/*
 * Copyright 2014 The Netty Project
 *
 * The Netty Project licenses this file to you 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.
 */

package io.netty.handler.ssl;

import java.io.File;

import javax.net.ssl.KeyManager;
import javax.net.ssl.KeyManagerFactory;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLException;
import javax.net.ssl.SSLSessionContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.TrustManagerFactory;

/**
 * A client-side {@link SslContext} which uses JDK's SSL/TLS implementation.
 */
public final class JdkSslClientContext extends JdkSslContext {

    private final SSLContext ctx;

    /**
     * Creates a new instance.
     */
    public JdkSslClientContext() throws SSLException {
        this(null, null);
    }

    /**
     * Creates a new instance.
     *
     * @param certChainFile an X.509 certificate chain file in PEM format.
     *                      {@code null} to use the system default
     */
    public JdkSslClientContext(File certChainFile) throws SSLException {
        this(certChainFile, null);
    }

    /**
     * Creates a new instance.
     *
     * @param trustManagerFactory the {@link TrustManagerFactory} that provides the {@link TrustManager}s
     *                            that verifies the certificates sent from servers.
     *                            {@code null} to use the default.
     */
    public JdkSslClientContext(TrustManagerFactory trustManagerFactory) throws SSLException {
        this(null, trustManagerFactory);
    }

    /**
     * Creates a new instance.
     *
     * @param certChainFile an X.509 certificate chain file in PEM format.
     *                      {@code null} to use the system default
     * @param trustManagerFactory the {@link TrustManagerFactory} that provides the {@link TrustManager}s
     *                            that verifies the certificates sent from servers.
     *                            {@code null} to use the default.
     */
    public JdkSslClientContext(File certChainFile, TrustManagerFactory trustManagerFactory) throws SSLException {
        this(certChainFile, trustManagerFactory, null, IdentityCipherSuiteFilter.INSTANCE,
                JdkDefaultApplicationProtocolNegotiator.INSTANCE, 0, 0);
    }

    /**
     * Creates a new instance.
     *
     * @param certChainFile an X.509 certificate chain file in PEM format.
     *                      {@code null} to use the system default
     * @param trustManagerFactory the {@link TrustManagerFactory} that provides the {@link TrustManager}s
     *                            that verifies the certificates sent from servers.
     *                            {@code null} to use the default.
     * @param ciphers the cipher suites to enable, in the order of preference.
     *                {@code null} to use the default cipher suites.
     * @param cipherFilter a filter to apply over the supplied list of ciphers
     * @param apn Provides a means to configure parameters related to application protocol negotiation.
     * @param sessionCacheSize the size of the cache used for storing SSL session objects.
     *                         {@code 0} to use the default value.
     * @param sessionTimeout the timeout for the cached SSL session objects, in seconds.
     *                       {@code 0} to use the default value.
     */
    public JdkSslClientContext(
            File certChainFile, TrustManagerFactory trustManagerFactory,
            Iterable<String> ciphers, CipherSuiteFilter cipherFilter, ApplicationProtocolConfig apn,
            long sessionCacheSize, long sessionTimeout) throws SSLException {
        this(certChainFile, trustManagerFactory, ciphers, cipherFilter,
                toNegotiator(apn, false), sessionCacheSize, sessionTimeout);
    }

    /**
     * Creates a new instance.
     *
     * @param certChainFile an X.509 certificate chain file in PEM format.
     *                      {@code null} to use the system default
     * @param trustManagerFactory the {@link TrustManagerFactory} that provides the {@link TrustManager}s
     *                            that verifies the certificates sent from servers.
     *                            {@code null} to use the default.
     * @param ciphers the cipher suites to enable, in the order of preference.
     *                {@code null} to use the default cipher suites.
     * @param cipherFilter a filter to apply over the supplied list of ciphers
     * @param apn Application Protocol Negotiator object.
     * @param sessionCacheSize the size of the cache used for storing SSL session objects.
     *                         {@code 0} to use the default value.
     * @param sessionTimeout the timeout for the cached SSL session objects, in seconds.
     *                       {@code 0} to use the default value.
     */
    public JdkSslClientContext(
            File certChainFile, TrustManagerFactory trustManagerFactory,
            Iterable<String> ciphers, CipherSuiteFilter cipherFilter, JdkApplicationProtocolNegotiator apn,
            long sessionCacheSize, long sessionTimeout) throws SSLException {
        this(certChainFile, trustManagerFactory, null, null, null, null,
                ciphers, cipherFilter, apn, sessionCacheSize, sessionTimeout);
    }

    /**
     * Creates a new instance.
     * @param trustCertChainFile an X.509 certificate chain file in PEM format.
     *                      {@code null} to use the system default
     * @param trustManagerFactory the {@link TrustManagerFactory} that provides the {@link TrustManager}s
     *                            that verifies the certificates sent from servers.
     *                            {@code null} to use the default or the results of parsing {@code trustCertChainFile}
     * @param keyCertChainFile an X.509 certificate chain file in PEM format.
     *                      This provides the public key for mutual authentication.
     *                      {@code null} to use the system default
     * @param keyFile a PKCS#8 private key file in PEM format.
     *                      This provides the private key for mutual authentication.
     *                      {@code null} for no mutual authentication.
     * @param keyPassword the password of the {@code keyFile}.
     *                    {@code null} if it's not password-protected.
     *                    Ignored if {@code keyFile} is {@code null}.
     * @param keyManagerFactory the {@link KeyManagerFactory} that provides the {@link KeyManager}s
     *                          that is used to encrypt data being sent to servers.
     *                          {@code null} to use the default or the results of parsing
     *                          {@code keyCertChainFile} and {@code keyFile}.
     * @param ciphers the cipher suites to enable, in the order of preference.
     *                {@code null} to use the default cipher suites.
     * @param cipherFilter a filter to apply over the supplied list of ciphers
     * @param apn Provides a means to configure parameters related to application protocol negotiation.
     * @param sessionCacheSize the size of the cache used for storing SSL session objects.
     *                         {@code 0} to use the default value.
     * @param sessionTimeout the timeout for the cached SSL session objects, in seconds.
     *                       {@code 0} to use the default value.
     */
    public JdkSslClientContext(File trustCertChainFile, TrustManagerFactory trustManagerFactory,
            File keyCertChainFile, File keyFile, String keyPassword, KeyManagerFactory keyManagerFactory,
            Iterable<String> ciphers, CipherSuiteFilter cipherFilter, ApplicationProtocolConfig apn,
            long sessionCacheSize, long sessionTimeout) throws SSLException {
        this(trustCertChainFile, trustManagerFactory, keyCertChainFile, keyFile, keyPassword, keyManagerFactory,
                ciphers, cipherFilter, toNegotiator(apn, false), sessionCacheSize, sessionTimeout);
    }

    /**
     * Creates a new instance.
     * @param trustCertChainFile an X.509 certificate chain file in PEM format.
     *                      {@code null} to use the system default
     * @param trustManagerFactory the {@link TrustManagerFactory} that provides the {@link TrustManager}s
     *                            that verifies the certificates sent from servers.
     *                            {@code null} to use the default or the results of parsing {@code trustCertChainFile}
     * @param keyCertChainFile an X.509 certificate chain file in PEM format.
     *                      This provides the public key for mutual authentication.
     *                      {@code null} to use the system default
     * @param keyFile a PKCS#8 private key file in PEM format.
     *                      This provides the private key for mutual authentication.
     *                      {@code null} for no mutual authentication.
     * @param keyPassword the password of the {@code keyFile}.
     *                    {@code null} if it's not password-protected.
     *                    Ignored if {@code keyFile} is {@code null}.
     * @param keyManagerFactory the {@link KeyManagerFactory} that provides the {@link KeyManager}s
     *                          that is used to encrypt data being sent to servers.
     *                          {@code null} to use the default or the results of parsing
     *                          {@code keyCertChainFile} and {@code keyFile}.
     * @param ciphers the cipher suites to enable, in the order of preference.
     *                {@code null} to use the default cipher suites.
     * @param cipherFilter a filter to apply over the supplied list of ciphers
     * @param apn Application Protocol Negotiator object.
     * @param sessionCacheSize the size of the cache used for storing SSL session objects.
     *                         {@code 0} to use the default value.
     * @param sessionTimeout the timeout for the cached SSL session objects, in seconds.
     *                       {@code 0} to use the default value.
     */
    public JdkSslClientContext(File trustCertChainFile, TrustManagerFactory trustManagerFactory,
            File keyCertChainFile, File keyFile, String keyPassword, KeyManagerFactory keyManagerFactory,
            Iterable<String> ciphers, CipherSuiteFilter cipherFilter, JdkApplicationProtocolNegotiator apn,
            long sessionCacheSize, long sessionTimeout) throws SSLException {
        super(ciphers, cipherFilter, apn);

        try {
            if (trustCertChainFile != null) {
                trustManagerFactory = buildTrustManagerFactory(trustCertChainFile, trustManagerFactory);
            }
            if (keyFile != null) {
                keyManagerFactory = buildKeyManagerFactory(keyCertChainFile, keyFile, keyPassword, keyManagerFactory);
            }
            ctx = SSLContext.getInstance(PROTOCOL);
            ctx.init(keyManagerFactory == null ? null : keyManagerFactory.getKeyManagers(),
                     trustManagerFactory == null ? null : trustManagerFactory.getTrustManagers(),
                     null);

            SSLSessionContext sessCtx = ctx.getClientSessionContext();
            if (sessionCacheSize > 0) {
                sessCtx.setSessionCacheSize((int) Math.min(sessionCacheSize, Integer.MAX_VALUE));
            }
            if (sessionTimeout > 0) {
                sessCtx.setSessionTimeout((int) Math.min(sessionTimeout, Integer.MAX_VALUE));
            }
        } catch (Exception e) {
            throw new SSLException("failed to initialize the client-side SSL context", e);
        }
    }

    @Override
    public boolean isClient() {
        return true;
    }

    @Override
    public SSLContext context() {
        return ctx;
    }
}
