"""
All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
its licensors.

For complete copyright and license terms please see the LICENSE at the root of this
distribution (the "License"). All use of this software is governed by the License,
or, if provided, by the license below or the license accompanying this file. Do not
remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
"""

from aws_cdk import (
    core,
    aws_athena as athena
)

from . import aws_metrics_constants


class BatchAnalytics:
    """
    Query the metrics stored in the S3 data lake via Amazon Athena
    """
    def __init__(self,
                 stack: core.Construct,
                 analytics_bucket_name: str,
                 events_database_name: str,
                 events_table_name) -> None:
        self._stack = stack
        self._analytics_bucket_name = analytics_bucket_name
        self._events_database_name = events_database_name
        self._events_table_name = events_table_name

        self._create_athena_work_group()
        self._create_athena_queries()

    def _create_athena_work_group(self) -> None:
        """
        Create a specific athena work group for access control.
        """
        self._athena_work_group = athena.CfnWorkGroup(
            self._stack,
            id='AthenaWorkGroup',
            name=f'{self._stack.stack_name}-AthenaWorkGroup',
            recursive_delete_option=True,
            state='ENABLED',
            work_group_configuration=athena.CfnWorkGroup.WorkGroupConfigurationProperty(
                publish_cloud_watch_metrics_enabled=True,
                result_configuration=athena.CfnWorkGroup.ResultConfigurationProperty(
                    encryption_configuration=athena.CfnWorkGroup.EncryptionConfigurationProperty(
                        encryption_option='SSE_S3'
                    ),
                    output_location=core.Fn.sub(
                        body='s3://${AnalyticsBucket}/${AthenaOutputDirectory}/',
                        variables={
                            'AnalyticsBucket': self._analytics_bucket_name,
                            'AthenaOutputDirectory': aws_metrics_constants.ATHENA_OUTPUT_DIRECTORY
                        }
                    )
                )
            )
        )

    def _create_athena_queries(self) -> None:
        """
        Create several example queries for reference.
        """
        self._named_queries = [
            athena.CfnNamedQuery(
                self._stack,
                id='NamedQuery-CreatePartitionedEventsJson',
                name=f'{self._stack.stack_name}-NamedQuery-CreatePartitionedEventsJson',
                database=self._events_database_name,
                query_string="CREATE TABLE events_json "
                             "WITH (format='JSON',partitioned_by=ARRAY['application_id']) "
                             "AS SELECT year, month, day, event_id, application_id "
                             f"FROM \"{self._events_database_name}\".\"{self._events_table_name}\"",
                description='This command demonstrates how to create a new table of raw events'
                            ' transformed to JSON format. Output is partitioned by Application',
                work_group=self._athena_work_group.name
            ),
            athena.CfnNamedQuery(
                self._stack,
                id='NamedQuery-TotalEventsLastMonth',
                name=f'{self._stack.stack_name}-NamedQuery-TotalEventsLastMonth',
                database=self._events_database_name,
                query_string="WITH detail AS "
                             "(SELECT date_trunc('month', date(date_parse(CONCAT(year, '-', month, '-', day), '%Y-%m-%d'))) as event_month, * "
                             f"FROM \"{self._events_database_name}\".\"{self._events_table_name}\") "
                             "SELECT "
                             "date_trunc('month', event_month) as month, application_id, count(DISTINCT event_id) as event_count "
                             "FROM detail "
                             "GROUP BY date_trunc('month', event_month), application_id",
                description='Total events over last month',
                work_group=self._athena_work_group.name
            ),
            athena.CfnNamedQuery(
                self._stack,
                id='NamedQuery-NewUsersLastMonth',
                name=f'{self._stack.stack_name}-NamedQuery-NewUsersLastMonth',
                database=self._events_database_name,
                query_string="WITH detail AS ("
                             "SELECT date_trunc('month', date(date_parse(CONCAT(year, '-', month, '-', day), '%Y-%m-%d'))) as event_month, * "
                             f"FROM \"{self._events_database_name}\".\"{self._events_table_name}\") "
                             "SELECT "
                             "date_trunc('month', event_month) as month, "
                             "count(*) as new_accounts "
                             "FROM detail "
                             "WHERE event_name = 'user_registration' "
                             "GROUP BY date_trunc('month', event_month)",
                description='New users over the last month',
                work_group=self._athena_work_group.name
            )
        ]

    @property
    def athena_work_group_name(self) -> athena.CfnWorkGroup.name:
        return self._athena_work_group.name