"""Image validation lambda function module."""

import config
from src import image_validator
from src.common import buffers_utils
from src.common import lambda_exceptions
from src.common import s3
from src.common import status
from src.common import util
from src.common.constants import errors
from src.constants import general


def _log_error(err, filename, bucket):
    status.send_general_status(
        function=config.LAMBDA_NAME,
        status_name=general.IMAGE_VALIDATION_ERROR_STATUS,
        filename=filename,
        bucket=bucket,
        errors=err)


def handler(event, context):
    """Lambda entry point."""
    try:
        buffers = None
        bucket, key, asset_config, file_type = util.extract_event(event)

        input_params = {
            'key': key,
            'bucket': bucket,
            'file_type': file_type,
            'transcoding_type': event.get('transcoding_type'),
            'config': asset_config
        }

        buffers = buffers_utils.allocate_buffers(1)
        buffer = buffers[0]
        buffer = s3.download_file_object(bucket, key, buffer)
        buffers[0] = buffer
        image_validator.validate_image(buffer)

        status.send_general_status(
            function=config.LAMBDA_NAME,
            status_name=general.IMAGE_VALIDATION_COMPLETE_STATUS,
            filename=key,
            bucket=bucket)

        return input_params

    except lambda_exceptions.LambdaStatusError as error:
        config.logger.exception(str(error))
        # if this is a malformed event but we have the key, we can send the error to the microserivce.
        # if the key is missing, then we cant post the status
        if 'key' in event:
            _log_error(error.errors, event.get('key'), event.get('bucket', None))
        raise

    except lambda_exceptions.LambdaError as error:
        config.logger.exception(str(error))
        raise

    except Exception as error:
        config.logger.exception(str(error))
        e = dict()
        e[errors.IMAGE_VALIDATION_ERROR_CODE] = errors.ERROR_MESSAGES[errors.IMAGE_VALIDATION_ERROR_CODE].format(
            message=str(error))
        _log_error(e, key, bucket)
        raise
    finally:
        if buffers:
            buffers_utils.release_allocated_buffers(buffers)