from __future__ import unicode_literals
import datetime
import json
from six.moves.urllib.parse import urlparse

from moto.core.responses import BaseResponse


class InstanceMetadataResponse(BaseResponse):

    def metadata_response(self, request, full_url, headers):
        """
        Mock response for localhost metadata

        http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/AESDG-chapter-instancedata.html
        """

        parsed_url = urlparse(full_url)
        tomorrow = datetime.datetime.utcnow() + datetime.timedelta(days=1)
        credentials = dict(
            AccessKeyId="test-key",
            SecretAccessKey="test-secret-key",
            Token="test-session-token",
            Expiration=tomorrow.strftime("%Y-%m-%dT%H:%M:%SZ")
        )

        path = parsed_url.path

        meta_data_prefix = "/latest/meta-data/"
        # Strip prefix if it is there
        if path.startswith(meta_data_prefix):
            path = path[len(meta_data_prefix):]

        if path == '':
            result = 'iam'
        elif path == 'iam':
            result = json.dumps({
                'security-credentials': {
                    'default-role': credentials
                }
            })
        elif path == 'iam/security-credentials/':
            result = 'default-role'
        elif path == 'iam/security-credentials/default-role':
            result = json.dumps(credentials)
        else:
            raise NotImplementedError(
                "The {0} metadata path has not been implemented".format(path))
        return 200, headers, result
