from typing import Optional, List
from sqlalchemy.ext.asyncio import AsyncSession

from app.models.category import Category
from app.repositories.category import CategoryRepository


class CategoryService:
    def __init__(self, db: AsyncSession):
        self.db = db
        self.repo = CategoryRepository(db)

    async def get_categories(self, level: Optional[int] = None, parent_id: Optional[int] = None) -> List[Category]:
        return await self.repo.get_all(level=level, parent_id=parent_id)

    async def get_category(self, category_id: int) -> Optional[Category]:
        return await self.repo.get_by_id(category_id)

    async def get_category_with_children(self, category_id: int) -> Optional[Category]:
        category = await self.repo.get_by_id(category_id)
        if category:
            category.children = await self.repo.get_children(category_id)
        return category

    async def create_category(self, data: dict) -> Category:
        return await self.repo.create(data)

    async def update_category(self, category_id: int, data: dict) -> Optional[Category]:
        return await self.repo.update(category_id, data)

    async def delete_category(self, category_id: int) -> bool:
        return await self.repo.delete(category_id)

    async def get_category_tree(self) -> List[dict]:
        root_categories = await self.repo.get_all(level=1)
        tree = []
        for category in root_categories:
            children = await self.repo.get_children(category.id)
            tree.append({
                "id": category.id,
                "name": category.name,
                "level": category.level,
                "icon": category.icon,
                "sort_order": category.sort_order,
                "children": [
                    {
                        "id": child.id,
                        "name": child.name,
                        "level": child.level,
                        "icon": child.icon,
                        "sort_order": child.sort_order
                    }
                    for child in children
                ]
            })
        return tree