com.github.switcherapi.client.model.Switcher Maven / Gradle / Ivy

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package com.github.switcherapi.client.model;

import com.github.switcherapi.client.SwitcherContext;
import com.github.switcherapi.client.SwitcherExecutor;
import com.github.switcherapi.client.exception.SwitcherException;
import com.github.switcherapi.client.model.response.CriteriaResponse;

import java.util.*;

/**
 * Switchers are the entry point to evaluate criteria and return the result.
 * 
To execute a criteria evaluation, use one of the available methods: {@link #isItOn()}.
 * 
 * @author Roger Floriano (petruki)
 * @since 2019-12-24
 * 
 * @see #isItOn()
 * @see #submit()
 */
public final class Switcher extends SwitcherBuilder {
	
	public static final String KEY = "key";
	
	public static final String SHOW_REASON = "showReason";
	
	public static final String BYPASS_METRIC = "bypassMetric";
	
	private final SwitcherExecutor context;
	
	private final String switcherKey;
	
	private final Set historyExecution;

	private AsyncSwitcher asyncSwitcher;
	
	/**
	 * Use {@link SwitcherContext#getSwitcher(String)} to create this object.
	 * 
	 * @param switcherKey name of the key created
	 * @param context client context in which the switcher will be executed (local/remote)
	 */
	public Switcher(final String switcherKey, final SwitcherExecutor context) {
		this.switcherKey = switcherKey;
		this.context = context;
		this.historyExecution = new HashSet<>();
	}
	
	private boolean canUseAsync() {
		return super.delay > 0 && !this.historyExecution.isEmpty();
	}
	
	private Optional getFromHistory() {
		for (CriteriaResponse criteriaResponse : historyExecution) {
			if (criteriaResponse.getEntry().equals(getEntry())) {
				return Optional.of(criteriaResponse);
			}
		}
		return Optional.empty();
	}

	@Override
	public Switcher build() {
		return this;
	}
	
	@Override
	public Switcher prepareEntry(final List entry) {
		this.entry = entry;
		return this;
	}
	
	@Override
	public Switcher prepareEntry(final Entry entry, final boolean add) {
		if (this.entry == null) {
			this.entry = new ArrayList<>();
		}

		if (!add) {
			this.entry.clear();
		}

		if (!this.entry.contains(entry)) {
			this.entry.add(entry);
		}
		
		return this;
	}
	
	@Override
	public Switcher prepareEntry(final Entry entry) {
		return this.prepareEntry(entry, false);
	}
	
	@Override
	public boolean isItOn() throws SwitcherException {
		final CriteriaResponse response = submit();
		return response.isItOn();
	}

	@Override
	public CriteriaResponse submit() throws SwitcherException {
		if (SwitcherExecutor.getBypass().containsKey(switcherKey)) {
			return SwitcherExecutor.getBypass().get(switcherKey).buildFromSwitcher(this);
		}

		if (canUseAsync()) {
			if (asyncSwitcher == null) {
				asyncSwitcher = new AsyncSwitcher();
			}

			asyncSwitcher.execute(this);
			final Optional response = getFromHistory();
			if (response.isPresent()) {
				return response.get();
			}
		}

		final CriteriaResponse response = this.context.executeCriteria(this);
		this.historyExecution.add(response);
		return response;
	}
	
	/**
	 * This method builds up the request made by the client to reach the Switcher API.
	 * 
	 * @return json input request
	 */
	public GsonInputRequest getInputRequest() {
		return new GsonInputRequest(
				this.entry != null ?
						this.entry.toArray(new Entry[0]) : null);
	}

	public boolean isBypassMetrics() {
		return bypassMetrics;
	}

	public String getSwitcherKey() {
		return this.switcherKey;
	}

	public List getEntry() {
		return this.entry;
	}
	
	public void resetEntry() {
		this.entry = new ArrayList<>();
	}

	public synchronized Set getHistoryExecution() {
		return this.historyExecution;
	}
	
	public SwitcherExecutor getContext() {
		return context;
	}

	@Override
	public String toString() {
		return String.format("Switcher [switcherKey= %s, entry= %s, bypassMetrics= %s]",
				switcherKey, entry, bypassMetrics);
	}
	
	public static class GsonInputRequest {
		
		private final Entry[] entry;
		
		public GsonInputRequest(final Entry[] entry) {
			this.entry = entry;
		}

		public Entry[] getEntry() {
			return this.entry;
		}
	}

}