#[cfg(test)]
mod integration_tests {
    use rota_lib::{
        config::{ToxicPair, UserConfig},
        fixtures::{
            complex_config, hard_config, manual_shifts_heavy_config, maximal_config, minimal_config,
        },
        schedule::MonthlySchedule,
        scheduler::Scheduler,
        slot::{Day, ShiftPosition, Slot},
        workload::{WorkloadBounds, WorkloadTracker},
    };
    use rstest::rstest;

    #[ctor::ctor]
    fn global_setup() {
        env_logger::builder()
            .filter_level(log::LevelFilter::Info)
            .init();
    }

    #[rstest]
    fn test_minimal_config(minimal_config: UserConfig) -> anyhow::Result<()> {
        let mut schedule = MonthlySchedule::new();
        let mut tracker = WorkloadTracker::default();
        let scheduler = Scheduler::new_with_config(minimal_config.clone());

        let solved = scheduler.run(&mut schedule, &mut tracker)?;
        println!("{}", schedule.report(&minimal_config, &tracker));
        assert!(solved);
        validate_all_constraints(&schedule, &tracker, &minimal_config);

        Ok(())
    }

    #[rstest]
    fn test_maximal_config(maximal_config: UserConfig) -> anyhow::Result<()> {
        let mut schedule = MonthlySchedule::new();
        let mut tracker = WorkloadTracker::default();
        let scheduler = Scheduler::new_with_config(maximal_config.clone());

        let solved = scheduler.run(&mut schedule, &mut tracker)?;
        println!("{}", schedule.report(&maximal_config, &tracker));
        assert!(solved);
        validate_all_constraints(&schedule, &tracker, &maximal_config);

        Ok(())
    }

    #[rstest]
    fn test_manual_shifts_heavy_config(
        manual_shifts_heavy_config: UserConfig,
    ) -> anyhow::Result<()> {
        let mut schedule = MonthlySchedule::new();
        let mut tracker = WorkloadTracker::default();
        let scheduler = Scheduler::new_with_config(manual_shifts_heavy_config.clone());

        let solved = scheduler.run(&mut schedule, &mut tracker)?;
        println!("{}", schedule.report(&manual_shifts_heavy_config, &tracker));
        assert!(solved);
        validate_all_constraints(&schedule, &tracker, &manual_shifts_heavy_config);

        Ok(())
    }

    #[rstest]
    fn test_complex_config(complex_config: UserConfig) -> anyhow::Result<()> {
        let mut schedule = MonthlySchedule::new();
        let mut tracker = WorkloadTracker::default();
        let scheduler = Scheduler::new_with_config(complex_config.clone());

        let solved = scheduler.run(&mut schedule, &mut tracker)?;
        println!("{}", schedule.report(&complex_config, &tracker));
        assert!(solved);
        validate_all_constraints(&schedule, &tracker, &complex_config);

        Ok(())
    }

    #[rstest]
    fn test_hard_config(hard_config: UserConfig) -> anyhow::Result<()> {
        let mut schedule = MonthlySchedule::new();
        let mut tracker = WorkloadTracker::default();
        let scheduler = Scheduler::new_with_config(hard_config.clone());

        let solved = scheduler.run(&mut schedule, &mut tracker)?;
        println!("{}", schedule.report(&hard_config, &tracker));
        assert!(solved);
        validate_all_constraints(&schedule, &tracker, &hard_config);

        Ok(())
    }

    fn validate_all_constraints(
        schedule: &MonthlySchedule,
        tracker: &WorkloadTracker,
        config: &UserConfig,
    ) {
        assert_eq!(schedule.0.len() as u8, config.total_slots);

        for d in 2..=config.total_days {
            let current: Vec<_> = [ShiftPosition::First, ShiftPosition::Second]
                .iter()
                .filter_map(|&p| schedule.get_resident_id(&Slot::new(Day(d), p)))
                .collect();
            let previous: Vec<_> = [ShiftPosition::First, ShiftPosition::Second]
                .iter()
                .filter_map(|&p| schedule.get_resident_id(&Slot::new(Day(d - 1), p)))
                .collect();
            for r in current {
                assert!(!previous.contains(&r));
            }
        }

        for d in 1..=config.total_days {
            let day = Day(d);
            if day.is_open_shift() {
                let r1 = schedule.get_resident_id(&Slot::new(day, ShiftPosition::First));
                let r2 = schedule.get_resident_id(&Slot::new(day, ShiftPosition::Second));
                assert_ne!(r1, r2);
                if let (Some(id1), Some(id2)) = (r1, r2) {
                    let pair = ToxicPair::from((*id1, *id2));
                    assert!(config.toxic_pairs.iter().all(|t| !t.matches(&pair)));
                }
            }
        }

        let bounds = WorkloadBounds::new_with_config(config);
        for (slot, r_id) in &schedule.0 {
            let r = config
                .residents
                .iter()
                .find(|r| &r.id == r_id)
                .expect("Resident not found");
            assert!(r.allowed_types.contains(&slot.shift_type()));
            assert!(!r.negative_shifts.contains(&slot.day));
        }

        for resident in &config.residents {
            let workload = tracker.current_workload(&resident.id);
            let max = *bounds.max_workloads.get(&resident.id).unwrap();
            assert!(workload <= max, "workload: {}, max: {}", workload, max);
        }
    }
}