DATABASE SCHEMA ARCHITECTURE
============================

OVERVIEW
--------
This document describes the RSpade database schema organization and the architectural
principles governing how framework and application data is stored.

Date: 2024-11-18
Status: Active framework architecture documentation

TABLE NAMING CONVENTIONS
-------------------------
RSpade uses table name prefixes to distinguish between different layers of the system:

1. SYSTEM TABLES (underscore prefix: _tablename)
   - Internal framework infrastructure
   - Managed entirely by framework subsystems
   - NOT meant to be accessed directly by application developers
   - May use direct DB::table() queries (exempt from ORM requirement)
   - Implementation details hidden from application layer

2. CORE TABLES (no prefix: tablename)
   - Built-in application infrastructure
   - Provided by framework but application-facing
   - Developers query, extend, and build upon these
   - MUST use ORM models (DB::table() prohibited)
   - Part of the developer-facing API

3. APPLICATION TABLES (no prefix: tablename)
   - Created by developers for their specific application
   - Business domain entities
   - MUST use ORM models (DB::table() prohibited)
   - Not shipped with framework (starter template only)

DATABASE ACCESS RULES
----------------------
The underscore prefix has enforcement implications:

SYSTEM TABLES (_tablename):
  - Direct queries allowed: DB::table('_task_queue')->where(...)->get()
  - No ORM model required
  - Code quality checker (PHP-DB-01) automatically skips these
  - Framework code optimizes for performance over abstraction

CORE & APPLICATION TABLES (tablename):
  - Direct queries PROHIBITED
  - ORM model REQUIRED
  - Code quality checker enforces this rule
  - Example: Client_Model::where(...)->get()

CURRENT SYSTEM TABLES
----------------------

_migrations
  Purpose: Laravel migration tracking system
  Managed by: Laravel framework migration subsystem
  Records: Migration batch history, execution timestamps

_task_queue
  Purpose: Background job queue and scheduled task execution
  Managed by: RSpade Task system (Task.php, Task_Instance.php)
  Records: Queued jobs, scheduled tasks, execution logs, status tracking
  Schema: class, method, params, status, logs, scheduled_for, worker_pid

_file_storage
  Purpose: Content-addressable blob storage backend
  Managed by: RSpade File attachment system
  Records: Deduplicated file blobs indexed by SHA-256 hash
  Implementation: Single-instance storage pattern - multiple attachments can
                  reference the same blob. Developers never access this directly.

_file_attachments
  Purpose: Polymorphic file attachment tracking
  Managed by: RSpade File attachment API
  Records: Attachment metadata, relationships, dimensions, session tracking
  Schema: key (UUID), file_storage_id (FK), fileable_type/id (polymorphic),
          fileable_category, site_id, session_id
  Developer API: Attachment methods, not direct table access

_flash_alerts
  Purpose: Transient flash message queue
  Managed by: Flash_Alert system
  Records: Session-scoped UI messages (success, error, warning, info)
  Lifecycle: Created on one request, displayed on next, then deleted
  Schema: session_id, type_id, message, timestamps

_search_indexes
  Purpose: Full-text search index storage
  Managed by: RSpade Search system
  Records: Extracted searchable content from polymorphic entities
  Schema: indexable_type/id (polymorphic), content (full-text), metadata (JSON),
          extraction_method, language, site_id
  Implementation: Automatic extraction from models, search API queries this

CURRENT CORE TABLES
--------------------

sites
  Purpose: Multi-tenancy root table
  Managed by: Multi-tenant subsystem
  Records: Tenant organizations, each with isolated data space
  Usage: Developers query to show "available sites", build tenant switchers
  Schema: name, domain, settings, active status

users
  Purpose: User account storage
  Managed by: Authentication subsystem
  Records: User credentials, profile data, authentication state
  Usage: Developers extend with additional fields, query for user listings
  Schema: email, password_hash, name, site_id (FK), active status

login_users
  Purpose: Authentication session/token tracking
  Managed by: RsxAuth system
  Records: Active login sessions with 365-day persistence
  Usage: Developers query for "active sessions", implement logout-all
  Schema: user_id (FK), session_token, ip_address, last_activity, expires_at

user_profiles
  Purpose: Extended user profile information
  Managed by: User management system
  Records: Additional user data beyond core authentication
  Usage: Developers customize profile fields for their application
  Schema: user_id (FK), bio, avatar, preferences (JSON), custom fields

user_verifications
  Purpose: Email verification and password reset token storage
  Managed by: Authentication subsystem
  Records: Temporary verification codes with expiration
  Lifecycle: Created on request, validated once, then deleted or expired
  Schema: user_id (FK), token, type (email_verify, password_reset), expires_at

user_invites
  Purpose: User invitation system
  Managed by: User invitation subsystem
  Records: Pending invitations with expiration (48 hours default)
  Lifecycle: Created by admin, accepted by invitee, then marked used or expired
  Schema: site_id (FK), email, token, invited_by (FK), expires_at, accepted_at

ip_addresses
  Purpose: IP address tracking and audit trail
  Managed by: Security/audit subsystem
  Records: IP addresses associated with user actions
  Usage: Developers query for login history, security audit reports
  Schema: ip_address, user_id (FK), action_type, created_at

file_attachments (DEPRECATED - will become _file_attachments)
  See SYSTEM TABLES section above. Currently core, moving to system.

CURRENT APPLICATION TABLES
---------------------------
These tables are part of the starter template demonstration application.
Developers typically replace these with their own domain entities.

clients
  Purpose: Demo business entity - client/customer records
  Business domain: B2B SaaS starter template
  Schema: name, email, phone, address, site_id (FK), status

client_departments
  Purpose: Demo organizational structure
  Business domain: Client organization hierarchy
  Schema: client_id (FK), name, parent_id (FK for nested structure)

contacts
  Purpose: Demo contact management
  Business domain: People associated with clients
  Schema: client_id (FK), name, email, phone, title, site_id (FK)

projects
  Purpose: Demo project tracking
  Business domain: Client projects/engagements
  Schema: client_id (FK), name, description, status, priority, due_date

tasks (NOTE: Confusing name - different from _task_queue!)
  Purpose: Demo user TODO/task list
  Business domain: User task management
  Schema: title, description, taskable_type/id (polymorphic), status, priority,
          assigned_to_user_id (FK), due_date, site_id (FK)
  WARNING: Name collision with _task_queue (background jobs). Consider renaming to
           user_task_queue or todo_items in future versions.

demo_products
  Purpose: Demo product catalog
  Business domain: Product/service offerings
  Schema: name, description, price, sku, category, active status

countries
  Purpose: Geographic reference data
  Business domain: International address support
  Records: ISO country codes and names
  Note: Reference data table, could be considered infrastructure

regions
  Purpose: Geographic subdivision reference data
  Business domain: State/province/region for addresses
  Records: Country subdivisions
  Note: Reference data table, could be considered infrastructure

ARCHITECTURAL PRINCIPLES
-------------------------

1. SEPARATION OF CONCERNS
   System tables implement framework features invisibly. Core tables provide
   developer-facing infrastructure. Application tables express business domain.

2. ABSTRACTION BOUNDARIES
   System table schemas are implementation details. Core table schemas are API
   contracts. System tables can change without migration pain if APIs remain stable.

3. PERFORMANCE VS CONSISTENCY
   System tables prioritize performance (direct queries, denormalization OK).
   Core/Application tables prioritize data integrity (ORM, relationships, validation).

4. MIGRATION STRATEGY
   All migrations run chronologically when `php artisan migrate` is executed,
   regardless of whether they affect system, core, or application tables.

   System tables: Migrations written and shipped by framework developers
   Core tables: Migrations written and shipped by framework developers
   Application tables: Migrations written by application developers

   When a developer does `git pull` and new framework migrations exist, they
   run alongside application migrations in date order when migrate is executed.

5. DOCUMENTATION LEVEL
   System tables: Internal documentation only
   Core tables: Full API documentation required
   Application tables: Developer-documented

FUTURE CONSIDERATIONS
---------------------

Planned Changes:
- Rename 'migrations' to '_migrations' (Laravel supports configuring this)
- Move 'file_attachments' to '_file_attachments' (pure system implementation detail)
- Consider renaming 'tasks' to 'user_task_queue' or 'todo_items' to avoid confusion with '_task_queue'

Potential System Tables:
- _cache (if implementing database cache driver)
- _jobs (if using database queue driver - currently using '_task_queue')
- _notifications (if implementing notification queue)
- _websocket_connections (if implementing WebSocket presence tracking)

MIGRATION MECHANICS
-------------------

When renaming a table to add underscore prefix:

1. Create migration to rename table
2. Update all Model classes: protected $table = '_newtablename';
3. Update direct queries in framework code
4. Update foreign key references in other tables (if any)
5. Update seeders, factories, tests
6. Run code quality checker to find missed references
7. Test all affected subsystems

Example migration:
  Schema::rename('file_storage', '_file_storage');

The underscore prefix is purely a naming convention - database engines treat
these identically to non-prefixed tables. The convention exists for developer
clarity and code quality enforcement.

DEVELOPER GUIDANCE
------------------

When creating new tables, ask:

Q: Will application developers query this directly?
   YES → Core/Application table (no prefix)
   NO → System table (underscore prefix)

Q: Is this an implementation detail of a framework subsystem?
   YES → System table (underscore prefix)
   NO → Core/Application table (no prefix)

Q: Would changing the schema break the developer-facing API?
   YES → Core table (no prefix) - schema is part of the API contract
   NO → System table (underscore prefix) - implementation detail

Examples:
- User login sessions? System (_login_sessions) - API is RsxAuth methods
- User accounts? Core (users) - developers extend and query this
- Search index? System (_search_indexes) - API is Search::query()
- Client records? Application (clients) - business domain entity

CONCLUSION
----------

The underscore prefix system creates a clear architectural boundary between
framework implementation details and developer-facing data structures. This
enables the framework to optimize system tables for performance while maintaining
API stability, and helps developers understand which tables are theirs to use
versus which are managed by framework subsystems.

For questions or clarification, consult:
- /system/app/RSpade/Core/Database/CLAUDE.md - Database subsystem documentation
- /system/app/RSpade/Core/Task/CLAUDE.md - Task system documentation
- /system/app/RSpade/Core/Files/CLAUDE.md - File attachment documentation
- /system/app/RSpade/CodeQuality/CLAUDE.md - Code quality rules including PHP-DB-01

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Document maintained by: Framework development team
Last updated: 2024-11-18