//Dstl (c) Crown Copyright 2017
package uk.gov.dstl.baleen.core.web.security;

import org.eclipse.jetty.http.HttpMethod;

import com.google.common.collect.Sets;

/**
 * A permission to access a web resource.
 *
 * 
 *
 */
public class WebPermission {

	private final boolean authenticated;
	private final String name;
	private final HttpMethod method;
	private final String[] roles;

	/**
	 * New instance.
	 *
	 * @param name
	 *            the human readable name of this permission
	 * @param authenticated
	 *            is an authenticated user required?
	 */
	public WebPermission(String name, boolean authenticated) {
		this(name, authenticated, null, new String[] {});
	}

	/**
	 * New instance requiring an authenticated user with specific roles.
	 *
	 * @param name
	 * @param roles
	 */
	public WebPermission(String name, String... roles) {
		this(name, null, roles);
	}

	/**
	 * New instance requiring an authenticated user with specific roles
	 * accessing via a specific HTTP method type.
	 *
	 * @param name
	 * @param method
	 * @param roles
	 */
	public WebPermission(String name, HttpMethod method, String... roles) {
		this(name, true, method, roles);
	}

	private WebPermission(String name, boolean authenticated, HttpMethod method, String... roles) {
		this.name = name;
		this.authenticated = authenticated;
		this.method = method;
		this.roles = roles == null ? new String[] {} : makeUnique(roles);
	}

	private static String[] makeUnique(String[] roles) {
		return Sets.newHashSet(roles).toArray(new String[] {});
	}

	/**
	 * Get the human friendly permission name.
	 *
	 * @return the name.
	 */
	public String getName() {
		return name;
	}

	/**
	 * The roles required for this permission.
	 *
	 * @return array (non-null, maybe empty)
	 */
	public String[] getRoles() {
		return roles;
	}

	/**
	 * Get the method which must be used to access a resource with this
	 * permission.
	 *
	 * @return method (or null if any method is allowed)
	 */
	public HttpMethod getMethod() {
		return method;
	}

	/**
	 * Check if this permission has a method restriction.
	 *
	 * @return true is has method (getMethod() will return non-null)
	 */
	public boolean hasMethod() {
		return method != null;
	}

	/**
	 * Check if this permission has roles restrictions.
	 *
	 * @return true is this permission has role restrictions (getRoles will be
	 *         non-empty)
	 */
	public boolean hasRoles() {
		return roles != null && roles.length > 0;
	}

	/**
	 * Is an authenticated user required by this permission?
	 *
	 * @return true is authentication is required.
	 */
	public boolean isAuthenticated() {
		return authenticated;
	}

	@Override
	public String toString() {
		return name;
	}

}