from abc import ABC, abstractmethod
from typing import Sequence

from PIL import Image

from services.progress import ProgressCallback
from services.services import TaskType, GenerationService
from services.text.TextGenerationResult import TextGenerationResult


class TextGenerator(GenerationService, ABC):
    """Base class for text generation backends."""

    task_type = TaskType.TEXT

    @abstractmethod
    def generate(
            self,
            prompt: str,
            images: Sequence[Image.Image] | None = None,
            *,
            progress: ProgressCallback | None = None,
    ) -> TextGenerationResult:
        """Generate text from a prompt and optional images."""
        raise NotImplementedError