fix(migration): properly transform v3 flat structure to v4 nested snmp config

The v3→v4 migration was only renaming upsList to upsDevices without
transforming the device structure. V3 had a flat structure with SNMP
fields directly on the device object, while v4 expects a nested 'snmp'
object.

This commit fixes the migration to:
- Move host, port, community, version, etc. into nested snmp object
- Convert version from string to number
- Add default timeout (5000ms)
- Create thresholds object with defaults
- Preserve all SNMPv1, v2c, and v3 authentication fields

Also includes install.sh fix for better non-interactive handling.

deno.json

@@ -1,6 +1,6 @@
 {
   "name": "@serve.zone/nupst",
-  "version": "4.0.2",
+  "version": "4.0.4",
   "exports": "./mod.ts",
   "tasks": {
     "dev": "deno run --allow-all mod.ts",

install.sh

@@ -98,7 +98,11 @@ if [ ! -t 0 ] || [ ! -t 1 ]; then
     echo "Script detected it's running in a non-interactive environment without -y flag."
     echo "Attempting to find a controlling terminal for interactive prompts..."
     # Try to use a controlling terminal for user input
-    exec < /dev/tty 2>/dev/null || INTERACTIVE=0
+    if exec < /dev/tty 2>/dev/null && [ -t 0 ]; then
+      INTERACTIVE=1
+    else
+      INTERACTIVE=0
+    fi
 
     if [ $INTERACTIVE -eq 0 ]; then
       echo "ERROR: No controlling terminal available for interactive prompts."

test/manualdocker/00-test-fresh-v4-install.sh

@@ -0,0 +1,168 @@
+#!/bin/bash
+#
+# Test fresh v4 installation from scratch
+# Tests the most common user scenario: clean install using curl | bash
+#
+
+set -e
+
+CONTAINER_NAME="nupst-test-fresh-v4"
+
+echo "================================================"
+echo "  NUPST Fresh v4 Installation Test"
+echo "================================================"
+echo ""
+
+# Check if container already exists
+if docker ps -a --format '{{.Names}}' | grep -q "^${CONTAINER_NAME}$"; then
+  echo "⚠️  Container ${CONTAINER_NAME} already exists"
+  read -p "Remove and recreate? (y/N): " -n 1 -r
+  echo
+  if [[ $REPLY =~ ^[Yy]$ ]]; then
+    echo "→ Stopping and removing existing container..."
+    docker stop ${CONTAINER_NAME} 2>/dev/null || true
+    docker rm ${CONTAINER_NAME} 2>/dev/null || true
+  else
+    echo "Exiting. Remove manually with: docker rm -f ${CONTAINER_NAME}"
+    exit 1
+  fi
+fi
+
+echo "→ Creating Docker container with systemd..."
+docker run -d \
+  --name ${CONTAINER_NAME} \
+  --privileged \
+  --cgroupns=host \
+  -v /sys/fs/cgroup:/sys/fs/cgroup:rw \
+  ubuntu:22.04 \
+  /bin/bash -c "apt-get update && apt-get install -y systemd systemd-sysv && exec /sbin/init"
+
+echo "→ Waiting for systemd to initialize..."
+sleep 10
+
+echo "→ Waiting for dpkg lock to be released..."
+docker exec ${CONTAINER_NAME} bash -c "
+  while fuser /var/lib/dpkg/lock-frontend >/dev/null 2>&1; do
+    echo '  Waiting for dpkg lock...'
+    sleep 2
+  done
+  echo '  dpkg lock released'
+"
+
+echo "→ Installing prerequisites (curl)..."
+docker exec ${CONTAINER_NAME} bash -c "
+  apt-get update -qq
+  apt-get install -y -qq curl
+"
+
+echo ""
+echo "→ Installing NUPST v4 using curl | bash..."
+echo "   Command: curl -sSL https://code.foss.global/serve.zone/nupst/raw/branch/main/install.sh | bash -s -- -y"
+echo ""
+
+docker exec ${CONTAINER_NAME} bash -c "
+  curl -sSL https://code.foss.global/serve.zone/nupst/raw/branch/main/install.sh | bash -s -- -y
+"
+
+echo ""
+echo "================================================"
+echo "  Verifying Installation"
+echo "================================================"
+echo ""
+
+echo "→ Checking binary location..."
+docker exec ${CONTAINER_NAME} bash -c "
+  if [ -f /opt/nupst/nupst ]; then
+    echo '  ✓ Binary exists at /opt/nupst/nupst'
+    ls -lh /opt/nupst/nupst
+  else
+    echo '  ✗ Binary not found at /opt/nupst/nupst'
+    exit 1
+  fi
+"
+
+echo ""
+echo "→ Checking symlink..."
+docker exec ${CONTAINER_NAME} bash -c "
+  if [ -L /usr/local/bin/nupst ]; then
+    echo '  ✓ Symlink exists at /usr/local/bin/nupst'
+    ls -lh /usr/local/bin/nupst
+  elif [ -L /usr/bin/nupst ]; then
+    echo '  ✓ Symlink exists at /usr/bin/nupst'
+    ls -lh /usr/bin/nupst
+  else
+    echo '  ✗ Symlink not found in /usr/local/bin or /usr/bin'
+    exit 1
+  fi
+"
+
+echo ""
+echo "→ Checking PATH integration..."
+docker exec ${CONTAINER_NAME} bash -c "
+  NUPST_PATH=\$(which nupst 2>/dev/null)
+  if [ -n \"\$NUPST_PATH\" ]; then
+    echo '  ✓ nupst found in PATH at: '\$NUPST_PATH
+  else
+    echo '  ✗ nupst not found in PATH'
+    echo '  PATH contents:'
+    echo \$PATH
+    exit 1
+  fi
+"
+
+echo ""
+echo "→ Testing nupst command execution..."
+docker exec ${CONTAINER_NAME} nupst --version
+
+echo ""
+echo "→ Creating minimal config for service test..."
+docker exec ${CONTAINER_NAME} bash -c "
+  mkdir -p /etc/nupst
+  cat > /etc/nupst/config.json << 'EOF'
+{
+  \"version\": \"4.0\",
+  \"upsDevices\": [],
+  \"groups\": [],
+  \"checkInterval\": 30000
+}
+EOF
+  echo '  ✓ Minimal config created'
+"
+
+echo ""
+echo "→ Testing service creation..."
+docker exec ${CONTAINER_NAME} bash -c "
+  echo '  Running: nupst service enable'
+  nupst service enable
+
+  if [ -f /etc/systemd/system/nupst.service ]; then
+    echo '  ✓ Service file created successfully'
+  else
+    echo '  ✗ Service file creation failed'
+    exit 1
+  fi
+"
+
+echo ""
+echo "→ Checking if service is enabled..."
+docker exec ${CONTAINER_NAME} systemctl is-enabled nupst
+
+echo ""
+echo "================================================"
+echo "  ✓ Fresh v4 Installation Test Complete"
+echo "================================================"
+echo ""
+echo "Installation verified successfully:"
+echo "  • Binary installed to /opt/nupst/nupst"
+echo "  • Symlink created for global access"
+echo "  • nupst command available in PATH"
+echo "  • Command executes correctly"
+echo "  • Systemd service file created"
+echo ""
+echo "Useful commands:"
+echo "  docker exec -it ${CONTAINER_NAME} bash"
+echo "  docker exec ${CONTAINER_NAME} nupst --help"
+echo "  docker exec ${CONTAINER_NAME} nupst service status"
+echo "  docker stop ${CONTAINER_NAME}"
+echo "  docker rm -f ${CONTAINER_NAME}"
+echo ""

test/manualdocker/01-setup-v3-container.sh

@@ -53,7 +53,7 @@ docker exec ${CONTAINER_NAME} bash -c "
 echo "→ Installing prerequisites in container..."
 docker exec ${CONTAINER_NAME} bash -c "
   apt-get update -qq
-  apt-get install -y -qq git curl sudo
+  apt-get install -y -qq git curl sudo jq
 "
 
 echo "→ Cloning NUPST v3 (commit ${V3_COMMIT})..."
@@ -66,35 +66,59 @@ docker exec ${CONTAINER_NAME} bash -c "
   git log -1 --oneline
 "
 
-echo "→ Running NUPST v3 installation script..."
+echo "→ Running NUPST v3 installation directly (bypassing install.sh auto-update)..."
 docker exec ${CONTAINER_NAME} bash -c "
   cd /opt/nupst
-  bash install.sh -y
+  # Run setup.sh directly to avoid install.sh trying to update to v4
+  bash setup.sh -y
 "
 
-echo "→ Creating dummy NUPST configuration for testing..."
-docker exec ${CONTAINER_NAME} bash -c "
-  mkdir -p /etc/nupst
-  cat > /etc/nupst/config.json << 'EOF'
+echo "→ Creating NUPST configuration using real UPS data from .nogit/env.json..."
+
+# Check if .nogit/env.json exists
+if [ ! -f "../../.nogit/env.json" ]; then
+  echo "❌ Error: .nogit/env.json not found"
+  echo "This file contains test UPS credentials and is required for testing"
+  exit 1
+fi
+
+# Read UPS data from .nogit/env.json and create v3 config
+docker exec ${CONTAINER_NAME} bash -c "mkdir -p /etc/nupst"
+
+# Generate config from .nogit/env.json using jq
+cat ../../.nogit/env.json | jq -r '
 {
-  \"upsList\": [
+  "upsList": [
     {
-      \"id\": \"test-ups\",
-      \"name\": \"Test UPS\",
-      \"host\": \"127.0.0.1\",
-      \"port\": 161,
-      \"community\": \"public\",
-      \"version\": \"2c\",
-      \"batteryLowOID\": \"1.3.6.1.4.1.935.1.1.1.3.3.1.0\",
-      \"onBatteryOID\": \"1.3.6.1.4.1.935.1.1.1.3.3.2.0\",
-      \"shutdownCommand\": \"echo 'Shutdown triggered'\"
+      "id": "test-ups-v1",
+      "name": "Test UPS (SNMP v1)",
+      "host": .testConfigV1.snmp.host,
+      "port": .testConfigV1.snmp.port,
+      "community": .testConfigV1.snmp.community,
+      "version": (.testConfigV1.snmp.version | tostring),
+      "batteryLowOID": "1.3.6.1.4.1.935.1.1.1.3.3.1.0",
+      "onBatteryOID": "1.3.6.1.4.1.935.1.1.1.3.3.2.0",
+      "shutdownCommand": "echo \"Shutdown triggered for test-ups-v1\""
+    },
+    {
+      "id": "test-ups-v3",
+      "name": "Test UPS (SNMP v3)",
+      "host": .testConfigV3.snmp.host,
+      "port": .testConfigV3.snmp.port,
+      "version": (.testConfigV3.snmp.version | tostring),
+      "securityLevel": .testConfigV3.snmp.securityLevel,
+      "username": .testConfigV3.snmp.username,
+      "authProtocol": .testConfigV3.snmp.authProtocol,
+      "authKey": .testConfigV3.snmp.authKey,
+      "batteryLowOID": "1.3.6.1.4.1.935.1.1.1.3.3.1.0",
+      "onBatteryOID": "1.3.6.1.4.1.935.1.1.1.3.3.2.0",
+      "shutdownCommand": "echo \"Shutdown triggered for test-ups-v3\""
     }
   ],
-  \"groups\": []
-}
-EOF
-  echo 'Dummy config created at /etc/nupst/config.json'
-"
+  "groups": []
+}' | docker exec -i ${CONTAINER_NAME} tee /etc/nupst/config.json > /dev/null
+
+echo "  ✓ Real UPS config created at /etc/nupst/config.json (from .nogit/env.json)"
 
 echo "→ Enabling NUPST systemd service..."
 docker exec ${CONTAINER_NAME} bash -c "

test/manualdocker/02-test-v3-to-v4-migration.sh

@@ -32,23 +32,10 @@ echo "→ Stopping v3 service..."
 docker exec ${CONTAINER_NAME} systemctl stop nupst
 echo ""
 
-echo "→ Pulling latest v4 code from migration/deno-v4 branch..."
+echo "→ Running v4 installation from main branch (should auto-detect v3 and migrate)..."
+echo "   Using: curl -sSL https://code.foss.global/serve.zone/nupst/raw/branch/main/install.sh | sudo bash"
 docker exec ${CONTAINER_NAME} bash -c "
-  cd /opt/nupst
-  git fetch origin
-  # Reset any local changes made by install.sh
-  git reset --hard HEAD
-  git clean -fd
-  git checkout migration/deno-v4
-  git pull origin migration/deno-v4
-  echo 'Now on:'
-  git log -1 --oneline
-"
-
-echo "→ Running install.sh (should auto-detect v3 and migrate)..."
-docker exec ${CONTAINER_NAME} bash -c "
-  cd /opt/nupst
-  bash install.sh -y
+  curl -sSL https://code.foss.global/serve.zone/nupst/raw/branch/main/install.sh | bash -s -- -y
 "
 
 echo "→ Checking service status after migration..."

ts/colors.ts

@@ -15,7 +15,6 @@ export const theme = {
   info: colors.cyan,
   dim: colors.dim,
   highlight: colors.bold,
-  bright: colors.bright,
 
   // Status indicators
   statusActive: (text: string) => colors.green(colors.bold(text)),

ts/daemon.ts

@@ -6,6 +6,7 @@ import { promisify } from 'node:util';
 import { NupstSnmp } from './snmp/manager.ts';
 import type { ISnmpConfig } from './snmp/types.ts';
 import { logger } from './logger.ts';
+import { MigrationRunner } from './migrations/index.ts';
 
 const execAsync = promisify(exec);
 const execFileAsync = promisify(execFile);
@@ -49,6 +50,8 @@ export interface IGroupConfig {
  * Configuration interface for the daemon
  */
 export interface INupstConfig {
+  /** Configuration format version */
+  version?: string;
   /** UPS devices configuration */
   upsDevices: IUpsConfig[];
   /** Groups configuration */
@@ -56,10 +59,12 @@ export interface INupstConfig {
   /** Check interval in milliseconds */
   checkInterval: number;
 
-  // Legacy fields for backward compatibility
-  /** SNMP configuration settings (legacy) */
+  // Legacy fields for backward compatibility (will be migrated away)
+  /** UPS list (v3 format - legacy) */
+  upsList?: IUpsConfig[];
+  /** SNMP configuration settings (v1 format - legacy) */
   snmp?: ISnmpConfig;
-  /** Threshold settings (legacy) */
+  /** Threshold settings (v1 format - legacy) */
   thresholds?: {
     /** Shutdown when battery below this percentage */
     battery: number;
@@ -91,6 +96,7 @@ export class NupstDaemon {
 
   /** Default configuration */
   private readonly DEFAULT_CONFIG: INupstConfig = {
+    version: '4.0',
     upsDevices: [
       {
         id: 'default',
@@ -153,29 +159,16 @@ export class NupstDaemon {
       const configData = fs.readFileSync(this.CONFIG_PATH, 'utf8');
       const parsedConfig = JSON.parse(configData);
 
-      // Handle legacy configuration format
-      if (!parsedConfig.upsDevices && parsedConfig.snmp) {
-        // Convert legacy format to new format
-        this.config = {
-          upsDevices: [
-            {
-              id: 'default',
-              name: 'Default UPS',
-              snmp: parsedConfig.snmp,
-              thresholds: parsedConfig.thresholds,
-              groups: [],
-            },
-          ],
-          groups: [],
-          checkInterval: parsedConfig.checkInterval,
-        };
+      // Run migrations to upgrade config format if needed
+      const migrationRunner = new MigrationRunner();
+      const { config: migratedConfig, migrated } = await migrationRunner.run(parsedConfig);
 
-        logger.log('Legacy configuration format detected. Converting to multi-UPS format.');
-
-        // Save the new format
+      // Save migrated config back to disk if any migrations ran
+      if (migrated) {
+        this.config = migratedConfig;
         await this.saveConfig(this.config);
       } else {
-        this.config = parsedConfig;
+        this.config = migratedConfig;
       }
 
       return this.config;
@@ -202,8 +195,17 @@ export class NupstDaemon {
       if (!fs.existsSync(configDir)) {
         fs.mkdirSync(configDir, { recursive: true });
       }
-      fs.writeFileSync(this.CONFIG_PATH, JSON.stringify(config, null, 2));
-      this.config = config;
+
+      // Ensure version is always set and remove legacy fields before saving
+      const configToSave: INupstConfig = {
+        version: '4.0',
+        upsDevices: config.upsDevices,
+        groups: config.groups,
+        checkInterval: config.checkInterval,
+      };
+
+      fs.writeFileSync(this.CONFIG_PATH, JSON.stringify(configToSave, null, 2));
+      this.config = configToSave;
 
       console.log('┌─ Configuration Saved ─────────────────────┐');
       console.log(`│ Location: ${this.CONFIG_PATH}`);

ts/migrations/base-migration.ts

@@ -0,0 +1,54 @@
+/**
+ * Abstract base class for configuration migrations
+ *
+ * Each migration represents an upgrade from one config version to another.
+ * Migrations run in order based on the `order` field, allowing users to jump
+ * multiple versions (e.g., v1 → v4 runs migrations 2, 3, and 4).
+ */
+export abstract class BaseMigration {
+  /**
+   * Migration order number
+   * - Order 2: v1 → v2
+   * - Order 3: v2 → v3
+   * - Order 4: v3 → v4
+   * etc.
+   */
+  abstract readonly order: number;
+
+  /**
+   * Source version this migration upgrades from
+   * e.g., "1.x", "3.x"
+   */
+  abstract readonly fromVersion: string;
+
+  /**
+   * Target version this migration upgrades to
+   * e.g., "2.0", "4.0"
+   */
+  abstract readonly toVersion: string;
+
+  /**
+   * Check if this migration should run on the given config
+   *
+   * @param config - Raw configuration object to check
+   * @returns True if migration should run, false otherwise
+   */
+  abstract shouldRun(config: any): Promise<boolean>;
+
+  /**
+   * Perform the migration on the given config
+   *
+   * @param config - Raw configuration object to migrate
+   * @returns Migrated configuration object
+   */
+  abstract migrate(config: any): Promise<any>;
+
+  /**
+   * Get human-readable name for this migration
+   *
+   * @returns Migration name
+   */
+  getName(): string {
+    return `Migration ${this.fromVersion} → ${this.toVersion}`;
+  }
+}

ts/migrations/index.ts

@@ -0,0 +1,10 @@
+/**
+ * Configuration migrations module
+ *
+ * Exports the migration system for upgrading configs between versions.
+ */
+
+export { BaseMigration } from './base-migration.ts';
+export { MigrationRunner } from './migration-runner.ts';
+export { MigrationV1ToV2 } from './migration-v1-to-v2.ts';
+export { MigrationV3ToV4 } from './migration-v3-to-v4.ts';

ts/migrations/migration-runner.ts

@@ -0,0 +1,69 @@
+import { BaseMigration } from './base-migration.ts';
+import { MigrationV1ToV2 } from './migration-v1-to-v2.ts';
+import { MigrationV3ToV4 } from './migration-v3-to-v4.ts';
+import { logger } from '../logger.ts';
+
+/**
+ * Migration runner
+ *
+ * Discovers all available migrations, sorts them by order,
+ * and runs applicable migrations in sequence.
+ */
+export class MigrationRunner {
+  private migrations: BaseMigration[];
+
+  constructor() {
+    // Register all migrations here
+    this.migrations = [
+      new MigrationV1ToV2(),
+      new MigrationV3ToV4(),
+      // Add future migrations here (v4→v5, v5→v6, etc.)
+    ];
+
+    // Sort by order to ensure they run in sequence
+    this.migrations.sort((a, b) => a.order - b.order);
+  }
+
+  /**
+   * Run all applicable migrations on the config
+   *
+   * @param config - Raw configuration object to migrate
+   * @returns Migrated configuration and whether migrations ran
+   */
+  async run(config: any): Promise<{ config: any; migrated: boolean }> {
+    let currentConfig = config;
+    let anyMigrationsRan = false;
+
+    logger.dim('Checking for required config migrations...');
+
+    for (const migration of this.migrations) {
+      const shouldRun = await migration.shouldRun(currentConfig);
+
+      if (shouldRun) {
+        logger.info(`Running ${migration.getName()}...`);
+        currentConfig = await migration.migrate(currentConfig);
+        anyMigrationsRan = true;
+      }
+    }
+
+    if (anyMigrationsRan) {
+      logger.success('Configuration migrations complete');
+    } else {
+      logger.dim('No migrations needed');
+    }
+
+    return {
+      config: currentConfig,
+      migrated: anyMigrationsRan,
+    };
+  }
+
+  /**
+   * Get all registered migrations
+   *
+   * @returns Array of all migrations sorted by order
+   */
+  getMigrations(): BaseMigration[] {
+    return [...this.migrations];
+  }
+}

ts/migrations/migration-v1-to-v2.ts

@@ -0,0 +1,56 @@
+import { BaseMigration } from './base-migration.ts';
+import { logger } from '../logger.ts';
+
+/**
+ * Migration from v1 (single SNMP config) to v2 (upsDevices array)
+ *
+ * Detects old format:
+ * {
+ *   snmp: { ... },
+ *   thresholds: { ... },
+ *   checkInterval: 30000
+ * }
+ *
+ * Converts to:
+ * {
+ *   version: "2.0",
+ *   upsDevices: [{ id: "default", name: "Default UPS", snmp: ..., thresholds: ... }],
+ *   groups: [],
+ *   checkInterval: 30000
+ * }
+ */
+export class MigrationV1ToV2 extends BaseMigration {
+  readonly order = 2;
+  readonly fromVersion = '1.x';
+  readonly toVersion = '2.0';
+
+  async shouldRun(config: any): Promise<boolean> {
+    // V1 format has snmp field directly at root, no upsDevices or upsList
+    return !!config.snmp && !config.upsDevices && !config.upsList;
+  }
+
+  async migrate(config: any): Promise<any> {
+    logger.info(`${this.getName()}: Converting single SNMP config to multi-UPS format...`);
+
+    const migrated = {
+      version: this.toVersion,
+      upsDevices: [
+        {
+          id: 'default',
+          name: 'Default UPS',
+          snmp: config.snmp,
+          thresholds: config.thresholds || {
+            battery: 60,
+            runtime: 20,
+          },
+          groups: [],
+        },
+      ],
+      groups: [],
+      checkInterval: config.checkInterval || 30000,
+    };
+
+    logger.success(`${this.getName()}: Migration complete`);
+    return migrated;
+  }
+}

ts/migrations/migration-v3-to-v4.ts

@@ -0,0 +1,106 @@
+import { BaseMigration } from './base-migration.ts';
+import { logger } from '../logger.ts';
+
+/**
+ * Migration from v3 (upsList) to v4 (upsDevices)
+ *
+ * Transforms v3 format with flat SNMP config:
+ * {
+ *   upsList: [
+ *     {
+ *       id: "ups-1",
+ *       name: "UPS 1",
+ *       host: "192.168.1.1",
+ *       port: 161,
+ *       community: "public",
+ *       version: "1"  // string
+ *     }
+ *   ]
+ * }
+ *
+ * To v4 format with nested SNMP config:
+ * {
+ *   version: "4.0",
+ *   upsDevices: [
+ *     {
+ *       id: "ups-1",
+ *       name: "UPS 1",
+ *       snmp: {
+ *         host: "192.168.1.1",
+ *         port: 161,
+ *         community: "public",
+ *         version: 1,  // number
+ *         timeout: 5000
+ *       },
+ *       thresholds: { battery: 60, runtime: 20 },
+ *       groups: []
+ *     }
+ *   ]
+ * }
+ */
+export class MigrationV3ToV4 extends BaseMigration {
+  readonly order = 4;
+  readonly fromVersion = '3.x';
+  readonly toVersion = '4.0';
+
+  async shouldRun(config: any): Promise<boolean> {
+    // V3 format has upsList instead of upsDevices
+    return !!config.upsList && !config.upsDevices;
+  }
+
+  async migrate(config: any): Promise<any> {
+    logger.info(`${this.getName()}: Migrating v3 config to v4 format...`);
+    logger.dim(`  - Renaming upsList → upsDevices`);
+    logger.dim(`  - Restructuring UPS devices (flat → nested snmp config)`);
+
+    // Transform each UPS device from v3 flat structure to v4 nested structure
+    const transformedDevices = config.upsList.map((device: any) => {
+      // Build SNMP config object
+      const snmpConfig: any = {
+        host: device.host,
+        port: device.port || 161,
+        version: typeof device.version === 'string' ? parseInt(device.version, 10) : device.version,
+        timeout: device.timeout || 5000,
+      };
+
+      // Add SNMPv1/v2c fields
+      if (device.community) {
+        snmpConfig.community = device.community;
+      }
+
+      // Add SNMPv3 fields
+      if (device.securityLevel) snmpConfig.securityLevel = device.securityLevel;
+      if (device.username) snmpConfig.username = device.username;
+      if (device.authProtocol) snmpConfig.authProtocol = device.authProtocol;
+      if (device.authKey) snmpConfig.authKey = device.authKey;
+      if (device.privProtocol) snmpConfig.privProtocol = device.privProtocol;
+      if (device.privKey) snmpConfig.privKey = device.privKey;
+
+      // Add UPS model if present
+      if (device.upsModel) snmpConfig.upsModel = device.upsModel;
+      if (device.customOIDs) snmpConfig.customOIDs = device.customOIDs;
+
+      // Return v4 format with nested structure
+      return {
+        id: device.id,
+        name: device.name,
+        snmp: snmpConfig,
+        thresholds: device.thresholds || {
+          battery: 60,
+          runtime: 20,
+        },
+        groups: device.groups || [],
+      };
+    });
+
+    const migrated = {
+      version: this.toVersion,
+      upsDevices: transformedDevices,
+      groups: config.groups || [],
+      checkInterval: config.checkInterval || 30000,
+    };
+
+    logger.success(`${this.getName()}: Migration complete (${transformedDevices.length} devices transformed)`);
+    return migrated;
+  }
+}