import os
import json
import os
from tqdm import tqdm
import torchaudio
from glob import glob
from collections import defaultdict

from utils.util import has_existed
from utils.io import save_audio
from utils.audio_slicer import Slicer
from preprocessors import GOLDEN_TEST_SAMPLES


def split_to_utterances(language_dir, output_dir):
    print("Splitting to utterances for {}...".format(language_dir))

    for wav_file in tqdm(glob("{}/*/*".format(language_dir))):
        # Load waveform
        singer_name, song_name = wav_file.split("/")[-2:]
        song_name = song_name.split(".")[0]
        waveform, fs = torchaudio.load(wav_file)

        # Split
        slicer = Slicer(sr=fs, threshold=-30.0, max_sil_kept=3000)
        chunks = slicer.slice(waveform)

        for i, chunk in enumerate(chunks):
            save_dir = os.path.join(output_dir, singer_name, song_name)
            os.makedirs(save_dir, exist_ok=True)

            output_file = os.path.join(save_dir, "{:04d}.wav".format(i))
            save_audio(output_file, chunk, fs)


def _main(dataset_path):
    """
    Split to utterances
    """
    utterance_dir = os.path.join(dataset_path, "utterances")

    for lang in ["chinese", "western"]:
        split_to_utterances(os.path.join(dataset_path, lang), utterance_dir)


def get_test_songs():
    golden_samples = GOLDEN_TEST_SAMPLES["opera"]
    # every item is a tuple (singer, song)
    golden_songs = [s.split("#")[:2] for s in golden_samples]
    # singer#song, eg:fem_01#neg_01
    return golden_songs


def opera_statistics(data_dir):
    singers = []
    songs = []
    singers2songs = defaultdict(lambda: defaultdict(list))

    singer_infos = glob(data_dir + "/*")

    for singer_info in singer_infos:
        singer = singer_info.split("/")[-1]

        song_infos = glob(singer_info + "/*")

        for song_info in song_infos:
            song = song_info.split("/")[-1]

            singers.append(singer)
            songs.append(song)

            utts = glob(song_info + "/*.wav")

            for utt in utts:
                uid = utt.split("/")[-1].split(".")[0]
                singers2songs[singer][song].append(uid)

    unique_singers = list(set(singers))
    unique_songs = list(set(songs))
    unique_singers.sort()
    unique_songs.sort()

    print(
        "opera: {} singers, {} utterances ({} unique songs)".format(
            len(unique_singers), len(songs), len(unique_songs)
        )
    )
    print("Singers: \n{}".format("\t".join(unique_singers)))
    return singers2songs, unique_singers


def main(output_path, dataset_path):
    print("-" * 10)
    print("Preparing test samples for opera...\n")

    if not os.path.exists(os.path.join(dataset_path, "utterances")):
        print("Spliting into utterances...\n")
        _main(dataset_path)

    save_dir = os.path.join(output_path, "opera")
    os.makedirs(save_dir, exist_ok=True)
    train_output_file = os.path.join(save_dir, "train.json")
    test_output_file = os.path.join(save_dir, "test.json")
    singer_dict_file = os.path.join(save_dir, "singers.json")
    utt2singer_file = os.path.join(save_dir, "utt2singer")
    if (
        has_existed(train_output_file)
        and has_existed(test_output_file)
        and has_existed(singer_dict_file)
        and has_existed(utt2singer_file)
    ):
        return
    utt2singer = open(utt2singer_file, "w")

    # Load
    opera_path = os.path.join(dataset_path, "utterances")

    singers2songs, unique_singers = opera_statistics(opera_path)
    test_songs = get_test_songs()

    # We select songs of standard samples as test songs
    train = []
    test = []

    train_index_count = 0
    test_index_count = 0

    train_total_duration = 0
    test_total_duration = 0

    for singer, songs in tqdm(singers2songs.items()):
        song_names = list(songs.keys())

        for chosen_song in song_names:
            for chosen_uid in songs[chosen_song]:
                res = {
                    "Dataset": "opera",
                    "Singer": singer,
                    "Uid": "{}#{}#{}".format(singer, chosen_song, chosen_uid),
                }
                res["Path"] = "{}/{}/{}.wav".format(singer, chosen_song, chosen_uid)
                res["Path"] = os.path.join(opera_path, res["Path"])
                assert os.path.exists(res["Path"])

                waveform, sample_rate = torchaudio.load(res["Path"])
                duration = waveform.size(-1) / sample_rate
                res["Duration"] = duration

                if duration <= 1e-8:
                    continue

                if ([singer, chosen_song]) in test_songs:
                    res["index"] = test_index_count
                    test_total_duration += duration
                    test.append(res)
                    test_index_count += 1
                else:
                    res["index"] = train_index_count
                    train_total_duration += duration
                    train.append(res)
                    train_index_count += 1

                utt2singer.write("{}\t{}\n".format(res["Uid"], res["Singer"]))

    print("#Train = {}, #Test = {}".format(len(train), len(test)))
    print(
        "#Train hours= {}, #Test hours= {}".format(
            train_total_duration / 3600, test_total_duration / 3600
        )
    )

    # Save train.json and test.json
    with open(train_output_file, "w") as f:
        json.dump(train, f, indent=4, ensure_ascii=False)
    with open(test_output_file, "w") as f:
        json.dump(test, f, indent=4, ensure_ascii=False)

    # Save singers.json
    singer_lut = {name: i for i, name in enumerate(unique_singers)}
    with open(singer_dict_file, "w") as f:
        json.dump(singer_lut, f, indent=4, ensure_ascii=False)
