# coding=utf-8

"""VoxCeleb dataset."""


import os
from typing import List
from pathlib import Path

import librosa
import datasets
from rich import print


DATA_DIR_STRUCTURE = """
test/
└── wav
    ├── id10270
    ...
    └── id10309
        ├── A3ZvNuG8_oM
        ...
        └── UbApEUoPvzY
            ├── 00001.wav
            ...
            └── 00005.wav
"""

SAMPLING_RATE = 16_000


class VoxCelebConfig(datasets.BuilderConfig):
    """BuilderConfig for VoxCeleb."""
    
    def __init__(self, features, **kwargs):
        super(VoxCelebConfig, self).__init__(version=datasets.Version("0.0.1", ""), **kwargs)
        self.features = features


class VoxCeleb(datasets.GeneratorBasedBuilder):

    BUILDER_CONFIGS = [
        VoxCelebConfig(
            features=datasets.Features(
                {
                    "audio": datasets.Audio(sampling_rate=SAMPLING_RATE),
                    "speaker": datasets.Value("string"), 
                    # "duration": datasets.Value("int32"), 
                }
            ),
            name="verification", 
            description="",
        ), 
    ]

    DEFAULT_CONFIG_NAME = "verification"

    def _info(self):
        return datasets.DatasetInfo(
            description="VoxCeleb for verification",
            features=self.config.features,
        )

    @property
    def manual_download_instructions(self):
        return (
            "To use VoxCeleb you have to download it manually. "
            "The tree structure of the downloaded data looks like: \n"
            f"{DATA_DIR_STRUCTURE}"
        )

    def _split_generators(self, dl_manager):

        data_dir = os.path.abspath(os.path.expanduser(dl_manager.manual_dir))

        if not os.path.exists(data_dir):
            raise FileNotFoundError(
                f"{data_dir} does not exist. "
                f"Manual download instructions: \n{self.manual_download_instructions}"
            )

        dev_archive_path = os.path.join(data_dir, 'dev', 'wav')
        test_archive_path = os.path.join(data_dir, 'test', 'wav')

        for path in [dev_archive_path, test_archive_path]:
            if not os.path.isdir(path):
                raise FileExistsError(f"{path} does not exist. Make sure you have converted m4a to wav format.")

        return [
            datasets.SplitGenerator(name=datasets.Split.TRAIN, gen_kwargs={"split": "train", "archive_path": dev_archive_path}),
            datasets.SplitGenerator(name=datasets.Split.TEST, gen_kwargs={"split": "test", "archive_path": test_archive_path}),
        ]

    def _generate_examples(self, split, archive_path):
        """Generate examples from VoxCeleb"""
        # Iterating the contents of the data to extract the relevant information
        extensions = ['.wav']

        _, wav_paths = fast_scandir(archive_path, extensions, recursive=True)

        for guid, wav_path in enumerate(wav_paths):
            fileid = Path(wav_path).name
            speaker = Path(wav_path).parent.parent.name
            # duration = librosa.get_duration(path=wav_path)
            # if duration <= 0:
            #     continue
            try:
                yield guid, {
                    "id": str(guid),
                    "audio": wav_path, 
                    "speaker": speaker, 
                    # "duration": duration
                }
            except:
                continue


def fast_scandir(path: str, extensions: List[str], recursive: bool = False):
    # Scan files recursively faster than glob
    # From github.com/drscotthawley/aeiou/blob/main/aeiou/core.py
    subfolders, files = [], []

    try: # hope to avoid 'permission denied' by this try
        for f in os.scandir(path):
            try:  # 'hope to avoid too many levels of symbolic links' error
                if f.is_dir():
                    subfolders.append(f.path)
                elif f.is_file():
                    if os.path.splitext(f.name)[1].lower() in extensions:
                        files.append(f.path)
            except Exception:
                pass
    except Exception:
        pass

    if recursive:
        for path in list(subfolders):
            sf, f = fast_scandir(path, extensions, recursive=recursive)
            subfolders.extend(sf)
            files.extend(f)  # type: ignore

    return subfolders, files