// Copyright 2016 Mozilla
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use
// this file except in compliance with the License. You may obtain a copy of the
// License at http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software distributed
// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
// CONDITIONS OF ANY KIND, either express or implied. See the License for the
// specific language governing permissions and limitations under the License.

extern crate mentat;
extern crate core_traits;

#[cfg(feature = "syncable")]
extern crate mentat_tolstoy;

#[cfg(feature = "syncable")]
mod tests {
    use std::collections::BTreeMap;

    use mentat::conn::Conn;

    use mentat::new_connection;
    use mentat_tolstoy::tx_processor::{
        Processor,
        TxReceiver,
        TxPart,
    };
    use mentat_tolstoy::errors::Result;
    use core_traits::{
        Entid,
        TypedValue,
        ValueType,
    };

    struct TxCountingReceiver {
        pub tx_count: usize,
        pub is_done: bool,
    }

    impl TxCountingReceiver {
        fn new() -> TxCountingReceiver {
            TxCountingReceiver {
                tx_count: 0,
                is_done: false,
            }
        }
    }

    impl TxReceiver for TxCountingReceiver {
        fn tx<T>(&mut self, _tx_id: Entid, _d: &mut T) -> Result<()>
            where T: Iterator<Item=TxPart> {
            self.tx_count = self.tx_count + 1;
            Ok(())
        }

        fn done(&mut self) -> Result<()> {
            self.is_done = true;
            Ok(())
        }
    }

    #[derive(Debug)]
    struct TestingReceiver {
        pub txes: BTreeMap<Entid, Vec<TxPart>>,
        pub is_done: bool,
    }

    impl TestingReceiver {
        fn new() -> TestingReceiver {
            TestingReceiver {
                txes: BTreeMap::new(),
                is_done: false,
            }
        }
    }

    impl TxReceiver for TestingReceiver {
        fn tx<T>(&mut self, tx_id: Entid, d: &mut T) -> Result<()>
            where T: Iterator<Item=TxPart> {
            let datoms = self.txes.entry(tx_id).or_insert(vec![]);
            datoms.extend(d);
            Ok(())
        }

        fn done(&mut self) -> Result<()> {
            self.is_done = true;
            Ok(())
        }
    }

    fn assert_tx_datoms_count(receiver: &TestingReceiver, tx_num: usize, expected_datoms: usize) {
        let tx = receiver.txes.keys().nth(tx_num).expect("first tx");
        let datoms = receiver.txes.get(tx).expect("datoms");
        assert_eq!(expected_datoms, datoms.len());
    }

    #[test]
    fn test_reader() {
        let mut c = new_connection("").expect("Couldn't open conn.");
        let mut conn = Conn::connect(&mut c).expect("Couldn't open DB.");
        {
            let db_tx = c.transaction().expect("db tx");
            // Don't inspect the bootstrap transaction, but we'd like to see it's there.
            let mut receiver = TxCountingReceiver::new();
            assert_eq!(false, receiver.is_done);
            Processor::process(&db_tx, None, &mut receiver).expect("processor");
            assert_eq!(true, receiver.is_done);
            assert_eq!(1, receiver.tx_count);
        }

        let ids = conn.transact(&mut c, r#"[
            [:db/add "s" :db/ident :foo/numba]
            [:db/add "s" :db/valueType :db.type/long]
            [:db/add "s" :db/cardinality :db.cardinality/one]
        ]"#).expect("successful transaction").tempids;
        let numba_entity_id = ids.get("s").unwrap();

        let bootstrap_tx;
        {
            let db_tx = c.transaction().expect("db tx");
            // Expect to see one more transaction of four parts (one for tx datom itself).
            let mut receiver = TestingReceiver::new();
            Processor::process(&db_tx, None, &mut receiver).expect("processor");

            println!("{:#?}", receiver);

            assert_eq!(2, receiver.txes.keys().count());
            assert_tx_datoms_count(&receiver, 1, 4);

            bootstrap_tx = Some(*receiver.txes.keys().nth(0).expect("bootstrap tx"));
        }

        let ids = conn.transact(&mut c, r#"[
            [:db/add "b" :foo/numba 123]
        ]"#).expect("successful transaction").tempids;
        let asserted_e = ids.get("b").unwrap();

        {
            let db_tx = c.transaction().expect("db tx");

            // Expect to see a single two part transaction
            let mut receiver = TestingReceiver::new();

            // Note that we're asking for the bootstrap tx to be skipped by the processor.
            Processor::process(&db_tx, bootstrap_tx, &mut receiver).expect("processor");

            assert_eq!(2, receiver.txes.keys().count());
            assert_tx_datoms_count(&receiver, 1, 2);

            // Inspect the transaction part.
            let tx_id = receiver.txes.keys().nth(1).expect("tx");
            let datoms = receiver.txes.get(tx_id).expect("datoms");
            let part = datoms.iter().find(|&part| &part.e == asserted_e).expect("to find asserted datom");

            assert_eq!(numba_entity_id, &part.a);
            assert!(part.v.matches_type(ValueType::Long));
            assert_eq!(TypedValue::Long(123), part.v);
            assert_eq!(true, part.added);
        }
    }

}