from dataclasses import dataclass
from operator import attrgetter

from campaigns.auth.dtos import User
from campaigns.connectors.db import Database, session_context
from campaigns.connectors.facebook.base import FacebookClient
from campaigns.core.handler import Handler
from campaigns.core.types import PlainToken
from campaigns.meta.dtos import CampaignPost
from campaigns.meta.services import CampaignService, FacebookPageTokenService


@dataclass(frozen=True)
class GetCampaignPostsRequest:
    user: User
    campaign_id: str


@dataclass
class GetCampaignPostsHandler(
    Handler[GetCampaignPostsRequest, list[CampaignPost]],
):
    db: Database
    facebook_client: FacebookClient
    campaign_service: CampaignService
    facebook_page_token_service: FacebookPageTokenService

    @session_context(in_transaction=False)
    async def handle(self, request: GetCampaignPostsRequest) -> list[CampaignPost]:
        campaign = await self.campaign_service.get_user_campaign(
            user=request.user, campaign_id=request.campaign_id
        )
        page = campaign.facebook_page
        page_token = await self.facebook_page_token_service.decrypt_token(page)

        facebook_posts = await self._get_facebook_posts(
            page_external_id=page.external_id,
            page_token=page_token,
        )

        instagram_posts = await self._get_instagram_posts(
            page_external_id=page.external_id,
            page_token=page_token,
        )

        return sorted(
            facebook_posts + instagram_posts, key=attrgetter("created_at"), reverse=True
        )

    async def _get_facebook_posts(
        self, page_external_id: str, page_token: PlainToken
    ) -> list[CampaignPost]:
        posts = await self.facebook_client.get_published_posts_for_page(
            page_id=page_external_id,
            page_access_token=page_token,
            limit=None,
        )

        return [
            CampaignPost.from_api_obj(post)
            for post in posts
            if post.is_eligible_for_promotion
        ]

    async def _get_instagram_posts(
        self, page_external_id: str, page_token: PlainToken
    ) -> list[CampaignPost]:
        posts = []

        instagram_business_account = (
            await self.facebook_client.get_instagram_business_account_for_page(
                page_id=page_external_id,
                page_access_token=page_token,
            )
        )

        if not instagram_business_account:
            return []

        async for post in self.facebook_client.get_instagram_media(
            instagram_account_id=instagram_business_account.id,
            page_access_token=page_token,
        ):
            posts.append(CampaignPost.from_api_obj(post))

        async for story in self.facebook_client.get_instagram_stories(
            instagram_account_id=instagram_business_account.id,
            page_access_token=page_token,
        ):
            posts.append(CampaignPost.from_api_obj(story))

        return posts