signalk-mqtt-import/src/index.ts

SignalK plugin to selectively import data from MQTT with webapp management interface

import * as fs from 'fs-extra';
import * as path from 'path';
import { Router } from 'express';
import { connect } from 'mqtt';
import {
  SignalKApp,
  SignalKPlugin,
  MQTTImportConfig,
  ImportRule,
  SignalKDelta,
  PluginState,
  TypedRequest,
  TypedResponse,
  RulesApiResponse,
  MQTTStatusApiResponse,
  StatsApiResponse,
  ApiResponse,
  RuleUpdateRequest,
  MQTTClientOptions,
} from './types';

// Global plugin state

export = function (app: SignalKApp): SignalKPlugin {
  const plugin: SignalKPlugin = {
    id: 'signalk-mqtt-import',
    name: 'SignalK MQTT Import Manager',
    description:
      'Selectively import SignalK data from MQTT with webapp management interface',
    schema: {},
    start: () => {},
    stop: () => {},
    registerWithRouter: undefined,
  };

  // Plugin state
  const state: PluginState = {
    mqttClient: null,
    importRules: [],
    lastReceivedMessages: new Map<string, number>(),
    selfVesselUrn: null,
    rulesFilePath: null,
    currentConfig: undefined,
  };

  plugin.start = function (options: Partial<MQTTImportConfig>): void {
    app.debug('Starting SignalK MQTT Import Manager plugin');

    const config: MQTTImportConfig = {
      mqttBroker: options?.mqttBroker || 'mqtt://localhost:1883',
      mqttClientId: options?.mqttClientId || 'signalk-mqtt-import',
      mqttUsername: options?.mqttUsername || '',
      mqttPassword: options?.mqttPassword || '',
      topicPrefix: options?.topicPrefix || '',
      enabled: options?.enabled !== false,
    };

    state.currentConfig = config;
    plugin.config = config;

    // Load rules from persistent storage (or migrate from old config)
    const migratedRules = migrateOldConfiguration(options as any);
    state.importRules = migratedRules || loadRulesFromStorage();

    app.debug(
      `Loaded ${state.importRules.length} import rules from persistent storage`
    );

    // Get self vessel URN for proper context mapping
    try {
      state.selfVesselUrn = app.selfId || app.getSelfPath('uuid');
      app.debug(`Self vessel URN: ${state.selfVesselUrn}`);
    } catch (error) {
      app.debug(
        `Warning: Could not get self vessel URN: ${(error as Error).message}`
      );
    }

    if (!config.enabled) {
      app.debug('MQTT Import plugin disabled');
      return;
    }

    // Initialize MQTT client
    initializeMQTTClient(config);

    app.debug('SignalK MQTT Import Manager plugin started');
  };

  plugin.stop = function (): void {
    app.debug('Stopping SignalK MQTT Import Manager plugin');

    // Disconnect MQTT client
    if (state.mqttClient) {
      state.mqttClient.end();
      state.mqttClient = null;
    }

    state.lastReceivedMessages.clear();
    app.debug('SignalK MQTT Import Manager plugin stopped');
  };

  // Initialize MQTT client
  function initializeMQTTClient(config: MQTTImportConfig): void {
    try {
      const mqttOptions: MQTTClientOptions = {
        clientId: config.mqttClientId,
        clean: true,
        reconnectPeriod: 5000,
        keepalive: 60,
      };

      if (config.mqttUsername && config.mqttPassword) {
        mqttOptions.username = config.mqttUsername;
        mqttOptions.password = config.mqttPassword;
      }

      state.mqttClient = connect(config.mqttBroker, mqttOptions);

      state.mqttClient.on('connect', () => {
        app.debug(`✅ Connected to MQTT broker: ${config.mqttBroker}`);
        subscribeToMQTTTopics();
      });

      state.mqttClient.on('error', (error: Error) => {
        app.debug(`❌ MQTT client error: ${error.message}`);
      });

      state.mqttClient.on('close', () => {
        app.debug('🔌 MQTT client disconnected');
      });

      state.mqttClient.on('reconnect', () => {
        app.debug('🔄 MQTT client reconnecting...');
      });

      state.mqttClient.on('message', (topic: string, message: Buffer) => {
        handleMQTTMessage(topic, message);
      });
    } catch (error) {
      app.debug(
        `Failed to initialize MQTT client: ${(error as Error).message}`
      );
    }
  }

  // Subscribe to MQTT topics based on import rules
  function subscribeToMQTTTopics(): void {
    if (!state.mqttClient || !state.mqttClient.connected) {
      return;
    }

    // Get all unique topics from enabled import rules
    const topics = new Set<string>();
    state.importRules
      .filter(rule => rule.enabled)
      .forEach(rule => {
        let topic = rule.mqttTopic;

        // Add topic prefix if configured
        if (state.currentConfig?.topicPrefix) {
          topic = `${state.currentConfig.topicPrefix}/${topic}`;
        }

        // Handle vessels/self/* topics by converting to actual URN format
        if (topic.includes('vessels/self/') && state.selfVesselUrn) {
          // Convert vessels/self/* to actual URN format for MQTT subscription
          const urnTopic = topic.replace(
            'vessels/self/',
            `vessels/${state.selfVesselUrn}/`
          );
          topics.add(urnTopic);
          app.debug(`Converted vessels/self rule to URN topic: ${urnTopic}`);
          // Also add underscore format if URN contains colons
          if (state.selfVesselUrn.includes(':')) {
            const underscoreUrn = urnToMqttFormat(state.selfVesselUrn);
            const underscoreTopic = topic.replace(
              'vessels/self/',
              `vessels/${underscoreUrn}/`
            );
            topics.add(underscoreTopic);
            app.debug(`Also added underscore format: ${underscoreTopic}`);
          }
        } else {
          // Add both underscore and colon formats for URN topics
          topics.add(topic);
          if (topic.includes('urn_mrn_imo_mmsi_')) {
            topics.add(
              topic.replace(/urn_mrn_imo_mmsi_/g, 'urn:mrn:imo:mmsi:')
            );
          }
        }
      });

    // Subscribe to all topics
    app.debug(`📡 Subscribing to ${topics.size} MQTT topics...`);
    topics.forEach(topic => {
      state.mqttClient!.subscribe(topic, { qos: 1 }, err => {
        if (err) {
          app.debug(`❌ Failed to subscribe to ${topic}: ${err.message}`);
        } else {
          app.debug(`✅ Subscribed to MQTT topic: ${topic}`);
        }
      });
    });

    app.debug(`Subscribed to ${topics.size} MQTT topics`);
  }

  // Handle incoming MQTT messages
  function handleMQTTMessage(topic: string, message: Buffer): void {
    try {
      const messageStr = message.toString();

      // Debug: Log incoming message
      app.debug(`📥 Received MQTT message on topic: ${topic}`);

      // Find matching import rule (that doesn't exclude this MMSI)
      let rule: ImportRule | null = null;
      for (const r of state.importRules) {
        if (!r.enabled) continue;

        let expectedTopic = r.mqttTopic;
        if (state.currentConfig?.topicPrefix) {
          expectedTopic = `${state.currentConfig.topicPrefix}/${expectedTopic}`;
        }

        // Debug: Log rule matching attempt
        app.debug(
          `🔍 Checking rule "${r.name}" with pattern: ${expectedTopic}`
        );

        // First check if topic matches the pattern
        let matches = false;

        // Use proper MQTT wildcard matching
        matches = mqttTopicMatches(topic, expectedTopic, state.selfVesselUrn);

        // If topic matches, check if MMSI should be excluded
        if (matches && isMMSIExcluded(topic, r)) {
          const mmsi = extractMMSIFromUrn(topic.split('/')[1]);
          app.debug(
            `🔍 Rule "${r.name}" matches but MMSI ${mmsi} is excluded - continuing search`
          );
          continue; // Continue looking for other rules
        }

        // If this rule matches and doesn't exclude, use it
        if (matches) {
          rule = r;
          break;
        }
      }

      if (!rule) {
        app.debug(`❌ No import rule found for topic: ${topic}`);
        return;
      }

      app.debug(`✅ Rule matched: "${rule.name}" for topic: ${topic}`);

      // Check for duplicate messages if enabled
      if (rule.ignoreDuplicates) {
        const messageKey = `${topic}:${messageStr}`;
        if (state.lastReceivedMessages.has(messageKey)) {
          return; // Skip duplicate message
        }
        state.lastReceivedMessages.set(messageKey, Date.now());

        // Clean up old messages (keep last 1000 messages)
        if (state.lastReceivedMessages.size > 1000) {
          const entries = Array.from(state.lastReceivedMessages.entries());
          const oldest = entries.slice(0, 500);
          oldest.forEach(([key]) => state.lastReceivedMessages.delete(key));
        }
      }

      // Parse the message based on expected format
      let signalKData: SignalKDelta | null;
      if (rule.payloadFormat === 'value-only') {
        signalKData = parseValueOnlyMessage(messageStr, rule, topic);
      } else {
        signalKData = parseFullSignalKMessage(messageStr, rule, topic);
      }

      if (signalKData) {
        sendToSignalK(signalKData, rule);
        app.debug(`📤 Successfully processed message for topic: ${topic}`);
      } else {
        app.debug(`⚠️ Failed to parse message for topic: ${topic}`);
      }
    } catch (error) {
      app.debug(
        `Error handling MQTT message from ${topic}: ${(error as Error).message}`
      );
    }
  }

  // Parse value-only message format
  function parseValueOnlyMessage(
    messageStr: string,
    rule: ImportRule,
    topic: string
  ): SignalKDelta | null {
    try {
      let value: any;

      // Try to parse as JSON first
      try {
        value = JSON.parse(messageStr);
      } catch {
        // If not JSON, treat as string/number
        value = isNaN(Number(messageStr)) ? messageStr : Number(messageStr);
      }

      // Extract context and path from topic or rule configuration
      const context = rule.signalKContext || extractContextFromTopic(topic);
      const path = rule.signalKPath || extractPathFromTopic(topic);

      return {
        context: context as any,
        updates: [
          {
            source: {
              label: rule.sourceLabel || '',
              type: 'mqtt',
            },
            timestamp: new Date().toISOString() as any,
            values: [
              {
                path: path as any,
                value: value,
              },
            ],
          },
        ],
      };
    } catch (error) {
      app.debug(
        `Error parsing value-only message: ${(error as Error).message}`
      );
      return null;
    }
  }

  // Parse full SignalK message format
  function parseFullSignalKMessage(
    messageStr: string,
    rule: ImportRule,
    topic: string
  ): SignalKDelta | null {
    try {
      const parsed = JSON.parse(messageStr);

      // If it's already a proper SignalK delta, use it directly
      if (parsed.context && parsed.updates) {
        return parsed as SignalKDelta;
      }

      // Otherwise, try to construct a SignalK delta
      const context =
        rule.signalKContext || parsed.context || extractContextFromTopic(topic);
      const path = rule.signalKPath || extractPathFromTopic(topic);

      return {
        context: context as any,
        updates: [
          {
            source: {
              label: rule.sourceLabel || '',
              type: 'mqtt',
            },
            timestamp: new Date().toISOString() as any,
            values: [
              {
                path: path as any,
                value: parsed,
              },
            ],
          },
        ],
      };
    } catch (error) {
      app.debug(
        `Error parsing full SignalK message: ${(error as Error).message}`
      );
      return null;
    }
  }

  // Helper function to convert URN format for MQTT topics
  function urnToMqttFormat(urn: string): string {
    if (!urn) return '';
    // Convert urn:mrn:imo:mmsi:368396230 to urn_mrn_imo_mmsi_368396230
    return urn.replace(/:/g, '_');
  }

  // Helper function to convert MQTT format back to URN
  function mqttFormatToUrn(mqttFormat: string): string {
    if (!mqttFormat) return '';
    // Convert urn_mrn_imo_mmsi_368396230 to urn:mrn:imo:mmsi:368396230
    return mqttFormat.replace(/_/g, ':');
  }

  // Helper function to extract MMSI from URN
  function extractMMSIFromUrn(urn: string): string | null {
    if (!urn) return null;
    // Extract MMSI from urn:mrn:imo:mmsi:368396230 or urn_mrn_imo_mmsi_368396230
    const match = urn.match(/urn[_:]+mrn[_:]+imo[_:]+mmsi[_:]+([0-9]+)/);
    return match ? match[1] : null;
  }

  // Helper function to parse MMSI exclusion list
  function parseMMSIExclusionList(excludeMMSI: string): string[] {
    if (!excludeMMSI || typeof excludeMMSI !== 'string') return [];
    return excludeMMSI
      .split(',')
      .map(mmsi => mmsi.trim())
      .filter(mmsi => mmsi.length > 0);
  }

  // Helper function to match MQTT topics with wildcard patterns
  function mqttTopicMatches(
    topic: string,
    pattern: string,
    selfVesselUrn?: string | null
  ): boolean {
    // Handle vessels/self/* patterns by expanding to all possible formats
    if (pattern.includes('vessels/self/') && selfVesselUrn) {
      // Create patterns for URN format and underscore format
      const urnPattern = pattern.replace(
        'vessels/self/',
        `vessels/${selfVesselUrn}/`
      );
      const underscoreUrn = urnToMqttFormat(selfVesselUrn);
      const underscorePattern = pattern.replace(
        'vessels/self/',
        `vessels/${underscoreUrn}/`
      );

      // Test against all possible patterns
      return (
        mqttTopicMatches(
          topic,
          pattern.replace('vessels/self/', 'vessels/+/')
        ) ||
        mqttTopicMatches(topic, urnPattern) ||
        (underscoreUrn ? mqttTopicMatches(topic, underscorePattern) : false)
      );
    }

    // Convert MQTT pattern to regex pattern
    let regexPattern = pattern
      .replace(/\+/g, '[^/]+') // + matches any characters except /
      .replace(/#$/, '.*') // # at end matches everything
      .replace(/#\//, '.*/'); // # in middle matches everything up to next /

    // Also handle URN format conversion (underscore to colon)
    const colonPattern = pattern.replace(
      /urn_mrn_imo_mmsi_/g,
      'urn:mrn:imo:mmsi:'
    );
    let colonRegexPattern = '';
    if (colonPattern !== pattern) {
      colonRegexPattern = colonPattern
        .replace(/\+/g, '[^/]+')
        .replace(/#$/, '.*')
        .replace(/#\//, '.*/');
    }

    // Create regex objects with anchors
    const regex = new RegExp(`^${regexPattern}$`);
    const colonRegex = colonRegexPattern
      ? new RegExp(`^${colonRegexPattern}$`)
      : null;

    // Test both underscore and colon formats
    return regex.test(topic) || (colonRegex ? colonRegex.test(topic) : false);
  }

  // Helper function to check if MMSI should be excluded
  function isMMSIExcluded(topic: string, rule: ImportRule): boolean {
    const exclusionList = parseMMSIExclusionList(rule.excludeMMSI || '');
    if (exclusionList.length === 0) return false;

    // Extract vessel ID from topic
    const parts = topic.split('/');
    if (parts.length < 2 || parts[0] !== 'vessels') return false;

    const vesselId = parts[1];
    const mmsi = extractMMSIFromUrn(vesselId);

    if (!mmsi) return false;

    const isExcluded = exclusionList.includes(mmsi);

    if (isExcluded) {
      app.debug(
        `MMSI ${mmsi} excluded by rule "${rule.name}" for topic: ${topic}`
      );
    }

    return isExcluded;
  }

  // Extract SignalK context from MQTT topic
  function extractContextFromTopic(topic: string): string {
    // Remove prefix if present
    let cleanTopic = topic;
    if (state.currentConfig?.topicPrefix) {
      cleanTopic = cleanTopic.replace(
        `${state.currentConfig.topicPrefix}/`,
        ''
      );
    }

    const parts = cleanTopic.split('/');

    if (parts[0] === 'vessels' && parts.length > 2) {
      const vesselId = parts[1];

      // Check if this is the self vessel's URN (handle both formats)
      if (
        state.selfVesselUrn &&
        (urnToMqttFormat(state.selfVesselUrn) === vesselId ||
          state.selfVesselUrn === vesselId)
      ) {
        return 'vessels.self';
      }

      // Handle URN format (both underscore and colon)
      if (vesselId.startsWith('urn_')) {
        return `vessels.${mqttFormatToUrn(vesselId)}`;
      } else if (vesselId.startsWith('urn:')) {
        return `vessels.${vesselId}`;
      }

      // Handle other formats
      return `vessels.${vesselId}`;
    }

    // Fallback to vessels.self
    return 'vessels.self';
  }

  // Extract SignalK path from MQTT topic
  function extractPathFromTopic(topic: string): string {
    // Remove prefix if present
    let cleanTopic = topic;
    if (state.currentConfig?.topicPrefix) {
      cleanTopic = cleanTopic.replace(
        `${state.currentConfig.topicPrefix}/`,
        ''
      );
    }

    // Default path extraction: convert topic to SignalK path
    // e.g., "vessels/self/navigation/position" -> "navigation.position"
    const parts = cleanTopic.split('/');

    // Remove context parts (vessels/self or vessels/urn_...)
    if (parts[0] === 'vessels' && parts.length > 2) {
      return parts.slice(2).join('.');
    }

    // Fallback: use the entire topic as path
    return cleanTopic.replace(/\//g, '.');
  }

  // Send data to SignalK
  function sendToSignalK(signalKData: SignalKDelta, rule: ImportRule): void {
    try {
      // Validate the data structure
      if (
        !signalKData.context ||
        !signalKData.updates ||
        !Array.isArray(signalKData.updates)
      ) {
        app.debug('Invalid SignalK data structure');
        return;
      }

      // Apply any transformations if configured
      if (rule.transformValue && typeof rule.transformValue === 'function') {
        signalKData.updates.forEach(update => {
          if ((update as any).values) {
            (update as any).values.forEach((valueUpdate: any) => {
              valueUpdate.value = rule.transformValue!(valueUpdate.value);
            });
          }
        });
      }

      // Send to SignalK
      app.handleMessage(plugin.id, signalKData as any);

      app.debug(
        `✅ Imported to SignalK: ${signalKData.context} - ${signalKData.updates.length} updates`
      );
    } catch (error) {
      app.debug(`Error sending to SignalK: ${(error as Error).message}`);
    }
  }

  // Get default import rules
  function getDefaultImportRules(): ImportRule[] {
    return [
      {
        id: 'vessels-all-data',
        name: 'All Vessel Data (Auto-detect Self)',
        mqttTopic: 'vessels/+/#',
        signalKContext: '', // Will be extracted from topic (auto-detect self)
        signalKPath: '', // Will be extracted from topic
        sourceLabel: '',
        enabled: true,
        payloadFormat: 'full',
        ignoreDuplicates: true,
        excludeMMSI: '',
      },
      {
        id: 'vessels-navigation',
        name: 'Navigation Data (All Vessels)',
        mqttTopic: 'vessels/+/navigation/#',
        signalKContext: '', // Will be extracted from topic (auto-detect self)
        signalKPath: '', // Will be extracted from topic
        sourceLabel: '',
        enabled: true,
        payloadFormat: 'full',
        ignoreDuplicates: true,
        excludeMMSI: '',
      },
      {
        id: 'vessels-environment',
        name: 'Environment Data (All Vessels)',
        mqttTopic: 'vessels/+/environment/#',
        signalKContext: '', // Will be extracted from topic (auto-detect self)
        signalKPath: '', // Will be extracted from topic
        sourceLabel: '',
        enabled: true,
        payloadFormat: 'full',
        ignoreDuplicates: true,
        excludeMMSI: '',
      },
      {
        id: 'vessels-electrical',
        name: 'Electrical Data (All Vessels)',
        mqttTopic: 'vessels/+/electrical/#',
        signalKContext: '', // Will be extracted from topic (auto-detect self)
        signalKPath: '', // Will be extracted from topic
        sourceLabel: '',
        enabled: false, // Disabled by default
        payloadFormat: 'full',
        ignoreDuplicates: true,
        excludeMMSI: '',
      },
      {
        id: 'vessels-propulsion',
        name: 'Propulsion Data (All Vessels)',
        mqttTopic: 'vessels/+/propulsion/#',
        signalKContext: '', // Will be extracted from topic (auto-detect self)
        signalKPath: '', // Will be extracted from topic
        sourceLabel: '',
        enabled: false, // Disabled by default
        payloadFormat: 'full',
        ignoreDuplicates: true,
        excludeMMSI: '',
      },
    ];
  }

  // Update MQTT subscriptions when rules change
  function updateMQTTSubscriptions(): void {
    if (state.mqttClient && state.mqttClient.connected) {
      // Unsubscribe from all topics first
      state.mqttClient.unsubscribe('#');

      // Re-subscribe based on current rules
      subscribeToMQTTTopics();
    }
  }

  // Plugin webapp routes
  plugin.registerWithRouter = function (router: Router): void {
    const express = require('express');

    app.debug('registerWithRouter called for MQTT import manager');

    // API Routes

    // Get current import rules
    router.get(
      '/api/rules',
      (_: TypedRequest, res: TypedResponse<RulesApiResponse>) => {
        res.json({
          success: true,
          rules: state.importRules,
          mqttConnected: state.mqttClient ? state.mqttClient.connected : false,
        });
      }
    );

    // Update import rules
    router.post(
      '/api/rules',
      (
        req: TypedRequest<RuleUpdateRequest>,
        res: TypedResponse<ApiResponse>
      ) => {
        try {
          const newRules = req.body.rules;
          if (!Array.isArray(newRules)) {
            return res
              .status(400)
              .json({ success: false, error: 'Rules must be an array' });
          }

          state.importRules = newRules;

          // Save rules to persistent storage
          if (saveRulesToStorage(newRules)) {
            // Update MQTT subscriptions with new rules
            updateMQTTSubscriptions();

            res.json({
              success: true,
              message: 'Import rules updated and saved to persistent storage',
            });
          } else {
            res.status(500).json({
              success: false,
              error: 'Failed to save rules to persistent storage',
            });
          }
        } catch (error) {
          res
            .status(500)
            .json({ success: false, error: (error as Error).message });
        }
      }
    );

    // Get MQTT connection status
    router.get(
      '/api/mqtt-status',
      (_: TypedRequest, res: TypedResponse<MQTTStatusApiResponse>) => {
        res.json({
          success: true,
          connected: state.mqttClient ? state.mqttClient.connected : false,
          broker: state.currentConfig?.mqttBroker,
          clientId: state.currentConfig?.mqttClientId,
        });
      }
    );

    // Test MQTT connection
    router.post(
      '/api/test-mqtt',
      (_: TypedRequest, res: TypedResponse<ApiResponse>) => {
        try {
          if (!state.mqttClient || !state.mqttClient.connected) {
            return res
              .status(503)
              .json({ success: false, error: 'MQTT not connected' });
          }

          res.json({
            success: true,
            message: 'MQTT connection is active and receiving messages',
          });
        } catch (error) {
          res
            .status(500)
            .json({ success: false, error: (error as Error).message });
        }
      }
    );

    // Get import statistics
    router.get(
      '/api/stats',
      (_: TypedRequest, res: TypedResponse<StatsApiResponse>) => {
        try {
          const stats = {
            totalRules: state.importRules.length,
            enabledRules: state.importRules.filter(r => r.enabled).length,
            messagesReceived: state.lastReceivedMessages.size,
            mqttConnected: state.mqttClient
              ? state.mqttClient.connected
              : false,
          };

          res.json({ success: true, stats: stats });
        } catch (error) {
          res
            .status(500)
            .json({ success: false, error: (error as Error).message });
        }
      }
    );

    // Serve static files
    const publicPath = path.join(__dirname, '../public');
    if (fs.existsSync(publicPath)) {
      router.use(express.static(publicPath));
      app.debug(`Static files served from: ${publicPath}`);
    }

    app.debug('MQTT Import Manager web routes registered');
  };

  // Configuration schema
  plugin.schema = {
    type: 'object',
    properties: {
      enabled: {
        type: 'boolean',
        title: 'Enable MQTT Import',
        description: 'Enable/disable the MQTT import functionality',
        default: true,
      },
      mqttBroker: {
        type: 'string',
        title: 'MQTT Broker URL',
        description:
          'MQTT broker connection string (e.g., mqtt://localhost:1883)',
        default: 'mqtt://localhost:1883',
      },
      mqttClientId: {
        type: 'string',
        title: 'MQTT Client ID',
        description: 'Unique client identifier for MQTT connection',
        default: 'signalk-mqtt-import',
      },
      mqttUsername: {
        type: 'string',
        title: 'MQTT Username',
        description: 'Username for MQTT authentication (optional)',
        default: '',
      },
      mqttPassword: {
        type: 'string',
        title: 'MQTT Password',
        description: 'Password for MQTT authentication (optional)',
        default: '',
      },
      topicPrefix: {
        type: 'string',
        title: 'Topic Prefix',
        description: 'Optional prefix for all MQTT topics',
        default: '',
      },
    },
  };

  // Persistent storage functions
  function getRulesFilePath(): string {
    if (!state.rulesFilePath) {
      const dataDir = app.getDataDirPath();
      state.rulesFilePath = path.join(dataDir, 'mqtt-import-rules.json');
    }
    return state.rulesFilePath;
  }

  function loadRulesFromStorage(): ImportRule[] {
    try {
      const filePath = getRulesFilePath();
      if (fs.existsSync(filePath)) {
        const data = fs.readFileSync(filePath, 'utf8');
        return JSON.parse(data) as ImportRule[];
      }
    } catch (error) {
      app.debug(
        `Error loading rules from storage: ${(error as Error).message}`
      );
    }
    return getDefaultImportRules();
  }

  function saveRulesToStorage(rules: ImportRule[]): boolean {
    try {
      const filePath = getRulesFilePath();
      fs.writeFileSync(filePath, JSON.stringify(rules, null, 2));
      app.debug(`Rules saved to: ${filePath}`);
      return true;
    } catch (error) {
      app.debug(`Error saving rules to storage: ${(error as Error).message}`);
      return false;
    }
  }

  function migrateOldConfiguration(options: any): ImportRule[] | null {
    // Migrate rules from old plugin config if they exist
    if (options.importRules && Array.isArray(options.importRules)) {
      app.debug(
        'Migrating import rules from plugin configuration to persistent storage'
      );
      saveRulesToStorage(options.importRules);
      return options.importRules;
    }
    return null;
  }

  return plugin;
};