#![feature(specialization)]
use std::{convert::TryInto, fmt};
use tyenum::tyenum;

#[derive(Debug, PartialEq)]
struct A;

impl fmt::Display for A {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "A")
    }
}

#[derive(Debug, PartialEq)]
struct B;

impl fmt::Display for B {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "B")
    }
}

#[derive(Debug, PartialEq)]
struct C;

#[tyenum(derive = [Name], trait_obj = [fmt::Display])]
#[derive(Debug, PartialEq)]
enum Test {
    A,
    BB(B),
    C(C),
}

trait Name {
    fn name(&self) -> String;
}

impl Name for A {
    fn name(&self) -> String {
        String::from("A")
    }
}

impl Name for B {
    fn name(&self) -> String {
        String::from("B")
    }
}

impl Name for C {
    fn name(&self) -> String {
        String::from("C")
    }
}

#[tyenum]
enum AnotherEnum {
    A,
    B,
}

#[test]
fn into() {
    assert_eq!(Test::A(A), A.into());
    assert_eq!(Test::BB(B), B.into());
    assert_ne!(Test::A(A), C.into());
}

#[test]
fn is() {
    assert!(Test::A(A).is::<A>());
    assert!(Test::BB(B).is::<B>());
    assert!(!Test::C(C).is::<A>());
}

#[test]
fn try_into() {
    assert_eq!(Test::A(A).try_into(), Ok(A));
    assert_eq!(Test::BB(B).try_into(), Ok(B));
    let a: Result<A, _> = Test::C(C).try_into();
    assert_eq!(a, Err(tyenum::TryFromTyenumError));
}

#[test]
fn derive() {
    let mut named = Test::A(A);
    assert_eq!("A", named.name());
    named = Test::BB(B);
    assert_eq!("B", named.name());
    named = Test::C(C);
    assert_eq!("C", named.name());
}

#[test]
fn try_into_trait_object() {
    let mut a = Test::A(A);
    let mut maybe_display: Option<&mut dyn fmt::Display> = a.trait_obj();
    println!("{}", maybe_display.unwrap());
    let mut b = Test::BB(B);
    maybe_display = b.trait_obj();
    assert!(maybe_display.is_some());
    let mut c = Test::C(C);
    maybe_display = c.trait_obj();
    assert!(maybe_display.is_none());
}