"""This module is responsible for transcoding job validation."""
import json

from trafaret import DataError

from src import trafaret_schema


class InvalidAudioError(Exception):
    """Exception for invalid audio asset."""

    def __init__(self, *, errors, metadata):
        """Initialize InvalidAudioError."""
        super().__init__(json.dumps({
            'errors': errors,
            'metadata': metadata,
        }))


def validate_audio_metadata(audio_metadata):
    """Validate audio asset metadata.

    Args:
        audio_metadata (dict): Audio metadata specification.
    Returns:
        dict: validated audio metadata.

    """
    try:
        return trafaret_schema.get_schema().check(audio_metadata)
    except DataError as trafaret_dataerror:
        raise InvalidAudioError(
            errors=trafaret_dataerror.as_dict(),
            metadata=audio_metadata,
        )