import tarfile
from datetime import datetime
from pathlib import Path
from typing import List

from core.logger import get_logger


logger = get_logger("core.backup")


class BackupManager:
    def __init__(self, root: Path) -> None:
        self.root = root
        self.backup_root = root / "backups"
        self.backup_root.mkdir(parents=True, exist_ok=True)

    def create(self, scope: str) -> Path:
        timestamp = datetime.utcnow().strftime("%Y-%m-%d_%H%M%S")
        if scope == "core":
            sources = ["core", "config", "requirements.txt", "README.md", "__main__.py"]
            dest_dir = self.backup_root / "core"
            name = f"core_{timestamp}.tar.gz"
        elif scope == "modules":
            sources = ["modules"]
            dest_dir = self.backup_root / "modules"
            name = f"modules_{timestamp}.tar.gz"
        elif scope == "plugins":
            sources = ["plugins/external"]
            dest_dir = self.backup_root / "plugins"
            name = f"plugins_{timestamp}.tar.gz"
        else:
            raise ValueError("Unknown backup scope")

        dest_dir.mkdir(parents=True, exist_ok=True)
        archive_path = dest_dir / name

        with tarfile.open(archive_path, "w:gz") as tar:
            for src in sources:
                src_path = self.root / src
                if src_path.exists():
                    tar.add(src_path, arcname=src)
        logger.info("Backup created: %s", archive_path)
        return archive_path

    def list(self, scope: str) -> List[str]:
        scope_dir = self.backup_root / scope
        if not scope_dir.exists():
            return []
        return sorted([item.name for item in scope_dir.iterdir() if item.is_file()])

    def delete(self, scope: str, name: str) -> None:
        target = self.backup_root / scope / name
        if target.exists():
            target.unlink()