from typing import Optional, Tuple

from mamba_ssm.models.mixer_seq_simple import MambaLMHeadModel
import torch
from transformers import GenerationMixin, PreTrainedModel
from transformers.generation import TextStreamer

from .configuration_mamba import MambaConfig

class MambaModel(PreTrainedModel):
    config_class = MambaConfig

    def __init__(
        self,
        config,
        initializer_cfg=None,
        device=None,
        dtype=None,
        **kwargs,
    ):
        super().__init__(
            config,
            **kwargs,
        )

        self.model = MambaLMHeadModel(
            config,
            initializer_cfg=initializer_cfg,
            device=device,
            dtype=dtype,
        )

    def forward(
            self,
            input_ids,
            position_ids=None,
            inference_params=None,
            num_last_tokens=0,
            **kwargs,
        ):
        return self.model.forward(
            input_ids,
            position_ids,
            inference_params,
            num_last_tokens
        )

class MambaModelForCausalLM(MambaModel, GenerationMixin):
    def generate(
        self,
        input_ids,
        max_length: int = 2048,
        top_k: int = 1,
        top_p: float = 0.0,
        temperature: float = 1.0,
        return_dict_in_generate: bool = False,
        output_scores: bool = False,
        repetition_penalty: float = 1.0,
        eos_token_id: Optional[int] = None,
        teacher_outputs: Optional[torch.Tensor] = None,
        vocab_size: Optional[int] = None,
        cg: bool = False,
        enable_timing: bool = False,
        streamer: Optional[TextStreamer] = None,
        **kwargs,
    ):
        return self.model.generate(
            input_ids=input_ids,
            max_length=max_length,
            top_k=top_k,
            top_p=top_p,
            temperature=temperature,
            return_dict_in_generate=return_dict_in_generate,
            output_scores=output_scores,
            repetition_penalty=repetition_penalty,
            eos_token_id=eos_token_id,
            teacher_outputs=teacher_outputs,
            vocab_size=vocab_size,
            cg=cg,
            enable_timing=enable_timing,
            streamer=streamer,
        )