from datetime import datetime
from pathlib import Path

from fastapi import UploadFile
from sqlalchemy.orm import Session

from app.common.errors.app_error import NotFoundAppError
from app.common.utils.id_gen import new_order_no
from app.core.storage import storage_service
from app.models.entities import MediaAsset
from app.modules.assets.repository import AssetsRepository


class AssetsService:
    def __init__(self, db: Session) -> None:
        self.db = db
        self.repository = AssetsRepository(db)

    def create_upload_token(self, media_type: str) -> dict:
        return {
            "uploadToken": new_order_no("upload"),
            "mediaType": media_type,
            "uploadMode": "multipart",
        }

    def save_asset(self, user_id: int, file: UploadFile, media_type: str) -> dict:
        stored = storage_service.save_upload(file, folder=f"uploads/{media_type}")
        asset = MediaAsset(
            asset_no=new_order_no("asset"),
            user_id=user_id,
            media_type=media_type,
            source_type="upload",
            original_filename=file.filename or "upload.bin",
            mime_type=file.content_type or "application/octet-stream",
            file_ext=Path(file.filename or "").suffix,
            file_size=stored["file_size"],
            storage_provider="local",
            storage_bucket="local",
            storage_key=stored["storage_key"],
            public_url=stored["public_url"],
            sha256=stored["sha256"],
            status="active",
        )
        self.db.add(asset)
        self.db.commit()
        self.db.refresh(asset)
        return self.serialize(asset)

    def list_assets(self, user_id: int) -> list[dict]:
        return [self.serialize(item) for item in self.repository.list_assets(user_id).all()]

    def delete_asset(self, user_id: int, asset_id: int) -> dict:
        asset = self.repository.get_asset(user_id, asset_id)
        if not asset:
            raise NotFoundAppError("asset not found", code=40003)
        asset.status = "deleted"
        asset.deleted_at = datetime.utcnow()
        self.db.commit()
        return {"assetId": asset_id, "deleted": True}

    @staticmethod
    def serialize(asset: MediaAsset) -> dict:
        return {
            "id": asset.id,
            "assetNo": asset.asset_no,
            "mediaType": asset.media_type,
            "originalFilename": asset.original_filename,
            "fileSize": asset.file_size,
            "publicUrl": asset.public_url,
            "createdAt": asset.created_at.isoformat(),
        }