"""This lambda responds for audio transcoding."""
import os
import boto3

transcoder_client = boto3.client('elastictranscoder')


def create_aws_filename(folder, key, extension):
    """Create path for file on s3.

    Args:
        key: (str): Path to file on S3.
        folder: (str): New folder path.
        extension: (str): New extension.
    """
    filename = os.path.basename(key).split('.')[0]
    aws_filename = os.path.join(
        folder, filename + extension
    )
    return aws_filename


def create_job(key, pipeline_id):
    """Create ElasticTranscoder Job.

    Args:
        key: (str): Path to file on S3.
        pipeline_id: (str): Pipeline arn.
    """
    output = transcoder_client.create_job(
        PipelineId=pipeline_id,
        Input={
            'Key': key,
            'FrameRate': 'auto',
            'Resolution': 'auto',
            'AspectRatio': 'auto',
            'Interlaced': 'auto',
            'Container': 'auto'
        },
        Outputs=[{
            'Key': create_aws_filename('audio/mp3_320', key, '.mp3'),
            'PresetId': '1351620000001-100110',
        },
            {
                'Key': create_aws_filename('audio/mp3_128', key, '.mp3'),
                'PresetId': '1351620000001-300040',
            }],
        UserMetadata={
            'extension': 'mp3',
            'input_key': key,
            '320k': '1351620000001-100110',
            '128k': '1351620000001-300040'
        }
    )
    return output


def handler(event, context):
    """Lambda handler.

    Args:
        event: (dict): Information about uploaded file.
        context: (dict): Environment state.
    Returns:
        dict: Dict with transcoding results.
    """
    key = event['key']
    try:
        pipeline_id = os.environ.get('PIPELINE_ID')
        result_job = create_job(key, pipeline_id)
    except Exception as e:
        print("Can't create transcoding job.")
        return {'status': 'Error', 'message': str(e.args)}
    return {'status': result_job['Status'], 'message': ''}