from datetime import datetime
from typing import Dict, List
from uuid import uuid4
from sqlalchemy import or_
from sqlalchemy.orm import Session
import logging

from app.db.models import (
    Box,
    File,
    StagedFileProduct,
    Product,
    OpenBoxCard,
    OpenBox,
    TCGPlayerGroups,
    Inventory
)
from app.db.utils import db_transaction
from app.schemas.box import CreateBoxRequest, UpdateBoxRequest, CreateOpenBoxRequest
from app.services.inventory import InventoryService

logger = logging.getLogger(__name__)

VALID_BOX_TYPES = {"collector", "play", "draft", "set", "commander"}

class BoxService:
    def __init__(self, db: Session, inventory_service: InventoryService):
        self.db = db
        self.inventory_service = inventory_service

    def get_staged_product_data(self, file_ids: List[str]) -> List[StagedFileProduct]:
        """Retrieve staged product data for given file IDs."""
        return self.db.query(StagedFileProduct).filter(
            StagedFileProduct.file_id.in_(file_ids)
        ).all()

    def aggregate_staged_product_data(self, staged_product_data: List[StagedFileProduct]) -> Dict[Product, int]:
        """Aggregate staged product data by product and quantity."""
        product_data = {}
        for row in staged_product_data:
            product = self.db.query(Product).filter(Product.id == row.product_id).first()
            if product:
                product_data[product] = product_data.get(product, 0) + row.quantity
        return product_data

    def add_products_to_open_box(self, open_box: OpenBox, product_data: Dict[Product, int]) -> None:
        """Add products to an open box."""
        for product, quantity in product_data.items(): # TODO BATCH THIS
            open_box_card = OpenBoxCard(
                id=str(uuid4()),
                open_box_id=open_box.id,
                card_id=product.id,
                quantity=quantity
            )
            self.db.add(open_box_card)

    def validate_box_type(self, box_type: str) -> bool:
        """Validate if the box type is supported."""
        return box_type in VALID_BOX_TYPES

    def validate_set_code(self, set_code: str) -> bool:
        """Validate if the set code exists in TCGPlayer groups."""
        return self.db.query(TCGPlayerGroups).filter(
            TCGPlayerGroups.abbreviation == set_code
        ).first() is not None

    def create_box(self, create_box_data: CreateBoxRequest) -> Box:
        """Create a new box."""
        if not self.validate_box_type(create_box_data.type):
            raise ValueError("Invalid box type")
        if not self.validate_set_code(create_box_data.set_code):
            raise ValueError("Invalid set code")

        existing_box = self.db.query(Box).filter(
            Box.type == create_box_data.type,
            Box.set_code == create_box_data.set_code,
            or_(Box.sku == create_box_data.sku, Box.sku.is_(None))
        ).first()

        if existing_box:
            return existing_box, False
        else:
            with db_transaction(self.db):
                product = Product(
                    id=str(uuid4()),
                    type='box',
                    product_line='mtg'
                )
                self.db.add(product)
                self.db.flush()
                box = Box(
                    product_id=product.id,
                    type=create_box_data.type,
                    set_code=create_box_data.set_code,
                    sku=create_box_data.sku,
                    num_cards_expected=create_box_data.num_cards_expected
                )
                self.db.add(box)

        return box, True

    def update_box(self, box_id: str, update_box_data: UpdateBoxRequest) -> Box:
        """Update an existing box."""
        box = self.db.query(Box).filter(Box.product_id == box_id).first()
        if not box:
            raise ValueError("Box not found")

        update_data = update_box_data.dict(exclude_unset=True)
        
        # Validate box type if it's being updated
        if "type" in update_data and update_data["type"] is not None:
            if not self.validate_box_type(update_data["type"]):
                raise ValueError(f"Invalid box type: {update_data['type']}")

        # Validate set code if it's being updated
        if "set_code" in update_data and update_data["set_code"] is not None:
            if not self.validate_set_code(update_data["set_code"]):
                raise ValueError(f"Invalid set code: {update_data['set_code']}")

        with db_transaction(self.db):
            for field, value in update_data.items():
                if value is not None:  # Only update non-None values
                    setattr(box, field, value)

        return box

    def delete_box(self, box_id: str) -> Box:
        """Delete a box."""
        box = self.db.query(Box).filter(Box.product_id == box_id).first()
        product = self.db.query(Product).filter(Product.id == box_id).first()
        if not box:
            raise ValueError("Box not found")

        with db_transaction(self.db):
            self.db.delete(box)
            self.db.delete(product)
        return box

    def open_box(self, box_id: str, box_data: CreateOpenBoxRequest) -> OpenBox:
        """Open a box and process its contents."""
        box = self.db.query(Box).filter(Box.product_id == box_id).first()
        if not box:
            raise ValueError("Box not found")

        with db_transaction(self.db):
            open_box = OpenBox(
                id=str(uuid4()),
                product_id=box_id,
                num_cards_actual=box_data.num_cards_actual,
                date_opened=datetime.strptime(box_data.date_opened, "%Y-%m-%d") if box_data.date_opened else datetime.now()
            )
            self.db.add(open_box)

            staged_product_data = self.get_staged_product_data(box_data.file_ids)
            product_data = self.aggregate_staged_product_data(staged_product_data)
            self.inventory_service.process_staged_products(product_data)
            self.add_products_to_open_box(open_box, product_data)

            # Update file box IDs
            self.db.query(File).filter(File.id.in_(box_data.file_ids)).update(
                {"box_id": open_box.id}, synchronize_session=False
            )

        return open_box
    
    def delete_open_box(self, box_id: str) -> OpenBox:
        # Fetch open box and related cards in one query
        open_box = (
            self.db.query(OpenBox)
            .filter(OpenBox.id == box_id)
            .first()
        )
        if not open_box:
            raise ValueError("Open box not found")
        
        # Get all open box cards and related inventory items in one query
        open_box_cards = (
            self.db.query(OpenBoxCard, Inventory)
            .join(
                Inventory,
                OpenBoxCard.card_id == Inventory.product_id
            )
            .filter(OpenBoxCard.open_box_id == open_box.id)
            .all()
        )

        # Process inventory adjustments
        for open_box_card, inventory_item in open_box_cards:
            if open_box_card.quantity > inventory_item.quantity:
                raise ValueError("Open box quantity exceeds inventory quantity")
            
            inventory_item.quantity -= open_box_card.quantity
            if inventory_item.quantity == 0:
                self.db.delete(inventory_item)
            
            # Delete the open box card
            self.db.delete(open_box_card)

        # Execute all database operations in a single transaction
        with db_transaction(self.db):
            self.db.delete(open_box)

        return open_box