#!/usr/bin/env python
# coding: utf-8

# In[7]:


from dataclasses import dataclass, field
from datetime import datetime
from typing import List, Optional
from transformers.file_utils import ExplicitEnum

task_to_keys = {
    "mimic3-50": ("mimic3-50"),
    "mimic3-full": ("mimic3-full"),
}

class TransformerLayerUpdateStrategy(ExplicitEnum):
    NO = "no"
    LAST = "last"
    ALL = "all"
    
class DocumentPoolingStrategy(ExplicitEnum):
    FLAT = "flat"
    MAX = "max"
    MEAN = "mean"


@dataclass
class DataTrainingArguments:
    """
    Arguments pertaining to what data we are going to input our model for training and eval.

    Using `HfArgumentParser` we can turn this class
    into argparse arguments to be able to specify them on
    the command line.
    """

    task_name: Optional[str] = field(
        default=None,
        metadata={"help": "The name of the task to train on: " + ", ".join(task_to_keys.keys())},
    )
    dataset_name: Optional[str] = field(
        default=None, metadata={"help": "The name of the dataset to use (via the datasets library)."}
    )
    dataset_config_name: Optional[str] = field(
        default=None, metadata={"help": "The configuration name of the dataset to use (via the datasets library)."}
    )
    max_seq_length: int = field(
        default=128,
        metadata={
            "help": "The maximum total input sequence length after tokenization. Sequences longer "
                    "than this will be truncated, sequences shorter will be padded."
        },
    )
    overwrite_cache: bool = field(
        default=False, metadata={"help": "Overwrite the cached preprocessed datasets or not."}
    )
    pad_to_max_length: bool = field(
        default=True,
        metadata={
            "help": "Whether to pad all samples to `max_seq_length`. "
                    "If False, will pad the samples dynamically when batching to the maximum length in the batch."
        },
    )
    max_train_samples: Optional[int] = field(
        default=None,
        metadata={
            "help": "For debugging purposes or quicker training, truncate the number of training examples to this "
                    "value if set."
        },
    )
    max_eval_samples: Optional[int] = field(
        default=None,
        metadata={
            "help": "For debugging purposes or quicker training, truncate the number of evaluation examples to this "
                    "value if set."
        },
    )
    max_predict_samples: Optional[int] = field(
        default=None,
        metadata={
            "help": "For debugging purposes or quicker training, truncate the number of prediction examples to this "
                    "value if set."
        },
    )
    train_file: Optional[str] = field(
        default=None, metadata={"help": "A csv or a json file containing the training data."}
    )
    validation_file: Optional[str] = field(
        default=None, metadata={"help": "A csv or a json file containing the validation data."}
    )
    test_file: Optional[str] = field(default=None, metadata={"help": "A csv or a json file containing the test data."})

    # customized data arguments
    label_dictionary_file: Optional[str] = field(
        default=None, metadata={"help": "The name of the test data file."}
    )
    code_max_seq_length: int = field(
        default=128,
        metadata={
            "help": "The maximum total input sequence length after tokenization for code long titles"
        },
    )
    code_batch_size: int = field(
        default=8,
        metadata={
            "help": "The batch size for generating code representation"
        },
    )
    ignore_keys_for_eval: Optional[List[str]] = field(
        default=None, metadata={"help": "The list of keys to be ignored during evaluation process."}
    )
    use_cached_datasets: bool = field(
        default=True,
        metadata={"help": "if use cached datasets to save preprocessing time. The cached datasets were preprocessed "
                          "and saved into data folder."})
    data_segmented: bool = field(
        default=False,
        metadata={"help": "if dataset is segmented or not"})

    lazy_loading: bool = field(
        default=False,
        metadata={"help": "if dataset is larger than 500MB, please use lazy_loading"})

    def __post_init__(self):
        if self.task_name is not None:
            self.task_name = self.task_name.lower()
            if self.task_name not in task_to_keys.keys():
                raise ValueError("Unknown task, you should pick one in " + ",".join(task_to_keys.keys()))
        elif self.dataset_name is not None:
            pass
        elif self.train_file is None or self.validation_file is None:
            raise ValueError("Need a training/validation file")
        elif self.label_dictionary_file is None:
            raise ValueError("label dictionary must be provided")
        else:
            train_extension = self.train_file.split(".")[-1]
            assert train_extension in ["csv", "json"], "`train_file` should be a csv or a json file."
            validation_extension = self.validation_file.split(".")[-1]
            assert (
                    validation_extension == train_extension
            ), "`validation_file` should have the same extension (csv or json) as `train_file`."


@dataclass
class ModelArguments:
    """
    Arguments pertaining to which model/config/tokenizer we are going to fine-tune from.
    """

    model_name_or_path: str = field(
        metadata={"help": "Path to pretrained model or model identifier from huggingface.co/models"}
    )
    config_name: Optional[str] = field(
        default=None, metadata={"help": "Pretrained config name or path if not the same as model_name"}
    )
    tokenizer_name: Optional[str] = field(
        default=None, metadata={"help": "Pretrained tokenizer name or path if not the same as model_name"}
    )
    cache_dir: Optional[str] = field(
        default=None,
        metadata={"help": "Where do you want to store the pretrained models downloaded from huggingface.co"},
    )
    use_fast_tokenizer: bool = field(
        default=True,
        metadata={"help": "Whether to use one of the fast tokenizer (backed by the tokenizers library) or not."},
    )
    model_revision: str = field(
        default="main",
        metadata={"help": "The specific model version to use (can be a branch name, tag name or commit id)."},
    )
    use_auth_token: bool = field(
        default=False,
        metadata={
            "help": "Will use the token generated when running `transformers-cli login` (necessary to use this script "
                    "with private models)."
        },
    )
    # Customized model arguments
    d_model: int = field(default=768, metadata={"help": "hidden size of model. should be the same as base transformer "
                                                        "model"})
    dropout: float = field(default=0.1, metadata={"help": "Dropout of transformer layer"})
    dropout_att: float = field(default=0.1, metadata={"help": "Dropout of label-wise attention layer"})
    num_chunks_per_document: int = field(default=0.1, metadata={"help": "Num of chunks per document"})
    transformer_layer_update_strategy: TransformerLayerUpdateStrategy = field(
        default="all",
        metadata={"help": "Update which transformer layers when training"})
    use_code_representation: bool = field(
        default=True,
        metadata={"help": "if use code representation as the "
                          "initial parameters of code vectors in attention layer"})
    multi_head_attention: bool = field(
        default=True,
        metadata={"help": "if use multi head attention for different chunks"})
    chunk_attention: bool = field(
        default=True,
        metadata={"help": "if use chunk attention for each label"})

    multi_head_chunk_attention: bool = field(
        default=True,
        metadata={"help": "if use multi head chunk attention for each label"})

    num_hidden_layers: int = field(
        default=2, metadata={"help": "NUm of hidden layers in longformer"}
    )

    linear_init_mean: float = field(default=0.0, metadata={"help": "mean value for initializing linear layer weights"})
    linear_init_std: float = field(default=0.03, metadata={"help": "standard deviation value for initializing linear "
                                                                   "layer weights"})
    document_pooling_strategy: DocumentPoolingStrategy = field(
        default="flat",
        metadata={"help": "how to pool document representation after label-wise attention layer for each label"})