diff --git a/internal/commands/commands.go b/internal/commands/commands.go
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+/*
+ * Copyright 2026 Safronov Grigorii
+ *
+ * Licensed under the CDDL, Version 1.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ *
+ * You may obtain a copy of the License at
+ * https://opensource.org/licenses/CDDL-1.0
+ */
+
+// Файл: internal/commands/commands.go
+// Назначение: Реализация MongoDB-подобных команд CRUD и команд управления кластером.
+// Добавлены команды для работы с индексами, ACL, триггерами, ограничениями и кросс-датацентровой миграцией.
+
+package commands
+
+import (
+    "futriis/pkg/utils"
+)
+
+// ShowHelp отображает справку по всем доступным командам
+func ShowHelp() {
+    helpText := `
+=== FUTRIIS DATABASE COMMANDS ===
+
+DATABASE MANAGEMENT:
+  use <db>                     - Switch to database
+  show dbs                     - List all databases
+  show collections             - List collections in current database
+
+COLLECTION OPERATIONS:
+  db.createCollection("<name>") - Create new collection
+  db.<collection>.insert({...}) - Insert document into collection
+  db.<collection>.find({_id: "..."}) - Find document by ID
+  db.<collection>.find()       - Find all documents in collection
+  db.<collection>.findByIndex("<index>", "<value>") - Find by secondary index
+  db.<collection>.update({_id: "..."}, {...}) - Update document
+  db.<collection>.remove({_id: "..."}) - Delete document
+
+INDEX MANAGEMENT:
+  db.<collection>.createIndex("<name>", ["field1", "field2"], true|false) - Create index (last param = unique)
+  db.<collection>.dropIndex("<name>") - Drop index
+  db.<collection>.listIndexes() - List all indexes
+
+CONSTRAINTS:
+  db.<collection>.addRequired("<field>") - Add required field constraint
+  db.<collection>.addUnique("<field>") - Add unique constraint
+  db.<collection>.addMin("<field>", <value>) - Add minimum value constraint
+  db.<collection>.addMax("<field>", <value>) - Add maximum value constraint
+  db.<collection>.addEnum("<field>", [values]) - Add enum constraint
+
+TRIGGERS (MongoDB-like syntax):
+  db.<collection>.createTrigger("<name>", "<event>", {
+    condition: { field: "<field>", operator: "<op>", value: <value> },
+    action: "<action>",
+    operations: [
+      { type: "set", field: "<field>", value: "<value>" },
+      { type: "inc", field: "<field>", value: <number> },
+      { type: "currentDate", field: "<field>" }
+    ]
+  })
+  
+  Events: BEFORE_INSERT, AFTER_INSERT, BEFORE_UPDATE, AFTER_UPDATE, BEFORE_DELETE, AFTER_DELETE
+  Actions: abort (cancel operation), skip (skip operation), modify (modify document), log (write to log), notify (send notification)
+  Special values: $$NOW (current timestamp), $$USER (current user), $$ROLE (current role)
+  
+  db.<collection>.dropTrigger("<name>") - Drop trigger
+  db.<collection>.listTriggers() - List all triggers on collection
+  db.<collection>.enableTrigger("<name>") - Enable trigger
+  db.<collection>.disableTrigger("<name>") - Disable trigger
+  db.getTriggerLog() - Show trigger execution log
+
+TRIGGER EXAMPLES:
+  // Auto-set updated_at timestamp on every update
+  db.users.createTrigger("update_timestamp", "BEFORE_UPDATE", {
+    action: "modify",
+    operations: [{ type: "set", field: "updated_at", value: "$$NOW" }]
+  })
+  
+  // Prevent deletion of active users
+  db.users.createTrigger("protect_active", "BEFORE_DELETE", {
+    condition: { field: "status", operator: "eq", value: "active" },
+    action: "abort"
+  })
+  
+  // Log all inserts
+  db.orders.createTrigger("audit_log", "AFTER_INSERT", {
+    action: "log",
+    description: "Log all order creations"
+  })
+  
+  // Increment counter on document insert
+  db.stats.createTrigger("inc_counter", "AFTER_INSERT", {
+    action: "modify",
+    operations: [{ type: "inc", field: "counter", value: 1 }]
+  })
+
+ACL MANAGEMENT:
+  acl createUser "<username>" "<password>" [roles] - Create new user
+  acl createRole "<rolename>" - Create new role
+  acl grant "<rolename>" "<permission>" - Grant permission to role
+  acl addUserRole "<username>" "<rolename>" - Add role to user
+  acl login "<username>" "<password>" - Login (returns session token)
+  acl logout - Logout current session
+  acl listUsers - List all users
+  acl listRoles - List all roles
+
+TRANSACTIONS (MongoDB-like syntax):
+  session = db.startSession()  - Start a new session
+  session.startTransaction()   - Begin a transaction
+  session.commitTransaction()  - Commit current transaction
+  session.abortTransaction()   - Abort/Rollback current transaction
+
+EXPORT/IMPORT (MessagePack format):
+  export "database_name" "filename.msgpack"   - Export entire database
+  import "database_name" "filename.msgpack"   - Import database from .msgpack file
+
+CROSS-DATACENTER MIGRATION COMMANDS:
+  migration status [task_id]                - Show migration status (current or specific)
+  migration list                            - List all migration tasks
+  migration start <source_dc> <target_dc> [database] [collection] - Start new migration
+  migration pause <task_id>                 - Pause a running migration
+  migration resume <task_id>                - Resume a paused migration
+  migration cancel <task_id>                - Cancel a migration
+  migration stats                           - Show migration statistics
+  migration config                          - Show migration configuration
+  migration queue                           - Show change queue status
+  migration validate <task_id>              - Validate a completed migration
+
+MIGRATION EXAMPLES:
+  // List all migration tasks
+  migration list
+  
+  // Check status of current migration
+  migration status
+  
+  // Check status of specific task
+  migration status mig_1234567890_dc-primary
+  
+  // Start migration: all databases, all collections
+  migration start dc-primary dc-secondary
+  
+  // Start migration: specific database, all collections
+  migration start dc-primary dc-secondary mydb
+  
+  // Start migration: specific database and collection
+  migration start dc-primary dc-secondary mydb users
+  
+  // Pause running migration
+  migration pause mig_1234567890_dc-primary
+  
+  // Resume paused migration
+  migration resume mig_1234567890_dc-primary
+  
+  // Cancel migration
+  migration cancel mig_1234567890_dc-primary
+  
+  // Show migration statistics
+  migration stats
+  
+  // Show current configuration
+  migration config
+  
+  // Show queue status
+  migration queue
+
+MIGRATION MODES (config.toml):
+  manual    - Fully manual: all operations require explicit commands
+  semi_auto - Semi-automatic: main migration manual, delta sync automatic (default)
+  auto      - Fully automatic: continuous migration with delta sync
+
+MIGRATION STATUS COLORS:
+  🟢 completed  - Migration successfully finished
+  🟡 migrating  - Migration in progress
+  🟡 delta_sync - Delta synchronization in progress
+  🔵 preparing  - Preparing metadata
+  🔵 validating - Validating data
+  🟠 paused     - Paused by user
+  🔴 failed     - Migration failed
+
+================================================================================
+
+CLUSTER MANAGEMENT:
+  cluster status               - Show cluster status
+  cluster nodes                - List all cluster nodes
+  cluster add <ip> <port>      - Add node to cluster
+  cluster remove <node_id>     - Remove node from cluster
+  cluster sync <db> <coll>     - Sync collection across cluster
+  cluster replication-factor [n] - Get or set replication factor
+  cluster leader               - Show cluster leader
+  cluster health               - Check cluster health
+
+HTTP API:
+  The database also exposes HTTP RESTful API on port 8080 (configurable)
+  See documentation for endpoints: /api/db/, /api/index/, /api/acl/, /api/constraint/, /api/trigger/, /api/migration/
+
+UTILITIES:
+  help                         - Show this help message
+  exit / quit                  - Exit database
+
+`
+    utils.Println(helpText)
+}
+
+// ShowMigrationHelp отображает справку по командам миграции
+func ShowMigrationHelp() {
+    migrationHelp := `
+=== CROSS-DATACENTER MIGRATION HELP ===
+
+OVERVIEW:
+  Cross-datacenter migration allows seamless data transfer between geographically
+  distributed futriix clusters without downtime.
+
+LIFECYCLE:
+  Idle → Preparing → Migrating → Delta Sync → Validating → Completed
+                      ↘           ↘            ↘
+                       Paused    Failed       (errors)
+
+COMMANDS:
+  migration status [task_id]     Show migration status
+  migration list                 List all migration tasks
+  migration start <src> <tgt> [database] [collection] - Start new migration
+  migration pause <task_id>      Pause migration
+  migration resume <task_id>     Resume migration
+  migration cancel <task_id>     Cancel migration
+  migration stats                Show statistics
+  migration config               Show configuration
+  migration queue                Show queue status
+  migration validate <task_id>   Validate migrated data
+
+CONFIGURATION (config.toml):
+  [migration]
+    enabled = false
+    mode = "semi_auto"          # manual, semi_auto, auto
+    
+    [migration.source]
+      name = "dc-primary"
+      endpoint = "localhost:8080"
+      timeout_sec = 30
+    
+    [migration.target]
+      name = "dc-secondary"
+      endpoint = "localhost:8081"
+      timeout_sec = 30
+    
+    [migration.settings]
+      batch_size = 1000
+      workers = 4
+      compression = "snappy"    # snappy, lz4, zstd
+      resume_enabled = true
+      checkpoint_interval_sec = 30
+      max_retries = 3
+      retry_backoff_sec = 5
+      collections = []
+      exclude_collections = []
+    
+    [migration.delta]
+      enabled = true
+      interval_sec = 60
+      max_lag_sec = 300
+    
+    [migration.validation]
+      enabled = true
+      sample_percent = 10
+      max_errors = 100
+
+FEATURES:
+  ✅ Resume after interruption (checkpoints)
+  ✅ Parallel transfer (configurable workers)
+  ✅ Compression (Snappy, LZ4, Zstd)
+  ✅ Delta sync (continuous replication)
+  ✅ Data validation (checksums)
+  ✅ Fault-tolerant (automatic retries)
+  ✅ Idempotent operations
+  ✅ Persistent change queue
+  ✅ Audit logging
+  ✅ Cross-datacenter support
+
+EXAMPLES:
+  # Start migration all databases
+  migration start dc-primary dc-secondary
+
+  # Start migration specific database
+  migration start dc-primary dc-secondary mydb
+
+  # Start migration specific collection
+  migration start dc-primary dc-secondary mydb users
+
+  # Check migration status
+  migration status
+
+  # Check specific task
+  migration status mig_1234567890_dc-primary
+
+  # List all migration tasks
+  migration list
+
+  # Validate migrated data
+  migration validate mig_1234567890_dc-primary
+
+  # Show migration statistics
+  migration stats
+
+  # Show queue status
+  migration queue
+`
+    utils.Println(migrationHelp)
+}
+
+// ShowMigrationStatusInfo отображает подробную информацию о статусе миграции
+func ShowMigrationStatusInfo() {
+    statusInfo := `
+=== MIGRATION STATUS DETAILS ===
+
+FIELD               DESCRIPTION
+─────────────────────────────────────────────────────────────────────────────
+ID                  Unique task identifier
+Source DC           Source datacenter name
+Target DC           Target datacenter name
+Status              Current migration state
+Progress            Migration progress percentage
+Total Docs          Total documents to migrate
+Migrated Docs       Successfully migrated documents
+Failed Docs         Failed documents
+Skipped Docs        Skipped documents
+Start Time          Migration start time
+End Time            Migration completion time
+Last Checkpoint     Last checkpoint timestamp
+Error               Error message if migration failed
+
+STATUS VALUES:
+  idle       - No active migration
+  preparing  - Collecting metadata
+  migrating  - Data transfer in progress
+  delta_sync - Synchronizing changes
+  validating - Validating data
+  completed  - Migration finished successfully
+  failed     - Migration failed with error
+  paused     - Migration paused by user
+
+TROUBLESHOOTING:
+  If migration fails, check:
+  1. Network connectivity between datacenters
+  2. Target datacenter is running
+  3. Configuration file is correct
+  4. Logs for detailed error messages
+
+  To recover from failure:
+  1. Check migration status
+  2. If status is "failed", check error message
+  3. Fix the issue
+  4. Resume migration: migration resume <task_id>
+  5. Or cancel and start new: migration cancel <task_id> && migration start <source> <target>
+`
+    utils.Println(statusInfo)
+}
+
+// ShowMigrationConfigInfo отображает информацию о конфигурации миграции
+func ShowMigrationConfigInfo() {
+    configInfo := `
+=== MIGRATION CONFIGURATION GUIDE ===
+
+GENERAL SETTINGS:
+  enabled                  - Enable/disable migration system
+  mode                     - Manual, semi_auto, or auto
+
+SOURCE DATACENTER:
+  name                     - Source datacenter identifier
+  endpoint                 - HTTP endpoint URL
+  timeout_sec              - Request timeout in seconds
+
+TARGET DATACENTER:
+  name                     - Target datacenter identifier
+  endpoint                 - HTTP endpoint URL
+  timeout_sec              - Request timeout in seconds
+
+MIGRATION SETTINGS:
+  batch_size               - Documents per batch (default: 1000)
+  workers                  - Parallel workers (default: 4)
+  compression              - Compression algorithm: snappy, lz4, zstd
+  resume_enabled           - Enable resume from checkpoint
+  checkpoint_interval_sec  - Checkpoint save interval
+  max_retries              - Maximum retry attempts
+  retry_backoff_sec        - Backoff between retries
+  collections              - Specific collections to migrate (empty = all)
+  exclude_collections      - Collections to exclude
+
+DELTA SYNC SETTINGS:
+  enabled                  - Enable delta synchronization
+  interval_sec             - Sync interval in seconds
+  max_lag_sec              - Maximum acceptable lag
+
+VALIDATION SETTINGS:
+  enabled                  - Enable data validation
+  sample_percent           - Percentage of documents to validate
+  max_errors               - Maximum errors before stopping
+
+EXAMPLE CONFIGURATION:
+  [migration]
+    enabled = true
+    mode = "semi_auto"
+    
+    [migration.settings]
+      batch_size = 2000
+      workers = 8
+      compression = "zstd"
+      resume_enabled = true
+      checkpoint_interval_sec = 60
+`
+    utils.Println(configInfo)
+}