"""AWS S3 related utility functions."""

import csv

from boto.exception import S3ResponseError
import boto3
from oto import response
import smart_open

from prs import config
from prs.connectors import sentry
from prs.constants import error
from prs.constants import s3
from prs.constants import tools_message


def write_csv_to_s3(s3_key, data):
    """Write data to csv file on S3.

    Args:
        s3_key (str): String of format '<tool_name>/<filename.csv>'
        data (dict): data of format
            {'columns': [id,name], 'rows': [(1, name1), (2,name2)]}
    """
    try:
        source_url = s3.FILE_URL.format(
            bucket_name=config.PRS_BUCKET_NAME, file_path=s3_key)
        with smart_open.smart_open(source_url, 'wb') as fileobj:
            writer = csv.writer(fileobj)
            writer.writerow(data['columns'])
            writer.writerows(data['rows'])
        return response.Response(
            message=tools_message.CSV_GENERATION_SUCCESS_MESSAGE)
    except S3ResponseError as ex:
        if sentry.sentry_client:
            sentry.sentry_client.captureException()
        return response.create_error_response(
            code=ex.error_code,
            message=ex.message,
            status=ex.status)
    except Exception as ex:
        if sentry.sentry_client:
            sentry.sentry_client.captureException()
        return response.create_error_response(
            code=error.ERROR_CODE_CSV_FILE_WRITE,
            message=str(ex)
        )


def get_presigned_url(s3_key):
    """Get presigned public URL for given S3 path.

    Args:
        s3_key (str): String of format '<tool_name>/<filename.csv>'

    Returns:
        url (str): Returns public URL for given S3 path
    """
    s3_client = boto3.client('s3')
    url = s3_client.generate_presigned_url(
        'get_object',
        Params={'Bucket': config.PRS_BUCKET_NAME, 'Key': s3_key},
        ExpiresIn=s3.SIGNED_URL_EXPIRATION_TIME)
    return url