// This file is part of ICU4X. For terms of use, please see the file
// called LICENSE at the top level of the ICU4X source tree
// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).

use std::borrow::Cow;
use std::fmt::Debug;

use zerofrom::ZeroFrom;
use zerovec::{ule::AsULE, *};

#[make_varule(VarStructULE)]
#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Debug, serde::Serialize, serde::Deserialize)]
#[zerovec::derive(Serialize, Deserialize, Debug)]
struct VarStruct<'a> {
    a: u32,
    b: char,
    #[serde(borrow)]
    c: Cow<'a, str>,
}

#[make_varule(VarStructOutOfOrderULE)]
#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Debug, serde::Serialize, serde::Deserialize)]
#[zerovec::derive(Serialize, Deserialize, Debug)]
struct VarStructOutOfOrder<'a> {
    a: u32,
    #[serde(borrow)]
    b: Cow<'a, str>,
    c: char,
    d: u8,
}

#[make_varule(VarTupleStructULE)]
#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Debug, serde::Serialize, serde::Deserialize)]
#[zerovec::derive(Serialize, Deserialize, Debug)]
struct VarTupleStruct<'a>(u32, char, #[serde(borrow)] VarZeroVec<'a, str>);

#[make_varule(NoKVULE)]
#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Debug, serde::Serialize, serde::Deserialize)]
#[zerovec::skip_derive(ZeroMapKV)]
#[zerovec::derive(Serialize, Deserialize, Debug)]
struct NoKV<'a>(u32, char, #[serde(borrow)] VarZeroVec<'a, str>);

#[make_varule(NoOrdULE)]
#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Debug, serde::Serialize, serde::Deserialize)]
#[zerovec::skip_derive(ZeroMapKV, Ord)]
#[zerovec::derive(Serialize, Deserialize, Debug)]
struct NoOrd<'a>(u32, char, #[serde(borrow)] VarZeroVec<'a, str>);

#[make_varule(MultiFieldStructULE)]
#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Debug, serde::Serialize, serde::Deserialize)]
#[zerovec::derive(Serialize, Deserialize, Debug)]
struct MultiFieldStruct<'a> {
    a: u32,
    b: char,
    #[serde(borrow)]
    c: Cow<'a, str>,
    d: u8,
    #[serde(borrow)]
    e: Cow<'a, str>,
    f: char,
}

#[make_varule(MultiFieldConsecutiveStructULE)]
#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Debug, serde::Serialize, serde::Deserialize)]
#[zerovec::derive(Serialize, Deserialize, Debug)]
#[zerovec::format(zerovec::vecs::Index8)]
struct MultiFieldConsecutiveStruct<'a> {
    #[serde(borrow)]
    a: Cow<'a, str>,
    #[serde(borrow)]
    b: Cow<'a, str>,
    #[serde(borrow)]
    c: Cow<'a, str>,
    #[serde(borrow)]
    d: Cow<'a, str>,
}

#[make_varule(CustomVarFieldULE)]
#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Debug, serde::Serialize, serde::Deserialize)]
#[zerovec::derive(Serialize, Deserialize, Debug)]
struct CustomVarField<'a> {
    #[zerovec::varule(MultiFieldStructULE)]
    #[serde(borrow)]
    a: MultiFieldStruct<'a>,
    b: u32,
}

#[make_varule(MultiFieldTupleULE)]
#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Debug, serde::Serialize, serde::Deserialize)]
#[zerovec::derive(Serialize, Deserialize, Debug)]
#[zerovec::format(zerovec::vecs::Index32)]
struct MultiFieldTuple<'a>(
    u8,
    char,
    #[serde(borrow)] VarZeroVec<'a, str>,
    #[serde(borrow)] VarZeroVec<'a, [u8]>,
    #[serde(borrow)] Cow<'a, str>,
);

/// The `assert` function should have the body `|(stack, zero)| assert_eq!(stack, &U::zero_from(&zero))`
///
/// We cannot do this internally because we technically need a different `U` with a shorter lifetime here
/// which would require some gnarly lifetime bounds and perhaps a Yoke dependency. This is just a test, so it's
/// not important to get this 100% perfect
fn assert_zerovec<T, U, F>(slice: &[U], assert: F)
where
    T: ule::VarULE + ?Sized + serde::Serialize,
    U: ule::EncodeAsVarULE<T> + serde::Serialize,
    F: Fn(&U, &T),
    for<'a> Box<T>: serde::Deserialize<'a>,
    for<'a> &'a T: serde::Deserialize<'a>,
    T: PartialEq + Debug,
{
    let varzerovec: VarZeroVec<T> = slice.into();

    assert_eq!(varzerovec.len(), slice.len());

    for (stack, zero) in slice.iter().zip(varzerovec.iter()) {
        assert(stack, zero)
    }

    let bytes = varzerovec.as_bytes();
    let name = std::any::type_name::<T>();
    let reparsed: VarZeroVec<T> = VarZeroVec::parse_bytes(bytes)
        .unwrap_or_else(|_| panic!("Parsing VarZeroVec<{name}> should succeed"));

    assert_eq!(reparsed.len(), slice.len());

    for (stack, zero) in slice.iter().zip(reparsed.iter()) {
        assert(stack, zero)
    }

    let bincode = bincode::serialize(&varzerovec).unwrap();
    let deserialized: VarZeroVec<T> = bincode::deserialize(&bincode).unwrap();

    for (stack, zero) in slice.iter().zip(deserialized.iter()) {
        assert(stack, zero)
    }

    let json_slice = serde_json::to_string(&slice).unwrap();
    let json_vzv = serde_json::to_string(&varzerovec).unwrap();

    assert_eq!(json_slice, json_vzv);

    let deserialized: VarZeroVec<T> = serde_json::from_str(&json_vzv).unwrap();

    for (stack, zero) in slice.iter().zip(deserialized.iter()) {
        assert(stack, zero)
    }

    if let Some(first) = varzerovec.get(0) {
        let bincode = bincode::serialize(first).unwrap();
        let deserialized: &T = bincode::deserialize(&bincode).unwrap();
        let deserialized_box: Box<T> = bincode::deserialize(&bincode).unwrap();
        assert_eq!(
            first, deserialized,
            "Single element roundtrips with bincode"
        );
        assert_eq!(
            first, &*deserialized_box,
            "Single element roundtrips with bincode"
        );

        let json = serde_json::to_string(first).unwrap();
        let deserialized: Box<T> = serde_json::from_str(&json).unwrap();
        assert_eq!(
            first, &*deserialized,
            "Single element roundtrips with serde"
        );
    }
}

fn main() {
    assert_zerovec::<VarStructULE, VarStruct, _>(TEST_VARSTRUCTS, |stack, zero| {
        assert_eq!(stack, &VarStruct::zero_from(zero))
    });

    assert_zerovec::<MultiFieldStructULE, MultiFieldStruct, _>(TEST_MULTIFIELD, |stack, zero| {
        assert_eq!(stack, &MultiFieldStruct::zero_from(zero))
    });

    assert_zerovec::<MultiFieldConsecutiveStructULE, MultiFieldConsecutiveStruct, _>(
        TEST_MULTICONSECUTIVE,
        |stack, zero| assert_eq!(stack, &MultiFieldConsecutiveStruct::zero_from(zero)),
    );

    let vartuples = &[
        VarTupleStruct(101, 'ø', TEST_STRINGS1.into()),
        VarTupleStruct(9499, '⸘', TEST_STRINGS2.into()),
        VarTupleStruct(3478, '月', TEST_STRINGS3.into()),
    ];
    assert_zerovec::<VarTupleStructULE, VarTupleStruct, _>(vartuples, |stack, zero| {
        assert_eq!(stack, &VarTupleStruct::zero_from(zero))
    });

    // Test that all fields are accessible on a type using multifieldule
    let multi_ule = ule::encode_varule_to_box(&TEST_MULTIFIELD[0]);
    assert_eq!(multi_ule.a, TEST_MULTIFIELD[0].a.to_unaligned());
    assert_eq!(multi_ule.b, TEST_MULTIFIELD[0].b.to_unaligned());
    assert_eq!(multi_ule.c(), TEST_MULTIFIELD[0].c);
    assert_eq!(multi_ule.d, TEST_MULTIFIELD[0].d);
    assert_eq!(multi_ule.e(), TEST_MULTIFIELD[0].e);
    assert_eq!(multi_ule.f, TEST_MULTIFIELD[0].f.to_unaligned());
}

const TEST_VARSTRUCTS: &[VarStruct<'static>] = &[
    VarStruct {
        a: 101,
        b: 'ø',
        c: Cow::Borrowed("testīng strīng"),
    },
    VarStruct {
        a: 9499,
        b: '⸘',
        c: Cow::Borrowed("a diffərənt ştring"),
    },
    VarStruct {
        a: 3478,
        b: '月',
        c: Cow::Borrowed("好多嘅 string"),
    },
];

const TEST_STRINGS1: &[&str] = &["foo", "bar", "baz"];
const TEST_STRINGS2: &[&str] = &["hellø", "wørłd"];
const TEST_STRINGS3: &[&str] = &["łořem", "ɨpsu₥"];

const TEST_MULTIFIELD: &[MultiFieldStruct<'static>] = &[
    MultiFieldStruct {
        a: 101,
        b: 'ø',
        c: Cow::Borrowed("testīng strīng"),
        d: 8,
        e: Cow::Borrowed("another testīng strīng"),
        f: 'å',
    },
    MultiFieldStruct {
        a: 9499,
        b: '⸘',
        c: Cow::Borrowed("a diffərənt ştring"),
        d: 120,
        e: Cow::Borrowed("a diffərənt testing ştring"),
        f: 'ł',
    },
    MultiFieldStruct {
        a: 3478,
        b: '月',
        c: Cow::Borrowed("好多嘅 string"),
        d: 89,
        e: Cow::Borrowed("many 好多嘅 string"),
        f: 'ə',
    },
];

const TEST_MULTICONSECUTIVE: &[MultiFieldConsecutiveStruct<'static>] =
    &[MultiFieldConsecutiveStruct {
        a: Cow::Borrowed("one"),
        b: Cow::Borrowed("2"),
        c: Cow::Borrowed("three"),
        d: Cow::Borrowed("four"),
    }];