# Copyright 2020 The HuggingFace Datasets Authors and the current dataset script contributor.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""TODO: Add a description here."""

import evaluate
import datasets
import numpy as np
from transformers import AutoModelForSequenceClassification, AutoTokenizer
import getpass
import pdb
import os
import torch
from rouge_score import scoring
from contextlib import contextmanager


# TODO: Add BibTeX citation
_CITATION = """\
@InProceedings{huggingface:module,
title = {A great new module},
authors={huggingface, Inc.},
year={2020}
}
"""

# TODO: Add description of the module here
_DESCRIPTION = """\
local coherecence with  classifier trained on the shuffle task, window=3 sentences
"""


# TODO: Add description of the arguments of the module here
_KWARGS_DESCRIPTION = """
Calculates how good are predictions given some references, using certain scores
Args:
    predictions: list of predictions to score. Each predictions
        should be a string with tokens separated by spaces.
    references: list of reference for each prediction. Each
        reference should be a string with tokens separated by spaces.
Returns:
    accuracy: description of the first score,
    another_score: description of the second score,
Examples:
    Examples should be written in doctest format, and should illustrate how
    to use the function.

    >>> my_new_module = evaluate.load("my_new_module")
    >>> results = my_new_module.compute(references=[0, 1], predictions=[0, 1])
    >>> print(results)
    {'accuracy': 1.0}
"""

WINDOW_SIZE = 3


@contextmanager
def filter_logging_context():
    def filter_log(record):
        return False if "This IS expected if you are initializing" in record.msg else True

    logger = datasets.utils.logging.get_logger("transformers.modeling_utils")
    logger.addFilter(filter_log)
    try:
        yield
    finally:
        logger.removeFilter(filter_log)


class Scorer:

    def __init__(
        self,
        model_type=None,
        batch_size=64,
        device=None,
        use_fast_tokenizer=False):
        
        if device is not None:
            # assert device in ["gpu", "cpu", "cuda"], "device should be either gpu or cpu."
            if device == "gpu":
                device = "cuda"
        else:
            device = "cuda" if torch.cuda.is_available() else "cpu"
        self.device = device
        self.model_type = model_type
        self.batch_size = batch_size
        self._tokenizer = AutoTokenizer.from_pretrained("roberta-large")
        self._model = AutoModelForSequenceClassification.from_pretrained(f"ronaldahmed/ccl_win-{model_type}")
        self._model.to(device)
        self._model.eval()

    @property
    def hash(self):
        return self.model_type

    def preprocess_adjacent_window(self,preds):
        pred_list = []
        lens = []
        for pred in preds:
            sents = pred.split("\n")
            ns = len(sents)
            if ns <= WINDOW_SIZE:
                pred_list.append(pred)
                lens.append(1)
            else:
                llen = 0
                for i in range(0,ns-WINDOW_SIZE+1):
                    sss = sents[i:i+WINDOW_SIZE]
                    ss = "\n".join(sss)
                    pred_list.append(ss)
                    llen += 1
                lens.append(llen)
        #
        return pred_list,lens


    def score(self,predictions):
        
        sent_lens = [len(x.split("\n")) for x in predictions]
        pred_list,len_by_sample = self.preprocess_adjacent_window(predictions)

        scores = []
        n_preds = len(pred_list)
        with torch.no_grad():
            for b in range(0,n_preds,self.batch_size):
                strides = [x.lower() for x in pred_list[b:b+self.batch_size]]
                tinput = self._tokenizer(strides,padding=True,truncation=True,max_length=512,return_tensors="pt")
                tinput = {k:v.to(self.device) for k,v in tinput.items()}
                output = self._model(**tinput)
                probs = torch.softmax(output.logits,dim=-1).detach().cpu().numpy()
                scores.extend(probs[:,0].tolist())
            #

        results = []
        offset = 0

        for i,_len in enumerate(len_by_sample):
            score = float(np.mean(scores[offset:offset+_len])) if sent_lens[i]>1 else 0.
            results.append(score)
            offset += _len
        #
        return results



@evaluate.utils.file_utils.add_start_docstrings(_DESCRIPTION, _KWARGS_DESCRIPTION)
class ccl_win(evaluate.Measurement):
    """TODO: Short description of my evaluation module."""
    

    def _info(self):
        # TODO: Specifies the evaluate.EvaluationModuleInfo object
        return evaluate.MeasurementInfo(
            # This is the description that will appear on the modules page.
            module_type="measurement",
            description=_DESCRIPTION,
            citation=_CITATION,
            inputs_description=_KWARGS_DESCRIPTION,
            # This defines the format of each prediction and reference
            features=datasets.Features({
                'predictions': datasets.Value('string'),
            }),
            # Homepage of the module for documentation
            homepage="http://module.homepage",
            # Additional links to the codebase or references
            codebase_urls=["http://github.com/path/to/codebase/of/new_module"],
            reference_urls=["http://path.to.reference.url/new_module"]
        )

    def _download_and_prepare(self, dl_manager):
        """Optional: download external resources useful to compute the scores"""
        # TODO: Download external resources if needed
        pass




    def _compute(self, predictions, dataset="arxiv", batch_size: int = 16, device=None, use_aggregator=True):
        """Returns the scores"""
        hashcode = dataset
        with filter_logging_context():
            if not hasattr(self, "cached_scorer") or self.cached_scorer.hash != hashcode:
                self.cached_scorer = Scorer(
                    model_type=dataset,
                    batch_size=batch_size,
                    device=device,
                )
        results = self.cached_scorer.score(predictions)
        outres = {}

        aggregator = None
        if use_aggregator:
            np.random.seed(42)
            aggregator = scoring.BootstrapAggregator()
            for score in results:
                aggregator.add_scores({"loc_coh_ccl": score})
            #

            res = aggregator.aggregate()
            for k in res:   outres[k] = res[k].mid
        else:
            outres = {"loc_coh_ccl": results}
        return outres