// Copyright 2009 Google Inc.
//
// 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.

package com.google.enterprise.secmgr.config;

import com.google.common.base.Objects;
import com.google.common.collect.ImmutableList;
import com.google.enterprise.secmgr.json.ProxyTypeAdapter;
import com.google.gson.GsonBuilder;

import java.util.List;

/**
 * LDAP configuration.
 */
public final class AuthnMechLdap extends AuthnMechanism {

  public static final String TYPE_NAME = "LDAP";
  private static final long DEFAULT_TRUST_DURATION = 20 * 60 * 1000;  // 20 mins

  private final boolean enableAuthn;
  private final boolean enableGroupLookup;

  private final String hostport;
  private final String bindDn;
  private final String password;
  private final String searchBase;
  private final String userSearchFilter;
  private final String groupSearchFilter;
  private final int sslSupport;
  private final int supportedAuthMethods;

  private final long trustDuration;

  /**
   * Make a new LDAP AuthN mechanism.
   *
   * @param hostport a hostname and port of the format "HOST:PORT"
   * @param bindDn the DN to bind with, or empty for anonymous binding
   * @param password the password to bind with, or empty for anonymous binding
   * @param searchBase component of DN common to all users
   * @param userSearchFilter filter used to search for user
   * @param groupSearchFilter filter used to find user's groups
   * @param sslSupport the type of SSL to use
   * @param supportedAuthMethods the auth methods supported by the server
   * @param enableAuthn whether this mech is enabled for authentication
   * @param enableGroupLookup whether this mech is enabled for doing groups lookup
   * @param trustDuration The number of milliseconds for which successfully
   *     verified credentials are trusted.  This must be a non-negative number.
   * @return A new mechanism with the given configuration
   */
  public static AuthnMechLdap make(String name, String hostport, String bindDn,
                                   String password, String searchBase,
                                   String userSearchFilter, String groupSearchFilter,
                                   int sslSupport, int supportedAuthMethods,
                                   boolean enableAuthn, boolean enableGroupLookup,
                                   long trustDuration) {
    return new AuthnMechLdap(name, hostport, bindDn, password, searchBase,
                             userSearchFilter, groupSearchFilter, sslSupport,
                             supportedAuthMethods, enableAuthn, enableGroupLookup,
                             trustDuration);
  }

  private AuthnMechLdap(String name, String hostport, String bindDn, String password,
                        String searchBase, String userSearchFilter, String groupSearchFilter,
                        int sslSupport, int supportedAuthMethods, boolean enableAuthn,
                        boolean enableGroupLookup, long trustDuration) {
    super(name);
    this.hostport = hostport;
    this.bindDn = bindDn;
    this.password = password;
    this.searchBase = searchBase;
    this.userSearchFilter = userSearchFilter;
    this.groupSearchFilter = groupSearchFilter;
    this.sslSupport = sslSupport;
    this.supportedAuthMethods = supportedAuthMethods;
    this.enableAuthn = enableAuthn;
    this.enableGroupLookup = enableGroupLookup;
    this.trustDuration = trustDuration;
  }

  public static AuthnMechLdap makeEmpty() {
    return new AuthnMechLdap();
  }

  private AuthnMechLdap() {
    super();
    this.hostport = null;
    this.bindDn = null;
    this.password = null;
    this.searchBase = null;
    this.userSearchFilter = null;
    this.groupSearchFilter = null;
    this.sslSupport = 0;
    this.supportedAuthMethods = 0;
    this.enableAuthn = false;
    this.enableGroupLookup = false;
    this.trustDuration = getDefaultTrustDuration();
  }

  public String getHostport() {
    return hostport;
  }

  public String getBindDn() {
    return bindDn;
  }

  public String getPassword() {
    return password;
  }

  public String getSearchBase() {
    return searchBase;
  }

  public String getUserSearchFilter() {
    return userSearchFilter;
  }

  public String getGroupSearchFilter() {
    return groupSearchFilter;
  }

  public int getSslSupport() {
    return sslSupport;
  }

  public int getSupportedAuthMethods() {
    return supportedAuthMethods;
  }

  public boolean isEnableAuthn() {
    return enableAuthn;
  }

  public boolean isEnableGroupLookup() {
    return enableGroupLookup;
  }

  @Override
  public long getTrustDuration() {
    return trustDuration;
  }

  @Override
  public String getTypeName() {
    return TYPE_NAME;
  }

  @Override
  public List<CredentialTransform> getCredentialTransforms() {
    ImmutableList.Builder<CredentialTransform> builder = ImmutableList.builder();
    if (isEnableAuthn()) {
      builder.add(
          CredentialTransform.make(
              CredentialTypeSet.PRINCIPAL_AND_PASSWORD,
              CredentialTypeSet.VERIFIED_PRINCIPAL_AND_PASSWORD));
    }
    if (isEnableGroupLookup()) {
      builder.add(
          CredentialTransform.make(
              CredentialTypeSet.VERIFIED_PRINCIPAL,
              CredentialTypeSet.VERIFIED_GROUPS));
    }
    return builder.build();
  }

  @Override
  public AuthnMechanism copyWithNewName(String name) {
    return make(name, getHostport(), getBindDn(), getPassword(), getSearchBase(),
        getUserSearchFilter(), getGroupSearchFilter(), getSslSupport(), getSupportedAuthMethods(),
        isEnableAuthn(), isEnableGroupLookup(), getTrustDuration());
  }

  public static long getDefaultTrustDuration() {
    return DEFAULT_TRUST_DURATION;
  }

  @Override
  public boolean equals(Object object) {
    if (object == this) { return true; }
    if (!(object instanceof AuthnMechLdap)) { return false; }
    AuthnMechLdap mech = (AuthnMechLdap) object;
    return super.equals(mech)
        && Objects.equal(getHostport(), mech.getHostport())
        && Objects.equal(getBindDn(), mech.getBindDn())
        && Objects.equal(getPassword(), mech.getPassword())
        && Objects.equal(getSearchBase(), mech.getSearchBase())
        && Objects.equal(getUserSearchFilter(), mech.getUserSearchFilter())
        && Objects.equal(getGroupSearchFilter(), mech.getGroupSearchFilter())
        && Objects.equal(getSslSupport(), mech.getSslSupport())
        && Objects.equal(getSupportedAuthMethods(), mech.getSupportedAuthMethods())
        && Objects.equal(isEnableAuthn(), mech.isEnableAuthn())
        && Objects.equal(isEnableGroupLookup(), mech.isEnableGroupLookup()
        && Objects.equal(getTrustDuration(), mech.getTrustDuration()));
  }

  @Override
  public int hashCode() {
    return super.hashCode(getHostport(), getBindDn(), getPassword(), getSearchBase(),
        getUserSearchFilter(), getGroupSearchFilter(), getSslSupport(), getSupportedAuthMethods(),
        isEnableAuthn(), isEnableGroupLookup(), getTrustDuration());
  }

  static void registerTypeAdapters(GsonBuilder builder) {
    builder.registerTypeAdapter(AuthnMechLdap.class,
        ProxyTypeAdapter.make(AuthnMechLdap.class, LocalProxy.class));
  }

  private static final class LocalProxy extends MechanismProxy<AuthnMechLdap> {
    boolean enableAuthn;
    boolean enableGroupLookup;
    String hostport;
    String bindDn;
    String password;
    String searchBase;
    String userSearchFilter;
    String groupSearchFilter;
    int sslSupport;
    int supportedAuthMethods;
    long trustDuration = DEFAULT_TRUST_DURATION;

    @SuppressWarnings("unused")
    LocalProxy() {
    }

    @SuppressWarnings("unused")
    LocalProxy(AuthnMechLdap mechanism) {
      super(mechanism);
      hostport = mechanism.getHostport();
      bindDn = mechanism.getBindDn();
      password = mechanism.getPassword();
      searchBase = mechanism.getSearchBase();
      userSearchFilter = mechanism.getUserSearchFilter();
      groupSearchFilter = mechanism.getGroupSearchFilter();
      sslSupport = mechanism.getSslSupport();
      supportedAuthMethods = mechanism.getSupportedAuthMethods();
      enableAuthn = mechanism.isEnableAuthn();
      enableGroupLookup = mechanism.isEnableGroupLookup();
      trustDuration = mechanism.getTrustDuration();
    }

    @Override
    public AuthnMechLdap build() {
      return make(name, hostport, bindDn, password, searchBase, userSearchFilter, groupSearchFilter,
          sslSupport, supportedAuthMethods, enableAuthn, enableGroupLookup, trustDuration);
    }
  }
}