clashmap 1.2.1

use super::one::RefMut;
use crate::tableref;
use core::mem;

pub enum Entry<'a, K, V> {
    Occupied(OccupiedEntry<'a, K, V>),
    Vacant(VacantEntry<'a, K, V>),
}

impl<'a, K, V> Entry<'a, K, V> {
    /// Apply a function to the stored value if it exists.
    pub fn and_modify(self, f: impl FnOnce(&mut V)) -> Self {
        match self {
            Entry::Occupied(mut entry) => {
                f(entry.get_mut());

                Entry::Occupied(entry)
            }

            Entry::Vacant(entry) => Entry::Vacant(entry),
        }
    }

    /// Get the key of the entry.
    pub fn key(&self) -> &K {
        match *self {
            Entry::Occupied(ref entry) => entry.key(),
            Entry::Vacant(ref entry) => entry.key(),
        }
    }

    /// Into the key of the entry.
    pub fn into_key(self) -> K {
        match self {
            Entry::Occupied(entry) => entry.into_key(),
            Entry::Vacant(entry) => entry.into_key(),
        }
    }

    /// Return a mutable reference to the element if it exists,
    /// otherwise insert the default and return a mutable reference to that.
    pub fn or_default(self) -> RefMut<'a, K, V>
    where
        V: Default,
    {
        match self {
            Entry::Occupied(entry) => entry.into_ref(),
            Entry::Vacant(entry) => entry.insert(V::default()),
        }
    }

    /// Return a mutable reference to the element if it exists,
    /// otherwise a provided value and return a mutable reference to that.
    pub fn or_insert(self, value: V) -> RefMut<'a, K, V> {
        match self {
            Entry::Occupied(entry) => entry.into_ref(),
            Entry::Vacant(entry) => entry.insert(value),
        }
    }

    /// Return a mutable reference to the element if it exists,
    /// otherwise insert the result of a provided function and return a mutable reference to that.
    pub fn or_insert_with(self, value: impl FnOnce() -> V) -> RefMut<'a, K, V> {
        match self {
            Entry::Occupied(entry) => entry.into_ref(),
            Entry::Vacant(entry) => entry.insert(value()),
        }
    }

    pub fn or_try_insert_with<E>(
        self,
        value: impl FnOnce() -> Result<V, E>,
    ) -> Result<RefMut<'a, K, V>, E> {
        match self {
            Entry::Occupied(entry) => Ok(entry.into_ref()),
            Entry::Vacant(entry) => Ok(entry.insert(value()?)),
        }
    }

    /// Sets the value of the entry, and returns a reference to the inserted value.
    pub fn insert(self, value: V) -> RefMut<'a, K, V> {
        match self {
            Entry::Occupied(mut entry) => {
                entry.insert(value);
                entry.into_ref()
            }
            Entry::Vacant(entry) => entry.insert(value),
        }
    }

    /// Sets the value of the entry, and returns an OccupiedEntry.
    ///
    /// If you are not interested in the occupied entry,
    /// consider [`insert`] as it doesn't need to clone the key.
    ///
    /// [`insert`]: Entry::insert
    pub fn insert_entry(self, value: V) -> OccupiedEntry<'a, K, V>
    where
        K: Clone,
    {
        match self {
            Entry::Occupied(mut entry) => {
                entry.insert(value);
                entry
            }
            Entry::Vacant(entry) => entry.insert_entry(value),
        }
    }
}

pub struct VacantEntry<'a, K, V> {
    entry: tableref::entry::VacantEntry<'a, (K, V)>,
    key: K,
}

impl<'a, K, V> VacantEntry<'a, K, V> {
    pub(crate) fn new(entry: tableref::entry::VacantEntry<'a, (K, V)>, key: K) -> Self {
        Self { key, entry }
    }

    pub fn insert(self, value: V) -> RefMut<'a, K, V> {
        self.entry.insert((self.key, value)).into()
    }

    /// Sets the value of the entry with the VacantEntry’s key, and returns an OccupiedEntry.
    pub fn insert_entry(self, value: V) -> OccupiedEntry<'a, K, V>
    where
        K: Clone,
    {
        let entry = self.entry.insert_entry((self.key.clone(), value));
        OccupiedEntry::new(entry, self.key)
    }

    pub fn into_key(self) -> K {
        self.key
    }

    pub fn key(&self) -> &K {
        &self.key
    }
}

pub struct OccupiedEntry<'a, K, V> {
    entry: tableref::entry::OccupiedEntry<'a, (K, V)>,
    key: K,
}

impl<'a, K, V> OccupiedEntry<'a, K, V> {
    pub(crate) fn new(entry: tableref::entry::OccupiedEntry<'a, (K, V)>, key: K) -> Self {
        Self { key, entry }
    }

    pub fn get(&self) -> &V {
        &self.entry.get().1
    }

    pub fn get_mut(&mut self) -> &mut V {
        &mut self.entry.get_mut().1
    }

    pub fn insert(&mut self, value: V) -> V {
        mem::replace(self.get_mut(), value)
    }

    pub fn into_ref(self) -> RefMut<'a, K, V> {
        self.entry.into_mut().into()
    }

    pub fn into_key(self) -> K {
        self.key
    }

    pub fn key(&self) -> &K {
        &self.entry.get().0
    }

    pub fn remove(self) -> V {
        self.entry.remove().1
    }

    pub fn remove_entry(self) -> (K, V) {
        self.entry.remove()
    }

    pub fn replace_entry(self, value: V) -> (K, V) {
        mem::replace(self.entry.into_mut().t, (self.key, value))
    }
}

#[cfg(test)]
mod tests {
    use crate::ClashMap;

    use super::*;

    #[test]
    fn test_insert_entry_into_vacant() {
        let map: ClashMap<u32, u32> = ClashMap::new();

        let entry = map.entry(1);

        assert!(matches!(entry, Entry::Vacant(_)));

        let entry = entry.insert_entry(2);

        assert_eq!(*entry.get(), 2);

        drop(entry);

        assert_eq!(*map.get(&1).unwrap(), 2);
    }

    #[test]
    fn test_insert_entry_into_occupied() {
        let map: ClashMap<u32, u32> = ClashMap::new();

        map.insert(1, 1000);

        let entry = map.entry(1);

        assert!(matches!(&entry, Entry::Occupied(entry) if *entry.get() == 1000));

        let entry = entry.insert_entry(2);

        assert_eq!(*entry.get(), 2);

        drop(entry);

        assert_eq!(*map.get(&1).unwrap(), 2);
    }
}