# app/modules/tenancy/services/merchant_store_service.py
"""
Merchant store service for store CRUD operations from the merchant portal.

Handles store management operations that merchant owners can perform:
- View store details (with ownership validation)
- Update store settings (name, description, contact info)
- Create new stores (with subscription limit checking)

Follows the service layer pattern — all DB operations go through here.
"""

import logging

from sqlalchemy import func
from sqlalchemy.exc import SQLAlchemyError
from sqlalchemy.orm import Session

from app.modules.tenancy.exceptions import (
    MerchantNotFoundException,
    StoreAlreadyExistsException,
    StoreNotFoundException,
    StoreValidationException,
)
from app.modules.tenancy.models.merchant import Merchant
from app.modules.tenancy.models.platform import Platform
from app.modules.tenancy.models.store import Role, Store
from app.modules.tenancy.models.store_platform import StorePlatform

logger = logging.getLogger(__name__)


class MerchantStoreService:
    """Service for merchant-initiated store operations."""

    def get_store_detail(
        self,
        db: Session,
        merchant_id: int,
        store_id: int,
    ) -> dict:
        """
        Get store detail with ownership validation.

        Args:
            db: Database session
            merchant_id: Merchant ID (for ownership check)
            store_id: Store ID

        Returns:
            Dict with store details and platform assignments

        Raises:
            StoreNotFoundException: If store not found or not owned by merchant
        """
        store = (
            db.query(Store)
            .filter(Store.id == store_id, Store.merchant_id == merchant_id)
            .first()
        )
        if not store:
            raise StoreNotFoundException(store_id, identifier_type="id")

        # Get platform assignments
        store_platforms = (
            db.query(StorePlatform)
            .join(Platform, StorePlatform.platform_id == Platform.id)
            .filter(StorePlatform.store_id == store.id)
            .all()
        )

        platforms = []
        for sp in store_platforms:
            platform = db.query(Platform).filter(Platform.id == sp.platform_id).first()
            if platform:
                platforms.append(
                    {
                        "id": platform.id,
                        "code": platform.code,
                        "name": platform.name,
                        "is_active": sp.is_active,
                    }
                )

        return {
            "id": store.id,
            "store_code": store.store_code,
            "subdomain": store.subdomain,
            "name": store.name,
            "description": store.description,
            "is_active": store.is_active,
            "is_verified": store.is_verified,
            "contact_email": store.contact_email,
            "contact_phone": store.contact_phone,
            "website": store.website,
            "business_address": store.business_address,
            "tax_number": store.tax_number,
            "default_language": store.default_language,
            "created_at": store.created_at.isoformat() if store.created_at else None,
            "platforms": platforms,
        }

    def update_store(
        self,
        db: Session,
        merchant_id: int,
        store_id: int,
        update_data: dict,
    ) -> dict:
        """
        Update store fields (merchant-allowed fields only).

        Args:
            db: Database session
            merchant_id: Merchant ID (for ownership check)
            store_id: Store ID
            update_data: Dict of fields to update

        Returns:
            Updated store detail dict

        Raises:
            StoreNotFoundException: If store not found or not owned by merchant
        """
        store = (
            db.query(Store)
            .filter(Store.id == store_id, Store.merchant_id == merchant_id)
            .first()
        )
        if not store:
            raise StoreNotFoundException(store_id, identifier_type="id")

        # Merchant-allowed update fields
        allowed_fields = {
            "name",
            "description",
            "contact_email",
            "contact_phone",
            "website",
            "business_address",
            "tax_number",
        }

        for field, value in update_data.items():
            if field in allowed_fields:
                setattr(store, field, value)

        db.flush()
        logger.info(
            f"Merchant {merchant_id} updated store {store.store_code}: "
            f"{list(update_data.keys())}"
        )

        return self.get_store_detail(db, merchant_id, store_id)

    def create_store(
        self,
        db: Session,
        merchant_id: int,
        store_data: dict,
    ) -> dict:
        """
        Create a new store under the merchant.

        Args:
            db: Database session
            merchant_id: Merchant ID
            store_data: Store creation data (name, store_code, subdomain, description, platform_ids)

        Returns:
            Created store detail dict

        Raises:
            MaxStoresReachedException: If store limit reached
            MerchantNotFoundException: If merchant not found
            StoreAlreadyExistsException: If store code already exists
            StoreValidationException: If subdomain taken or validation fails
        """
        # Check store creation limits
        can_create, message = self.can_create_store(db, merchant_id)
        if not can_create:
            from app.modules.tenancy.exceptions import MaxStoresReachedException

            raise MaxStoresReachedException(max_stores=0)

        # Validate merchant exists
        merchant = db.query(Merchant).filter(Merchant.id == merchant_id).first()
        if not merchant:
            raise MerchantNotFoundException(merchant_id, identifier_type="id")

        store_code = store_data["store_code"].upper()
        subdomain = store_data["subdomain"].lower()

        # Check store code uniqueness
        existing = (
            db.query(Store)
            .filter(func.upper(Store.store_code) == store_code)
            .first()
        )
        if existing:
            raise StoreAlreadyExistsException(store_code)

        # Check subdomain uniqueness
        existing_sub = (
            db.query(Store)
            .filter(func.lower(Store.subdomain) == subdomain)
            .first()
        )
        if existing_sub:
            raise StoreValidationException(
                f"Subdomain '{subdomain}' is already taken",
                field="subdomain",
            )

        try:
            # Create store
            store = Store(
                merchant_id=merchant_id,
                store_code=store_code,
                subdomain=subdomain,
                name=store_data["name"],
                description=store_data.get("description"),
                is_active=True,
                is_verified=False,  # Pending admin verification
            )
            db.add(store)
            db.flush()

            # Create default roles
            self._create_default_roles(db, store.id)

            # Assign to platforms if provided
            platform_ids = store_data.get("platform_ids", [])
            store_platforms = []
            for pid in platform_ids:
                platform = db.query(Platform).filter(Platform.id == pid).first()
                if platform:
                    store_platforms.append(StorePlatform(
                        store_id=store.id,
                        platform_id=pid,
                        is_active=True,
                    ))
            if store_platforms:
                db.add_all(store_platforms)

            db.flush()
            db.refresh(store)

            logger.info(
                f"Merchant {merchant_id} created store {store.store_code} "
                f"(ID: {store.id}, platforms: {platform_ids})"
            )

            return self.get_store_detail(db, merchant_id, store.id)

        except (
            StoreAlreadyExistsException,
            MerchantNotFoundException,
            StoreValidationException,
        ):
            raise
        except SQLAlchemyError as e:
            logger.error(f"Failed to create store for merchant {merchant_id}: {e}")
            raise StoreValidationException(
                f"Failed to create store: {e}",
                field="store",
            )

    def can_create_store(
        self,
        db: Session,
        merchant_id: int,
    ) -> tuple[bool, str | None]:
        """
        Check if merchant can create a new store based on subscription limits.

        Returns:
            Tuple of (allowed, message). message explains why if not allowed.
        """
        try:
            from app.modules.billing.services.feature_service import feature_service

            return feature_service.check_resource_limit(
                db,
                feature_code="stores_limit",
                merchant_id=merchant_id,
            )
        except Exception:  # noqa: EXC-003
            # If billing module not available, allow creation
            return True, None

    def get_subscribed_platform_ids(
        self,
        db: Session,
        merchant_id: int,
    ) -> list[dict]:
        """
        Get platforms the merchant has active subscriptions on.

        Returns:
            List of platform dicts with id, code, name
        """
        try:
            from app.modules.billing.services.subscription_service import (
                subscription_service,
            )

            platform_ids = subscription_service.get_active_subscription_platform_ids(
                db, merchant_id
            )
        except Exception:  # noqa: EXC-003
            platform_ids = []

        platforms = []
        for pid in platform_ids:
            platform = db.query(Platform).filter(Platform.id == pid).first()
            if platform:
                platforms.append(
                    {
                        "id": platform.id,
                        "code": platform.code,
                        "name": platform.name,
                    }
                )
        return platforms

    def _create_default_roles(self, db: Session, store_id: int):
        """Create default roles for a new store."""
        default_roles = [
            {"name": "Owner", "permissions": ["*"]},
            {
                "name": "Manager",
                "permissions": [
                    "products.*",
                    "orders.*",
                    "customers.view",
                    "inventory.*",
                    "team.view",
                ],
            },
            {
                "name": "Editor",
                "permissions": [
                    "products.view",
                    "products.edit",
                    "orders.view",
                    "inventory.view",
                ],
            },
            {
                "name": "Viewer",
                "permissions": [
                    "products.view",
                    "orders.view",
                    "customers.view",
                    "inventory.view",
                ],
            },
        ]

        roles = [
            Role(
                store_id=store_id,
                name=role_data["name"],
                permissions=role_data["permissions"],
            )
            for role_data in default_roles
        ]
        db.add_all(roles)


    def get_merchant_team_overview(self, db: Session, merchant_id: int) -> dict:
        """
        Get team members across all stores owned by the merchant.

        Returns a list of stores with their team members grouped by store.
        """
        from app.modules.tenancy.models.store import StoreUser

        merchant = db.query(Merchant).filter(Merchant.id == merchant_id).first()
        if not merchant:
            raise MerchantNotFoundException(merchant_id)

        stores = (
            db.query(Store)
            .filter(Store.merchant_id == merchant_id)
            .order_by(Store.name)
            .all()
        )

        result = []
        for store in stores:
            members = (
                db.query(StoreUser)
                .filter(StoreUser.store_id == store.id)
                .all()
            )

            store_team = {
                "store_id": store.id,
                "store_name": store.name,
                "store_code": store.store_code,
                "is_active": store.is_active,
                "members": [
                    {
                        "id": m.id,
                        "user_id": m.user_id,
                        "email": m.user.email if m.user else None,
                        "first_name": m.user.first_name if m.user else None,
                        "last_name": m.user.last_name if m.user else None,
                        "role_name": m.role.name if m.role else None,
                        "is_active": m.is_active,
                        "invitation_accepted_at": (
                            m.invitation_accepted_at.isoformat()
                            if m.invitation_accepted_at
                            else None
                        ),
                        "created_at": m.created_at.isoformat() if m.created_at else None,
                    }
                    for m in members
                ],
                "member_count": len(members),
            }
            result.append(store_team)

        return {
            "merchant_name": merchant.business_name or merchant.brand_name,
            "owner_email": merchant.owner.email if merchant.owner else None,
            "stores": result,
            "total_members": sum(s["member_count"] for s in result),
        }


# Singleton instance
merchant_store_service = MerchantStoreService()

__all__ = ["MerchantStoreService", "merchant_store_service"]