from DataVaultGenerator.Components import ErrorCollection, GeneratorEntity, DBEntity


class GenericTransformation(GeneratorEntity):
    def __init__(self, model, filename, definition: dict = None):
        GeneratorEntity.__init__(self, model, filename, definition)

        self._layername = definition.get('layer', self.model.config.entitydefaults[self.type]['layer'])
       
    @property
    def dbentity(self):
        return DBEntity(self.name,
                        self,
                        self.model.config.layer.get(self._layername).get('defaultdatabaseobject'),
                        self._definition.get('dbentity'))

    @property
    def layer(self):
        """Returns the entity layer."""
        return self.model.get_layer(self._layername)

    def validate(self):

        errors = ErrorCollection()
        
        # Validating entity references:

        for e in self._definition.get('sources'):
            if self.model.get_entity(e) is None:
               errors.add("VALIDATION ERROR",
                           (self.filename, "Generic Transformation", "<" + self.name + ">"),
                           f'source <{e}> not found')

        for e in self._definition.get('targets'):
            if self.model.get_entity(e) is None:
               errors.add("VALIDATION ERROR",
                           (self.filename, "Generic Transformation", "<" + self.name + ">"),
                           f'target <{e}> not found')

        for name, e in self.get_query_entities().items():
            if e is None:
               errors.add("VALIDATION ERROR",
                           (self.filename, "Generic Transformation", "<" + self.name + ">"),
                           f'query-entity <{name}> not found.')

        for name, e in self.get_query_entities().items():
            if name not in self._definition.get('sources') and name not in self._definition.get('targets'):
               errors.add("VALIDATION ERROR",
                           (self.filename, "Generic Transformation", "<" + self.name + ">"),
                           f'query-entity <{name}> not specified as source or target.')

        return errors

    def get_source_entities(self):
        """returns a list of linked entities."""
        return [self.model.get_entity(h) for h in self._definition['sources']]

    def get_target_entities(self):
        """returns a list of linked entities."""
        return [self.model.get_entity(h) for h in self._definition['targets']]

    @property
    def query(self):
        return self.model.get_parsed_query(self, self.rawquery)

    def get_query_entities(self):
        return self.model.get_query_entities(self.rawquery)

    @property
    def rawquery(self):
        return self._definition.get('query', '')

    def get_component_entities(self):
        return [{'entity': self, 'component': c, 'type': c.type} for c in self.get_source_entities()]

    def get_attributes(self, roles=(), exclude=()):
        return []