from openenv.core.env_server.interfaces import Message


class MockTokenizer:
    """Mock tokenizer for testing without requiring transformers library."""

    def apply_chat_template(
        self,
        conversation: list[Message],
        tokenize: bool = True,
        return_tensors: str | None = None,
        **kwargs,
    ):
        """Mock implementation that creates deterministic token IDs from text."""
        text = " ".join([msg["content"] for msg in conversation])
        tokens = [ord(c) % 256 for c in text]

        if return_tensors == "pt":
            try:
                import torch

                return torch.tensor([tokens])
            except ImportError:
                return [tokens]
        return tokens

    def decode(self, token_ids, skip_special_tokens: bool = False, **kwargs) -> str:
        """Mock decode that reverses the encoding process."""
        if hasattr(token_ids, "tolist"):
            token_ids = token_ids.tolist()
        return "".join(chr(t) for t in token_ids)