import os
from collections import Counter

import numpy as np
import soundfile as sf
from datasets import load_dataset

dataset = load_dataset(
    "parquet",
    data_files={
        "train": [
            "data/test-00000-of-00017.parquet",
            "data/test-00001-of-00017.parquet",
            "data/test-00002-of-00017.parquet",
            "data/test-00003-of-00017.parquet",
            "data/test-00004-of-00017.parquet",
            "data/test-00005-of-00017.parquet",
            "data/test-00006-of-00017.parquet",
            "data/test-00007-of-00017.parquet",
            "data/test-00008-of-00017.parquet",
            "data/test-00009-of-00017.parquet",
            "data/test-00010-of-00017.parquet",
            "data/test-00011-of-00017.parquet",
            "data/test-00012-of-00017.parquet",
            "data/test-00013-of-00017.parquet",
            "data/test-00014-of-00017.parquet",
            "data/test-00015-of-00017.parquet",
            "data/test-00016-of-00017.parquet",
        ]
    }
)

MAX_DURATION = 60.0
MAX_SPEAKERS = 4


def crop_longest_60s(example):
    starts = example["timestamps_start"]
    ends = example["timestamps_end"]
    speakers = example["speakers"]
    n = len(starts)

    best_left, best_right, best_dur = 0, 0, 0
    left = 0
    spk_count = Counter()
    for right in range(n):
        spk_count[speakers[right]] += 1
        while left <= right and (ends[right] - starts[left] > MAX_DURATION or len(spk_count) > MAX_SPEAKERS):
            spk_count[speakers[left]] -= 1
            if spk_count[speakers[left]] == 0:
                del spk_count[speakers[left]]
            left += 1
        if left > right:
            continue
        dur = ends[right] - starts[left]
        if dur > best_dur:
            best_dur = dur
            best_left, best_right = left, right

    sr = example["audio"]["sampling_rate"]
    start_sample = int(starts[best_left] * sr)
    end_sample = int(ends[best_right] * sr)
    offset = starts[best_left]

    example["audio"]["array"] = example["audio"]["array"][start_sample:end_sample]
    example["timestamps_start"] = [t - offset for t in starts[best_left:best_right + 1]]
    example["timestamps_end"] = [t - offset for t in ends[best_left:best_right + 1]]
    example["speakers"] = example["speakers"][best_left:best_right + 1]
    return example


filenames = [os.path.basename(example["audio"]["path"]) for example in dataset["train"]]

dataset["train"] = dataset["train"].map(crop_longest_60s)

os.makedirs("wavs", exist_ok=True)
for i, example in enumerate(dataset["train"]):
    audio = example["audio"]
    filename = filenames[i]
    duration = len(audio["array"]) / audio["sampling_rate"]
    sf.write(f"wavs/{filename}", np.array(audio["array"]), audio["sampling_rate"])
    num_speakers = len(set(example["speakers"]))
    print(f"[{i + 1}/16] Saved wavs/{filename}, duration: {duration:.2f}s, segments: {len(example['timestamps_start'])}, speakers: {num_speakers}")