import torch
import enum
import os

from loguru import logger
from transformers.configuration_utils import PretrainedConfig
from transformers.models.auto import modeling_auto
from huggingface_hub import hf_hub_download, HfApi
from typing import Optional, List
from pathlib import Path

from text_generation_server.utils.speculate import get_speculate, set_speculate
from text_generation_server.models.model import Model
from text_generation_server.models.causal_lm import CausalLM, CausalLMBatchKeysLast
from text_generation_server.models.custom_modeling.opt_modeling import OPTForCausalLM
from text_generation_server.models.custom_modeling.mpt_modeling import (
    MPTForCausalLM,
)
from text_generation_server.models.bloom import BloomCausalLMBatch
from text_generation_server.models.custom_modeling.bloom_modeling import (
    BloomForCausalLM,
)
from text_generation_server.models.seq2seq_lm import Seq2SeqLM
from text_generation_server.models.galactica import GalacticaCausalLMBatch
from text_generation_server.models.custom_modeling.neox_modeling import (
    GPTNeoxForCausalLM,
)
from text_generation_server.models.custom_modeling.phi_modeling import (
    PhiConfig,
    PhiForCausalLM,
)
from text_generation_server.models.custom_modeling.t5_modeling import (
    T5ForConditionalGeneration,
)

from text_generation_server.utils.import_utils import SYSTEM
from text_generation_server.utils.log import log_master

# The flag below controls whether to allow TF32 on matmul. This flag defaults to False
# in PyTorch 1.12 and later.
torch.backends.cuda.matmul.allow_tf32 = True

# The flag below controls whether to allow TF32 on cuDNN. This flag defaults to True.
torch.backends.cudnn.allow_tf32 = True

# Disable gradients
torch.set_grad_enabled(False)

__all__ = [
    "Model",
    "CausalLM",
    "Seq2SeqLM",
    "get_model",
]

FLASH_ATT_ERROR_MESSAGE = "{} requires Flash Attention enabled models."

FLASH_ATTENTION = True

try:
    from text_generation_server.models.flash_causal_lm import FlashCausalLM
    from text_generation_server.models.vlm_causal_lm import VlmCausalLM
    from text_generation_server.models.custom_modeling.flash_deepseek_v2_modeling import (
        FlashDeepseekV2ForCausalLM,
        DeepseekV2Config,
    )
    from text_generation_server.models.custom_modeling.flash_llama_modeling import (
        FlashLlamaForCausalLM,
    )
    from text_generation_server.models.custom_modeling.flash_cohere_modeling import (
        FlashCohereForCausalLM,
    )
    from text_generation_server.models.custom_modeling.flash_gemma_modeling import (
        FlashGemmaForCausalLM,
    )
    from text_generation_server.models.custom_modeling.flash_gemma2_modeling import (
        FlashGemma2ForCausalLM,
    )
    from text_generation_server.models.custom_modeling.flash_dbrx_modeling import (
        FlashDbrxForCausalLM,
        DbrxConfig,
    )
    from text_generation_server.models.custom_modeling.flash_rw_modeling import (
        RWConfig,
        FlashRWForCausalLM,
    )
    from text_generation_server.models.custom_modeling.flash_neox_modeling import (
        FlashGPTNeoXForCausalLM,
    )
    from text_generation_server.models.pali_gemma import (
        PaliGemmaBatch,
    )
    from text_generation_server.models.custom_modeling.flash_pali_gemma_modeling import (
        PaliGemmaForConditionalGeneration,
    )
    from text_generation_server.models.custom_modeling.flash_phi_modeling import (
        FlashPhiForCausalLM,
    )
    from text_generation_server.models.idefics import IDEFICSSharded
    from text_generation_server.models.custom_modeling.llava_next import (
        LlavaNextForConditionalGeneration,
    )

    from text_generation_server.models.custom_modeling.flash_santacoder_modeling import (
        FlashSantacoderForCausalLM,
    )
    from text_generation_server.models.custom_modeling.flash_starcoder2_modeling import (
        FlashStarcoder2ForCausalLM,
    )
    from text_generation_server.models.custom_modeling.flash_qwen2_modeling import (
        Qwen2ForCausalLM,
    )
    from text_generation_server.models.custom_modeling.flash_mistral_modeling import (
        FlashMistralForCausalLM,
    )
    from text_generation_server.models.custom_modeling.flash_mixtral_modeling import (
        FlashMixtralForCausalLM,
    )
    from text_generation_server.models.custom_modeling.flash_gpt2_modeling import (
        FlashGPT2ForCausalLM,
    )
    from text_generation_server.models.custom_modeling.idefics2 import (
        Idefics2ForConditionalGeneration,
    )
    from text_generation_server.layers.attention import SUPPORTS_WINDOWING
except ImportError as e:
    log_master(logger.warning, f"Could not import Flash Attention enabled models: {e}")
    SUPPORTS_WINDOWING = False
    FLASH_ATTENTION = False

if FLASH_ATTENTION:
    __all__.append(FlashCausalLM)
    __all__.append(IDEFICSSharded)

MAMBA_AVAILABLE = True
try:
    from text_generation_server.models.mamba import Mamba
except ImportError as e:
    log_master(logger.warning, f"Could not import Mamba: {e}")
    MAMBA_AVAILABLE = False

if MAMBA_AVAILABLE:
    __all__.append(Mamba)


class ModelType(enum.Enum):
    DEEPSEEK_V2 = {
        "type": "deepseek_v2",
        "name": "Deepseek V2",
        "url": "https://huggingface.co/deepseek-ai/DeepSeek-V2",
    }
    IDEFICS2 = {
        "type": "idefics2",
        "name": "Idefics 2",
        "url": "https://huggingface.co/HuggingFaceM4/idefics2-8b",
        "multimodal": True,
    }
    LLAVA_NEXT = {
        "type": "llava_next",
        "name": "Llava Next (1.6)",
        "url": "https://huggingface.co/llava-hf/llava-v1.6-vicuna-13b-hf",
        "multimodal": True,
    }
    LLAMA = {
        "type": "llama",
        "name": "Llama",
        "url": "https://huggingface.co/meta-llama/Meta-Llama-3-8B-Instruct",
    }
    PHI3 = {
        "type": "phi3",
        "name": "Phi 3",
        "url": "https://huggingface.co/microsoft/Phi-3-mini-4k-instruct",
    }
    GEMMA = {
        "type": "gemma",
        "name": "Gemma",
        "url": "https://huggingface.co/google/gemma-7b",
    }
    PALIGEMMA = {
        "type": "paligemma",
        "name": "PaliGemma",
        "url": "https://huggingface.co/google/paligemma-3b-pt-224",
    }
    GEMMA2 = {
        "type": "gemma2",
        "name": "Gemma2",
        "url": "https://huggingface.co/google/gemma2-9b",
    }
    COHERE = {
        "type": "cohere",
        "name": "Cohere",
        "url": "https://huggingface.co/CohereForAI/c4ai-command-r-plus",
    }
    DBRX = {
        "type": "dbrx",
        "name": "Dbrx",
        "url": "https://huggingface.co/databricks/dbrx-instruct",
    }
    MAMBA = {
        "type": "ssm",
        "name": "Mamba",
        "url": "https://huggingface.co/state-spaces/mamba-2.8b-slimpj",
    }
    MISTRAL = {
        "type": "mistral",
        "name": "Mistral",
        "url": "https://huggingface.co/mistralai/Mistral-7B-Instruct-v0.2",
    }
    MIXTRAL = {
        "type": "mixtral",
        "name": "Mixtral",
        "url": "https://huggingface.co/mistralai/Mixtral-8x22B-Instruct-v0.1",
    }
    GPT_BIGCODE = {
        "type": "gpt_bigcode",
        "name": "Gpt Bigcode",
        "url": "https://huggingface.co/bigcode/gpt_bigcode-santacoder",
    }
    PHI = {
        "type": "phi",
        "name": "Phi",
        "url": "https://huggingface.co/microsoft/phi-1_5",
    }
    BAICHUAN = {
        "type": "baichuan",
        "name": "Baichuan",
        "url": "https://huggingface.co/baichuan-inc/Baichuan2-7B-Chat",
    }
    FALCON = {
        "type": "falcon",
        "name": "Falcon",
        "url": "https://huggingface.co/tiiuae/falcon-7b-instruct",
    }
    STARCODER2 = {
        "type": "starcoder2",
        "name": "StarCoder 2",
        "url": "https://huggingface.co/bigcode/starcoder2-15b-instruct-v0.1",
    }
    QWEN2 = {
        "type": "qwen2",
        "name": "Qwen 2",
        "url": "https://huggingface.co/collections/Qwen/qwen2-6659360b33528ced941e557f",
    }
    OPT = {
        "type": "opt",
        "name": "Opt",
        "url": "https://huggingface.co/facebook/opt-6.7b",
    }
    T5 = {
        "type": "t5",
        "name": "T5",
        "url": "https://huggingface.co/google/flan-t5-xxl",
    }
    GALACTICA = {
        "type": "galactica",
        "name": "Galactica",
        "url": "https://huggingface.co/facebook/galactica-120b",
    }
    SANTACODER = {
        "type": "santacoder",
        "name": "SantaCoder",
        "url": "https://huggingface.co/bigcode/santacoder",
    }
    BLOOM = {
        "type": "bloom",
        "name": "Bloom",
        "url": "https://huggingface.co/bigscience/bloom-560m",
    }
    MPT = {
        "type": "mpt",
        "name": "Mpt",
        "url": "https://huggingface.co/mosaicml/mpt-7b-instruct",
    }
    GPT2 = {
        "type": "gpt2",
        "name": "Gpt2",
        "url": "https://huggingface.co/openai-community/gpt2",
    }
    GPT_NEOX = {
        "type": "gpt_neox",
        "name": "Gpt Neox",
        "url": "https://huggingface.co/EleutherAI/gpt-neox-20b",
    }
    IDEFICS = {
        "type": "idefics",
        "name": "Idefics",
        "url": "https://huggingface.co/HuggingFaceM4/idefics-9b",
        "multimodal": True,
    }


__GLOBALS = locals()
for data in ModelType:
    __GLOBALS[data.name] = data.value["type"]


def get_model(
    model_id: str,
    lora_adapter_ids: Optional[List[str]],
    revision: Optional[str],
    sharded: bool,
    quantize: Optional[str],
    speculate: Optional[int],
    dtype: Optional[str],
    trust_remote_code: bool,
    max_input_tokens: int,
) -> Model:
    global FLASH_ATTENTION

    config_dict, _ = PretrainedConfig.get_config_dict(
        model_id, revision=revision, trust_remote_code=trust_remote_code
    )
    model_type = config_dict.get("model_type", None)

    quantization_config = config_dict.get("quantization_config", None)
    if quantization_config is not None and quantize is None:
        method = quantization_config.get("quant_method", None)
        if method in {"gptq", "awq", "exl2"}:
            log_master(logger.info, f"Auto selecting quantization method {method}")
            quantize = method
        elif method == "fbgemm_fp8":
            log_master(logger.info, "Auto selecting quantization method fp8")
            quantize = "fp8"
        else:
            log_master(logger.warning, f"Unknown quantization method {method}")

    if dtype is None:
        if quantize in ["awq", "exl2", "gptq", "marlin"]:
            # These quantizers only work with float16 params.
            dtype = torch.float16
        elif quantize == "fp8":
            from text_generation_server.layers.fp8 import FBGEMM_DYN_AVAILABLE

            if FBGEMM_DYN_AVAILABLE:
                # fbgemm kernels are fp8xfp8->bf16
                dtype = torch.bfloat16
        else:
            # Keep it as default for now and let
            # every model resolve their own default dtype.
            dtype = None
    elif dtype == "float16":
        dtype = torch.float16
    elif dtype == "bfloat16":
        dtype = torch.bfloat16
    else:
        raise RuntimeError(f"Unknown dtype {dtype}")

    if speculate is not None:
        set_speculate(speculate)
    else:
        set_speculate(0)

    speculator = None
    if "medusa_num_heads" in config_dict:
        medusa_model_id = model_id
        medusa_revision = revision
        model_id = config_dict["base_model_name_or_path"]
        revision = "main"
        speculate_medusa = config_dict["medusa_num_heads"]
        if speculate is not None:
            if speculate > speculate_medusa:
                raise RuntimeError(
                    f"Speculate is set to `{speculate}` but this medusa models only has `{speculate_medusa}` heads, please make them match"
                )
            else:
                set_speculate(speculate)
        else:
            set_speculate(speculate_medusa)

        config_dict, _ = PretrainedConfig.get_config_dict(
            model_id, revision=revision, trust_remote_code=trust_remote_code
        )
        # Reload model type from parent.
        model_type = config_dict.get("model_type", None)
        is_local = Path(medusa_model_id).exists()
        if not is_local:
            medusa_config = hf_hub_download(
                medusa_model_id, revision=medusa_revision, filename="config.json"
            )
            hf_hub_download(
                medusa_model_id,
                revision=medusa_revision,
                filename="medusa_lm_head.safetensors",
            )
            speculator = {
                "path": Path(medusa_config).parent,
                "model_paths": ["medusa_lm_head.safetensors"],
            }
        else:
            speculator = {
                "path": Path(medusa_model_id),
                "model_paths": ["medusa_lm_head.safetensors"],
            }

        method = "medusa"
    elif model_type == "mlp_speculator":
        mlp_model_id = model_id
        mlp_revision = revision
        model_id = config_dict["base_model_name_or_path"]
        revision = "main"
        speculate_mlp = config_dict["n_predict"]
        if speculate is not None:
            if speculate > speculate_mlp:
                raise RuntimeError(
                    f"Speculate is set to `{speculate}` but this mlp_speculator models only has `{speculate_mlp}` heads, please make them match"
                )
            else:
                set_speculate(speculate)
        else:
            set_speculate(speculate_mlp)

        config_dict, _ = PretrainedConfig.get_config_dict(
            model_id, revision=revision, trust_remote_code=trust_remote_code
        )
        # Reload model type from parent.
        model_type = config_dict.get("model_type", None)
        is_local = Path(mlp_model_id).exists()
        extension = ".safetensors"
        if not is_local:
            mlp_speculator_config = hf_hub_download(
                mlp_model_id, revision=mlp_revision, filename="config.json"
            )
            api = HfApi()
            info = api.model_info(mlp_model_id, revision=mlp_revision)
            filenames = [
                s.rfilename
                for s in info.siblings
                if s.rfilename.endswith(extension)
                and len(s.rfilename.split("/")) == 1
                and "arguments" not in s.rfilename
                and "args" not in s.rfilename
                and "training" not in s.rfilename
            ]
            for filename in filenames:
                hf_hub_download(
                    mlp_model_id,
                    revision=mlp_revision,
                    filename=filename,
                )
            speculator = {
                "path": Path(mlp_speculator_config).parent,
                "model_paths": filenames,
            }
        else:
            speculator = Path(mlp_model_id)
            filenames = [p for p in os.listdir(speculator) if p.endswith(extension)]
            speculator = {"path": speculator, "model_paths": filenames}
        method = "mlp_speculator"
    else:
        method = "n-gram"

    speculate = get_speculate()
    if speculate > 0:
        log_master(
            logger.info, f"Using speculation {method} with {speculate} input ids."
        )

    if model_type is None:
        # TODO: fix how we determine model type for Mamba
        if "ssm_cfg" in config_dict:
            # *only happens in Mamba case
            model_type = "ssm"
        else:
            raise RuntimeError(
                f"Could not determine model type for {model_id} revision {revision}"
            )

    if quantize == "exl2" and sharded:
        raise RuntimeError(
            "Sharding is currently not supported with `exl2` quantization"
        )
    sliding_window = config_dict.get("sliding_window", -1)

    if (
        (sliding_window is not None and sliding_window != -1)
        and not SUPPORTS_WINDOWING
        and max_input_tokens > sliding_window
    ):
        raise ValueError(
            f"The backend {SYSTEM} does not support sliding window attention that is used by the model type {model_type}. To use this model nonetheless with the {SYSTEM} backend, please launch TGI with the argument `--max-input-tokens` smaller than sliding_window={sliding_window} (got here max_input_tokens={max_input_tokens})."
        )

    if model_type == DEEPSEEK_V2:
        if FLASH_ATTENTION:
            head_size = max(
                config_dict.get("qk_nope_dim", 128)
                + config_dict.get("qk_rope_dim", 64),
                config_dict.get("v_head_dim", 128),
            )
            return FlashCausalLM(
                model_id=model_id,
                model_class=FlashDeepseekV2ForCausalLM,
                revision=revision,
                quantize=quantize,
                speculator=speculator,
                default_dtype=torch.bfloat16,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
                lora_adapter_ids=lora_adapter_ids,
                config_class=DeepseekV2Config,
                head_size=head_size,
            )
        elif sharded:
            raise NotImplementedError(
                FLASH_ATT_ERROR_MESSAGE.format("Sharded Deepseek V2")
            )
        else:
            return CausalLM.fallback(
                model_id,
                revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )
    elif model_type == MAMBA:
        return Mamba(
            model_id,
            revision,
            quantize=quantize,
            speculator=speculator,
            dtype=dtype,
            trust_remote_code=trust_remote_code,
        )

    if model_id.startswith("facebook/galactica"):
        return CausalLM(
            model_id=model_id,
            # Yes galactica is just an OPT model.
            model_class=OPTForCausalLM,
            revision=revision,
            quantize=quantize,
            speculator=speculator,
            dtype=dtype,
            trust_remote_code=trust_remote_code,
            batch_class=GalacticaCausalLMBatch,
        )

    if (
        model_type == GPT_BIGCODE
        or model_type == GPT2
        and model_id.startswith("bigcode/")
    ):
        if FLASH_ATTENTION:
            return FlashCausalLM(
                model_id=model_id,
                model_class=FlashSantacoderForCausalLM,
                revision=revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
                lora_adapter_ids=lora_adapter_ids,
                aliases={"transformer.wte.weight": ["lm_head.weight"]},
                num_kv_heads=1,
            )
        elif sharded:
            raise NotImplementedError(
                FLASH_ATT_ERROR_MESSAGE.format("Sharded Santacoder")
            )
        else:
            return CausalLM.fallback(
                model_id=model_id,
                revision=revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )

    if model_type == BLOOM:
        return CausalLM(
            model_id=model_id,
            model_class=BloomForCausalLM,
            revision=revision,
            quantize=quantize,
            speculator=speculator,
            dtype=dtype,
            trust_remote_code=trust_remote_code,
            batch_class=BloomCausalLMBatch,
        )
    elif model_type == MPT:
        return CausalLM(
            model_id=model_id,
            model_class=MPTForCausalLM,
            revision=revision,
            quantize=quantize,
            speculator=speculator,
            dtype=dtype,
            trust_remote_code=trust_remote_code,
            batch_class=CausalLMBatchKeysLast,
        )
    elif model_type == GPT2:
        if FLASH_ATTENTION:
            try:
                return FlashCausalLM(
                    model_id=model_id,
                    model_class=FlashGPT2ForCausalLM,
                    revision=revision,
                    quantize=quantize,
                    speculator=speculator,
                    dtype=dtype,
                    trust_remote_code=trust_remote_code,
                    lora_adapter_ids=lora_adapter_ids,
                )
            except RuntimeError as e:
                # Lots of legacy models with various weight names.
                log_master(logger.warning, f"Couldn't load flash gpt2 variant: {e}")
                return CausalLM.fallback(
                    model_id,
                    revision,
                    quantize=quantize,
                    speculator=speculator,
                    dtype=dtype,
                    trust_remote_code=trust_remote_code,
                )
        elif sharded:
            raise NotImplementedError(FLASH_ATT_ERROR_MESSAGE.format("Sharded GPT-2"))
        else:
            return CausalLM.fallback(
                model_id,
                revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )
    elif model_type == GPT_NEOX:
        if FLASH_ATTENTION:
            from text_generation_server.models.custom_modeling.flash_neox_modeling import (
                GPTNeoXConfig,
            )

            return FlashCausalLM(
                model_id=model_id,
                model_class=FlashGPTNeoXForCausalLM,
                revision=revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
                lora_adapter_ids=lora_adapter_ids,
                config_class=GPTNeoXConfig,
            )
        elif sharded:
            return CausalLM(
                model_id=model_id,
                model_class=GPTNeoxForCausalLM,
                revision=revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )
        else:
            return CausalLM.fallback(
                model_id,
                revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )

    elif model_type == PHI:
        if FLASH_ATTENTION:
            return FlashCausalLM(
                model_id=model_id,
                model_class=FlashPhiForCausalLM,
                revision=revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
                lora_adapter_ids=lora_adapter_ids,
            )
        else:
            return CausalLM.fallback(
                model_id,
                revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )

    elif model_type == "phi-msft":
        if FLASH_ATTENTION:
            raise NotImplementedError(
                "Legacy phi-msft is not supported with Flash Attention"
            )
        else:
            return CausalLM(
                model_id=model_id,
                model_class=PhiForCausalLM,
                config_class=PhiConfig,
                revision=revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )

    elif model_type == LLAMA or model_type == BAICHUAN or model_type == PHI3:
        if FLASH_ATTENTION:
            return FlashCausalLM(
                model_id=model_id,
                model_class=FlashLlamaForCausalLM,
                revision=revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
                lora_adapter_ids=lora_adapter_ids,
            )
        elif sharded:
            raise NotImplementedError(FLASH_ATT_ERROR_MESSAGE.format("Sharded Llama"))
        else:
            return CausalLM.fallback(
                model_id,
                revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )
    if model_type == GEMMA:
        if FLASH_ATTENTION:
            return FlashCausalLM(
                model_id=model_id,
                model_class=FlashGemmaForCausalLM,
                revision=revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                # Works better for these models
                default_dtype=torch.bfloat16,
                trust_remote_code=trust_remote_code,
                lora_adapter_ids=lora_adapter_ids,
            )
        elif sharded:
            raise NotImplementedError(FLASH_ATT_ERROR_MESSAGE.format("Sharded Gemma"))
        else:
            return CausalLM.fallback(
                model_id,
                revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )
    elif model_type == GEMMA2:
        if FLASH_ATTENTION:
            return FlashCausalLM(
                model_id=model_id,
                model_class=FlashGemma2ForCausalLM,
                revision=revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                # Works better for these models
                default_dtype=torch.bfloat16,
                trust_remote_code=trust_remote_code,
                lora_adapter_ids=lora_adapter_ids,
                # hidden_size / num_attention_heads is wrong in `google/gemma-2-9b-it`
                head_size=config_dict["head_dim"],
            )
        elif sharded:
            raise NotImplementedError(FLASH_ATT_ERROR_MESSAGE.format("Sharded Gemma2"))
        else:
            return CausalLM.fallback(
                model_id,
                revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )

    if model_type == COHERE:
        if FLASH_ATTENTION:
            return FlashCausalLM(
                model_id=model_id,
                model_class=FlashCohereForCausalLM,
                revision=revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
                lora_adapter_ids=lora_adapter_ids,
            )
        elif sharded:
            raise NotImplementedError(FLASH_ATT_ERROR_MESSAGE.format("Sharded Cohere"))
        else:
            return CausalLM.fallback(
                model_id,
                revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )

    if model_type == DBRX:
        if FLASH_ATTENTION:
            return FlashCausalLM(
                model_id=model_id,
                model_class=FlashDbrxForCausalLM,
                revision=revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                # Dbrx works better in bfloat16.
                default_dtype=torch.bfloat16,
                trust_remote_code=trust_remote_code,
                lora_adapter_ids=lora_adapter_ids,
                config_class=DbrxConfig,
            )
        elif sharded:
            raise NotImplementedError(FLASH_ATT_ERROR_MESSAGE.format("Sharded DBRX"))
        else:
            return CausalLM.fallback(
                model_id,
                revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )

    if model_type in ["RefinedWeb", "RefinedWebModel", FALCON]:
        if sharded:
            if FLASH_ATTENTION:
                if config_dict.get("alibi", False):
                    raise NotImplementedError("sharded is not supported for this model")
                return FlashCausalLM(
                    model_id=model_id,
                    model_class=FlashRWForCausalLM,
                    revision=revision,
                    quantize=quantize,
                    speculator=speculator,
                    dtype=dtype,
                    aliases={
                        "lm_head.weight": ["transformer.word_embeddings.weight"],
                        "transformer.word_embeddings.weight": ["lm_head.weight"],
                    },
                    trust_remote_code=trust_remote_code,
                    lora_adapter_ids=lora_adapter_ids,
                    config_class=RWConfig,
                )
            raise NotImplementedError(FLASH_ATT_ERROR_MESSAGE.format(f"Sharded Falcon"))
        else:
            if FLASH_ATTENTION and not config_dict.get("alibi", False):
                return FlashCausalLM(
                    model_id=model_id,
                    model_class=FlashRWForCausalLM,
                    revision=revision,
                    quantize=quantize,
                    speculator=speculator,
                    dtype=dtype,
                    aliases={
                        "lm_head.weight": ["transformer.word_embeddings.weight"],
                        "transformer.word_embeddings.weight": ["lm_head.weight"],
                    },
                    trust_remote_code=trust_remote_code,
                    lora_adapter_ids=lora_adapter_ids,
                    config_class=RWConfig,
                )
            else:
                return CausalLM.fallback(
                    model_id,
                    revision,
                    quantize=quantize,
                    speculator=speculator,
                    dtype=dtype,
                    trust_remote_code=trust_remote_code,
                )

    if model_type == MISTRAL:
        if FLASH_ATTENTION:
            return FlashCausalLM(
                model_id=model_id,
                model_class=FlashMistralForCausalLM,
                revision=revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
                lora_adapter_ids=lora_adapter_ids,
            )
        elif sharded:
            raise NotImplementedError(FLASH_ATT_ERROR_MESSAGE.format("Sharded Mistral"))
        else:
            return CausalLM.fallback(
                model_id,
                revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )

    if model_type == MIXTRAL:
        if FLASH_ATTENTION:
            return FlashCausalLM(
                model_id=model_id,
                model_class=FlashMixtralForCausalLM,
                revision=revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
                lora_adapter_ids=lora_adapter_ids,
            )
        elif sharded:
            raise NotImplementedError(FLASH_ATT_ERROR_MESSAGE.format("Sharded Mixtral"))
        else:
            return CausalLM.fallback(
                model_id,
                revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )

    if model_type == STARCODER2:
        if FLASH_ATTENTION:
            return FlashCausalLM(
                model_id=model_id,
                model_class=FlashStarcoder2ForCausalLM,
                revision=revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
                lora_adapter_ids=lora_adapter_ids,
            )
        elif sharded:
            raise NotImplementedError(
                FLASH_ATT_ERROR_MESSAGE.format("Sharded Starcoder2")
            )
        else:
            return CausalLM.fallback(
                model_id,
                revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )

    if model_type == QWEN2:
        if FLASH_ATTENTION:
            return FlashCausalLM(
                model_id=model_id,
                model_class=Qwen2ForCausalLM,
                revision=revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
                lora_adapter_ids=lora_adapter_ids,
            )
        elif sharded:
            raise NotImplementedError(FLASH_ATT_ERROR_MESSAGE.format("Sharded Qwen2"))
        else:
            return CausalLM.fallback(
                model_id,
                revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )

    if model_type == OPT:
        return CausalLM(
            model_id=model_id,
            model_class=OPTForCausalLM,
            revision=revision,
            quantize=quantize,
            speculator=speculator,
            dtype=dtype,
            trust_remote_code=trust_remote_code,
        )

    if model_type == T5:
        return Seq2SeqLM(
            model_id=model_id,
            model_class=T5ForConditionalGeneration,
            revision=revision,
            quantize=quantize,
            speculator=speculator,
            dtype=dtype,
            trust_remote_code=trust_remote_code,
            aliases={
                "shared.weight": [
                    "encoder.embed_tokens.weight",
                    "decoder.embed_tokens.weight",
                ]
            },
        )
    if model_type == IDEFICS:
        if FLASH_ATTENTION:
            return IDEFICSSharded(
                model_id,
                revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )
        else:
            raise NotImplementedError(FLASH_ATT_ERROR_MESSAGE.format("Idefics"))
    if model_type == IDEFICS2:
        if FLASH_ATTENTION:
            return VlmCausalLM(
                model_id=model_id,
                model_class=Idefics2ForConditionalGeneration,
                revision=revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
                lora_adapter_ids=lora_adapter_ids,
                # XXX: Extremely important to cap resolution in order to limit
                # VRAM usage.
                processor_kwargs={"size": {"longest_edge": 448, "shortest_edge": 378}},
            )
        else:
            raise NotImplementedError(FLASH_ATT_ERROR_MESSAGE.format("Idefics"))
    if model_type == PALIGEMMA:
        if FLASH_ATTENTION:
            return VlmCausalLM(
                model_id=model_id,
                model_class=PaliGemmaForConditionalGeneration,
                revision=revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                # Works better for these models
                default_dtype=torch.bfloat16,
                trust_remote_code=trust_remote_code,
                lora_adapter_ids=lora_adapter_ids,
                batch_class=PaliGemmaBatch,
            )
        else:
            raise NotImplementedError(FLASH_ATT_ERROR_MESSAGE.format("Idefics"))

    if model_type == LLAVA_NEXT:
        if FLASH_ATTENTION:
            return VlmCausalLM(
                model_class=LlavaNextForConditionalGeneration,
                model_id=model_id,
                revision=revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )
        else:
            raise NotImplementedError(FLASH_ATT_ERROR_MESSAGE.format("LlavaNext"))

    if sharded:
        raise NotImplementedError("sharded is not supported for AutoModel")
    if quantize == "gptq":
        raise NotImplementedError(
            "gptq quantization is not supported for AutoModel, you can try to quantize it with `text-generation-server quantize ORIGINAL_MODEL_ID NEW_MODEL_ID`"
        )
    if quantize == "awq":
        raise NotImplementedError("awq quantization is not supported for AutoModel")
    elif (quantize == "bitsandbytes-fp4") or (quantize == "bitsandbytes-nf4"):
        raise NotImplementedError("4bit quantization is not supported for AutoModel")
    elif quantize == "eetq":
        raise NotImplementedError("Eetq quantization is not supported for AutoModel")
    elif quantize == "exl2":
        raise NotImplementedError("exl2 quantization is not supported for AutoModel")
    if model_type in modeling_auto.MODEL_FOR_CAUSAL_LM_MAPPING_NAMES:
        return CausalLM.fallback(
            model_id,
            revision,
            quantize=quantize,
            speculator=speculator,
            dtype=dtype,
            trust_remote_code=trust_remote_code,
        )
    if model_type in modeling_auto.MODEL_FOR_SEQ_TO_SEQ_CAUSAL_LM_MAPPING_NAMES:
        return Seq2SeqLM.fallback(
            model_id,
            revision,
            quantize=quantize,
            speculator=speculator,
            dtype=dtype,
            trust_remote_code=trust_remote_code,
        )

    auto_map = config_dict.get("auto_map", None)
    if trust_remote_code and auto_map is not None:
        if "AutoModelForCausalLM" in auto_map.keys():
            return CausalLM.fallback(
                model_id,
                revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )
        if "AutoModelForSeq2SeqLM" in auto_map.keys():
            return Seq2SeqLM.fallback(
                model_id,
                revision,
                quantize=quantize,
                speculator=speculator,
                dtype=dtype,
                trust_remote_code=trust_remote_code,
            )

    raise ValueError(f"Unsupported model type {model_type}")
