"""
Copyright (c) Contributors to the Open 3D Engine Project.
For complete copyright and license terms please see the LICENSE at the root of this distribution.

SPDX-License-Identifier: Apache-2.0 OR MIT
"""

from constructs import Construct
from aws_cdk import (
    CfnOutput,
    Fn,
    aws_apigateway as apigateway,
    aws_iam as iam,
    aws_kinesis as kinesis
)

import json

from . import aws_metrics_constants
from .aws_utils import resource_name_sanitizer


class DataIngestion:
    """
    Create the service API via APIGateway and Kinesis data stream to ingest metrics events.
    """

    def __init__(self, stack: Construct, application_name: str) -> None:
        self._stack = stack

        # create the input Kinesis stream
        self._input_stream = kinesis.Stream(
            self._stack,
            id='InputStream',
            stream_name=resource_name_sanitizer.sanitize_resource_name(
                f'{self._stack.stack_name}-InputStream', 'kinesis_stream'),
            shard_count=1
        )

        apigateway_role = self._create_apigateway_role()

        # create the REST API resource
        self._rest_api = apigateway.SpecRestApi(
            self._stack,
            'RestApi',
            rest_api_name=f'{self._stack.stack_name}-RestApi',
            endpoint_export_name=f'{application_name}:RestApiEndpoint',
            api_definition=apigateway.ApiDefinition.from_asset('api_spec.json'),
            deploy_options=apigateway.StageOptions(
                method_options={
                    "/*/*": apigateway.MethodDeploymentOptions(
                        metrics_enabled=True,
                        logging_level=apigateway.MethodLoggingLevel.INFO
                    )
                },
                stage_name=aws_metrics_constants.APIGATEWAY_STAGE
            )
        )

        # read api_spec.json and replace the template variables
        with open("api_spec.json", "r") as api_spec:
            content = api_spec.read()
        content = content.replace("${ApiGatewayRoleArn}", apigateway_role.role_arn)
        content = content.replace("${InputStreamName}", self._input_stream.stream_name)
        api_definition = json.loads(content)

        # use escape hatches to override the API definitions with the actual resource information
        # https://docs.aws.amazon.com/cdk/latest/guide/cfn_layer.html
        cfn_rest_api = self._rest_api.node.default_child
        cfn_rest_api.add_property_override("Body", api_definition)
        cfn_rest_api.add_property_deletion_override("BodyS3Location")
        cfn_rest_api.add_property_override("FailOnWarnings", True)

        CfnOutput(
            self._stack,
            id='RESTApiId',
            description='Service API Id for the analytics pipeline',
            export_name=f"{application_name}:RestApiId",
            value=self._rest_api.rest_api_id)

        CfnOutput(
            self._stack,
            id='RESTApiStage',
            description='Stage for the REST API deployment',
            export_name=f"{application_name}:DeploymentStage",
            value=self._rest_api.deployment_stage.stage_name)

    def _create_apigateway_role(self) -> iam.Role:
        """
        Generate the IAM role for the REST API to integration with Kinesis.

        :return: The created IAM role.
        """
        api_gateway_put_kinesis_policy_document = iam.PolicyDocument(
            statements=[
                iam.PolicyStatement(
                    actions=[
                        "kinesis:PutRecord",
                        "kinesis:PutRecords"
                    ],
                    effect=iam.Effect.ALLOW,
                    resources=[
                        Fn.sub(
                            body="arn:${AWS::Partition}:kinesis:${AWS::Region}:${AWS::AccountId}:stream/${EventsStream}",
                            variables={
                                "EventsStream": self._input_stream.stream_name
                            }
                        )
                    ]
                )
            ]
        )

        apigateway_role = iam.Role(
            self._stack,
            id=f'{self._stack.stack_name}-ApiGatewayRole',
            assumed_by=iam.ServicePrincipal(
                service="apigateway.amazonaws.com"
            ),
            inline_policies={
                "ApiGatewayPutKinesisPolicy": api_gateway_put_kinesis_policy_document
            }
        )

        return apigateway_role

    @property
    def input_stream_arn(self) -> kinesis.Stream.stream_arn:
        return self._input_stream.stream_arn

    @property
    def input_stream_name(self) -> kinesis.Stream.stream_name:
        return self._input_stream.stream_name

    @property
    def rest_api_id(self) -> apigateway.RestApi.rest_api_id:
        return self._rest_api.rest_api_id

    @property
    def deployment_stage(self) -> str:
        return aws_metrics_constants.APIGATEWAY_STAGE

    @property
    def execute_api_arn(self) -> apigateway.RestApi.arn_for_execute_api:
        return self._rest_api.arn_for_execute_api(stage=aws_metrics_constants.APIGATEWAY_STAGE)