use std::cell::Cell;
use std::sync::Arc;

use rand::seq::SliceRandom;
use rand::thread_rng;

use phreak_engine::condition::ConditionBuilder;
use phreak_engine::Phreak;
use phreak_facts::FactsBuilder;
use phreak_rules::ProductionCallback;

#[derive(Debug)]
struct CountCallback { counter: Arc<Cell<usize>> }

impl ProductionCallback for CountCallback {
    fn activate(&self) {
        self.counter.replace(self.counter.take() + 1);
    }

    fn deactivate(&self) {
        self.counter.replace(self.counter.take() - 1);
    }
}

#[test]
fn api_test() {
    use uuid;
    use phreak_facts::Value;

    let mut phreak = Phreak::new();

    let counter1: Arc<Cell<usize>> = Arc::new(Cell::new(0));
    let callback = Box::new(CountCallback { counter: counter1.clone() });

    // we are looking for small cars, but we don't like blue ones
    phreak.add_production(&[
        ConditionBuilder::new(String::from("car"))
            .variable_field1(String::from("id"))
            .const_field2(String::from("size"))
            .const_field3(String::from("small"))
            .build()
        ,
        ConditionBuilder::new(String::from("car"))
            .negative(String::from("car"))
            .variable_field1(String::from("id"))
            .const_field2(String::from("color"))
            .const_field3(String::from("blue"))
            .build()
    ], callback);

    for _j in 0..3 {
        let mut arr = Vec::new();
        let colors = ["red", "blue", "yellow", "green", "purple", "black", "orange"];
        let sizes = ["small", "medium", "large"];

        let mut verification_counter = 0;
        for i in 0..40 {
            let id = uuid::Uuid::new_v4();
            arr.push(FactsBuilder::new("car".to_string())
                .add_values(Value::from(id), Value::from("color"), Value::from(colors[i % colors.len()]))
                .add_values(Value::from(id), Value::from("size"), Value::from(sizes[i % sizes.len()]))
                .build()
            );

            // size[0] == "small", color[1] == "blue"
            if (i % sizes.len() == 0) && (i % colors.len() != 1) {
                verification_counter += 1;
            }
        }
        phreak.add_facts(&arr);

        assert_eq!(counter1.get(), verification_counter);

        let mut rng = thread_rng();
        arr.shuffle(&mut rng);
        phreak.remove_facts(&arr);

        assert_eq!(counter1.get(), 0);
    }
}