import subprocess
import os
import tarfile
import datetime
from fastapi import HTTPException
from starlette.responses import FileResponse


class BackupService:
    def __init__(self, db_url: str, app_files_dir: str, backup_dir: str, pg_dump_path: str):
        self.db_url = db_url
        self.app_files_dir = app_files_dir
        self.backup_dir = backup_dir
        self.pg_dump_path = pg_dump_path
        os.makedirs(backup_dir, exist_ok=True)

    async def create_backup(self) -> FileResponse:
        try:
            timestamp = datetime.datetime.now().strftime("%Y%m%d_%H%M%S")
            backup_name = f"backup_{timestamp}"
            backup_path = os.path.join(self.backup_dir, backup_name)

            db_dump_path = f"{os.getcwd()}/{backup_path}.sql"
            dump_cmd = f'"{self.pg_dump_path}" -Fc -d {self.db_url} -f "{db_dump_path}"'
            subprocess.run(dump_cmd, shell=True, check=True)

            with tarfile.open(f"{backup_path}.tar.gz", "w:gz") as tar:
                tar.add(self.app_files_dir, arcname=self.app_files_dir)
                tar.add(db_dump_path, arcname="db_dump.sql")

            os.remove(db_dump_path)
            return FileResponse(
                f"{backup_path}.tar.gz",
                media_type="application/gzip",
                filename=backup_name,
            )

        except subprocess.CalledProcessError as e:
            print(e)
            raise HTTPException(500, f"Ошибка создания бэкапа: {e}")