mediator_coordinator.rs

mediator_coordinator.rs

// Coordinator is playing a mediator role which ensure the only place to
pub trait Coordinator {
    fn arrival(&mut self, aircraft_id: &str) -> bool;
    fn gate_available(&mut self) -> Option<i8>;
    fn departure(&mut self, aircraft_id: &str);
}

impl Coordinator for Airport {
    fn arrival(&mut self, aircraft_id: &str) -> bool {
        /*
            There is 3 condition to meet in order to let the aircraft arrival
            1. get the available platform
                1.1. update arrival aircraft_on_gate 
                1.2. update arrival update the gate available hashmaps
            2. if not available then put the aircraft to the aircraft queue and denied the arrival
        */
        match self.gate_available() {
            Some(gate_id) => {
                println!("[{:?}] gate [{:?}] available for aircraft : {:?}",  self.name, gate_id, aircraft_id);
                self.aircraft_on_gate.insert(gate_id, aircraft_id.into());
                self.gates.entry(gate_id).and_modify(|available| *available = false ).or_insert(false);
                return true;
            },
            None => {
                println!("[{:?}] no gate available for aircraft : {:?}",  self.name, aircraft_id);
                self.aircraft_queue.push_back(aircraft_id.into());
                return false
            },
        }
    }

    fn gate_available(&mut self) -> Option<i8> {
        /*
            Iterate over the available platform and get the first available platform id
        */
        self.gates
            .iter()
            .find_map(|(gate_id, &val)| if val { Some(*gate_id) } else { None })
    }

    fn departure(&mut self, aircraft_id: &str) {
        /*
            There are 3 steps for notification
            1. get the aircraft gate_id from the aircraft_on_gate by the aircraft_id.
            2. update the gates available by the gate_id.
            3. get the first aircraft in the aircraft queue and go over the can_arrival verfication process.
        */
        let gate_id = self.aircraft_on_gate
            .iter()
            .find_map(|(gate_id, val)| if val== aircraft_id { Some(*gate_id) } else { None }).unwrap();

        self.gates.entry(gate_id).and_modify(|available| *available = true ).or_insert(true);

        if let Some(next_aircraft_id) = self.aircraft_queue.pop_front() {
            self.arrival(&next_aircraft_id);
        }
    }
}