"""Snowflake connector class for Dynamo sync tasks."""

from snowflake_connector.etl_connector import SnowflakeSQLExecutor
from snowflake_connector.etl_connector import SQLLoader

sql_loader = SQLLoader(__file__)


class SnowflakeSyncExecutor(SnowflakeSQLExecutor):
    """Helper class for sync data queries."""

    def unload_to_s3(
            self, model_type, s3_path, sync_from_date, full_refresh, aws):
        """Unload required data to S3.

        This method uses `COPY INTO` SQL statement for uploading data to S3.
        The query for selecting of data is based on passed model type.

        Args:
             model_type (str): One of the acceptable model types.
             sync_from_date (str): We're looking for any changes after
                this date.
             full_refresh (bool): The flag whether the run is incremental or
                the full refresh.
             s3_path (str): S3 path for data uploading.
             aws (dict): AWS credentials.

        """
        data_query_template = sql_loader.load_query(model_type)
        data_query_params = {
            'db': self.sf_config['db'],
            'schema': self.sf_config['schema']}
        data_sql, _ = (
            self.validator.format_identifiers(
                data_query_template, data_query_params))
        unload_template = sql_loader.load_query('unload_to_s3')
        params = {
            's3_path': s3_path,
            'aws_key_id': aws['access_key'],
            'aws_secret_key': aws['access_secret'],
            'full_refresh': full_refresh,
            'sync_from_date': sync_from_date}
        unload_data_sql = unload_template.format(select_query=data_sql)
        self.execute(unload_data_sql, params=params)