from myunit import Suite, assert_true
from subtypes import is_subtype
from typefixture import TypeFixture, InterfaceTypeFixture


class SubtypingSuite(Suite):
    def set_up(self):
        self.fx = TypeFixture()
    
    def test_trivial_cases(self):
        for simple in self.fx.void, self.fx.a, self.fx.o, self.fx.b:
            self.assert_subtype(simple, simple)
    
    def test_instance_subtyping(self):
        self.assert_proper_subtype(self.fx.a, self.fx.o)
        self.assert_proper_subtype(self.fx.b, self.fx.o)
        self.assert_proper_subtype(self.fx.b, self.fx.a)
        
        self.assert_not_subtype(self.fx.a, self.fx.d)
        self.assert_not_subtype(self.fx.b, self.fx.c)
    
    def test_simple_generic_instance_subtyping(self):
        self.assert_subtype(self.fx.ga, self.fx.ga)
        self.assert_subtype(self.fx.hab, self.fx.hab)
        
        self.assert_not_subtype(self.fx.ga, self.fx.g2a)
        self.assert_not_subtype(self.fx.ga, self.fx.gb)
        self.assert_not_subtype(self.fx.gb, self.fx.ga)
    
    def test_generic_subtyping_with_inheritance(self):
        self.assert_subtype(self.fx.gsab, self.fx.gb)
        self.assert_not_subtype(self.fx.gsab, self.fx.ga)
    
    def test_interface_subtyping(self):
        self.assert_subtype(self.fx.e, self.fx.f)
        self.assert_equivalent(self.fx.f, self.fx.f)
        self.assert_not_subtype(self.fx.a, self.fx.f)
    
    def test_generic_interface_subtyping(self):
        # TODO make this work
        self.skip()
        
        fx2 = InterfaceTypeFixture()
        
        self.assert_subtype(fx2.m1, fx2.gfa)
        self.assert_not_subtype(fx2.m1, fx2.gfb)
        
        self.assert_equivalent(fx2.gfa, fx2.gfa)
    
    def test_basic_callable_subtyping(self):
        self.assert_unrelated(self.fx.callable(self.fx.o, self.fx.d),
                              self.fx.callable(self.fx.a, self.fx.d))
        self.assert_proper_subtype(self.fx.callable(self.fx.d, self.fx.b),
                                   self.fx.callable(self.fx.d, self.fx.a))
        
        self.assert_unrelated(self.fx.callable(self.fx.a, self.fx.a),
                              self.fx.callable(self.fx.a, self.fx.void))
        
        self.assert_unrelated(
            self.fx.callable(self.fx.a, self.fx.a, self.fx.a),
            self.fx.callable(self.fx.a, self.fx.a))
    
    def test_default_arg_callable_subtyping(self):
        self.assert_proper_subtype(
            self.fx.callable_default(1, self.fx.a, self.fx.d, self.fx.a),
            self.fx.callable(self.fx.a, self.fx.d, self.fx.a))
        
        self.assert_proper_subtype(
            self.fx.callable_default(1, self.fx.a, self.fx.d, self.fx.a),
            self.fx.callable(self.fx.a, self.fx.a))
        
        self.assert_proper_subtype(
            self.fx.callable_default(0, self.fx.a, self.fx.d, self.fx.a),
            self.fx.callable_default(1, self.fx.a, self.fx.d, self.fx.a))
        
        self.assert_unrelated(
            self.fx.callable_default(1, self.fx.a, self.fx.d, self.fx.a),
            self.fx.callable(self.fx.d, self.fx.d, self.fx.a))
        
        self.assert_unrelated(
            self.fx.callable_default(0, self.fx.a, self.fx.d, self.fx.a),
            self.fx.callable_default(1, self.fx.a, self.fx.a, self.fx.a))
        
        self.assert_unrelated(
            self.fx.callable_default(1, self.fx.a, self.fx.a),
            self.fx.callable(self.fx.a, self.fx.a, self.fx.a))
    
    def test_var_arg_callable_subtyping(self):
        self.assert_unrelated(
            self.fx.callable_var_arg(0, self.fx.a, self.fx.a),
            self.fx.callable_var_arg(0, self.fx.b, self.fx.a))
        
        self.assert_unrelated(
            self.fx.callable_var_arg(0, self.fx.a, self.fx.a),
            self.fx.callable(self.fx.a, self.fx.a))
        
        self.assert_proper_subtype(
            self.fx.callable_var_arg(0, self.fx.a, self.fx.a),
            self.fx.callable(self.fx.a))
        
        self.assert_proper_subtype(
            self.fx.callable_var_arg(1, self.fx.a, self.fx.d, self.fx.a),
            self.fx.callable(self.fx.a, self.fx.a))
        
        self.assert_proper_subtype(
            self.fx.callable_var_arg(0, self.fx.a, self.fx.d, self.fx.a),
            self.fx.callable(self.fx.a, self.fx.a))
    
    def test_type_callable_subtyping(self):
        self.assert_proper_subtype(
            self.fx.callable_type(self.fx.d, self.fx.a), self.fx.std_type)
        
        self.assert_proper_subtype(
            self.fx.callable_type(self.fx.d, self.fx.b),
            self.fx.callable(self.fx.d, self.fx.a))
        
        self.assert_proper_subtype(self.fx.callable_type(self.fx.a, self.fx.b),
                                   self.fx.callable(self.fx.a, self.fx.b))
    
    # IDEA: Maybe add these test cases (they are tested pretty well in type
    #       checker tests already):
    #  * more interface subtyping test cases
    #  * more generic interface subtyping test cases
    #  * type variables
    #  * tuple types
    #  * void type
    #  * nil type
    #  * dynamic type
    #  * generic function types
    
    def assert_subtype(self, s, t):
        assert_true(is_subtype(s, t), '{} not subtype of {}'.format(s, t))
    
    def assert_not_subtype(self, s, t):
        assert_true(not is_subtype(s, t), '{} subtype of {}'.format(s, t))
    
    def assert_proper_subtype(self, s, t):
        self.assert_subtype(s, t)
        self.assert_not_subtype(t, s)
    
    def assert_equivalent(self, s, t):
        self.assert_subtype(s, t)
        self.assert_subtype(t, s)
    
    def assert_unrelated(self, s, t):
        self.assert_not_subtype(s, t)
        self.assert_not_subtype(t, s)