import itertools

import ObjectCapacities.ArgumentsChecker as ArgumentsChecker
from ObjectCapacities.Basic import AttributeFromCallable, MethodFromCallable, InternalAttribute, SeveralAttributePolicies
from ObjectCapacities.List import ExternalListOfObjects, ListGetable, ElementCreatable, ElementGetable, ElementAddable, ElementRemovable, ElementHasable, ListAddable, ListSetable, ListDeletable
from ObjectCapacities.TypePolicies import SimpleTypePolicy, ObjectTypePolicy

class BadGithubObjectException( Exception ):
    pass

def InternalSimpleAttribute( attributeName ):
    return InternalAttribute( attributeName, SimpleTypePolicy() )

def InternalSimpleAttributes( *attributeNames ):
    return SeveralAttributePolicies( [ InternalSimpleAttribute( attributeName ) for attributeName in attributeNames ] )

def InternalObjectAttribute( attributeName, type ):
    return InternalAttribute( attributeName, ObjectTypePolicy( type ) )

def BaseUrl( baseUrl ):
    return AttributeFromCallable( "_baseUrl", baseUrl )

def Identity( identity ):
    return AttributeFromCallable( "_identity", identity )

class Editable( MethodFromCallable ):
    def __init__( self, mandatoryParameters, optionalParameters ):
        MethodFromCallable.__init__( self, "edit", self.__execute )
        self.__argumentsChecker = ArgumentsChecker.ArgumentsChecker( mandatoryParameters, optionalParameters )

    def __execute( self, obj, *args, **kwds ):
        data = self.__argumentsChecker.check( args, kwds )
        attributes = obj._github._dataRequest( "PATCH", obj._baseUrl, None, data )
        obj._updateAttributes( attributes )

class Deletable( MethodFromCallable ):
    def __init__( self ):
        MethodFromCallable.__init__( self, "delete", self.__execute )

    def __execute( self, obj, *args, **kwds ):
        obj._github._statusRequest( "DELETE", obj._baseUrl, None, None )

def GithubObject( className, *attributePolicies ):
    class GithubObject:
        __attributeDefinitions = dict()
        __methodDefinitions = dict()

        @staticmethod
        def _addAttributePolicy( attributePolicy ):
            attributePolicy.apply( GithubObject )

        @staticmethod
        def _addAttribute( attributeName, attributeDefinition ):
            GithubObject.__checkAttributeName( attributeName )
            GithubObject.__attributeDefinitions[ attributeName ] = attributeDefinition

        @staticmethod
        def _addMethod( methodName, methodDefinition ):
            GithubObject.__checkAttributeName( methodName )
            GithubObject.__methodDefinitions[ methodName ] = methodDefinition

        @staticmethod
        def __checkAttributeName( attributeName ):
            if attributeName in GithubObject.__attributeDefinitions or attributeName in GithubObject.__methodDefinitions:
                raise BadGithubObjectException( "Same attribute defined by two policies" )

        def __init__( self, github, attributes, lazy ):
            self._github = github
            self.__attributes = dict()
            self._updateAttributes( attributes )
            if not lazy:
                for attributeName in GithubObject.__attributeDefinitions:
                    if attributeName not in self.__attributes:
                        self.__fetchAttribute( attributeName )

        def __getattr__( self, attributeName ):
            if attributeName in GithubObject.__methodDefinitions:
                return lambda *args, **kwds: GithubObject.__methodDefinitions[ attributeName ]( self, *args, **kwds )
            elif attributeName in GithubObject.__attributeDefinitions:
                if attributeName not in self.__attributes:
                    self.__fetchAttribute( attributeName )
                return self.__attributes[ attributeName ]
            else:
                raise AttributeError( attributeName )

        def _updateAttributes( self, attributes ):
            for attributeName, attributeValue in attributes.iteritems():
                attributeDefinition = GithubObject.__attributeDefinitions[ attributeName ]
                self.__attributes[ attributeName ] = attributeDefinition.getValueFromRawValue( self, attributeValue )

        def _markAsCompleted( self ):
            for attributeName, attributeDefinition in GithubObject.__attributeDefinitions.iteritems():
                if attributeDefinition.isLazy() and attributeName not in self.__attributes:
                    self.__attributes[ attributeName ] = None

        def __dir__( self ):
            return GithubObject.__attributeDefinitions.keys()

        def __fetchAttribute( self, attributeName ):
            attributeDefinition = GithubObject.__attributeDefinitions[ attributeName ]
            attributeDefinition.updateAttributes( self )

    GithubObject.__name__ = className
    GithubObject._addAttributePolicy( SeveralAttributePolicies( attributePolicies ) )

    return GithubObject