import ckan.lib.base as base
import ckan.lib.helpers as helpers
import ckan.plugins as plugins
import importlib
import logging
import pylons.config as config

from ckan.common import response

log = logging.getLogger(__name__)

PARSER_CONFIG_PROP = 'ckan.privatedatasets.parser'


class AdquiredDatasetsController(base.BaseController):

    def __call__(self, environ, start_response):
        # avoid status_code_redirect intercepting error responses
        environ['pylons.status_code_redirect'] = True
        return base.BaseController.__call__(self, environ, start_response)

    def add_user(self):

        # Get the parser from the configuration
        class_path = config.get(PARSER_CONFIG_PROP, '')

        if class_path != '':
            try:
                class_package = class_path.split(':')[0]
                class_name = class_path.split(':')[1]
                parser = getattr(importlib.import_module(class_package), class_name)
                # Parse the result using the parser set in the configuration
                result = parser().parse_notification()
            except Exception as e:
                result = {'errors': [str(e)]}
        else:
            result = {'errors': ['%s not configured' % PARSER_CONFIG_PROP]}

        # Introduce the users into the datasets
        # Expected result: {'errors': ["...", "...", ...]
        #                   'users_datasets': [{'user': 'user_name', 'datasets': ['ds1', 'ds2', ...]}, ...]}
        warns = []

        if 'errors' in result and len(result['errors']) > 0:
            log.warn('Errors arised parsing the request: ' + str(result['errors']))
            response.status_int = 400
            return helpers.json.dumps({'errors': result['errors']})
        elif 'users_datasets' in result:
            for user_info in result['users_datasets']:
                for dataset_id in user_info['datasets']:
                    try:
                        # Get dataset data
                        dataset = plugins.toolkit.get_action('package_show')({'ignore_auth': True}, {'id': dataset_id})

                        # Generate default set of users if it does not exist
                        if 'allowed_users' not in dataset:
                            dataset['allowed_users'] = ''

                        # Only new users will be inserted
                        allowed_users = dataset['allowed_users'].split(',')
                        if user_info['user'] not in allowed_users:

                            # Comma is only introduced when there are more than one user in the list of allowed users
                            separator = '' if dataset['allowed_users'] == '' else ','
                            dataset['allowed_users'] += separator + user_info['user']

                            # Update dataset data
                            plugins.toolkit.get_action('package_update')({'ignore_auth': True}, dataset)
                        else:
                            log.warn('The user %s is already allowed to access the %s dataset' % (user_info['user'], dataset_id))

                    except plugins.toolkit.ObjectNotFound:
                        # If a dataset does not exist in the instance, an error message will be returned to the user.
                        # However the process won't stop and the process will continue with the remaining datasets.
                        log.warn('Dataset %s was not found in this instance' % dataset_id)
                        warns.append('Dataset %s was not found in this instance' % dataset_id)
                    except plugins.toolkit.ValidationError as e:
                        # Some datasets does not allow to introduce the list of allowed users since this property is
                        # only valid for private datasets outside an organization. In this case, a wanr will return
                        # but the process will continue
                        warns.append('Dataset %s: %s' % (dataset_id, e.error_dict['allowed_users'][0]))

        # Return warnings that inform about non-existing datasets
        if len(warns) > 0:
            return helpers.json.dumps({'warns': warns})