# coding=utf-8

"""AudioSet sound event classification dataset."""


import os
import json
import gzip
import joblib
import shutil
import pathlib
import logging
import zipfile
import textwrap
import datasets
import requests
import itertools
import typing as tp
import pandas as pd
from pathlib import Path
from copy import deepcopy
from tqdm.auto import tqdm
from rich.logging import RichHandler

from ._audioset import ID2LABEL

logger = logging.getLogger(__name__)
logger.addHandler(RichHandler())
logger.setLevel(logging.INFO)


DATA_DIR_STRUCTURE = """
audios/
├── balanced_train_segments [20550 entries]
├── eval_segments [18887 entries]
└── unbalanced_train_segments
    ├── unbalanced_train_segments_part00 [46940 entries]
    ...
    └── unbalanced_train_segments_part40 [9844 entries]
"""

LABEL2ID = {v:k for k, v in ID2LABEL.items()}
CLASSES = list(ID2LABEL.values())


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


class AudioSet(datasets.GeneratorBasedBuilder):

    BUILDER_CONFIGS = [
        AudioSetConfig(
            features=datasets.Features(
                {
                    "file": datasets.Value("string"),
                    "audio": datasets.Audio(sampling_rate=None),
                    "sound": datasets.Sequence(datasets.Value("string")), 
                    "label": datasets.Sequence(datasets.features.ClassLabel(names=CLASSES)), 
                }
            ),
            name="20k", 
            description="",
        ), 
        AudioSetConfig(
            features=datasets.Features(
                {
                    "file": datasets.Value("string"),
                    "audio": datasets.Audio(sampling_rate=None),
                    "sound": datasets.Sequence(datasets.Value("string")), 
                    "label": datasets.Sequence(datasets.features.ClassLabel(names=CLASSES)), 
                }
            ),
            name="500k", 
            description="",
        ), 
        AudioSetConfig(
            features=datasets.Features(
                {
                    "file": datasets.Value("string"),
                    "audio": datasets.Audio(sampling_rate=None),
                    "sound": datasets.Sequence(datasets.Value("string")), 
                    "label": datasets.Sequence(datasets.features.ClassLabel(names=CLASSES)), 
                }
            ),
            name="2m", 
            description="",
        ), 
    ]

    def _info(self):
        return datasets.DatasetInfo(
            description="",
            features=self.config.features,
            supervised_keys=None,
            homepage="",
            citation="",
            task_templates=None,
        )

    @property
    def manual_download_instructions(self):
        return (
            "To use AudioSet you have to download it manually. "
            "Please download the dataset from https://huggingface.co/datasets/confit/audioset-full \n"
            "Then extract all files in one folder called `audios` and load the dataset with: "
            "`datasets.load_dataset('confit/audioset', 'balanced', data_dir='path/to/folder')`\n"
            "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. Make sure you insert a manual dir via "
                f"`datasets.load_dataset('confit/audioset', 'balanced', data_dir=...)` that includes files unzipped from all the zip files. "
                f"Manual download instructions: {self.manual_download_instructions}"
            )

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

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

        if split == 'train':
            if self.config.name == '20k':
                archive_path = os.path.join(data_dir, 'audios', 'balanced_train_segments')
                metadata_url = 'https://huggingface.co/datasets/confit/audioset/resolve/main/metadata/audioset-20k.jsonl'
            elif self.config.name == '500k':
                archive_path = os.path.join(data_dir, 'audios', 'unbalanced_train_segments')
                metadata_url = 'https://huggingface.co/datasets/confit/audioset/resolve/main/metadata/audioset-500k.jsonl'
            elif self.config.name == '2m':
                archive_path = os.path.join(data_dir, 'audios', 'unbalanced_train_segments')
                metadata_url = 'https://huggingface.co/datasets/confit/audioset/resolve/main/metadata/audioset-2m.jsonl'
        elif split == 'test':
            archive_path = os.path.join(data_dir, 'audios', 'eval_segments')
            metadata_url = 'https://huggingface.co/datasets/confit/audioset/resolve/main/metadata/audioset-eval.jsonl'

        response = requests.get(metadata_url)
        if response.status_code == 200:
            # Split the content by lines and parse each line as JSON
            # Each line is like {"filename":"YN6UbMsh-q1c.wav","label":["Vehicle","Car"]}
            data_list = [json.loads(line) for line in response.text.splitlines()]
            fileid2labels = {item['filename']:item['labels'] for item in data_list}
        else:
            logger.info(f"Failed to retrieve data: Status code {response.status_code}")
        
        _, wav_paths = fast_scandir(archive_path, extensions, recursive=True)
        wav_paths = [wav_path for wav_path in wav_paths if Path(wav_path).name in fileid2labels]

        for guid, wav_path in enumerate(wav_paths):
            fileid = Path(wav_path).name
            sound = fileid2labels.get(fileid)
            try:
                yield guid, {
                    "id": str(guid),
                    "file": wav_path, 
                    "audio": wav_path, 
                    "sound": sound, 
                    "label": sound, 
                }
            except:
                continue


def fast_scandir(path: str, extensions: tp.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