gql.py

from followthemoney import model
from followthemoney.types import registry
from followthemoney.graph import Graph, Node

# Some inspiration:
#
# https://github.com/nchah/freebase-mql#mql-and-graphql
# https://rdflib.readthedocs.io/en/stable/intro_to_graphs.html#basic-triple-matching

# Queries:
# * Node inbound degree query
# * Entity inbound (degree) query

query = {
    'subject': 'NODE_ID',
    'property': 'QNAME',
    'object': 'NODE_ID',
    'degree': 'NONE to request DEGREE',
    'limit': 'NUMBER TO REQUEST RESULTS',
}


class GraphQuery(object):

    def __init__(self, graph, authz=None):
        self.graph = graph
        self.authz = authz
        self.clauses = []

    def add(self, node=None, prop=None, value=None, limit=0, count=None):
        clause = QueryClause(self, node, prop, value, limit, count)
        self.clauses.append(clause)
        return clause

    def execute(self):
        pass


class QueryClause(object):

    def __init__(self, query, node=None, prop=None, value=None,
                 limit=0, count=None):
        self.query = query
        self.node = node
        self.prop = prop
        self.value = value
        self.limit = limit
        self.count = count

    @property
    def schemata(self):
        """The schema (and hence indexes) affected by this query."""
        pass


def demo():
    proxy = model.get_proxy({
        'id': 'banana',
        'schema': 'Person',
        'properties': {
            'name': ['John Doe'],
            'phone': ['+4923239271777']
        }
    })

    # UC 1: Tags query
    query = GraphQuery(Graph())
    for prop, value in proxy.itervalues():
        if not prop.type.matchable:
            continue
        node = Node(prop.type, value)
        query.add(node=node, count=True)

    # UC 2: References query
    query = GraphQuery(Graph())
    for prop in proxy.schema.properties:
        if not prop.stub:
            continue
        node = Node(registry.entity, proxy.id, proxy=proxy)
        query.add(prop=prop.reverse, value=node, count=True)

    # UC 3: Expand query
    graph = Graph()
    query = GraphQuery(graph)
    for prop in proxy.schema.properties:
        if not prop.stub:
            continue
        node = Node(registry.entity, proxy.id, proxy=proxy)
        query.add(prop=prop.reverse, value=node, limit=200, count=True)


if __name__ == '__main__':
    demo()