from torch.utils.data import Dataset
import torch.nn.functional as F
import torch
import torchaudio
import os
import random
import torchaudio.transforms as T
import AudioUtils

class AudioDataset(Dataset):
    audio_sample_rates = [11025]
    MAX_LENGTH = 44100  # Define your desired maximum length here

    def __init__(self, input_dir, device):
        self.input_files = [os.path.join(root, f) for root, _, files in os.walk(input_dir) for f in files if f.endswith('.wav')]
        self.device = device

    def __len__(self):
        return len(self.input_files)

    def __getitem__(self, idx):
        # Load high-quality audio
        high_quality_audio, original_sample_rate = torchaudio.load(self.input_files[idx], normalize=True)

        # Generate low-quality audio with random downsampling
        mangled_sample_rate = random.choice(self.audio_sample_rates)
        resample_transform_low = torchaudio.transforms.Resample(original_sample_rate, mangled_sample_rate)
        low_quality_audio = resample_transform_low(high_quality_audio)

        resample_transform_high = torchaudio.transforms.Resample(mangled_sample_rate, original_sample_rate)
        low_quality_audio = resample_transform_high(low_quality_audio)

        high_quality_audio = AudioUtils.stereo_tensor_to_mono(high_quality_audio)
        low_quality_audio = AudioUtils.stereo_tensor_to_mono(low_quality_audio)

        # Pad or truncate high-quality audio
        if high_quality_audio.shape[1] < self.MAX_LENGTH:
            padding = self.MAX_LENGTH - high_quality_audio.shape[1]
            high_quality_audio = F.pad(high_quality_audio, (0, padding))
        elif high_quality_audio.shape[1] > self.MAX_LENGTH:
            high_quality_audio = high_quality_audio[:, :self.MAX_LENGTH]

        # Pad or truncate low-quality audio
        if low_quality_audio.shape[1] < self.MAX_LENGTH:
            padding = self.MAX_LENGTH - low_quality_audio.shape[1]
            low_quality_audio = F.pad(low_quality_audio, (0, padding))
        elif low_quality_audio.shape[1] > self.MAX_LENGTH:
            low_quality_audio = low_quality_audio[:, :self.MAX_LENGTH]

        high_quality_audio = high_quality_audio.to(self.device)
        low_quality_audio = low_quality_audio.to(self.device)

        return (high_quality_audio, original_sample_rate), (low_quality_audio, mangled_sample_rate)