import os
import random
import hashlib
import datasets
import pandas as pd
from datasets.tasks import AudioClassification


_SYSTEM_TONIC = [
    "C",
    "#C/bD",
    "D",
    "#D/bE",
    "E",
    "F",
    "#F/bG",
    "G",
    "#G/bA",
    "A",
    "#A/bB",
    "B",
]

_PATTERN = [
    "Gong",
    "Shang",
    "Jue",
    "Zhi",
    "Yu",
]

_TYPE = [
    "Pentatonic",
    "Hexatonic_Qingjue",
    "Hexatonic_Biangong",
    "Heptatonic_Yayue",
    "Heptatonic_Qingyue",
    "Heptatonic_Yanyue",
]

_HOMEPAGE = f"https://www.modelscope.cn/datasets/ccmusic-database/{os.path.basename(__file__)[:-3]}"

_DOMAIN = f"{_HOMEPAGE}/resolve/master/data"

_URLS = {
    "audio": f"{_DOMAIN}/audio.zip",
    "mel": f"{_DOMAIN}/mel.zip",
    "label": f"{_DOMAIN}/label.csv",
}


class CNPM(datasets.GeneratorBasedBuilder):
    def _info(self):
        return datasets.DatasetInfo(
            features=datasets.Features(
                {
                    "audio": datasets.Audio(sampling_rate=44100),
                    "mel": datasets.Image(),
                    "title": datasets.Value("string"),
                    "artist": datasets.Value("string"),
                    "system": datasets.features.ClassLabel(names=_SYSTEM_TONIC),
                    "tonic": datasets.features.ClassLabel(names=_SYSTEM_TONIC),
                    "pattern": datasets.features.ClassLabel(names=_PATTERN),
                    "type": datasets.features.ClassLabel(names=_TYPE),
                    "mode_name": datasets.Value("string"),
                    "length": datasets.Value("string"),
                }
            ),
            supervised_keys=("audio", "type"),
            homepage=_HOMEPAGE,
            license="CC-BY-NC-ND",
            version="1.2.0",
            task_templates=[
                AudioClassification(
                    task="audio-classification",
                    audio_column="audio",
                    label_column="type",
                )
            ],
        )

    def _str2md5(self, original_string: str):
        md5_obj = hashlib.md5()
        md5_obj.update(original_string.encode("utf-8"))
        return md5_obj.hexdigest()

    def _val_of_key(self, labels: pd.DataFrame, key: str, col: str):
        try:
            return labels.loc[key][col]

        except KeyError:
            return ""

    def _split_generators(self, dl_manager):
        audio_files = dl_manager.download_and_extract(_URLS["audio"])
        mel_files = dl_manager.download_and_extract(_URLS["mel"])
        label_file = dl_manager.download(_URLS["label"])
        labels = pd.read_csv(label_file, index_col="文件名/File Name", encoding="gbk")
        files = {}
        for fpath in dl_manager.iter_files([audio_files]):
            fname: str = os.path.basename(fpath)
            if fname.endswith(".wav") or fname.endswith(".mp3"):
                song_id = self._str2md5(fname.split(".")[0])
                files[song_id] = {"audio": fpath}

        for fpath in dl_manager.iter_files([mel_files]):
            fname = os.path.basename(fpath)
            if fname.endswith(".png"):
                song_id = self._str2md5(fname.split(".")[0])
                files[song_id]["mel"] = fpath

        dataset = []
        for path in files.values():
            fname = os.path.basename(path["audio"])
            dataset.append(
                {
                    "audio": path["audio"],
                    "mel": path["mel"],
                    "title": self._val_of_key(labels, fname, "曲名/Title"),
                    "artist": self._val_of_key(labels, fname, "演奏者/Artist"),
                    "system": _SYSTEM_TONIC[
                        int(self._val_of_key(labels, fname, "同宫系统/System"))
                    ],
                    "tonic": _SYSTEM_TONIC[
                        int(self._val_of_key(labels, fname, "主音音名/Tonic"))
                    ],
                    "pattern": _PATTERN[
                        int(self._val_of_key(labels, fname, "样式/Pattern"))
                    ],
                    "type": _TYPE[int(self._val_of_key(labels, fname, "种类/Type"))],
                    "mode_name": self._val_of_key(labels, fname, "调式全称/Mode Name"),
                    "length": self._val_of_key(labels, fname, "时长/Length"),
                }
            )

        random.shuffle(dataset)
        return [
            datasets.SplitGenerator(
                name=datasets.Split.TRAIN,
                gen_kwargs={"files": dataset},
            ),
        ]

    def _generate_examples(self, files):
        for i, item in enumerate(files):
            yield i, item