from typing import List, Optional
from datetime import datetime, UTC

from repos.dao import DAO
from models.Post import Post


class PostService:
    def __init__(self, dao: DAO):
        self.dao = dao

    async def create_post(
        self,
        date: datetime,
        topic: str,
        generation_ids: List[str],
        project_id: Optional[str],
        user_id: str,
    ) -> Post:
        post = Post(
            date=date,
            topic=topic,
            generation_ids=generation_ids,
            project_id=project_id,
            created_by=user_id,
        )
        post_id = await self.dao.posts.create_post(post)
        post.id = post_id
        return post

    async def get_post(self, post_id: str) -> Optional[Post]:
        return await self.dao.posts.get_post(post_id)

    async def get_posts(
        self,
        project_id: Optional[str],
        user_id: str,
        limit: int = 20,
        offset: int = 0,
        date_from: Optional[datetime] = None,
        date_to: Optional[datetime] = None,
    ) -> List[Post]:
        return await self.dao.posts.get_posts(project_id, user_id, limit, offset, date_from, date_to)

    async def update_post(
        self,
        post_id: str,
        date: Optional[datetime] = None,
        topic: Optional[str] = None,
    ) -> Optional[Post]:
        post = await self.dao.posts.get_post(post_id)
        if not post:
            return None

        updates: dict = {"updated_at": datetime.now(UTC)}
        if date is not None:
            updates["date"] = date
        if topic is not None:
            updates["topic"] = topic

        await self.dao.posts.update_post(post_id, updates)

        # Return refreshed post
        return await self.dao.posts.get_post(post_id)

    async def delete_post(self, post_id: str) -> bool:
        return await self.dao.posts.delete_post(post_id)

    async def add_generations(self, post_id: str, generation_ids: List[str]) -> bool:
        post = await self.dao.posts.get_post(post_id)
        if not post:
            return False
        return await self.dao.posts.add_generations(post_id, generation_ids)

    async def remove_generation(self, post_id: str, generation_id: str) -> bool:
        post = await self.dao.posts.get_post(post_id)
        if not post:
            return False
        return await self.dao.posts.remove_generation(post_id, generation_id)