"""Validate interactive inputs on CPU before reserving any GPU time."""
from pathlib import Path
MAX_FILE_BYTES = 15 * 1024 * 1024
MAX_TEXT_CHARS = 600
MAX_TRANSCRIPT_CHARS = 600


def validate_request(text, reference_path, reference_text):
    if not isinstance(text, str) or not text.strip():
        raise ValueError('Please enter the text you want to hear.')
    text = text.strip()
    if len(text) > MAX_TEXT_CHARS:
        raise ValueError('Please keep the target text to 600 characters or fewer.')
    if not reference_path:
        raise ValueError('Choose a reference voice or upload a recording.')
    if not isinstance(reference_text, str) or not reference_text.strip():
        raise ValueError('Please enter the exact words spoken in your reference recording.')
    reference_text = reference_text.strip()
    if len(reference_text) > MAX_TRANSCRIPT_CHARS:
        raise ValueError('Please keep the reference transcript to 600 characters or fewer.')
    path = Path(reference_path)
    if not path.is_file() or path.stat().st_size > MAX_FILE_BYTES:
        raise ValueError('Please upload an audio file smaller than 15 MB.')
    import soundfile as sf
    try:
        info = sf.info(path)
    except (RuntimeError, OSError):
        raise ValueError('The reference could not be read. Try a WAV, MP3 or FLAC recording.') from None
    if not (3 <= info.duration <= 15):
        raise ValueError('Please use a reference recording between 3 and 15 seconds.')
    if not (8000 <= info.samplerate <= 192000) or info.channels not in {1, 2}:
        raise ValueError('Please upload a mono or stereo recording with a standard audio sample rate.')
    return text, str(path), reference_text