orion/app/modules/base.py

# app/modules/base.py
"""
Base module definition class.

A Module is a self-contained unit of functionality that can be enabled/disabled
per platform. Each module contains:
- Features: Granular capabilities for tier-based access control
- Menu items: Sidebar entries per frontend type
- Routes: API and page routes (future: dynamically registered)
- Services: Business logic (optional, for self-contained modules)
- Models: Database models (optional, for self-contained modules)
- Schemas: Pydantic schemas (optional, for self-contained modules)
- Templates: Jinja2 templates (optional, for self-contained modules)

Self-Contained Module Structure:
    app/modules/<code>/
    ├── __init__.py
    ├── definition.py        # ModuleDefinition instance
    ├── config.py            # Module configuration schema (optional)
    ├── exceptions.py        # Module-specific exceptions (optional)
    ├── routes/              # FastAPI routers
    ├── services/            # Business logic
    ├── models/              # SQLAlchemy models
    ├── schemas/             # Pydantic schemas
    └── templates/           # Jinja2 templates (namespaced)
"""

from dataclasses import dataclass, field
from pathlib import Path
from typing import TYPE_CHECKING

if TYPE_CHECKING:
    from fastapi import APIRouter

from models.database.admin_menu_config import FrontendType


@dataclass
class ModuleDefinition:
    """
    Definition of a platform module.

    A module groups related functionality that can be enabled/disabled per platform.
    Core modules cannot be disabled and are always available.

    Self-contained modules include their own services, models, schemas, and templates.
    The path attributes describe where these components are located.

    Attributes:
        code: Unique identifier (e.g., "billing", "marketplace")
        name: Display name (e.g., "Billing & Subscriptions")
        description: Description of what this module provides
        requires: List of module codes this module depends on
        features: List of feature codes this module provides
        menu_items: Dict mapping FrontendType to list of menu item IDs
        is_core: Core modules cannot be disabled
        admin_router: FastAPI router for admin routes
        vendor_router: FastAPI router for vendor routes
        services_path: Path to services subpackage (e.g., "app.modules.billing.services")
        models_path: Path to models subpackage (e.g., "app.modules.billing.models")
        schemas_path: Path to schemas subpackage (e.g., "app.modules.billing.schemas")
        templates_path: Path to templates directory (relative to module)
        exceptions_path: Path to exceptions module (e.g., "app.modules.billing.exceptions")
        is_self_contained: Whether module uses self-contained structure

    Example (traditional thin wrapper):
        billing_module = ModuleDefinition(
            code="billing",
            name="Billing & Subscriptions",
            description="Subscription tiers, billing history, and payment processing",
            features=["subscription_management", "billing_history", "stripe_integration"],
            menu_items={
                FrontendType.ADMIN: ["subscription-tiers", "subscriptions", "billing-history"],
                FrontendType.VENDOR: ["billing"],
            },
        )

    Example (self-contained module):
        cms_module = ModuleDefinition(
            code="cms",
            name="Content Management",
            description="Content pages, media library, and vendor themes.",
            features=["cms_basic", "cms_custom_pages"],
            menu_items={
                FrontendType.ADMIN: ["content-pages"],
                FrontendType.VENDOR: ["content-pages", "media"],
            },
            is_self_contained=True,
            services_path="app.modules.cms.services",
            models_path="app.modules.cms.models",
            schemas_path="app.modules.cms.schemas",
            templates_path="templates",
            exceptions_path="app.modules.cms.exceptions",
        )
    """

    # Identity
    code: str
    name: str
    description: str = ""

    # Dependencies
    requires: list[str] = field(default_factory=list)

    # Components
    features: list[str] = field(default_factory=list)
    menu_items: dict[FrontendType, list[str]] = field(default_factory=dict)

    # Status
    is_core: bool = False

    # Routes (registered dynamically)
    admin_router: "APIRouter | None" = None
    vendor_router: "APIRouter | None" = None

    # Self-contained module paths (optional)
    is_self_contained: bool = False
    services_path: str | None = None
    models_path: str | None = None
    schemas_path: str | None = None
    templates_path: str | None = None  # Relative to module directory
    exceptions_path: str | None = None

    def get_menu_items(self, frontend_type: FrontendType) -> list[str]:
        """Get menu item IDs for a specific frontend type."""
        return self.menu_items.get(frontend_type, [])

    def get_all_menu_items(self) -> set[str]:
        """Get all menu item IDs across all frontend types."""
        all_items = set()
        for items in self.menu_items.values():
            all_items.update(items)
        return all_items

    def has_feature(self, feature_code: str) -> bool:
        """Check if this module provides a specific feature."""
        return feature_code in self.features

    def has_menu_item(self, menu_item_id: str) -> bool:
        """Check if this module provides a specific menu item."""
        return menu_item_id in self.get_all_menu_items()

    def check_dependencies(self, enabled_modules: set[str]) -> list[str]:
        """
        Check if all required modules are enabled.

        Args:
            enabled_modules: Set of enabled module codes

        Returns:
            List of missing required module codes
        """
        return [req for req in self.requires if req not in enabled_modules]

    # =========================================================================
    # Self-Contained Module Methods
    # =========================================================================

    def get_module_dir(self) -> Path:
        """
        Get the filesystem path to this module's directory.

        Returns:
            Path to app/modules/<code>/
        """
        return Path(__file__).parent / self.code

    def get_templates_dir(self) -> Path | None:
        """
        Get the filesystem path to this module's templates directory.

        Returns:
            Path to templates directory, or None if not self-contained
        """
        if not self.is_self_contained or not self.templates_path:
            return None
        return self.get_module_dir() / self.templates_path

    def get_import_path(self, component: str) -> str | None:
        """
        Get the Python import path for a module component.

        Args:
            component: One of "services", "models", "schemas", "exceptions"

        Returns:
            Import path string, or None if not configured
        """
        paths = {
            "services": self.services_path,
            "models": self.models_path,
            "schemas": self.schemas_path,
            "exceptions": self.exceptions_path,
        }
        return paths.get(component)

    def validate_structure(self) -> list[str]:
        """
        Validate that self-contained module has expected directory structure.

        Returns:
            List of missing or invalid paths (empty if valid)
        """
        if not self.is_self_contained:
            return []

        issues = []
        module_dir = self.get_module_dir()

        if not module_dir.exists():
            issues.append(f"Module directory not found: {module_dir}")
            return issues

        # Check optional directories
        expected_dirs = []
        if self.services_path:
            expected_dirs.append("services")
        if self.models_path:
            expected_dirs.append("models")
        if self.schemas_path:
            expected_dirs.append("schemas")
        if self.templates_path:
            expected_dirs.append(self.templates_path)

        for dir_name in expected_dirs:
            dir_path = module_dir / dir_name
            if not dir_path.exists():
                issues.append(f"Missing directory: {dir_path}")

        return issues

    def __hash__(self) -> int:
        return hash(self.code)

    def __eq__(self, other: object) -> bool:
        if isinstance(other, ModuleDefinition):
            return self.code == other.code
        return False

    def __repr__(self) -> str:
        sc = ", self_contained" if self.is_self_contained else ""
        return f"<Module({self.code}, core={self.is_core}{sc})>"