MksDdn Migrate Content is a clean-room migration suite that packages your site into deterministic .wpbkp archives. Each bundle contains a manifest, checksum, database segments, media, selected files, and user decisions, so imports are predictable and reversible.

Why MksDdn Migrate Content?

• Dual export modes – choose Full Site (database + uploads/plugins/themes) or Selected Content (multi-select posts/pages/CPTs) with or without referenced media.
• Chunked pipeline – large archives stream through AJAX endpoints with resume tokens, so multi‑GB transfers survive flaky networks.
• Snapshots, history & rollback – every import stores a snapshot, logs metadata, enforces a global job lock, and lets you roll back with one click.
• User merge control – compare archive vs current users, decide how to merge/conflict, and log every change for audit.
• Automation & retention – schedule recurring full-site exports via WP-Cron, cap storage with retention rules, and review run logs in the admin UI.
• Integrity & safety – .wpbkp archives ship with manifests and checksums; imports verify capabilities, nonces, and disk space before touching data.

Feature Highlights

• Archive format with manifest, checksum, and payload folders (content.json, media/, options/, filesystem slices).
• Media scanner that collects featured images, galleries, attachments referenced inside blocks or shortcodes.
• File-system coverage for wp-content/uploads, wp-content/plugins, wp-content/themes with filters to skip VCS/system files.
• Chunked upload/download JS client with live progress, auto-resume, and graceful fallback to direct transfer.
• Recovery center showing history, statuses, archive paths, rollback controls, and inline notices when a job lock is active.
• Scheduler UI to enable cron-based backups, tweak recurrence, and enforce “keep last N archives”.
• Custom .wpbkp drag-and-drop uploader with checksum guardrails (UI polish deferred to next milestone, functionality already complete).

Architecture

The plugin follows SOLID principles and WordPress Coding Standards with a clean, modular architecture:

Service Container & Dependency Injection

• Centralized ServiceContainer manages all dependencies
• Service Providers (CoreServiceProvider, AdminServiceProvider, ExportServiceProvider, ImportServiceProvider, ChunkServiceProvider) register services
• All dependencies resolved through container, eliminating direct instantiation
• Full support for interface-based dependency injection

Request Handlers

• ExportRequestHandler – handles export requests
• ImportRequestHandler – delegates to specialized import services
• RecoveryRequestHandler – manages snapshots and rollbacks
• ScheduleRequestHandler – handles automation scheduling
• UserMergeRequestHandler – processes user merge operations
• All handlers implement corresponding interfaces for testability

Service Layer

• SelectedContentImportService – handles selected content imports
• FullSiteImportService – manages full site imports
• ImportFileValidator – validates uploaded files
• ImportPayloadPreparer – prepares import payloads
• ResponseHandler – manages redirects and status messages
• NotificationService – handles user notifications
• ProgressService – tracks operation progress

Contracts (Interfaces)

All key components implement interfaces:
* ExporterInterface, ImporterInterface
* MediaCollectorInterface, SnapshotManagerInterface
* HistoryRepositoryInterface, ChunkJobRepositoryInterface
* ScheduleManagerInterface, UserPreviewStoreInterface
* NotificationServiceInterface, ProgressServiceInterface
* Request handler interfaces for all handlers

Error Handling

• Specialized exceptions: ValidationException, FileOperationException, DatabaseOperationException, ImportException, ExportException
• Centralized ErrorHandler for consistent error processing
• Proper logging and user-friendly error messages

Performance

• BatchLoader for optimized database queries (prevents N+1 problems)
• Efficient media collection with batch processing
• Chunked transfer for large files
• Memory-efficient streaming for large archives

Security

• All admin operations check current_user_can('manage_options')
• Nonce verification for all forms and AJAX requests
• Input sanitization using WordPress sanitization functions
• Output escaping with esc_html(), esc_attr(), esc_url()
• File upload validation with MIME type checking