# app/modules/routes.py
"""
Module route discovery for FastAPI.

Provides utilities to:
- Discover route modules from all registered modules
- Auto-register API and page routes from self-contained modules

This module bridges the gap between the module system and FastAPI,
allowing routes to be defined within modules and automatically
discovered and registered.

Route Discovery:
    Routes are discovered from these file locations in each module:
    - routes/api/admin.py      -> /api/v1/admin/*
    - routes/api/vendor.py     -> /api/v1/vendor/*
    - routes/api/storefront.py -> /api/v1/storefront/*
    - routes/pages/admin.py    -> /admin/*
    - routes/pages/vendor.py   -> /vendor/*

Usage:
    # In app/api/v1/{admin,vendor,storefront}/__init__.py
    from app.modules.routes import get_admin_api_routes  # or vendor/storefront

    for route_info in get_admin_api_routes():
        router.include_router(
            route_info.router,
            prefix=route_info.custom_prefix or "",
            tags=route_info.tags,
        )

Route Configuration:
    Modules can export a ROUTE_CONFIG dict to customize route registration:

    ROUTE_CONFIG = {
        "prefix": "/content-pages",  # Custom prefix (replaces default)
        "tags": ["admin-content-pages"],  # Custom tags
        "priority": 100,  # Higher = registered later (for catch-all routes)
    }
"""

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

if TYPE_CHECKING:
    from fastapi import APIRouter

logger = logging.getLogger(__name__)


@dataclass
class RouteInfo:
    """Information about a discovered route."""

    router: "APIRouter"
    prefix: str
    tags: list[str]
    include_in_schema: bool = True
    module_code: str = ""
    route_type: str = ""  # "api" or "pages"
    frontend: str = ""  # "admin", "vendor", "shop"
    priority: int = 0  # Higher = registered later (for catch-all routes)
    custom_prefix: str = ""  # Custom prefix from ROUTE_CONFIG


def discover_module_routes() -> list[RouteInfo]:
    """
    Discover routes from all registered self-contained modules.

    Scans all modules in the registry and returns RouteInfo objects for
    modules that have routes directories.

    Route discovery looks for:
    - routes/api/admin.py -> admin API routes
    - routes/api/vendor.py -> vendor API routes
    - routes/api/shop.py -> shop API routes
    - routes/pages/admin.py -> admin page routes
    - routes/pages/vendor.py -> vendor page routes

    Returns:
        List of RouteInfo objects with router and registration info

    Example:
        >>> routes = discover_module_routes()
        >>> for route in routes:
        ...     print(f"{route.module_code}: {route.route_type}/{route.frontend}")
        analytics: pages/vendor
        cms: api/admin
        cms: api/vendor
        cms: pages/admin
        cms: pages/vendor
    """
    # Import here to avoid circular imports
    from app.modules.registry import MODULES

    routes: list[RouteInfo] = []

    for module in MODULES.values():
        if not module.is_self_contained:
            continue

        module_routes = _discover_module_routes(module.code)
        routes.extend(module_routes)

    logger.info(f"Discovered {len(routes)} routes from self-contained modules")
    return routes


def _discover_module_routes(module_code: str) -> list[RouteInfo]:
    """
    Discover routes for a specific module.

    Args:
        module_code: Module code (e.g., "analytics", "cms")

    Returns:
        List of RouteInfo for this module
    """
    routes: list[RouteInfo] = []
    dir_name = module_code.replace("-", "_")
    module_path = Path(__file__).parent / dir_name

    if not module_path.exists():
        return routes

    routes_path = module_path / "routes"
    if not routes_path.exists():
        return routes

    # Discover API routes (with fallback to routes/ for legacy modules)
    api_routes = _discover_routes_in_dir(
        module_code, dir_name, routes_path / "api", "api",
        fallback_dir=routes_path  # Allow routes/admin.py as fallback
    )
    routes.extend(api_routes)

    # Discover page routes
    page_routes = _discover_routes_in_dir(
        module_code, dir_name, routes_path / "pages", "pages"
    )
    routes.extend(page_routes)

    return routes


def _discover_routes_in_dir(
    module_code: str, dir_name: str, routes_dir: Path, route_type: str,
    fallback_dir: Path | None = None
) -> list[RouteInfo]:
    """
    Discover routes in a specific directory (api/ or pages/).

    Args:
        module_code: Module code for tags
        dir_name: Directory name (module_code with _ instead of -)
        routes_dir: Path to routes/api/ or routes/pages/
        route_type: "api" or "pages"
        fallback_dir: Optional fallback directory (e.g., routes/ for modules
                     with routes/admin.py instead of routes/api/admin.py)

    Returns:
        List of RouteInfo for discovered routes
    """
    routes: list[RouteInfo] = []

    # Look for admin.py, vendor.py, storefront.py, public.py, webhooks.py
    frontends = {
        "admin": {
            "api_prefix": "/api/v1/admin",
            "pages_prefix": "/admin",
            "include_in_schema": True,
        },
        "vendor": {
            "api_prefix": "/api/v1/vendor",
            "pages_prefix": "/vendor",
            "include_in_schema": True if route_type == "api" else False,
        },
        "storefront": {
            "api_prefix": "/api/v1/storefront",
            "pages_prefix": "/storefront",
            "include_in_schema": True if route_type == "api" else False,
        },
        "platform": {
            "api_prefix": "/api/v1/platform",
            "pages_prefix": "/platform",
            "include_in_schema": True,
        },
        "webhooks": {
            "api_prefix": "/api/v1/webhooks",
            "pages_prefix": "/webhooks",
            "include_in_schema": True,
        },
    }

    for frontend, config in frontends.items():
        # Check primary location first, then fallback
        route_file = routes_dir / f"{frontend}.py" if routes_dir.exists() else None
        use_fallback = False

        if route_file is None or not route_file.exists():
            if fallback_dir and fallback_dir.exists():
                fallback_file = fallback_dir / f"{frontend}.py"
                if fallback_file.exists():
                    route_file = fallback_file
                    use_fallback = True

        if route_file is None or not route_file.exists():
            continue

        try:
            # Import the module
            if use_fallback:
                import_path = f"app.modules.{dir_name}.routes.{frontend}"
            else:
                import_path = f"app.modules.{dir_name}.routes.{route_type}.{frontend}"
            route_module = importlib.import_module(import_path)

            # Get the router (try common names)
            router = None
            for attr_name in ["router", f"{frontend}_router", "api_router", "page_router"]:
                if hasattr(route_module, attr_name):
                    router = getattr(route_module, attr_name)
                    break

            if router is None:
                logger.warning(f"No router found in {import_path}")
                continue

            # Read ROUTE_CONFIG if present
            route_config = getattr(route_module, "ROUTE_CONFIG", {})
            custom_prefix = route_config.get("prefix", "")
            custom_tags = route_config.get("tags", [])
            priority = route_config.get("priority", 0)

            # Determine prefix based on route type
            if route_type == "api":
                prefix = config["api_prefix"]
            else:
                prefix = config["pages_prefix"]

            # Build tags - use custom tags if provided, otherwise default
            if custom_tags:
                tags = custom_tags
            else:
                tags = [f"{frontend}-{module_code}"]

            route_info = RouteInfo(
                router=router,
                prefix=prefix,
                tags=tags,
                include_in_schema=config["include_in_schema"],
                module_code=module_code,
                route_type=route_type,
                frontend=frontend,
                priority=priority,
                custom_prefix=custom_prefix,
            )
            routes.append(route_info)

            logger.debug(f"Discovered route: {module_code} {route_type}/{frontend}")

        except ImportError as e:
            logger.warning(f"Failed to import {import_path}: {e}")
        except Exception as e:
            logger.error(f"Error discovering routes in {route_file}: {e}")

    return routes


def get_api_routes() -> list[RouteInfo]:
    """Get only API routes from modules."""
    return [r for r in discover_module_routes() if r.route_type == "api"]


def get_page_routes() -> list[RouteInfo]:
    """Get only page routes from modules."""
    return [r for r in discover_module_routes() if r.route_type == "pages"]


def get_vendor_page_routes() -> list[RouteInfo]:
    """Get vendor page routes from modules."""
    return [r for r in discover_module_routes() if r.route_type == "pages" and r.frontend == "vendor"]


def get_admin_page_routes() -> list[RouteInfo]:
    """Get admin page routes from modules."""
    return [r for r in discover_module_routes() if r.route_type == "pages" and r.frontend == "admin"]


def get_admin_api_routes() -> list[RouteInfo]:
    """
    Get admin API routes from modules, sorted by priority.

    Returns routes sorted by priority (lower first, higher last).
    This ensures catch-all routes (priority 100+) are registered after
    specific routes.
    """
    routes = [
        r for r in discover_module_routes()
        if r.route_type == "api" and r.frontend == "admin"
    ]
    return sorted(routes, key=lambda r: r.priority)


def get_vendor_api_routes() -> list[RouteInfo]:
    """
    Get vendor API routes from modules, sorted by priority.

    Returns routes sorted by priority (lower first, higher last).
    This ensures catch-all routes (priority 100+) are registered after
    specific routes.
    """
    routes = [
        r for r in discover_module_routes()
        if r.route_type == "api" and r.frontend == "vendor"
    ]
    return sorted(routes, key=lambda r: r.priority)


def get_storefront_api_routes() -> list[RouteInfo]:
    """
    Get storefront API routes from modules, sorted by priority.

    Returns routes sorted by priority (lower first, higher last).
    This ensures catch-all routes (priority 100+) are registered after
    specific routes.
    """
    routes = [
        r for r in discover_module_routes()
        if r.route_type == "api" and r.frontend == "storefront"
    ]
    return sorted(routes, key=lambda r: r.priority)


def get_platform_api_routes() -> list[RouteInfo]:
    """
    Get platform API routes from modules, sorted by priority.

    Platform routes are unauthenticated endpoints for marketing pages,
    pricing info, and other public-facing features.
    """
    routes = [
        r for r in discover_module_routes()
        if r.route_type == "api" and r.frontend == "platform"
    ]
    return sorted(routes, key=lambda r: r.priority)


def get_webhooks_api_routes() -> list[RouteInfo]:
    """
    Get webhook API routes from modules, sorted by priority.

    Webhook routes handle callbacks from external services
    (Stripe, payment providers, etc.).
    """
    routes = [
        r for r in discover_module_routes()
        if r.route_type == "api" and r.frontend == "webhooks"
    ]
    return sorted(routes, key=lambda r: r.priority)


def get_platform_page_routes() -> list[RouteInfo]:
    """
    Get platform (marketing) page routes from modules, sorted by priority.

    Platform pages are unauthenticated marketing pages like:
    - Homepage (/)
    - Pricing (/pricing)
    - Signup (/signup)
    - Find shop (/find-shop)
    - CMS catch-all (/{slug})

    Note: CMS routes should have priority=100 to be registered last
    since they have catch-all patterns.
    """
    routes = [
        r for r in discover_module_routes()
        if r.route_type == "pages" and r.frontend == "platform"
    ]
    return sorted(routes, key=lambda r: r.priority)


def get_storefront_page_routes() -> list[RouteInfo]:
    """
    Get storefront (customer shop) page routes from modules, sorted by priority.

    Storefront pages include:
    - Catalog pages (/, /products, /products/{id}, /categories/{slug})
    - Cart and checkout (/cart, /checkout)
    - Account pages (/account/*)
    - CMS content pages (/{slug})

    Note: CMS routes should have priority=100 to be registered last
    since they have catch-all patterns.
    """
    routes = [
        r for r in discover_module_routes()
        if r.route_type == "pages" and r.frontend == "storefront"
    ]
    return sorted(routes, key=lambda r: r.priority)


__all__ = [
    "RouteInfo",
    "discover_module_routes",
    "get_api_routes",
    "get_page_routes",
    "get_vendor_page_routes",
    "get_admin_page_routes",
    "get_admin_api_routes",
    "get_vendor_api_routes",
    "get_storefront_api_routes",
    "get_platform_api_routes",
    "get_webhooks_api_routes",
    "get_platform_page_routes",
    "get_storefront_page_routes",
]