import csv
import os
import datasets
import pandas as pd

# Metadata

_DESCRIPTION = """\

Mumospee is a continuously growing, comprehensive, multilingual dataset across different modalities. 
This is the small version include no more 1000 rows.

"""

_LICENSE = "Creative Commons Attribution 4.0 International"

_LANGUAGES = ["en", "bg", "de", "ar"] 

_TAGS = ["CoVoST", "GigaSpeech", "peoples_speech", "Librispeech", "LibriTTS", "Emilia", "MOSEL"]

_SPLITS = ["train", "validation", "test"]

# BuilderConfig class for your dataset
class MumospeeDatasetConfig(datasets.BuilderConfig):
    def __init__(self, split, language=None, tag=None, **kwargs):
        super().__init__(**kwargs)
        self.split=split
        self.language = language
        self.tag = tag
    




class MumospeeDataset(datasets.GeneratorBasedBuilder):

    VERSION = datasets.Version("1.0.0")

    # Define the available configurations (could be subsets like split or language)
    BUILDER_CONFIGS = [
        MumospeeDatasetConfig(
            name="default",
            version=datasets.Version("1.0.0"),
            description=_DESCRIPTION,
            split="train",
            language=None,
            tag=None
            )
        ]
    DEFAULT_CONFIG_NAME = "default"

    def _info(self):
        # Define the features of your dataset
        features = datasets.Features({
            "path": datasets.Value("string"),
            "url": datasets.Value("string"),
            "type": datasets.Value("string"),
            "duration": datasets.Value("string"),
            "language": datasets.Value("string"),
            "transcript": datasets.Value("string"),
            "tag": datasets.Value("string"),
            "split": datasets.Value("string"),
            "license": datasets.Value("string")
        })
        return datasets.DatasetInfo(
            description=_DESCRIPTION,
            features=features,
            license=_LICENSE,
        )
    
    def _adapt_args(self, arg, accepted_arg):
        """
        Adpat the input and make sure it outs as list 
        and all the elements within the list are accpeted.
        """

        if arg and isinstance(arg, str):
            adapted_arg = [arg]
            for aa in adapted_arg:
                if aa not in accepted_arg:
                    raise ValueError(f"Invalid input: '{aa}'. Accepted values are: {', '.join(accepted_arg)}.")
        else:
            adapted_arg = arg
        

        return adapted_arg
    


    def _split_generators(self, dl_manager):
        """Split the dataset into train, validation, and test."""
        # Your dataset might have specific splits like "train", "dev", "test"
        splits = ["train", "validation", "test"]

        csv_path = dl_manager.download_and_extract("dataset.csv")


        # ===To download the url
        # Load CSV to retrieve URLs for audio files
        # data = pd.read_csv(csv_path)
        # url_list = data["url"].tolist()  # List of all URLs in the CSV file
        # url_list = list(set(url_list))

        # # Download all files listed in the 'url' column and store the local paths
        # downloaded_files = dl_manager.download(url_list)

        # # Add the downloaded file paths to the DataFrame to make them accessible in `_generate_examples`
        # data["local_path"] = downloaded_files

        #===




        # Define the splits and pass the language and tag filters to _generate_examples
        return [
            datasets.SplitGenerator(
                name=datasets.Split.TRAIN,
                gen_kwargs={"filepath": csv_path}
            ),
            datasets.SplitGenerator(
                name=datasets.Split.VALIDATION,
                gen_kwargs={"filepath": csv_path}
            ),
            datasets.SplitGenerator(
                name=datasets.Split.TEST,
                gen_kwargs={"filepath": csv_path}
            ),
        ]


    def _generate_examples(self, filepath):

        data = pd.read_csv(filepath)
        split = self.config.split
      
        language = self.config.language
        tag = self.config.tag

        print(f'Return {split} dataset in langauge of {language}, originally from {tag}.')

        data_split = data[data["split"] == split]

        language_list = self._adapt_args(language, _LANGUAGES)
        tag_list = self._adapt_args(tag, _TAGS)


        if language_list:
            data_split = data_split[data_split["language"].isin(language_list)]
        if tag_list:
            data_split = data_split[data_split["tag"].isin(tag_list)]

        
        if data_split.empty:
            print(f"No data found for split='{split}', language='{language}', tag='{tag}'. Returning None.")
            return  # This exits the generator without yielding any examples

        else:

            for i, row in data_split.iterrows():
                yield i, {
                    "path": row["path"],
                    #"local_path": row["local_path"],
                    "url": row["url"],
                    "type": row["type"],
                    "duration": float(row["duration"]),
                    "language": row["language"],
                    "transcript": row["transcript"],
                    "tag": row["tag"],
                    "split": row["split"],
                    "license": row["license"]
                }



    def _download_audio(self, audio_url):
        """Download audio from a URL if needed (you could also implement streaming)."""
        # This is an example function for downloading audio if it's needed
        # You can integrate this within your data processing pipeline if required
        pass