use cpp_oop::gen_oop;
use cpp_oop::CastPtr;

gen_oop! {
    #[default]
    struct Foo {
        foo: u32,
    }

    struct FooLayout {
        foo: fn(this: &Self, a: i32) -> u32,
        foo2: fn(this: &Self) -> u32,
    }

    impl FooMethodsInner for Foo {
        extern "C" fn foo_inner(_this: &Self, _a: i32) -> u32 {
            1
        }

        extern "C" fn foo2_inner(_this: &Self) -> u32 {
            2
        }
    }
}

gen_oop! {
    #[default]
    #[base(Foo)]
    struct Bar {
        bar: u32,
    }

    struct BarLayout {
        bar: fn(this: &Self) -> u32,
    }

    impl BarMethodsInner for Bar {
        extern "C" fn bar_inner(_this: &Self) -> u32 {
            3
        }
    }

    impl FooMethodsInner for Bar {
        extern "C" fn foo_inner(_this: &Self, _a: i32) -> u32 {
            10
        }

        #[unused]
        extern "C" fn foo2_inner(_this: &Self) -> u32 {}
    }
}

#[test]
fn layout() {
    assert_eq!(std::mem::size_of::<Foo>(), std::mem::size_of::<u32>());
    assert_eq!(std::mem::size_of::<Bar>(), std::mem::size_of::<u32>() * 2);
}

#[test]
fn basic() {
    let b = Bar::default();
    let b_ptr = &b as *const Bar;
    let f_ptr: *const Foo = Foo::cast_const(b_ptr);

    assert_eq!(Foo::foo_inner(&b.base_foo, 0), 1); // manual selection of the method to call
    assert_eq!(Bar::foo_inner(&b, 0), 10); // manual selection of the method to call

    assert_eq!(Foo::foo2_inner(&b.base_foo), 2); // manual selection of the method to call
                                                 // Bar::foo2_inner will give an error cuz its unused

    assert_eq!(Bar::bar_inner(&b), 3); // manual selection of the method to call

    assert_eq!(b.foo(0), 10); // static dispatch
    assert_eq!(b.foo2(), 2); // static dispatch
    assert_eq!(b.bar(), 3); // static dispatch

    assert_eq!(f_ptr.foo(0), 1); // this one has no vtable (no virtual methods) so it will use static dispatch
    assert_eq!(f_ptr.foo2(), 2); // this one has no vtable (no virtual methods) so it will use static dispatch

    assert_eq!(b_ptr.foo(0), 10); // this one has no vtable (no virtual methods) so it will use static dispatch
    assert_eq!(b_ptr.foo2(), 2); // this one has no vtable (no virtual methods) so it will use static dispatch
    assert_eq!(b_ptr.bar(), 3); // this one has no vtable (no virtual methods) so it will use static dispatch
}