#![cfg(feature = "derive")]

#[derive(bincode::Encode, PartialEq, Debug)]
pub(crate) struct Test<T> {
    a: T,
    b: u32,
    c: u8,
}

#[derive(bincode::Decode, PartialEq, Debug, Eq)]
pub struct Test2<T> {
    a: T,
    b: u32,
    c: u32,
}

#[derive(bincode::BorrowDecode, bincode::Encode, PartialEq, Debug, Eq)]
pub struct Test3<'a> {
    a: &'a str,
    b: u32,
    c: u32,
    d: Option<&'a [u8]>,
}

#[derive(bincode::Encode, bincode::Decode, PartialEq, Debug, Eq)]
pub struct TestTupleStruct(u32, u32, u32);

#[derive(bincode::Encode, bincode::Decode, PartialEq, Debug, Eq)]
pub enum TestEnum {
    Foo,
    Bar { name: u32 },
    Baz(u32, u32, u32),
}

#[derive(bincode::Encode, bincode::BorrowDecode, PartialEq, Debug, Eq)]
pub enum TestEnum2<'a> {
    Foo,
    Bar { name: &'a str },
    Baz(u32, u32, u32),
}

#[test]
fn test_encode() {
    let start = Test {
        a: 5i32,
        b: 10u32,
        c: 20u8,
    };
    let mut slice = [0u8; 1024];
    let bytes_written =
        bincode::encode_into_slice(start, &mut slice, bincode::config::standard()).unwrap();
    assert_eq!(bytes_written, 3);
    assert_eq!(&slice[..bytes_written], &[10, 10, 20]);
}

#[test]
fn test_decode() {
    let start = Test2 {
        a: 5u32,
        b: 10u32,
        c: 1024u32,
    };
    let slice = [5, 10, 251, 0, 4];
    let (result, len): (Test2<u32>, usize) =
        bincode::decode_from_slice(&slice, bincode::config::standard()).unwrap();
    assert_eq!(result, start);
    assert_eq!(len, 5);
}

#[test]
fn test_encode_decode_str() {
    let start = Test3 {
        a: "Foo bar",
        b: 10u32,
        c: 1024u32,
        d: Some(b"Foo bar"),
    };
    let mut slice = [0u8; 100];

    let len = bincode::encode_into_slice(&start, &mut slice, bincode::config::standard()).unwrap();
    assert_eq!(len, 21);
    let (end, len): (Test3, usize) =
        bincode::decode_from_slice(&slice[..len], bincode::config::standard()).unwrap();
    assert_eq!(end, start);
    assert_eq!(len, 21);
}

#[test]
fn test_encode_tuple() {
    let start = TestTupleStruct(5, 10, 1024);
    let mut slice = [0u8; 1024];
    let bytes_written =
        bincode::encode_into_slice(start, &mut slice, bincode::config::standard()).unwrap();
    assert_eq!(bytes_written, 5);
    assert_eq!(&slice[..bytes_written], &[5, 10, 251, 0, 4]);
}

#[test]
fn test_decode_tuple() {
    let start = TestTupleStruct(5, 10, 1024);
    let mut slice = [5, 10, 251, 0, 4];
    let (result, len): (TestTupleStruct, usize) =
        bincode::decode_from_slice(&mut slice, bincode::config::standard()).unwrap();
    assert_eq!(result, start);
    assert_eq!(len, 5);
}

#[test]
fn test_encode_enum_struct_variant() {
    let start = TestEnum::Bar { name: 5u32 };
    let mut slice = [0u8; 1024];
    let bytes_written =
        bincode::encode_into_slice(start, &mut slice, bincode::config::standard()).unwrap();
    assert_eq!(bytes_written, 2);
    assert_eq!(&slice[..bytes_written], &[1, 5]);
}

#[test]
fn test_decode_enum_struct_variant() {
    let start = TestEnum::Bar { name: 5u32 };
    let mut slice = [1, 5];
    let (result, len): (TestEnum, usize) =
        bincode::decode_from_slice(&mut slice, bincode::config::standard()).unwrap();
    assert_eq!(result, start);
    assert_eq!(len, 2);
}

#[test]
fn test_encode_enum_tuple_variant() {
    let start = TestEnum::Baz(5, 10, 1024);
    let mut slice = [0u8; 1024];
    let bytes_written =
        bincode::encode_into_slice(start, &mut slice, bincode::config::standard()).unwrap();
    assert_eq!(bytes_written, 6);
    assert_eq!(&slice[..bytes_written], &[2, 5, 10, 251, 0, 4]);
}

#[test]
fn test_decode_enum_unit_variant() {
    let start = TestEnum::Foo;
    let mut slice = [0];
    let (result, len): (TestEnum, usize) =
        bincode::decode_from_slice(&mut slice, bincode::config::standard()).unwrap();
    assert_eq!(result, start);
    assert_eq!(len, 1);
}

#[test]
fn test_encode_enum_unit_variant() {
    let start = TestEnum::Foo;
    let mut slice = [0u8; 1024];
    let bytes_written =
        bincode::encode_into_slice(start, &mut slice, bincode::config::standard()).unwrap();
    assert_eq!(bytes_written, 1);
    assert_eq!(&slice[..bytes_written], &[0]);
}

#[test]
fn test_decode_enum_tuple_variant() {
    let start = TestEnum::Baz(5, 10, 1024);
    let mut slice = [2, 5, 10, 251, 0, 4];
    let (result, len): (TestEnum, usize) =
        bincode::decode_from_slice(&mut slice, bincode::config::standard()).unwrap();
    assert_eq!(result, start);
    assert_eq!(len, 6);
}

#[derive(bincode::Decode, bincode::Encode, PartialEq, Eq, Debug)]
enum CStyleEnum {
    A = 1,
    B = 2,
    C,
    D = 5,
    E,
}

#[test]
fn test_c_style_enum() {
    fn ser(e: CStyleEnum) -> u8 {
        let mut slice = [0u8; 10];
        let bytes_written =
            bincode::encode_into_slice(e, &mut slice, bincode::config::standard()).unwrap();
        assert_eq!(bytes_written, 1);
        slice[0]
    }

    assert_eq!(ser(CStyleEnum::A), 1);
    assert_eq!(ser(CStyleEnum::B), 2);
    assert_eq!(ser(CStyleEnum::C), 3);
    assert_eq!(ser(CStyleEnum::D), 5);
    assert_eq!(ser(CStyleEnum::E), 6);

    fn de(num: u8) -> Result<CStyleEnum, bincode::error::DecodeError> {
        let (result, len) = bincode::decode_from_slice(&[num], bincode::config::standard())?;
        assert_eq!(len, 1);
        Ok(result)
    }

    fn expected_err(idx: u32) -> Result<CStyleEnum, bincode::error::DecodeError> {
        Err(bincode::error::DecodeError::UnexpectedVariant {
            type_name: "CStyleEnum",
            allowed: bincode::error::AllowedEnumVariants::Allowed(&[1, 2, 3, 5, 6]),
            found: idx,
        })
    }

    assert_eq!(de(0), expected_err(0));
    assert_eq!(de(1).unwrap(), CStyleEnum::A);
    assert_eq!(de(2).unwrap(), CStyleEnum::B);
    assert_eq!(de(3).unwrap(), CStyleEnum::C);
    assert_eq!(de(4), expected_err(4));
    assert_eq!(de(5).unwrap(), CStyleEnum::D);
    assert_eq!(de(6).unwrap(), CStyleEnum::E);
    assert_eq!(de(7), expected_err(7));
}

macro_rules! macro_newtype {
    ($name:ident) => {
        #[derive(bincode::Encode, bincode::Decode, PartialEq, Eq, Debug)]
        pub struct $name(pub usize);
    };
}
macro_newtype!(MacroNewType);

#[test]
fn test_macro_newtype() {
    for val in [0, 100, usize::MAX] {
        let mut usize_slice = [0u8; 10];
        let usize_len =
            bincode::encode_into_slice(val, &mut usize_slice, bincode::config::standard()).unwrap();

        let mut newtype_slice = [0u8; 10];
        let newtype_len = bincode::encode_into_slice(
            MacroNewType(val),
            &mut newtype_slice,
            bincode::config::standard(),
        )
        .unwrap();

        assert_eq!(usize_len, newtype_len);
        assert_eq!(usize_slice, newtype_slice);

        let (newtype, len) = bincode::decode_from_slice::<MacroNewType, _>(
            &newtype_slice,
            bincode::config::standard(),
        )
        .unwrap();
        assert_eq!(newtype, MacroNewType(val));
        assert_eq!(len, newtype_len);
    }
}

#[derive(bincode::Encode, bincode::Decode, Debug)]
pub enum EmptyEnum {}

#[derive(bincode::Encode, bincode::BorrowDecode, Debug)]
pub enum BorrowedEmptyEnum {}

#[test]
fn test_empty_enum_decode() {
    let err =
        bincode::decode_from_slice::<EmptyEnum, _>(&[], bincode::config::standard()).unwrap_err();
    assert_eq!(
        err,
        bincode::error::DecodeError::EmptyEnum {
            type_name: "derive::EmptyEnum"
        }
    );
}