use iddqd::{
    IdHashItem, IdHashMap, id_hash_map, id_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, assert_iter_eq,
        test_item_permutation_strategy,
    },
};
use proptest::prelude::*;
use std::{
    borrow::Cow,
    path::{Path, PathBuf},
};
use test_strategy::{Arbitrary, proptest};

#[derive(Clone, Debug)]
struct SimpleItem {
    key: u32,
}

impl IdHashItem for SimpleItem {
    type Key<'a> = u32;

    fn key(&self) -> Self::Key<'_> {
        self.key
    }

    id_upcast!();
}

#[test]
fn debug_impls() {
    let mut map = IdHashMap::<SimpleItem, HashBuilder, Alloc>::make_new();
    map.insert_unique(SimpleItem { key: 1 }).unwrap();
    map.insert_unique(SimpleItem { key: 20 }).unwrap();
    map.insert_unique(SimpleItem { key: 10 }).unwrap();

    assert_eq!(
        format!("{map:?}"),
        // Iteration is in insertion order.
        r#"{1: SimpleItem { key: 1 }, 20: SimpleItem { key: 20 }, 10: SimpleItem { key: 10 }}"#
    );
    assert_eq!(
        format!("{:?}", map.get_mut(&1).unwrap()),
        "SimpleItem { key: 1 }"
    );
}

#[test]
fn debug_impls_borrowed() {
    let before = id_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#"{"a": BorrowedItem { key1: "a", key2: [98, 48], key3: "path0" }, "b": BorrowedItem { key1: "b", key2: [98, 49], key3: "path1" }, "c": BorrowedItem { key1: "c", key2: [98, 50], key3: "path2" }}"#
    );

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

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

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

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

    // Add an element.
    let v1 = TestItem::new(20, '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(20, 'b', "y", "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 key2. IdHashMap only uses key1 here, so this
    // should be allowed.
    let v3 = TestItem::new(5, 'a', "y", "v");
    map.insert_unique(v3.clone()).unwrap();

    // Add a duplicate against key1, which should error out.
    let v4 = TestItem::new(5, 'b', "x", "v");
    let error = map.insert_unique(v4.clone()).unwrap_err();
    assert_eq!(error.new_item(), &v4);

    // Iterate over the items mutably. This ensures that miri detects UB if it
    // exists.
    let mut items: Vec<id_hash_map::RefMut<_, HashBuilder>> =
        map.iter_mut().collect();
    items.sort_by(|a, b| a.key().cmp(&b.key()));
    let e1 = &items[0];
    assert_eq!(**e1, v3);

    // Test that the RefMut Debug impl looks good.
    assert!(
        format!("{e1:?}").starts_with(
            r#"TestItem { key1: 5, key2: 'a', key3: "y", value: "v""#,
        ),
        "RefMut Debug impl should forward to TestItem",
    );

    let e2 = &*items[1];
    assert_eq!(*e2, v1);
}

// Test that the unsafe block within RefMut doesn't trip up miri.
#[test]
fn test_ref_mut_aliasing() {
    let mut map = IdHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    for i in 0..16_u8 {
        map.insert_unique(TestItem::new(i, 'a', "x", "v")).unwrap();
    }

    let mut items: Vec<_> = map.iter_mut().collect();
    for (i, item) in items.iter_mut().enumerate() {
        item.value = format!("written-{i}");
    }
    drop(items);

    for i in 0..16_u8 {
        let item = map.get(&TestKey1::new(&i)).unwrap();
        assert!(item.value.starts_with("written-"));
    }
}

#[test]
fn test_extend() {
    let mut map = IdHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    let items = vec![
        TestItem::new(1, 'a', "x", "v"),
        TestItem::new(2, 'b', "y", "w"),
        TestItem::new(1, 'c', "z", "overwritten"), // duplicate key, should overwrite
    ];
    map.extend(items.clone());
    assert_eq!(map.len(), 2);
    assert_eq!(map.get(&TestKey1::new(&1)).unwrap().value, "overwritten");
    assert_eq!(map.get(&TestKey1::new(&2)).unwrap().value, "w");
}

#[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)]
    EntryInsertOverwrite(TestItem),
    #[weight(2)]
    EntryRemove(u8),
    #[weight(2)]
    Get(u8),
    #[weight(2)]
    Remove(u8),
    #[weight(2)]
    RetainValueContains(char, bool),
    #[weight(2)]
    RetainModulo(#[strategy(0..3_u8)] u8, #[strategy(1..4_u8)] u8, bool),
    #[weight(2)]
    Extend(
        #[strategy(prop::collection::vec(any::<TestItem>(), 0..16))]
        Vec<TestItem>,
    ),
    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 {
            Operation::InsertUnique(_)
            | Operation::Get(_)
            | Operation::Reserve(_)
            | Operation::TryReserve(_) => CompactnessChange::NoChange,
            // The act of removing items, including calls to insert_overwrite,
            // can make the map non-compact.
            Operation::InsertOverwrite(_)
            | Operation::EntryInsertOverwrite(_)
            | Operation::EntryRemove(_)
            | Operation::Remove(_)
            | Operation::RetainValueContains(_, _)
            | Operation::RetainModulo(_, _, _)
            | Operation::Extend(_) => CompactnessChange::NoLongerCompact,
            // Clear empties the map, so it is de-facto compact. Shrink
            // operations fully compact the backing store, restoring the
            // `Compact` invariant.
            Operation::Clear
            | Operation::ShrinkToFit
            | Operation::ShrinkTo(_) => CompactnessChange::BecomesCompact,
        }
    }
}

#[proptest(cases = 16)]
fn proptest_ops(
    #[strategy(prop::collection::vec(any::<Operation>(), 0..1024))] ops: Vec<
        Operation,
    >,
) {
    let mut map = IdHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    let mut naive_map = NaiveMap::new_key1();

    let mut compactness = ValidateCompact::Compact;

    // Now perform the operations on both maps.
    for op in ops {
        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());
                if let Err(map_err) = map_res {
                    let naive_err = naive_res.unwrap_err();
                    assert_eq!(map_err.new_item(), naive_err.new_item());
                    assert_eq!(map_err.duplicates(), naive_err.duplicates());
                }

                map.validate(compactness).expect("map should be valid");
            }
            Operation::InsertOverwrite(item) => {
                let map_dups = map.insert_overwrite(item.clone());
                let mut naive_dups = naive_map.insert_overwrite(item.clone());
                assert!(naive_dups.len() <= 1, "max one conflict");
                let naive_dup = naive_dups.pop();

                assert_eq!(
                    map_dups, naive_dup,
                    "map and naive map should agree on insert_overwrite dup"
                );
                map.validate(compactness).expect("map should be valid");
            }
            Operation::EntryInsertOverwrite(item) => {
                let map_res = match map.entry(item.key()) {
                    id_hash_map::Entry::Occupied(mut entry) => {
                        Some(entry.insert(item.clone()))
                    }
                    id_hash_map::Entry::Vacant(_) => None,
                };

                let occupied = naive_map.get1(item.key1).is_some();
                let naive_res = occupied.then(|| {
                    let mut dups = naive_map.insert_overwrite(item.clone());
                    assert!(dups.len() <= 1, "max one conflict");
                    dups.pop().expect("occupied entry has one duplicate")
                });

                assert_eq!(
                    map_res, naive_res,
                    "map and naive map should agree on Entry::insert"
                );
                map.validate(compactness).expect("map should be valid");
            }
            Operation::EntryRemove(key) => {
                let map_res = match map.entry(TestKey1::new(&key)) {
                    id_hash_map::Entry::Occupied(entry) => Some(entry.remove()),
                    id_hash_map::Entry::Vacant(_) => None,
                };

                let naive_res = naive_map.remove1(key);

                assert_eq!(
                    map_res, naive_res,
                    "map and naive map should agree on Entry::remove"
                );
                map.validate(compactness).expect("map should be valid");
            }

            Operation::Get(key) => {
                let map_res = map.get(&TestKey1::new(&key));
                let naive_res = naive_map.get1(key);

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

                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::Extend(items) => {
                map.extend(items.clone());
                naive_map.extend(items);
                map.validate(compactness).expect("map should be valid");
            }
            Operation::Clear => {
                map.clear();
                naive_map.clear();
                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();
                // The naive map has no shrink operation.
                map.validate(compactness).expect("map should be valid");
            }
            Operation::ShrinkTo(min_capacity) => {
                map.shrink_to(min_capacity);
                // The naive map has no shrink operation.
                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.key().cmp(&b.key()));

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

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

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

    assert_eq_props(&map1, &map2);
}

// Test various conditions for non-equality.
#[test]
fn test_permutation_eq_examples() {
    let mut map1 = IdHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    let mut map2 = IdHashMap::<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 the same key2 and key3 but 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 the same key1 and key3 but 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 with the same key1 and key2 but a different key3.
        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, 'b', "z", "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 = "key changed during RefMut borrow")]
fn get_mut_panics_if_key_changes() {
    let mut map = IdHashMap::<TestItem, HashBuilder, Alloc>::make_new();
    map.insert_unique(TestItem::new(128, 'b', "y", "x")).unwrap();
    map.get_mut(&TestKey1::new(&128)).unwrap().key1 = 2;
}

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

    let id_hash_map::Entry::Vacant(entry) = map.entry(item1.key()) else {
        panic!("expected VacantEntry")
    };
    let mut entry = entry.insert_entry(item1.clone());

    assert_eq!(entry.get(), &item1);
    assert_eq!(entry.get_mut().into_ref(), &item1);
    assert_eq!(entry.into_ref(), &item1);

    // Try looking up another item with the same key1.
    let item2 = TestItem::new(0, 'b', "y", "x");

    let id_hash_map::Entry::Occupied(mut entry) = map.entry(item2.key()) else {
        panic!("expected OccupiedEntry");
    };
    assert_eq!(entry.insert(item2.clone()), item1);

    assert_eq!(entry.remove(), item2);

    // Put item2 back in via the Entry API.
    let item2_mut = map.entry(item2.key()).or_insert(item2.clone());
    assert_eq!(item2_mut.into_ref(), &item2);

    // Add another item using or_insert_with.
    let item3 = TestItem::new(1, 'b', "y", "x");
    let item3_mut = map.entry(item3.key()).or_insert_with(|| item3.clone());
    assert_eq!(item3_mut.into_ref(), &item3);

    // item4 is similar to item3 except with a different value.
    let item4 = TestItem::new(1, 'b', "y", "some-other-value");
    // item4 should *not* be inserted via this path.
    let item3_mut = map.entry(item4.key()).or_insert(item4.clone());
    assert_eq!(item3_mut.into_ref(), &item3);

    // Similarly, item4 should *not* be inserted via the or_insert_with path.
    let item3_mut = map
        .entry(item4.key())
        .or_insert_with(|| panic!("or_insert_with called for existing key"));
    assert_eq!(item3_mut.into_ref(), &item3);

    // The and_modify path should be called, however.
    let mut and_modify_called = false;
    map.entry(item4.key()).and_modify(|_| and_modify_called = true);
    assert!(and_modify_called);
}

#[test]
#[should_panic = "key hashes do not match"]
fn insert_panics_for_non_matching_key() {
    let v1 = TestItem::new(0, 'a', "foo", "value");
    let mut map = IdHashMap::<_, 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.key());
    assert!(matches!(entry, id_hash_map::Entry::Vacant(_)));
    // Try inserting v1, which is present in the map.
    entry.or_insert(v1);
}

#[test]
#[should_panic = "key hashes do not match"]
fn insert_entry_panics_for_non_matching_key() {
    let v1 = TestItem::new(0, 'a', "foo", "value");
    let mut map = IdHashMap::<_, 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.key());
    assert!(matches!(entry, id_hash_map::Entry::Vacant(_)));
    // Try inserting v1, which is present in the map.
    if let id_hash_map::Entry::Vacant(vacant_entry) = entry {
        vacant_entry.insert_entry(v1);
    } else {
        panic!("expected VacantEntry");
    }
}

#[test]
fn borrowed_item() {
    let mut map = IdHashMap::<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.get("foo").unwrap().key1, "foo");
    assert_eq!(map.get("bar").unwrap().key1, "bar");

    // Check that we can iterate over them.
    let keys: Vec<_> = map.iter().map(|item| item.key()).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: &IdHashMap<BorrowedItem<'_>, HashBuilder, Alloc>,
    ) -> String {
        format!("{map:?}")
    }

    #[cfg(feature = "serde")]
    fn serialize_as_map(
        map: &IdHashMap<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);
        id_hash_map::IdHashMapAsMap::serialize(map, &mut ser)?;
        Ok(String::from_utf8(out)
            .expect("serde_json should always emit valid UTF-8"))
    }

    static DEBUG_OUTPUT: &str = "{\"foo\": BorrowedItem { \
        key1: \"foo\", key2: [102, 111, 111], key3: \"foo\" }, \
        \"bar\": 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: IdHashMap<BorrowedItem<'_>, HashBuilder, Alloc> =
            iddqd_test_utils::serde_json::from_str(&map_string).unwrap();
        assert_eq!(map, deserialized);
    }
}

#[test]
fn borrowed_item_retain_non_static() {
    let foo_key = String::from("foo");
    let bar_key = String::from("bar");
    let foo_bytes = b"foo".to_vec();
    let bar_bytes = b"bar".to_vec();
    let foo_path = PathBuf::from("foo");
    let bar_path = PathBuf::from("bar");

    let mut map = IdHashMap::<BorrowedItem<'_>, HashBuilder, Alloc>::default();
    map.insert_unique(BorrowedItem {
        key1: foo_key.as_str(),
        key2: Cow::Borrowed(foo_bytes.as_slice()),
        key3: foo_path.as_path(),
    })
    .unwrap();
    map.insert_unique(BorrowedItem {
        key1: bar_key.as_str(),
        key2: Cow::Borrowed(bar_bytes.as_slice()),
        key3: bar_path.as_path(),
    })
    .unwrap();

    map.retain(|item| item.key1 == foo_key.as_str());

    assert_eq!(map.len(), 1);
    assert!(map.get(foo_key.as_str()).is_some());
    assert!(map.get(bar_key.as_str()).is_none());
}

#[test]
fn test_retain_all() {
    let mut map = IdHashMap::<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.get(&TestKey1::new(&1)).expect("key 1 should be present");
    map.get(&TestKey1::new(&2)).expect("key 2 should be present");
    map.get(&TestKey1::new(&3)).expect("key 3 should be present");
}

#[test]
fn test_retain_none() {
    let mut map = IdHashMap::<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 = IdHashMap::<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.get(&TestKey1::new(&2)).expect("key 2 (bar) should be present");
    map.get(&TestKey1::new(&3)).expect("key 3 (baz) should be present");
    assert!(
        map.get(&TestKey1::new(&1)).is_none(),
        "key 1 (foo) should be removed"
    );
    assert!(
        map.get(&TestKey1::new(&4)).is_none(),
        "key 4 (qux) should be removed"
    );
}

#[test]
fn test_retain_modulo() {
    let mut map = IdHashMap::<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.get(&TestKey1::new(&1)).expect("key 1 should be present");
    map.get(&TestKey1::new(&4)).expect("key 4 should be present");
    assert!(map.get(&TestKey1::new(&0)).is_none(), "key 0 should be removed");
    assert!(map.get(&TestKey1::new(&2)).is_none(), "key 2 should be removed");
    assert!(map.get(&TestKey1::new(&3)).is_none(), "key 3 should be removed");
    assert!(map.get(&TestKey1::new(&5)).is_none(), "key 5 should be removed");

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

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

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

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

#[test]
fn test_clear_empty_map() {
    let mut map = IdHashMap::<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 = IdHashMap::<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.remove(&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");
}

mod macro_tests {
    use super::*;

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

    impl IdHashItem for User {
        type Key<'a> = u32;
        fn key(&self) -> Self::Key<'_> {
            self.id
        }
        id_upcast!();
    }

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

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

    #[test]
    fn macro_with_hasher() {
        let map = id_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.get(&3).unwrap().name, "Charlie");
        assert_eq!(map.get(&4).unwrap().name, "David");
    }

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

    #[cfg(feature = "default-hasher")]
    #[test]
    fn macro_without_trailing_comma() {
        let map = id_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_key() {
        let _map = id_hash_map! {
            User { id: 1, name: "Alice".to_string() },
            User { id: 1, name: "Bob".to_string() },
        };
    }
}

#[cfg(feature = "proptest")]
#[proptest(cases = 16)]
fn proptest_arbitrary_map(map: IdHashMap<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 its key.
        assert_eq!(map.get(&item.key()), Some(item));
    }
    assert_eq!(count, len);
}

#[cfg(feature = "serde")]
mod serde_tests {
    use iddqd::IdHashMap;
    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::<IdHashMap<TestItem, HashBuilder, Alloc>>(
            values,
        );
    }
}

#[cfg(all(feature = "default-hasher", feature = "allocator-api2"))]
#[derive(Clone, Debug)]
struct PanickyHashItem {
    key: u32,
}

#[cfg(all(feature = "default-hasher", feature = "allocator-api2"))]
impl IdHashItem for PanickyHashItem {
    type Key<'a> = iddqd_test_utils::panic_safety::PanickyKey;

    fn key(&self) -> Self::Key<'_> {
        iddqd_test_utils::panic_safety::observe_panicky_call("key");
        iddqd_test_utils::panic_safety::PanickyKey(self.key)
    }

    id_upcast!();
}

#[cfg(all(feature = "default-hasher", feature = "allocator-api2"))]
impl Drop for PanickyHashItem {
    fn drop(&mut self) {
        iddqd_test_utils::panic_safety::observe_panicky_call("item-drop");
    }
}

#[cfg(all(feature = "default-hasher", feature = "allocator-api2"))]
mod proptest_panic_safety {
    use super::*;
    use allocator_api2::alloc::Global;
    use iddqd_test_utils::panic_safety::{
        PANIC_PROPTEST_CASES, PANIC_PROPTEST_MAX_OPS, PanicSafety,
        PanickyAlloc, PanickyKey, PanickyOp, PanickySearchKey,
        assert_panic_fired_as_expected, assert_post_op_invariants,
        drop_unarmed, record_observation, run_armed, sorted_keys,
    };

    /// Map type used by these tests.
    type PanickyMap = IdHashMap<
        PanickyHashItem,
        iddqd::DefaultHashBuilder,
        PanickyAlloc<Global>,
    >;

    // Keys are kept in a small range so collisions, hits, and misses
    // all happen frequently against a 16-ish-element map.
    #[derive(Debug, Arbitrary)]
    enum PanickyAction {
        #[weight(4)]
        InsertUnique(#[strategy(0..32_u32)] u32),
        #[weight(3)]
        InsertOverwrite(#[strategy(0..32_u32)] u32),
        #[weight(3)]
        EntryInsertOverwrite(#[strategy(0..32_u32)] u32),
        #[weight(2)]
        EntryRemove(#[strategy(0..32_u32)] u32),
        #[weight(2)]
        Remove(#[strategy(0..32_u32)] u32),
        #[weight(2)]
        Get(#[strategy(0..32_u32)] u32),
        #[weight(1)]
        ContainsKey(#[strategy(0..32_u32)] u32),
        #[weight(2)]
        RetainModulo(
            #[strategy(0..3_u32)] u32,
            #[strategy(1..4_u32)] u32,
            bool,
        ),
        #[weight(2)]
        Extend(#[strategy(prop::collection::vec(0..32_u32, 0..8))] Vec<u32>),
        Clear,
        ShrinkToFit,
        ShrinkTo(#[strategy(0..32_usize)] usize),
    }

    impl PanickyAction {
        /// Classify panic safety for this action.
        ///
        /// * `RetainModulo` and `Clear` loop over per-step atomic item
        ///   destruction.
        /// * `Extend` is a sequence of per-step atomic `insert_overwrite`
        ///   calls; a mid-sequence panic leaves earlier inserts committed.
        fn panic_safety(&self) -> PanicSafety {
            match self {
                PanickyAction::InsertUnique(_)
                | PanickyAction::InsertOverwrite(_)
                | PanickyAction::EntryInsertOverwrite(_)
                | PanickyAction::EntryRemove(_)
                | PanickyAction::Remove(_)
                | PanickyAction::Get(_)
                | PanickyAction::ContainsKey(_)
                | PanickyAction::ShrinkToFit
                | PanickyAction::ShrinkTo(_) => PanicSafety::Atomic,
                PanickyAction::RetainModulo(_, _, _)
                | PanickyAction::Extend(_)
                | PanickyAction::Clear => PanicSafety::StepAtomic,
            }
        }

        fn run(self, map: &mut PanickyMap) {
            match self {
                PanickyAction::InsertUnique(key) => {
                    drop_unarmed(map.insert_unique(PanickyHashItem { key }));
                }
                PanickyAction::InsertOverwrite(key) => {
                    drop_unarmed(map.insert_overwrite(PanickyHashItem { key }));
                }
                PanickyAction::EntryInsertOverwrite(key) => {
                    let entry = map.entry(PanickyKey(key));

                    if let id_hash_map::Entry::Occupied(mut entry) = entry {
                        drop_unarmed(entry.insert(PanickyHashItem { key }));
                    }
                }
                PanickyAction::EntryRemove(key) => {
                    let entry = map.entry(PanickyKey(key));

                    if let id_hash_map::Entry::Occupied(entry) = entry {
                        drop_unarmed(entry.remove());
                    }
                }
                PanickyAction::Remove(key) => {
                    drop_unarmed(map.remove(&PanickySearchKey(key)));
                }
                PanickyAction::Get(key) => {
                    let _ = map.get(&PanickySearchKey(key));
                }
                PanickyAction::ContainsKey(key) => {
                    let _ = map.contains_key(&PanickySearchKey(key));
                }
                PanickyAction::RetainModulo(rem, modulo, keep) => {
                    map.retain(|item| {
                        let matches = item.key % modulo == rem;
                        if keep { matches } else { !matches }
                    });
                }
                PanickyAction::Extend(keys) => {
                    map.extend(
                        keys.into_iter().map(|key| PanickyHashItem { key }),
                    );
                }
                PanickyAction::Clear => map.clear(),
                PanickyAction::ShrinkToFit => map.shrink_to_fit(),
                PanickyAction::ShrinkTo(min_capacity) => {
                    map.shrink_to(min_capacity);
                }
            }
        }
    }

    #[proptest(cases = PANIC_PROPTEST_CASES)]
    fn proptest_panic_ops(
        #[strategy(prop::collection::vec(
            any::<PanickyOp<PanickyAction>>(), 0..PANIC_PROPTEST_MAX_OPS,
        ))]
        ops: Vec<PanickyOp<PanickyAction>>,
    ) {
        let mut map: PanickyMap = IdHashMap::with_hasher_in(
            iddqd::DefaultHashBuilder::default(),
            PanickyAlloc::default(),
        );

        for (i, op) in ops.into_iter().enumerate() {
            let action = op.action;
            let action_label = format!("{action:?}");
            let panic_safety = action.panic_safety();
            let armed = op.armed;

            let pre_state = sorted_keys(&map, |item| item.key);
            let (panicked, ops) = run_armed(armed, || action.run(&mut map));
            record_observation("id_hash_map", &action_label, ops);
            assert_panic_fired_as_expected(&action_label, armed, panicked, ops);

            // `NonCompact` since step-atomic panics leave compactness
            // in an indeterminate state.
            map.validate(ValidateCompact::NonCompact).unwrap_or_else(|err| {
                panic!(
                    "map invalid after op {i} ({action_label}, \
                     armed: {armed:?}, panicked: {panicked}): {err}"
                )
            });

            let post_state = sorted_keys(&map, |item| item.key);
            assert_post_op_invariants(
                i,
                &action_label,
                armed,
                panicked,
                panic_safety,
                &pre_state,
                &post_state,
                |&k| map.contains_key(&PanickySearchKey(k)),
            );
        }
    }
}
