//! Property testing for map index as a rust collection.

// cspell:ignore oneof

use modifier::Modifier;
use proptest::{
    collection::vec, num, prop_assert, prop_assert_eq, prop_oneof, proptest, strategy,
    strategy::Strategy, test_runner::TestCaseResult,
};

use std::{collections::HashMap, hash::Hash, rc::Rc};

use metaldb::{access::AccessExt, BinaryValue, Fork, MapIndex, TemporaryDB};

use crate::common::{compare_collections, AsForkAction, ForkAction, FromFork, ACTIONS_MAX_LEN};

mod common;
mod key;

#[derive(Debug, Clone)]
enum MapAction<K, V> {
    // Should be applied to a small subset of keys (like modulo 8 for int).
    Put(K, V),
    // Should be applied to a small subset of keys (like modulo 8 for int).
    Remove(K),
    Clear,
    MergeFork,
}

impl<K, V> AsForkAction for MapAction<K, V> {
    fn as_fork_action(&self) -> Option<ForkAction> {
        match self {
            MapAction::MergeFork => Some(ForkAction::Merge),
            _ => None,
        }
    }
}

impl<K, V> Modifier<HashMap<K, V>> for MapAction<K, V>
where
    K: Eq + Hash,
{
    fn modify(self, map: &mut HashMap<K, V>) {
        match self {
            MapAction::Put(k, v) => {
                map.insert(k, v);
            }
            MapAction::Remove(k) => {
                map.remove(&k);
            }
            MapAction::Clear => {
                map.clear();
            }
            _ => unreachable!(),
        }
    }
}

impl<V> Modifier<MapIndex<Rc<Fork>, u8, V>> for MapAction<u8, V>
where
    V: BinaryValue,
{
    fn modify(self, map: &mut MapIndex<Rc<Fork>, u8, V>) {
        match self {
            MapAction::Put(k, v) => {
                map.put(&k, v);
            }
            MapAction::Remove(k) => {
                map.remove(&k);
            }
            MapAction::Clear => {
                map.clear();
            }
            _ => unreachable!(),
        }
    }
}

impl<V: BinaryValue> FromFork for MapIndex<Rc<Fork>, u8, V> {
    fn from_fork(fork: Rc<Fork>) -> Self {
        fork.get_map("test")
    }

    fn clear(&mut self) {
        self.clear();
    }
}

fn compare_map(map: &MapIndex<Rc<Fork>, u8, i32>, ref_map: &HashMap<u8, i32>) -> TestCaseResult {
    for k in ref_map.keys() {
        prop_assert!(map.contains(k));
    }
    for (k, v) in map.iter() {
        prop_assert_eq!(Some(&v), ref_map.get(&k));
    }
    Ok(())
}

fn generate_action() -> impl Strategy<Value = MapAction<u8, i32>> {
    prop_oneof![
        (num::u8::ANY, num::i32::ANY).prop_map(|(i, v)| MapAction::Put(i, v)),
        num::u8::ANY.prop_map(MapAction::Remove),
        strategy::Just(MapAction::Clear),
        strategy::Just(MapAction::MergeFork),
    ]
}

#[test]
fn compare_map_to_hash_map() {
    let db = TemporaryDB::new();
    proptest!(|(ref actions in vec(generate_action(), 1..ACTIONS_MAX_LEN))| {
        compare_collections(&db, actions, compare_map)?;
    });
}