import json

from moto.core.exceptions import InvalidNextTokenException
from moto.core.models import ConfigQueryModel
from moto.s3 import s3_backends


class S3ConfigQuery(ConfigQueryModel):

    def list_config_service_resources(self, resource_ids, resource_name, limit, next_token, backend_region=None, resource_region=None):
        # S3 need not care about "backend_region" as S3 is global. The resource_region only matters for aggregated queries as you can
        # filter on bucket regions for them. For other resource types, you would need to iterate appropriately for the backend_region.

        # Resource IDs are the same as S3 bucket names
        # For aggregation -- did we get both a resource ID and a resource name?
        if resource_ids and resource_name:
            # If the values are different, then return an empty list:
            if resource_name not in resource_ids:
                return [], None

        # If no filter was passed in for resource names/ids then return them all:
        if not resource_ids and not resource_name:
            bucket_list = list(self.backends['global'].buckets.keys())

        else:
            # Match the resource name / ID:
            bucket_list = []
            filter_buckets = [resource_name] if resource_name else resource_ids

            for bucket in self.backends['global'].buckets.keys():
                if bucket in filter_buckets:
                    bucket_list.append(bucket)

        # If a resource_region was supplied (aggregated only), then filter on bucket region too:
        if resource_region:
            region_buckets = []

            for bucket in bucket_list:
                if self.backends['global'].buckets[bucket].region_name == resource_region:
                    region_buckets.append(bucket)

            bucket_list = region_buckets

        if not bucket_list:
            return [], None

        # Pagination logic:
        sorted_buckets = sorted(bucket_list)
        new_token = None

        # Get the start:
        if not next_token:
            start = 0
        else:
            # Tokens for this moto feature is just the bucket name:
            # For OTHER non-global resource types, it's the region concatenated with the resource ID.
            if next_token not in sorted_buckets:
                raise InvalidNextTokenException()

            start = sorted_buckets.index(next_token)

        # Get the list of items to collect:
        bucket_list = sorted_buckets[start:(start + limit)]

        if len(sorted_buckets) > (start + limit):
            new_token = sorted_buckets[start + limit]

        return [{'type': 'AWS::S3::Bucket', 'id': bucket, 'name': bucket, 'region': self.backends['global'].buckets[bucket].region_name}
                for bucket in bucket_list], new_token

    def get_config_resource(self, resource_id, resource_name=None, backend_region=None, resource_region=None):
        # backend_region is ignored for S3 as the backend is 'global'

        # Get the bucket:
        bucket = self.backends['global'].buckets.get(resource_id, {})

        if not bucket:
            return

        # Are we filtering based on region?
        if resource_region and bucket.region_name != resource_region:
            return

        # Are we also filtering on bucket name?
        if resource_name and bucket.name != resource_name:
            return

        # Format the bucket to the AWS Config format:
        config_data = bucket.to_config_dict()

        # The 'configuration' field is also a JSON string:
        config_data['configuration'] = json.dumps(config_data['configuration'])

        # Supplementary config need all values converted to JSON strings if they are not strings already:
        for field, value in config_data['supplementaryConfiguration'].items():
            if not isinstance(value, str):
                config_data['supplementaryConfiguration'][field] = json.dumps(value)

        return config_data


s3_config_query = S3ConfigQuery(s3_backends)