/**
 * ============LICENSE_START====================================================
 * org.onap.aaf
 * ===========================================================================
 * Copyright (c) 2018 AT&T Intellectual Property. All rights reserved.
 * ===========================================================================
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * ============LICENSE_END====================================================
 *
 */

package org.onap.aaf.cadi.taf;

import java.io.IOException;
import java.net.URI;
import java.util.List;

import javax.servlet.http.HttpServletResponse;

import org.onap.aaf.cadi.Access;
import org.onap.aaf.cadi.Locator;
import org.onap.aaf.cadi.Access.Level;
import org.onap.aaf.cadi.Locator.Item;

public class LoginPageTafResp extends AbsTafResp {
	private final HttpServletResponse httpResp;
	private final String loginPageURL;

	private LoginPageTafResp(Access access, final HttpServletResponse resp, String loginPageURL) {
		super(access, "LoginPage", null, "Multiple Possible HTTP Logins available.  Redirecting to Login Choice Page");
		httpResp = resp;
		this.loginPageURL = loginPageURL;
	}

	@Override
	public RESP authenticate() throws IOException {
		httpResp.sendRedirect(loginPageURL);
		return RESP.HTTP_REDIRECT_INVOKED;
	}
	
	@Override
	public RESP isAuthenticated() {
		return RESP.TRY_AUTHENTICATING;
	}
	
	public static TafResp create(Access access, Locator<URI> locator, final HttpServletResponse resp, List<Redirectable> redirectables) {
		if (locator == null) {
			if (!redirectables.isEmpty()) { 
				access.log(Level.DEBUG,"LoginPage Locator is not configured. Taking first Redirectable Taf");
				return redirectables.get(0);
			}
			return NullTafResp.singleton();
		}

		try {
			Item item = locator.best();
			URI uri = locator.get(item);
			if (uri == null) {
				return NullTafResp.singleton();
			}

			StringBuilder sb = new StringBuilder(uri.toString());
			String query = uri.getQuery();
			boolean first = ((query == null) || (query.length() == 0));
			for (Redirectable redir : redirectables) {
				if (first) {
					sb.append('?');
					first = false;
				}
				else {
					sb.append('&');
				}
				sb.append(redir.get());
			}
			if (!redirectables.isEmpty()) {
				return new LoginPageTafResp(access, resp, sb.toString());
			}
		} catch (Exception e) {
			access.log(e, "Error deriving Login Page location");
		}

		return NullTafResp.singleton();
	}
	
	@Override
	public String taf() {
		return "LoginPage";
	}

}