from argparse import ArgumentParser, Namespace

from logging import getLogger

from transformers import AutoModel, AutoTokenizer
from transformers.commands import BaseTransformersCLICommand


def convert_command_factory(args: Namespace):
    """
    Factory function used to convert a model TF 1.0 checkpoint in a PyTorch checkpoint.
    :return: ServeCommand
    """
    return ConvertCommand(
        args.model_type, args.tf_checkpoint, args.pytorch_dump_output, args.config, args.finetuning_task_name
    )


class ConvertCommand(BaseTransformersCLICommand):
    @staticmethod
    def register_subcommand(parser: ArgumentParser):
        """
        Register this command to argparse so it's available for the transformer-cli
        :param parser: Root parser to register command-specific arguments
        :return:
        """
        train_parser = parser.add_parser(
            "convert",
            help="CLI tool to run convert model from original "
            "author checkpoints to Transformesr PyTorch checkpoints.",
        )
        train_parser.add_argument("--model_type", type=str, required=True, help="Model's type.")
        train_parser.add_argument(
            "--tf_checkpoint", type=str, required=True, help="TensorFlow checkpoint path or folder."
        )
        train_parser.add_argument(
            "--pytorch_dump_output", type=str, required=True, help="Path to the PyTorch savd model output."
        )
        train_parser.add_argument("--config", type=str, default="", help="Configuration file path or folder.")
        train_parser.add_argument(
            "--finetuning_task_name",
            type=str,
            default=None,
            help="Optional fine-tuning task name if the TF model was a finetuned model.",
        )
        train_parser.set_defaults(func=convert_command_factory)

    def __init__(
        self,
        model_type: str,
        tf_checkpoint: str,
        pytorch_dump_output: str,
        config: str,
        finetuning_task_name: str,
        *args
    ):
        self._logger = getLogger("transformers-cli/converting")

        self._logger.info("Loading model {}".format(model_type))
        self._model_type = model_type
        self._tf_checkpoint = tf_checkpoint
        self._pytorch_dump_output = pytorch_dump_output
        self._config = config
        self._finetuning_task_name = finetuning_task_name

    def run(self):
        if self._model_type == "bert":
            try:
                from transformers.convert_bert_original_tf_checkpoint_to_pytorch import (
                    convert_tf_checkpoint_to_pytorch,
                )
            except ImportError:
                msg = (
                    "transformers can only be used from the commandline to convert TensorFlow models in PyTorch, "
                    "In that case, it requires TensorFlow to be installed. Please see "
                    "https://www.tensorflow.org/install/ for installation instructions."
                )
                raise ImportError(msg)

            convert_tf_checkpoint_to_pytorch(self._tf_checkpoint, self._config, self._pytorch_dump_output)
        elif self._model_type == "gpt":
            from transformers.convert_openai_original_tf_checkpoint_to_pytorch import (
                convert_openai_checkpoint_to_pytorch,
            )

            convert_openai_checkpoint_to_pytorch(self._tf_checkpoint, self._config, self._pytorch_dump_output)
        elif self._model_type == "transfo_xl":
            try:
                from transformers.convert_transfo_xl_original_tf_checkpoint_to_pytorch import (
                    convert_transfo_xl_checkpoint_to_pytorch,
                )
            except ImportError:
                msg = (
                    "transformers can only be used from the commandline to convert TensorFlow models in PyTorch, "
                    "In that case, it requires TensorFlow to be installed. Please see "
                    "https://www.tensorflow.org/install/ for installation instructions."
                )
                raise ImportError(msg)

            if "ckpt" in self._tf_checkpoint.lower():
                TF_CHECKPOINT = self._tf_checkpoint
                TF_DATASET_FILE = ""
            else:
                TF_DATASET_FILE = self._tf_checkpoint
                TF_CHECKPOINT = ""
            convert_transfo_xl_checkpoint_to_pytorch(
                TF_CHECKPOINT, self._config, self._pytorch_dump_output, TF_DATASET_FILE
            )
        elif self._model_type == "gpt2":
            try:
                from transformers.convert_gpt2_original_tf_checkpoint_to_pytorch import (
                    convert_gpt2_checkpoint_to_pytorch,
                )
            except ImportError:
                msg = (
                    "transformers can only be used from the commandline to convert TensorFlow models in PyTorch, "
                    "In that case, it requires TensorFlow to be installed. Please see "
                    "https://www.tensorflow.org/install/ for installation instructions."
                )
                raise ImportError(msg)

            convert_gpt2_checkpoint_to_pytorch(self._tf_checkpoint, self._config, self._pytorch_dump_output)
        elif self._model_type == "xlnet":
            try:
                from transformers.convert_xlnet_original_tf_checkpoint_to_pytorch import (
                    convert_xlnet_checkpoint_to_pytorch,
                )
            except ImportError:
                msg = (
                    "transformers can only be used from the commandline to convert TensorFlow models in PyTorch, "
                    "In that case, it requires TensorFlow to be installed. Please see "
                    "https://www.tensorflow.org/install/ for installation instructions."
                )
                raise ImportError(msg)

            convert_xlnet_checkpoint_to_pytorch(
                self._tf_checkpoint, self._config, self._pytorch_dump_output, self._finetuning_task_name
            )
        elif self._model_type == "xlm":
            from transformers.convert_xlm_original_pytorch_checkpoint_to_pytorch import (
                convert_xlm_checkpoint_to_pytorch,
            )

            convert_xlm_checkpoint_to_pytorch(self._tf_checkpoint, self._pytorch_dump_output)
        else:
            raise ValueError("--model_type should be selected in the list [bert, gpt, gpt2, transfo_xl, xlnet, xlm]")
