pub mod backend;
pub use crate::backend::*;

pub mod buildable;
pub use crate::buildable::*;

pub mod collection_builder;
pub use crate::collection_builder::*;

pub mod value_builder;
pub use crate::value_builder::*;


#[cfg(test)]
mod dummy_bool_test {
    use super::*;

    struct DummyBackend;
    impl Backend for DummyBackend {
        type Error = ();

        fn bool_builder(&self) -> Box<dyn ValueBuilder<Output = bool, Error = Self::Error>> {
            Box::new(BoolValBuilder)
        }
        fn u8_builder(&self)     -> Box<dyn ValueBuilder<Output = u8, Error = Self::Error>> {
            unimplemented!()
        }
        fn u16_builder(&self)    -> Box<dyn ValueBuilder<Output = u16, Error = Self::Error>> {
            unimplemented!()
        }
        fn u32_builder(&self)    -> Box<dyn ValueBuilder<Output = u32, Error = Self::Error>> {
            unimplemented!()
        }
        fn u64_builder(&self)    -> Box<dyn ValueBuilder<Output = u64, Error = Self::Error>> {
            unimplemented!()
        }
        fn u128_builder(&self)   -> Box<dyn ValueBuilder<Output = u128, Error = Self::Error>> {
            unimplemented!()
        }
        fn i8_builder(&self)     -> Box<dyn ValueBuilder<Output = i8, Error = Self::Error>> {
            unimplemented!()
        }
        fn i16_builder(&self)    -> Box<dyn ValueBuilder<Output = i16, Error = Self::Error>> {
            unimplemented!()
        }
        fn i32_builder(&self)    -> Box<dyn ValueBuilder<Output = i32, Error = Self::Error>> {
            unimplemented!()
        }
        fn i64_builder(&self)    -> Box<dyn ValueBuilder<Output = i64, Error = Self::Error>> {
            unimplemented!()
        }
        fn i128_builder(&self)   -> Box<dyn ValueBuilder<Output = i128, Error = Self::Error>> {
            unimplemented!()
        }
        fn usize_builder(&self)  -> Box<dyn ValueBuilder<Output = usize, Error = Self::Error>> {
            unimplemented!()
        }
        fn isize_builder(&self)  -> Box<dyn ValueBuilder<Output = isize, Error = Self::Error>> {
            unimplemented!()
        }
        fn f32_builder(&self)    -> Box<dyn ValueBuilder<Output = f32, Error = Self::Error>> {
            unimplemented!()
        }
        fn f64_builder(&self)    -> Box<dyn ValueBuilder<Output = f64, Error = Self::Error>> {
            unimplemented!()
        }
        fn char_builder(&self)   -> Box<dyn ValueBuilder<Output = char, Error = Self::Error>> {
            unimplemented!()
        }
        fn string_builder(&self) -> Box<dyn ValueBuilder<Output = String, Error = Self::Error>> {
            unimplemented!()
        }

        fn vec_builder<T>(&self) -> Box<dyn CollectionBuilder<Output = Vec<T>, Error = Self::Error>>
            where T: 'static + BuildableValue
        {
            unimplemented!()
        }
    }

    struct BoolValBuilder;
    impl ValueBuilder for BoolValBuilder {
        type Output = bool;
        type Error = ();

        fn build_value(&self, _question: &str) -> Result<Self::Output, Self::Error> {
            Ok(true)
        }
    }

    #[test]
    fn test_build_value() {
        let v = bool::builder(DummyBackend).build_value("Are you sure?").unwrap();
        assert!(v);
    }

}

#[cfg(test)]
mod vec_test {
    use super::*;

    struct DummyBackend;
    impl Backend for DummyBackend {
        type Error = ();

        fn bool_builder(&self) -> Box<dyn ValueBuilder<Output = bool, Error = Self::Error>> {
            Box::new(BoolValBuilder)
        }
        fn u8_builder(&self)     -> Box<dyn ValueBuilder<Output = u8, Error = Self::Error>> {
            unimplemented!()
        }
        fn u16_builder(&self)    -> Box<dyn ValueBuilder<Output = u16, Error = Self::Error>> {
            unimplemented!()
        }
        fn u32_builder(&self)    -> Box<dyn ValueBuilder<Output = u32, Error = Self::Error>> {
            unimplemented!()
        }
        fn u64_builder(&self)    -> Box<dyn ValueBuilder<Output = u64, Error = Self::Error>> {
            unimplemented!()
        }
        fn u128_builder(&self)   -> Box<dyn ValueBuilder<Output = u128, Error = Self::Error>> {
            unimplemented!()
        }
        fn i8_builder(&self)     -> Box<dyn ValueBuilder<Output = i8, Error = Self::Error>> {
            unimplemented!()
        }
        fn i16_builder(&self)    -> Box<dyn ValueBuilder<Output = i16, Error = Self::Error>> {
            unimplemented!()
        }
        fn i32_builder(&self)    -> Box<dyn ValueBuilder<Output = i32, Error = Self::Error>> {
            unimplemented!()
        }
        fn i64_builder(&self)    -> Box<dyn ValueBuilder<Output = i64, Error = Self::Error>> {
            unimplemented!()
        }
        fn i128_builder(&self)   -> Box<dyn ValueBuilder<Output = i128, Error = Self::Error>> {
            unimplemented!()
        }
        fn usize_builder(&self)  -> Box<dyn ValueBuilder<Output = usize, Error = Self::Error>> {
            unimplemented!()
        }
        fn isize_builder(&self)  -> Box<dyn ValueBuilder<Output = isize, Error = Self::Error>> {
            unimplemented!()
        }
        fn f32_builder(&self)    -> Box<dyn ValueBuilder<Output = f32, Error = Self::Error>> {
            unimplemented!()
        }
        fn f64_builder(&self)    -> Box<dyn ValueBuilder<Output = f64, Error = Self::Error>> {
            unimplemented!()
        }
        fn char_builder(&self)   -> Box<dyn ValueBuilder<Output = char, Error = Self::Error>> {
            unimplemented!()
        }
        fn string_builder(&self) -> Box<dyn ValueBuilder<Output = String, Error = Self::Error>> {
            unimplemented!()
        }
        fn vec_builder<T>(&self) -> Box<dyn CollectionBuilder<Output = Vec<T>, Error = Self::Error>>
            where T: 'static + BuildableValue
        {
            Box::new(VecBuilder::<T>(std::marker::PhantomData))
        }
    }

    struct BoolValBuilder;
    impl ValueBuilder for BoolValBuilder {
        type Output = bool;
        type Error = ();

        fn build_value(&self, _question: &str) -> Result<Self::Output, Self::Error> {
            Ok(true)
        }
    }

    pub struct VecBuilder<T: 'static + BuildableValue>(std::marker::PhantomData<T>);
    impl<T: BuildableValue> CollectionBuilder for VecBuilder<T> {
        type Output = Vec<T>;
        type Error = ();

        fn build_collection(&self, value_desc: &str) -> Result<Self::Output, Self::Error> {
            let mut buf = vec![];

            loop {
                let v: T = T::builder(DummyBackend).build_value(value_desc)?;
                buf.push(v);

                if buf.len() == 3 {
                    break
                }
            }

            Ok(buf)
        }
    }

    #[test]
    fn test_build_vec() {
        let v = Vec::<bool>::builder(DummyBackend).build_collection("flag").unwrap();
        assert_eq!(v, vec![true, true, true]);
    }
}