use iddqd::{
    BiHashItem, BiHashMap, bi_hash_map, bi_upcast, internal::ValidateCompact,
};
use iddqd_test_utils::{
    borrowed_item::BorrowedItem,
    eq_props::{assert_eq_props, assert_ne_props},
    naive_map::NaiveMap,
    test_item::{
        Alloc, HashBuilder, ItemMap, TestItem, TestKey1, TestKey2,
        assert_iter_eq, test_item_permutation_strategy,
    },
};
use proptest::prelude::*;
use std::{borrow::Cow, path::Path};
use test_strategy::{Arbitrary, proptest};

#[derive(Clone, Debug)]
struct SimpleItem {
    key1: u32,
    key2: char,
}

impl BiHashItem for SimpleItem {
    type K1<'a> = u32;
    type K2<'a> = char;

    fn key1(&self) -> Self::K1<'_> {
        self.key1
    }

    fn key2(&self) -> Self::K2<'_> {
        self.key2
    }

    bi_upcast!();
}

#[test]
fn debug_impls() {
    let mut map = BiHashMap::<SimpleItem, HashBuilder, Alloc>::make_new();
    map.insert_unique(SimpleItem { key1: 1, key2: 'a' }).unwrap();
    map.insert_unique(SimpleItem { key1: 20, key2: 'b' }).unwrap();
    map.insert_unique(SimpleItem { key1: 10, key2: 'c' }).unwrap();

    assert_eq!(
        format!("{map:?}"),
        // This is a small-enough map that the order of iteration is
        // deterministic.
        "{{k1: 1, k2: 'a'}: SimpleItem { key1: 1, key2: 'a' }, \
          {k1: 10, k2: 'c'}: SimpleItem { key1: 10, key2: 'c' }, \
          {k1: 20, k2: 'b'}: SimpleItem { key1: 20, key2: 'b' }}",
    );
    assert_eq!(
        format!("{:?}", map.get1_mut(&1).unwrap()),
        "SimpleItem { key1: 1, key2: 'a' }"
    );
}

#[test]
fn debug_impls_borrowed() {
    let before = bi_hash_map! {
        HashBuilder;
        BorrowedItem { key1: "a", key2: Cow::Borrowed(b"b0"), key3: Path::new("path0") },
        BorrowedItem { key1: "b", key2: Cow::Borrowed(b"b1"), key3: Path::new("path1") },
        BorrowedItem { key1: "c", key2: Cow::Borrowed(b"b2"), key3: Path::new("path2") },
    };

    assert_eq!(
        format!("{before:?}"),
        r#"{{k1: "a", k2: [98, 48]}: BorrowedItem { key1: "a", key2: [98, 48], key3: "path0" }, {k1: "c", k2: [98, 50]}: BorrowedItem { key1: "c", key2: [98, 50], key3: "path2" }, {k1: "b", k2: [98, 49]}: BorrowedItem { key1: "b", key2: [98, 49], key3: "path1" }}"#
    );

    #[cfg(feature = "daft")]
    {
        use daft::Diffable;

        let after = bi_hash_map! {
            HashBuilder;
            BorrowedItem { key1: "a", key2: Cow::Borrowed(b"b0"), key3: Path::new("path0") },
            BorrowedItem { key1: "c", key2: Cow::Borrowed(b"b3"), key3: Path::new("path3") },
            BorrowedItem { key1: "d", key2: Cow::Borrowed(b"b4"), key3: Path::new("path4") },
        };

        let diff = before.diff(&after).by_unique();
        assert_eq!(
            format!("{diff:?}"),
            r#"Diff { common: {{k1: "a", k2: [98, 48]}: IdLeaf { before: BorrowedItem { key1: "a", key2: [98, 48], key3: "path0" }, after: BorrowedItem { key1: "a", key2: [98, 48], key3: "path0" } }}, added: {{k1: "d", k2: [98, 52]}: BorrowedItem { key1: "d", key2: [98, 52], key3: "path4" }, {k1: "c", k2: [98, 51]}: BorrowedItem { key1: "c", key2: [98, 51], key3: "path3" }}, removed: {{k1: "c", k2: [98, 50]}: BorrowedItem { key1: "c", key2: [98, 50], key3: "path2" }, {k1: "b", k2: [98, 49]}: BorrowedItem { key1: "b", key2: [98, 49], key3: "path1" }} }"#
        );
    }
}

#[test]
fn with_capacity() {
    let map = BiHashMap::<TestItem, HashBuilder>::with_capacity_and_hasher(
        1024,
        HashBuilder::default(),
    );
    assert!(map.capacity() >= 1024);
}

#[test]
fn test_insert_unique() {
    let mut map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();

    // Add an element.
    let v1 = TestItem::new(0, 'a', "x", "v");
    map.insert_unique(v1.clone()).unwrap();

    // Add an exact duplicate, which should error out.
    let error = map.insert_unique(v1.clone()).unwrap_err();
    assert_eq!(error.new_item(), &v1);
    assert_eq!(error.duplicates(), vec![&v1]);

    // Add a duplicate against just key1, which should error out.
    let v2 = TestItem::new(0, 'b', "x", "v");
    let error = map.insert_unique(v2.clone()).unwrap_err();
    assert_eq!(error.new_item(), &v2);
    assert_eq!(error.duplicates(), vec![&v1]);

    // Add a duplicate against just key2, which should error out.
    let v3 = TestItem::new(1, 'a', "x", "v");
    let error = map.insert_unique(v3.clone()).unwrap_err();
    assert_eq!(error.new_item(), &v3);

    // Add an item that doesn't have any conflicts. (key3 is the same, but
    // BiHashMap doesn't index on it.)
    let v4 = TestItem::new(1, 'b', "x", "v");
    map.insert_unique(v4.clone()).unwrap();

    // Iterate over the items mutably. This ensures that miri detects UB if it
    // exists.
    {
        let mut items: Vec<bi_hash_map::RefMut<_, HashBuilder>> =
            map.iter_mut().collect();
        items.sort_by(|a, b| a.key1().cmp(&b.key1()));
        let e1 = &items[0];
        assert_eq!(**e1, v1);

        // Test that the RefMut Debug impl looks good.
        assert!(
            format!("{e1:?}").starts_with(
                r#"TestItem { key1: 0, key2: 'a', key3: "x", value: "v""#,
            ),
            "RefMut Debug impl should forward to TestItem"
        );

        let e2 = &*items[1];
        assert_eq!(*e2, v4);
    }

    // Check that the *unique methods work.
    assert!(map.contains_key_unique(&v4.key1(), &v4.key2()));
    assert_eq!(map.get_unique(&v4.key1(), &v4.key2()), Some(&v4));
    assert_eq!(*map.get_mut_unique(&v4.key1(), &v4.key2()).unwrap(), &v4);
    assert_eq!(map.remove_unique(&v4.key1(), &v4.key2()), Some(v4));
}

#[test]
fn test_extend() {
    let mut map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    let items = vec![
        TestItem::new(1, 'a', "x", "v"),
        TestItem::new(2, 'b', "y", "w"),
        TestItem::new(3, 'c', "a", "b"),
        TestItem::new(1, 'c', "z", "overwrote key1"),
        TestItem::new(3, 'b', "q", "overwrote key1 and key2"),
        TestItem::new(4, 'x', "y", "z"),
    ];
    map.extend(items.clone());
    assert_eq!(map.len(), 3);
    assert_eq!(map.get1(&TestKey1::new(&1)).unwrap().value, "overwrote key1");
    assert_eq!(map.get1(&TestKey1::new(&2)), None);
    assert_eq!(
        map.get1(&TestKey1::new(&3)).unwrap().value,
        "overwrote key1 and key2"
    );
    assert_eq!(map.get1(&TestKey1::new(&4)).unwrap().value, "z");
}

// Example-based test for insert_overwrite.
//
// Can be used to write down examples seen from the property-based operation
// test, for easier debugging.
#[test]
fn test_insert_overwrite() {
    let mut map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();

    // Add an element.
    let v1 = TestItem::new(20, 'a', "x", "v");
    assert_eq!(map.insert_overwrite(v1.clone()), Vec::<TestItem>::new());

    // Add an element with the same keys but a different value.
    let v2 = TestItem::new(20, 'a', "y", "w");
    assert_eq!(map.insert_overwrite(v2.clone()), vec![v1]);

    map.validate(ValidateCompact::NonCompact).expect("validation failed");
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum CompactnessChange {
    /// The operation makes the map non-compact.
    NoLongerCompact,
    /// The operation makes the map compact.
    BecomesCompact,
    /// The operation doesn't change compactness.
    NoChange,
}

impl CompactnessChange {
    /// Applies this compactness change to the given compactness state.
    fn apply(self, compactness: ValidateCompact) -> ValidateCompact {
        match (compactness, self) {
            (ValidateCompact::Compact, CompactnessChange::NoLongerCompact) => {
                ValidateCompact::NonCompact
            }
            (
                ValidateCompact::NonCompact,
                CompactnessChange::BecomesCompact,
            ) => ValidateCompact::Compact,
            _ => compactness,
        }
    }
}

#[derive(Debug, Arbitrary)]
enum Operation {
    // Make inserts a bit more common to try and fill up the map.
    #[weight(4)]
    InsertUnique(TestItem),
    #[weight(3)]
    InsertOverwrite(TestItem),
    #[weight(2)]
    Get1(u8),
    #[weight(2)]
    Get2(char),
    #[weight(2)]
    Remove1(u8),
    #[weight(2)]
    Remove2(char),
    #[weight(2)]
    RetainValueContains(char, bool),
    #[weight(2)]
    RetainModulo(#[strategy(0..3_u8)] u8, #[strategy(1..4_u8)] u8, bool),
    Clear,
    // `additional` is kept modest so that reservations frequently
    // exceed the current `growth_left` and so trigger hashbrown's
    // rehash path.
    Reserve(#[strategy(0..256_usize)] usize),
    TryReserve(#[strategy(0..256_usize)] usize),
    ShrinkToFit,
    ShrinkTo(#[strategy(0..256_usize)] usize),
}

impl Operation {
    fn compactness_change(&self) -> CompactnessChange {
        match self {
            // `shrink_to_fit` / `shrink_to` flow through hashbrown's
            // rehash path the same way `reserve` does; like `reserve`
            // they touch the allocation, not the item set's index
            // space, so compactness is unchanged.
            Operation::InsertUnique(_)
            | Operation::Get1(_)
            | Operation::Get2(_)
            | Operation::Reserve(_)
            | Operation::TryReserve(_)
            | Operation::ShrinkToFit
            | Operation::ShrinkTo(_) => CompactnessChange::NoChange,
            // The act of removing items, including calls to insert_overwrite,
            // can make the map non-compact.
            Operation::InsertOverwrite(_)
            | Operation::Remove1(_)
            | Operation::Remove2(_)
            | Operation::RetainValueContains(_, _)
            | Operation::RetainModulo(_, _, _) => {
                CompactnessChange::NoLongerCompact
            }
            // Clear always makes the map compact (empty).
            Operation::Clear => CompactnessChange::BecomesCompact,
        }
    }
}

#[proptest(cases = 16)]
fn proptest_ops(
    #[strategy(prop::collection::vec(any::<Operation>(), 0..1024))] ops: Vec<
        Operation,
    >,
) {
    let mut map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    let mut naive_map = NaiveMap::new_key12();

    let mut compactness = ValidateCompact::Compact;

    // Now perform the operations on both maps.
    for op in ops.into_iter() {
        compactness = op.compactness_change().apply(compactness);

        match op {
            Operation::InsertUnique(item) => {
                let map_res = map.insert_unique(item.clone());
                let naive_res = naive_map.insert_unique(item.clone());

                assert_eq!(
                    map_res.is_ok(),
                    naive_res.is_ok(),
                    "map and naive map should agree on insert result"
                );
                if let Err(map_err) = map_res {
                    let naive_err = naive_res.unwrap_err();
                    assert_eq!(map_err.new_item(), naive_err.new_item());
                    // The duplicates may be in any order, so sort them before
                    // comparing.
                    let mut map_err_dups = map_err.duplicates().to_vec();
                    let mut naive_err_dups = naive_err.duplicates().to_vec();
                    map_err_dups.sort();
                    naive_err_dups.sort();
                    assert_eq!(map_err_dups, naive_err_dups);
                }

                map.validate(compactness).expect("map should be valid");
            }
            Operation::InsertOverwrite(item) => {
                let mut map_dups = map.insert_overwrite(item.clone());
                map_dups.sort();
                let mut naive_dups = naive_map.insert_overwrite(item.clone());
                naive_dups.sort();

                assert_eq!(
                    map_dups, naive_dups,
                    "map and naive map should agree on insert_overwrite dups"
                );
                map.validate(compactness).expect("map should be valid");
            }
            Operation::Get1(key1) => {
                let map_res = map.get1(&TestKey1::new(&key1));
                let naive_res = naive_map.get1(key1);

                assert_eq!(map_res, naive_res);
            }
            Operation::Get2(key2) => {
                let map_res = map.get2(&TestKey2::new(key2));
                let naive_res = naive_map.get2(key2);

                assert_eq!(map_res, naive_res);
            }
            Operation::Remove1(key1) => {
                let map_res = map.remove1(&TestKey1::new(&key1));
                let naive_res = naive_map.remove1(key1);

                assert_eq!(map_res, naive_res);
                map.validate(compactness).expect("map should be valid");
            }
            Operation::Remove2(key2) => {
                let map_res = map.remove2(&TestKey2::new(key2));
                let naive_res = naive_map.remove2(key2);

                assert_eq!(map_res, naive_res);
                map.validate(compactness).expect("map should be valid");
            }
            Operation::RetainValueContains(ch, equals) => {
                map.retain(|item| {
                    let contains = item.value.contains(ch);
                    if equals { contains } else { !contains }
                });
                naive_map.retain(|item| {
                    let contains = item.value.contains(ch);
                    if equals { contains } else { !contains }
                });
                map.validate(compactness).expect("map should be valid");
            }
            Operation::RetainModulo(a, b, equals) => {
                let modulo = a + b;
                let remainder = a;
                map.retain(|item| {
                    let matches = item.key1 % modulo == remainder;
                    if equals { matches } else { !matches }
                });
                naive_map.retain(|item| {
                    let matches = item.key1 % modulo == remainder;
                    if equals { matches } else { !matches }
                });
                map.validate(compactness).expect("map should be valid");
            }
            Operation::Reserve(additional) => {
                map.reserve(additional);
                // `reserve` has no observable effect beyond capacity; the
                // naive map has no equivalent. `validate` is the real
                // check — it iterates items and asks `find_index` for
                // each, which catches a hash-table left mis-bucketed by
                // a regrowth rehash.
                map.validate(compactness).expect("map should be valid");
            }
            Operation::TryReserve(additional) => {
                // Mirror `Reserve`; we don't assert `Ok` because the
                // allocator could (legitimately) refuse a large request,
                // and bailing on that would mask the actual regression
                // we care about (silent hash-table corruption).
                let _ = map.try_reserve(additional);
                map.validate(compactness).expect("map should be valid");
            }
            Operation::ShrinkToFit => {
                map.shrink_to_fit();
                map.validate(compactness).expect("map should be valid");
            }
            Operation::ShrinkTo(min_capacity) => {
                map.shrink_to(min_capacity);
                map.validate(compactness).expect("map should be valid");
            }
            Operation::Clear => {
                map.clear();
                naive_map.clear();
                map.validate(compactness).expect("map should be valid");
            }
        }

        // Check that the iterators work correctly.
        let mut naive_items = naive_map.iter().collect::<Vec<_>>();
        naive_items.sort_by(|a, b| a.key1().cmp(&b.key1()));

        assert_iter_eq(map.clone(), naive_items);
    }
}

#[proptest(cases = 64)]
fn proptest_permutation_eq(
    #[strategy(test_item_permutation_strategy::<BiHashMap<TestItem, HashBuilder, Alloc>>(0..256))]
    items: (Vec<TestItem>, Vec<TestItem>),
) {
    let (items1, items2) = items;
    let mut map1 = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    let mut map2 = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();

    for item in items1 {
        map1.insert_unique(item.clone()).unwrap();
    }
    for item in items2 {
        map2.insert_unique(item.clone()).unwrap();
    }

    assert_eq_props(map1, map2);
}

// Test various conditions for non-equality.
//
// It's a bit difficult to capture mutations in a proptest, so this is a small
// example-based test.
#[test]
fn test_permutation_eq_examples() {
    let mut map1 = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    let mut map2 = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();

    // Two empty maps are equal.
    assert_eq!(map1, map2);

    // Insert a single item into one map.
    let item = TestItem::new(0, 'a', "x", "v");
    map1.insert_unique(item.clone()).unwrap();

    // The maps are not equal.
    assert_ne_props(&map1, &map2);

    // Insert the same item into the other map.
    map2.insert_unique(item.clone()).unwrap();

    // The maps are now equal.
    assert_eq_props(&map1, &map2);

    {
        // Insert an item with a different key1.
        let mut map1 = map1.clone();
        map1.insert_unique(TestItem::new(1, 'b', "y", "v")).unwrap();
        assert_ne_props(&map1, &map2);

        let mut map2 = map2.clone();
        map2.insert_unique(TestItem::new(2, 'b', "y", "v")).unwrap();
        assert_ne_props(&map1, &map2);
    }

    {
        // Insert an item with a different key2.
        let mut map1 = map1.clone();
        map1.insert_unique(TestItem::new(1, 'b', "y", "v")).unwrap();
        assert_ne_props(&map1, &map2);

        let mut map2 = map2.clone();
        map2.insert_unique(TestItem::new(1, 'c', "y", "v")).unwrap();
        assert_ne_props(&map1, &map2);
    }

    {
        // Insert an item where all the keys are the same, but the value is
        // different.
        let mut map1 = map1.clone();
        map1.insert_unique(TestItem::new(1, 'b', "y", "w")).unwrap();
        assert_ne_props(&map1, &map2);

        let mut map2 = map2.clone();
        map2.insert_unique(TestItem::new(1, 'b', "y", "x")).unwrap();
        assert_ne_props(&map1, &map2);
    }
}

#[test]
#[should_panic(expected = "key1 changed during RefMut borrow")]
fn get_mut_panics_if_key1_changes() {
    let mut map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    map.insert_unique(TestItem::new(128, 'b', "y", "x")).unwrap();
    map.get1_mut(&TestKey1::new(&128)).unwrap().key1 = 2;
}

#[test]
#[should_panic(expected = "key2 changed during RefMut borrow")]
fn get_mut_panics_if_key2_changes() {
    let mut map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    map.insert_unique(TestItem::new(128, 'b', "y", "x")).unwrap();
    map.get1_mut(&TestKey1::new(&128)).unwrap().key2 = 'c';
}

#[test]
fn entry_examples() {
    let mut map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    let item1 = TestItem::new(0, 'a', "x", "v");

    let bi_hash_map::Entry::Vacant(entry) =
        map.entry(item1.key1(), item1.key2())
    else {
        panic!("expected VacantEntry")
    };
    let mut entry = entry.insert_entry(item1.clone());

    assert!(entry.is_unique());
    assert!(!entry.is_non_unique());
    assert_eq!(entry.get().as_unique(), Some(&item1));
    assert_eq!(entry.get().by_key1(), Some(&item1));
    assert_eq!(entry.get().by_key2(), Some(&item1));
    assert_eq!(entry.get_mut().as_unique().unwrap().into_ref(), &item1);
    assert_eq!(entry.get_mut().by_key1().unwrap().into_ref(), &item1);
    assert_eq!(entry.get_mut().by_key2().unwrap().into_ref(), &item1);
    assert_eq!(entry.into_ref().as_unique(), Some(&item1));

    // Test a non-unique item.
    let item2 = TestItem::new(0, 'b', "x", "v");
    let bi_hash_map::Entry::Occupied(mut entry) =
        map.entry(item2.key1(), item2.key2())
    else {
        panic!("expected OccupiedEntry")
    };

    assert!(!entry.is_unique());
    assert!(entry.is_non_unique());
    assert_eq!(entry.get().as_unique(), None);
    assert_eq!(entry.get().by_key1(), Some(&item1));
    assert_eq!(entry.get().by_key2(), None);
    assert!(entry.get_mut().as_unique().is_none());
    assert_eq!(entry.get_mut().by_key1().unwrap().into_ref(), &item1);
    assert!(entry.get_mut().by_key2().is_none());

    // Try inserting item2 into the map.
    let old_items = entry.insert(item2.clone());
    assert_eq!(old_items, vec![item1]);

    // The entry should now be unique.
    assert!(entry.is_unique());
    assert!(!entry.is_non_unique());
    assert_eq!(entry.get().as_unique(), Some(&item2));
    assert_eq!(entry.get().by_key1(), Some(&item2));
    assert_eq!(entry.get().by_key2(), Some(&item2));

    // Try removing the entry.
    let removed = entry.remove();
    assert_eq!(removed, vec![item2]);
    // There should be no items left in the map.
    assert_eq!(map.len(), 0);

    // Try adding an item with or_insert_with.
    let item3 = TestItem::new(1, 'c', "x", "v");
    {
        let mut item3_mut = map
            .entry(item3.key1(), item3.key2())
            .or_insert_with(|| item3.clone());
        assert_eq!(item3_mut.as_unique().unwrap().into_ref(), &item3);
    }

    // item4 has some conflicts so it should *not* be inserted via the
    // or_insert_with path.
    let item4 = TestItem::new(1, 'd', "x", "v");
    {
        let mut item3_mut = map
            .entry(item4.key1(), item4.key2())
            .or_insert_with(|| item4.clone());
        assert_eq!(item3_mut.by_key1().unwrap().into_ref(), &item3);
    }

    // item5 has no conflicts.
    let item5 = TestItem::new(2, 'e', "x", "v");
    {
        let mut item5_mut = map
            .entry(item5.key1(), item5.key2())
            .or_insert_with(|| item5.clone());
        assert_eq!(item5_mut.as_unique().unwrap().into_ref(), &item5);
    }

    // item6 conflicts with both item3 and item5, so `and_modify` should be
    // called twice.
    let item6 = TestItem::new(2, 'c', "x", "v");
    {
        let mut item3_seen = false;
        let mut item5_seen = false;
        let entry = map.entry(item6.key1(), item6.key2()).and_modify(|item| {
            if *item == item3 {
                item3_seen = true;
            } else if *item == item5 {
                item5_seen = true;
            }
        });
        assert!(matches!(entry, bi_hash_map::Entry::Occupied(_)));
        assert!(item3_seen);
        assert!(item5_seen);
    }
}

#[test]
#[should_panic = "key1 hashes do not match"]
fn insert_panics_for_non_matching_key1() {
    let v1 = TestItem::new(0, 'a', "foo", "value");
    let mut map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    map.insert_unique(v1.clone()).expect("insert_unique succeeded");

    let v2 = TestItem::new(1, 'b', "bar", "value");
    let entry = map.entry(TestKey1::new(&2), TestKey2::new('b'));
    assert!(matches!(entry, bi_hash_map::Entry::Vacant(_)));
    // Try inserting v2 which matches v1's key2 but not key1.
    entry.or_insert(v2);
}

#[test]
#[should_panic = "key2 hashes do not match"]
fn insert_panics_for_non_matching_key2() {
    let v1 = TestItem::new(0, 'a', "foo", "value");
    let mut map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    map.insert_unique(v1.clone()).expect("insert_unique succeeded");

    let v2 = TestItem::new(1, 'b', "bar", "value");
    let entry = map.entry(TestKey1::new(&1), TestKey2::new('c'));
    assert!(matches!(entry, bi_hash_map::Entry::Vacant(_)));
    // Try inserting v2 which matches v1's key1 but not key2.
    entry.or_insert(v2);
}

#[test]
fn entry_insert_non_matching_key1() {
    let v1 = TestItem::new(0, 'a', "foo", "value");
    let mut map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    map.insert_unique(v1.clone()).expect("insert_unique succeeded");

    let v2 = TestItem::new(1, 'a', "bar", "value");
    let entry = map.entry(v2.key1(), v2.key2());
    let bi_hash_map::Entry::Occupied(mut entry) = entry else {
        panic!("expected OccupiedEntry");
    };
    // Try inserting v1, which is present in the map.
    assert!(!entry.is_unique(), "only key1 matches");
    let old_items = entry.insert(v2);
    assert_eq!(old_items, vec![v1]);
    assert!(entry.is_unique(), "entry is now unique");
}

#[test]
fn entry_insert_non_matching_key2() {
    let v1 = TestItem::new(0, 'a', "foo", "value");
    let mut map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    map.insert_unique(v1.clone()).expect("insert_unique succeeded");

    let v2 = TestItem::new(0, 'b', "bar", "value");
    let entry = map.entry(v2.key1(), v2.key2());
    let bi_hash_map::Entry::Occupied(mut entry) = entry else {
        panic!("expected OccupiedEntry");
    };
    // Try inserting v1, which is present in the map.
    assert!(!entry.is_unique(), "only key1 matches");
    let old_items = entry.insert(v2);
    assert_eq!(old_items, vec![v1]);
    assert!(entry.is_unique(), "entry is now unique");
}

#[test]
#[should_panic = "key1 hashes do not match"]
fn insert_entry_panics_for_non_matching_keys() {
    let v1 = TestItem::new(0, 'a', "foo", "value");
    let mut map = BiHashMap::<_, HashBuilder, Alloc>::make_new();
    map.insert_unique(v1.clone()).expect("insert_unique succeeded");

    let v2 = TestItem::new(1, 'b', "bar", "value");
    let entry = map.entry(v2.key1(), v2.key2());
    assert!(matches!(entry, bi_hash_map::Entry::Vacant(_)));
    // Try inserting v1, which is present in the map.
    if let bi_hash_map::Entry::Vacant(entry) = entry {
        entry.insert_entry(v1);
    } else {
        panic!("expected VacantEntry");
    }
}

#[test]
fn borrowed_item() {
    let mut map = BiHashMap::<BorrowedItem, HashBuilder, Alloc>::default();
    let item1 = BorrowedItem {
        key1: "foo",
        key2: Cow::Borrowed(b"foo"),
        key3: Path::new("foo"),
    };
    let item2 = BorrowedItem {
        key1: "bar",
        key2: Cow::Borrowed(b"bar"),
        key3: Path::new("bar"),
    };

    // Insert items.
    map.insert_unique(item1.clone()).unwrap();
    map.insert_unique(item2.clone()).unwrap();

    // Check that we can retrieve them.
    assert_eq!(map.get1("foo").unwrap().key1, "foo");
    assert_eq!(map.get1("bar").unwrap().key1, "bar");

    // Check that we can iterate over them.
    let keys: Vec<_> = map.iter().map(|item| item.key1()).collect();
    assert_eq!(keys, vec!["foo", "bar"]);

    // Check that we can print a Debug representation, even within a function
    // (supporting this requires a little bit of unsafe code to get the
    // lifetimes to line up).
    fn fmt_debug(
        map: &BiHashMap<BorrowedItem<'_>, HashBuilder, Alloc>,
    ) -> String {
        format!("{map:?}")
    }

    #[cfg(feature = "serde")]
    fn serialize_as_map(
        map: &BiHashMap<BorrowedItem<'_>, HashBuilder, Alloc>,
    ) -> Result<String, iddqd_test_utils::serde_json::Error> {
        let mut out: Vec<u8> = Vec::new();
        let mut ser = iddqd_test_utils::serde_json::Serializer::new(&mut out);
        bi_hash_map::BiHashMapAsMap::serialize(map, &mut ser)?;
        Ok(String::from_utf8(out)
            .expect("serde_json should always emit valid UTF-8"))
    }

    static DEBUG_OUTPUT: &str = "{{k1: \"foo\", k2: [102, 111, 111]}: BorrowedItem { \
        key1: \"foo\", key2: [102, 111, 111], key3: \"foo\" }, \
        {k1: \"bar\", k2: [98, 97, 114]}: BorrowedItem { \
        key1: \"bar\", key2: [98, 97, 114], key3: \"bar\" }}";

    assert_eq!(format!("{map:?}"), DEBUG_OUTPUT);
    assert_eq!(fmt_debug(&map), DEBUG_OUTPUT);

    #[cfg(feature = "serde")]
    {
        let map_string = serialize_as_map(&map).unwrap();
        let deserialized: BiHashMap<BorrowedItem<'_>, HashBuilder, Alloc> =
            iddqd_test_utils::serde_json::from_str(&map_string).unwrap();
        assert_eq!(map, deserialized);
    }
}

#[test]
fn test_retain_all() {
    let mut map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    map.insert_unique(TestItem::new(1, 'a', "x", "foo")).unwrap();
    map.insert_unique(TestItem::new(2, 'b', "y", "bar")).unwrap();
    map.insert_unique(TestItem::new(3, 'c', "z", "baz")).unwrap();

    let original_len = map.len();
    map.retain(|_| true);

    assert_eq!(map.len(), original_len);
    assert_eq!(map.len(), 3);
    map.get1(&TestKey1::new(&1)).expect("key1=1 should be present");
    map.get1(&TestKey1::new(&2)).expect("key1=2 should be present");
    map.get1(&TestKey1::new(&3)).expect("key1=3 should be present");
}

#[test]
fn test_retain_none() {
    let mut map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    map.insert_unique(TestItem::new(1, 'a', "x", "foo")).unwrap();
    map.insert_unique(TestItem::new(2, 'b', "y", "bar")).unwrap();
    map.insert_unique(TestItem::new(3, 'c', "z", "baz")).unwrap();

    map.retain(|_| false);

    assert_eq!(map.len(), 0);
    assert!(map.is_empty());
}

#[test]
fn test_retain_value_contains() {
    let mut map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    map.insert_unique(TestItem::new(1, 'a', "x", "foo")).unwrap();
    map.insert_unique(TestItem::new(2, 'b', "y", "bar")).unwrap();
    map.insert_unique(TestItem::new(3, 'c', "z", "baz")).unwrap();
    map.insert_unique(TestItem::new(4, 'd', "w", "qux")).unwrap();

    map.retain(|item| item.value.contains('a'));

    assert_eq!(map.len(), 2);
    map.get1(&TestKey1::new(&2)).expect("key1=2 (bar) should be present");
    map.get1(&TestKey1::new(&3)).expect("key1=3 (baz) should be present");
    assert!(
        map.get1(&TestKey1::new(&1)).is_none(),
        "key1=1 (foo) should be removed"
    );
    assert!(
        map.get1(&TestKey1::new(&4)).is_none(),
        "key1=4 (qux) should be removed"
    );
}

#[test]
fn test_retain_modulo() {
    let mut map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    map.insert_unique(TestItem::new(0, 'a', "x", "v0")).unwrap();
    map.insert_unique(TestItem::new(1, 'b', "y", "v1")).unwrap();
    map.insert_unique(TestItem::new(2, 'c', "z", "v2")).unwrap();
    map.insert_unique(TestItem::new(3, 'd', "w", "v3")).unwrap();
    map.insert_unique(TestItem::new(4, 'e', "u", "v4")).unwrap();
    map.insert_unique(TestItem::new(5, 'f', "t", "v5")).unwrap();

    map.retain(|item| item.key1 % 3 == 1);

    assert_eq!(map.len(), 2);
    map.get1(&TestKey1::new(&1)).expect("key1=1 should be present");
    map.get1(&TestKey1::new(&4)).expect("key1=4 should be present");
    assert!(map.get1(&TestKey1::new(&0)).is_none(), "key1=0 should be removed");
    assert!(map.get1(&TestKey1::new(&2)).is_none(), "key1=2 should be removed");
    assert!(map.get1(&TestKey1::new(&3)).is_none(), "key1=3 should be removed");
    assert!(map.get1(&TestKey1::new(&5)).is_none(), "key1=5 should be removed");

    // Test with a larger map for miri coverage.
    let mut large_map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    for i in 0..32_u8 {
        large_map
            .insert_unique(TestItem::new(i, char::from(b'a' + i), "y", "z"))
            .unwrap();
    }

    large_map.retain(|item| item.key1 % 7 == 3);

    for i in 0..32_u8 {
        if i % 7 == 3 {
            large_map
                .get1(&TestKey1::new(&i))
                .unwrap_or_else(|| panic!("key1={} should be present", i));
        } else {
            assert!(
                large_map.get1(&TestKey1::new(&i)).is_none(),
                "key1={} should be removed",
                i
            );
        }
    }
}

#[test]
fn test_retain_empty_map() {
    let mut map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    map.retain(|_| true);
    assert!(map.is_empty());
}

#[test]
fn test_clear_empty_map() {
    let mut map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    map.clear();
    assert!(map.is_empty());
    map.validate(ValidateCompact::Compact)
        .expect("empty cleared map should be compact");
}

#[test]
fn test_clear_makes_compact() {
    let mut map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();

    // Add items
    map.insert_unique(TestItem::new(1, 'a', "x", "v1")).unwrap();
    map.insert_unique(TestItem::new(2, 'b', "y", "v2")).unwrap();
    map.insert_unique(TestItem::new(3, 'c', "z", "v3")).unwrap();

    // Remove an item to make it non-compact
    map.remove1(&TestKey1::new(&2));
    map.validate(ValidateCompact::NonCompact)
        .expect("map should be valid but non-compact");

    // Clear should make it compact again
    map.clear();
    assert!(map.is_empty());
    map.validate(ValidateCompact::Compact)
        .expect("cleared map should be compact");
}

#[test]
fn test_retain_verifies_both_keys() {
    let mut map = BiHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    map.insert_unique(TestItem::new(1, 'a', "x", "foo")).unwrap();
    map.insert_unique(TestItem::new(2, 'b', "y", "bar")).unwrap();
    map.insert_unique(TestItem::new(3, 'c', "z", "baz")).unwrap();

    // Retain only key1=2
    map.retain(|item| item.key1 == 2);

    // Verify both key1 and key2 work
    map.get1(&TestKey1::new(&2)).expect("key1=2 should be present");
    map.get2(&TestKey2::new('b')).expect("key2='b' should be present");
    assert!(map.get1(&TestKey1::new(&1)).is_none());
    assert!(map.get2(&TestKey2::new('a')).is_none());
}

mod macro_tests {
    use super::*;

    #[derive(Debug, PartialEq)]
    struct User {
        id: u32,
        name: String,
    }

    impl BiHashItem for User {
        type K1<'a> = u32;
        type K2<'a> = &'a str;
        fn key1(&self) -> Self::K1<'_> {
            self.id
        }
        fn key2(&self) -> Self::K2<'_> {
            &self.name
        }
        bi_upcast!();
    }

    #[cfg(feature = "default-hasher")]
    #[test]
    fn macro_basic() {
        let map = bi_hash_map! {
            User { id: 1, name: "Alice".to_string() },
            User { id: 2, name: "Bob".to_string() },
        };

        assert_eq!(map.len(), 2);
        assert_eq!(map.get1(&1).unwrap().name, "Alice");
        assert_eq!(map.get2("Bob").unwrap().id, 2);
    }

    #[test]
    fn macro_with_hasher() {
        let map = bi_hash_map! {
            HashBuilder;
            User { id: 3, name: "Charlie".to_string() },
            User { id: 4, name: "David".to_string() },
        };

        assert_eq!(map.len(), 2);
        assert_eq!(map.get1(&3).unwrap().name, "Charlie");
        assert_eq!(map.get2("David").unwrap().id, 4);
    }

    #[cfg(feature = "default-hasher")]
    #[test]
    fn macro_empty() {
        let empty_map: BiHashMap<User> = bi_hash_map! {};
        assert!(empty_map.is_empty());
    }

    #[cfg(feature = "default-hasher")]
    #[test]
    fn macro_without_trailing_comma() {
        let map = bi_hash_map! {
            User { id: 1, name: "Alice".to_string() }
        };
        assert_eq!(map.len(), 1);
    }

    #[cfg(feature = "default-hasher")]
    #[test]
    #[should_panic(expected = "DuplicateItem")]
    fn macro_duplicate_key1() {
        let _map = bi_hash_map! {
            User { id: 1, name: "Alice".to_string() },
            User { id: 1, name: "Bob".to_string() },
        };
    }

    #[cfg(feature = "default-hasher")]
    #[test]
    #[should_panic(expected = "DuplicateItem")]
    fn macro_duplicate_key2() {
        let _map = bi_hash_map! {
            User { id: 1, name: "Alice".to_string() },
            User { id: 2, name: "Alice".to_string() },
        };
    }
}

#[cfg(feature = "serde")]
mod serde_tests {
    use iddqd::BiHashMap;
    use iddqd_test_utils::{
        serde_utils::assert_serialize_roundtrip,
        test_item::{Alloc, HashBuilder, TestItem},
    };
    use test_strategy::proptest;

    #[proptest]
    fn proptest_serialize_roundtrip(values: Vec<TestItem>) {
        assert_serialize_roundtrip::<BiHashMap<TestItem, HashBuilder, Alloc>>(
            values,
        );
    }
}

#[cfg(feature = "proptest")]
#[proptest(cases = 16)]
fn proptest_arbitrary_map(map: BiHashMap<TestItem, HashBuilder, Alloc>) {
    // Test that the arbitrarily generated map is valid.
    map.validate(ValidateCompact::NonCompact).expect("map should be valid");

    // Test that we can perform basic operations on the generated map.
    let len = map.len();
    assert_eq!(map.is_empty(), len == 0);

    // Test that we can iterate over the map.
    let mut count = 0;
    for item in &map {
        count += 1;
        // Each item should be findable by both keys.
        assert_eq!(map.get1(&item.key1()), Some(item));
        assert_eq!(map.get2(&item.key2()), Some(item));
    }
    assert_eq!(count, len);
}
