#
# Functions for interacting with the node_types table in the database
#
#

from PLC.Faults import *
from PLC.Parameter import Parameter
from PLC.Storage.AlchemyObject import AlchemyObj

class NodeType(AlchemyObj):
    """
    Representation of a row in the node_types table. To use,
    instantiate with a dict of values.
    """

    tablename = 'node_types'
    join_tables = ['nodes']
    fields = {
        'node_type': Parameter(str, "Node type", max = 20, primary_key=True),
        }

    def validate_node_type(self, name):
        # Make sure name is not blank
        if not len(name):
            raise PLCInvalidArgument, "Node type must be specified"

        # Make sure node type does not alredy exist
        conflicts = NodeTypes(self.api, [name])
        if conflicts:
            raise PLCInvalidArgument, "Node type name already in use"

        return name

    def sync(self, commit=True, validate=True):
        AlchemyObj.sync(self, commit=commit, validate=validate)
        AlchemyObj.insert(self, dict(self))

    def delete(self, commit=True):
        assert 'node_type' in self
        AlcemyObj.delete(self, dict(self))  

class NodeTypes(list):
    """
    Representation of the node_types table in the database.
    """

    def __init__(self, api, node_types = None):
        if not node_types:
            result = NodeType().select()
        elif isinstance(node_types, (StringTypes, list, tuple, set)):
            result = NodeType().select(filter={'node_type': node_types})
        else:
            raise PLCInvalidArgument, "Wrong node type filter %r" % node_types

        self.extend(result)