package eu.eudat.logic.utilities.circuitbreaker;

import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

/**
 * Created by ikalyvas on 2/25/2019.
 */


public final class Circuit {
	private final String url;
	private final String method;
	private Integer numberOfFails;
	private CircuitState state;
	private final Integer MAX_NUMBER_OF_FAILS = 5;
	public String getUrl() {
		return url;
	}

	public String getMethod() {
		return method;
	}

	public Integer getNumberOfFails() {
		return numberOfFails;
	}

	public Circuit(String url, String method, Integer numberOfFails) {
		this.url = url;
		this.method = method;
		this.numberOfFails = numberOfFails;
		ScheduledExecutorService executor = Executors.newScheduledThreadPool(1);
		executor.scheduleAtFixedRate(this::halfOpenCircuit, 0, 20, TimeUnit.SECONDS);
	}

	public enum CircuitState {
		CLOSED, HALF_OPENED, OPENED
	}

	public static class CircuitBuilder {
		private String url;
		private String method;

		public CircuitBuilder url(String url) {
			this.url = url;
			return this;
		}

		public CircuitBuilder method(String method) {
			this.method = method;
			return this;
		}

		public Circuit build() {
			return new Circuit(url, method, 0);
		}
	}

	@Override
	public boolean equals(Object o) {
		if (this == o) return true;
		if (o == null || getClass() != o.getClass()) return false;

		Circuit circuit = (Circuit) o;

		if (!url.equals(circuit.url)) return false;
		return method.equals(circuit.method);
	}

	@Override
	public int hashCode() {
		int result = url.hashCode();
		result = 31 * result + method.hashCode();
		return result;
	}

	private void halfOpenCircuit() {
		if (this.state == CircuitState.CLOSED) {
			this.state = CircuitState.HALF_OPENED;
		}
	}

	public void addFailure() {
		this.numberOfFails++;
		if(this.state == CircuitState.OPENED && this.numberOfFails > MAX_NUMBER_OF_FAILS){
			this.state = CircuitState.CLOSED;
		}
		else if(this.state == CircuitState.HALF_OPENED){
			this.state = CircuitState.CLOSED;
		}
	}

	public boolean isOpen(){
		return this.state == CircuitState.OPENED;
	}
}