"""Common S3 DDEX helper functions."""
import json

import boto3
from ddex_ingester_common.schemas.state_machine_schema import TrackSchema


def load_ddex_json(event):
    """Get DDEX JSON data from S3 file.

    Args:
        event (event): Event received by lambdas
    Returns:
        json
    """
    bucket = event.get('bucket')
    key = event.get('key')
    s3_client = boto3.client('s3')

    split_key = f"{key.rsplit('/', 1)[0]}/"
    json_file_path = f'{split_key}parsed_ddex.json'

    ddex_json_data = s3_client.get_object(
        Bucket=bucket,
        Key=json_file_path
    )['Body'].read().decode('utf-8')
    return json.loads(ddex_json_data)


def get_s3_track(parsed_ddex, context_track):
    """Get S3 track with the same ISRC as a given context track.

    Args:
        parsed_ddex (object): S3 DDEX object
        context_track (Context Track): Track with ISRC to match
    Returns:
        S3 Track
    """
    for s3_track in parsed_ddex.tracks:
        if context_track.isrc == s3_track.isrc:
            return s3_track

    raise Exception('No matching S3 track for context track: '
                    f'{TrackSchema().dump(context_track)}')