTimestamp,
  saveState,
  persistSession: (groupFolder, sessionId) => {
    sessions[groupFolder] = sessionId;
    setSession(groupFolder, sessionId);
  },
  clearSession: (groupFolder) => {
    delete sessions[groupFolder];
    deleteSession(groupFolder);
  },
});

function loadState(): void {
  lastTimestamp = getRouterState('last_timestamp') || '';
  const agentTs = getRouterState('last_agent_timestamp');
  try {
    lastAgentTimestamp = agentTs ? JSON.parse(agentTs) : {};
  } catch {
    logger.warn('Corrupted last_agent_timestamp in DB, resetting');
    lastAgentTimestamp = {};
  }
  sessions = getAllSessions();
  registeredGroups = getAllRegisteredGroups(SERVICE_AGENT_TYPE);
  logger.info(
    { groupCount: Object.keys(registeredGroups).length },
    'State loaded',
  );
}

function saveState(): void {
  setRouterState('last_timestamp', lastTimestamp);
  setRouterState('last_agent_timestamp', JSON.stringify(lastAgentTimestamp));
}

function registerGroup(jid: string, group: RegisteredGroup): void {
  let groupDir: string;
  try {
    groupDir = resolveGroupFolderPath(group.folder);
  } catch (err) {
    logger.warn(
      { jid, folder: group.folder, err },
      'Rejecting group registration with invalid folder',
    );
    return;
  }

  registeredGroups[jid] = group;
  setRegisteredGroup(jid, group);

  // Create group folder
  fs.mkdirSync(path.join(groupDir, 'logs'), { recursive: true });

  logger.info(
    { jid, name: group.name, folder: group.folder },
    'Group registered',
  );
}

/**
 * Get available groups list for the agent.
 * Returns groups ordered by most recent activity.
 */
export function getAvailableGroups(): AvailableGroup[] {
  return getAvailableGroupsForRegisteredGroups(registeredGroups);
}

/** @internal - exported for testing */
export function _setRegisteredGroups(
  groups: Record<string, RegisteredGroup>,
): void {
  registeredGroups = groups;
}

async function main(): Promise<void> {
  initDatabase();
  logger.info('Database initialized');
  loadState();

  // Graceful shutdown handlers
  const shutdown = async (signal: string) => {
    logger.info({ signal }, 'Shutdown signal received');
    await queue.shutdown(10000);
    for (const ch of channels) await ch.disconnect();
    process.exit(0);
  };
  process.on('SIGTERM', () => shutdown('SIGTERM'));
  process.on('SIGINT', () => shutdown('SIGINT'));

  // Channel callbacks (shared by all channels)
  const channelOpts = {
    onMessage: (chatJid: string, msg: NewMessage) => {
      // Sender allowlist drop mode: discard messages from denied senders before storing
      if (!msg.is_from_me && !msg.is_bot_message && registeredGroups[chatJid]) {
        const cfg = loadSenderAllowlist();
        if (
          shouldDropMessage(chatJid, cfg) &&
          !isSenderAllowed(chatJid, msg.sender, cfg)
        ) {
          if (cfg.logDenied) {
            logger.debug(
              { chatJid, sender: msg.sender },
              'sender-allowlist: dropping message (drop mode)',
            );
          }
          return;
        }
      }
      storeMessage(msg);
    },
    onChatMetadata: (
      chatJid: string,
      timestamp: string,
      name?: string,
      channel?: string,
      isGroup?: boolean,
    ) => storeChatMetadata(chatJid, timestamp, name, channel, isGroup),
    registeredGroups: () => registeredGroups,
  };

  // Create and connect all registered channels.
  // Each channel self-registers via the barrel import above.
  // Factories return null when credentials are missing, so unconfigured channels are skipped.
  for (const channelName of getRegisteredChannelNames()) {
    const factory = getChannelFactory(channelName)!;
    const channel = factory(channelOpts);
    if (!channel) {
      logger.warn(
        { channel: channelName },
        'Channel installed but credentials missing — skipping. Check .env or re-run the channel skill.',
      );
      continue;
    }
    channels.push(channel);
    await channel.connect();
  }
  if (channels.length === 0) {
    logger.fatal('No channels connected');
    process.exit(1);
  }

  // Start subsystems (independently of connection handler)
  startSchedulerLoop({
    registeredGroups: () => registeredGroups,
    getSessions: () => sessions,
    queue,
    onProcess: (groupJid, proc, processName, groupFolder) =>
      queue.registerProcess(groupJid, proc, processName, groupFolder),
    sendMessage: async (jid, rawText) => {
      const channel = findChannel(channels, jid);
      if (!channel) {
        logger.warn({ jid }, 'No channel owns JID, cannot send message');
        return;
      }
      const text = formatOutbound(rawText);
      if (text) await channel.sendMessage(jid, text);
    },
  });
  startIpcWatcher({
    sendMessage: (jid, text) => {
      const channel = findChannel(channels, jid);
      if (!channel) throw new Error(`No channel for JID: ${jid}`);
      return channel.sendMessage(jid, text);
    },
    registeredGroups: () => registeredGroups,
    registerGroup,
    syncGroups: async (force: boolean) => {
      await Promise.all(
        channels
          .filter((ch) => ch.syncGroups)
          .map((ch) => ch.syncGroups!(force)),
      );
    },
    getAvailableGroups,
    writeGroupsSnapshot: (gf, im, ag) => writeGroupsSnapshot(gf, im, ag),
  });
  queue.setProcessMessagesFn(messageRuntime.processGroupMessages);
  messageRuntime.recoverPendingMessages();
  const dashboardOpts = {
    assistantName: ASSISTANT_NAME,
    channels,
    getSessions: () => sessions,
    queue,
    registeredGroups: () => registeredGroups,
    statusChannelId: STATUS_CHANNEL_ID,
    statusUpdateInterval: STATUS_UPDATE_INTERVAL,
    usageUpdateInterval: USAGE_UPDATE_INTERVAL,
  };
  await purgeDashboardChannel(dashboardOpts);
  await startStatusDashboard(dashboardOpts);
  await startUsageDashboard(dashboardOpts);
  messageRuntime.startMessageLoop().catch((err) => {
    logger.fatal({ err }, 'Message loop crashed unexpectedly');
    process.exit(1);
  });
}

// Guard: only run when executed directly, not when imported by tests
const isDirectRun =
  process.argv[1] &&
  new URL(import.meta.url).pathname ===
    new URL(`file://${process.argv[1]}`).pathname;

if (isDirectRun) {
  main().catch((err) => {
    logger.error({ err }, 'Failed to start NanoClaw');
    process.exit(1);
  });
}