import json 

from manifold.manifoldapi import ManifoldAPI

class MetaData:

    def __init__ (self, auth):
        self.auth=auth
        self.hash_by_subject={}

    def fetch (self):
        manifold_api = ManifoldAPI(self.auth)
        fields = ['table', 'column.column',
                  'column.description','column.header', 'column.title',
                  'column.unit', 'column.info_type',
                  'column.resource_type', 'column.value_type',
                  'column.allowed_values', 'column.platforms.platform',
                  'column.platforms.platform_url']
        results = manifold_api.Get('metadata:table', [], [], fields)
        self.hash_by_subject = dict ( [ (result['table'], result) for result in results ] )

    def to_json(self):
        return json.dumps(self.hash_by_subject)

    def details_by_subject (self, subject):
        return self.hash_by_subject[subject]

    def sorted_fields_by_subject (self, subject):
        return self.hash_by_subject[subject]['columns'].sort()