/**
 *    Copyright (C) 2013 10gen Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
 *    as published by the Free Software Foundation.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU Affero General Public License for more details.
 *
 *    You should have received a copy of the GNU Affero General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the GNU Affero General Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

/**
 * This module describes free functions for logging various operations of interest to a
 * party interested in generating logs of user activity in a MongoDB server instance.
 */

#pragma once

#include "mongo/base/error_codes.h"
#include "mongo/db/auth/privilege.h"
#include "mongo/db/auth/user.h"

namespace mongo {

    class AuthorizationSession;
    class BSONObj;
    class ClientBasic;
    class NamespaceString;
    class ReplSetConfig;
    class StringData;
    class UserName;

namespace mutablebson {
    class Document;
}  // namespace mutablebson

namespace audit {

    /**
     * Logs the result of an authentication attempt.
     */
    void logAuthentication(ClientBasic* client,
                           const StringData& mechanism,
                           const UserName& user,
                           ErrorCodes::Error result);

    //
    // Authorization (authz) logging functions.
    //
    // These functions generate log messages describing the disposition of access control
    // checks.
    //

    /**
     * Logs the result of a command authorization check.
     */
    void logCommandAuthzCheck(
            ClientBasic* client,
            const NamespaceString& ns,
            const mutablebson::Document& cmdObj,
            ErrorCodes::Error result);

    /**
     * Logs the result of an authorization check for an OP_DELETE wire protocol message.
     */
    void logDeleteAuthzCheck(
            ClientBasic* client,
            const NamespaceString& ns,
            const BSONObj& pattern,
            ErrorCodes::Error result);

    /**
     * Logs the result of an authorization check for the "unlock" pseudo-command.
     */
    void logFsyncUnlockAuthzCheck(
            ClientBasic* client,
            ErrorCodes::Error result);

    /**
     * Logs the result of an authorization check for an OP_GET_MORE wire protocol message.
     */
    void logGetMoreAuthzCheck(
            ClientBasic* client,
            const NamespaceString& ns,
            long long cursorId,
            ErrorCodes::Error result);

    /**
     * Logs the result of an authorization check for an "inprog" pseudo-command.
     */
    void logInProgAuthzCheck(
            ClientBasic* client,
            const BSONObj& filter,
            ErrorCodes::Error result);

    /**
     * Logs the result of an authorization check for an OP_INSERT wire protocol message.
     */
    void logInsertAuthzCheck(
            ClientBasic* client,
            const NamespaceString& ns,
            const BSONObj& insertedObj,
            ErrorCodes::Error result);

    /**
     * Logs the result of an authorization check for an OP_KILL_CURSORS wire protocol message.
     */
    void logKillCursorsAuthzCheck(
            ClientBasic* client,
            const NamespaceString& ns,
            long long cursorId,
            ErrorCodes::Error result);

    /**
     * Logs the result of an authorization check for a "killop" pseudo-command.
     */
    void logKillOpAuthzCheck(
            ClientBasic* client,
            const BSONObj& filter,
            ErrorCodes::Error result);

    /**
     * Logs the result of an authorization check for an OP_QUERY wire protocol message.
     */
    void logQueryAuthzCheck(
            ClientBasic* client,
            const NamespaceString& ns,
            const BSONObj& query,
            ErrorCodes::Error result);

    /**
     * Logs the result of an authorization check for an OP_UPDATE wire protocol message.
     */
    void logUpdateAuthzCheck(
            ClientBasic* client,
            const NamespaceString& ns,
            const BSONObj& query,
            const BSONObj& updateObj,
            bool isUpsert,
            bool isMulti,
            ErrorCodes::Error result);

    /**
     * Logs the result of a createUser command.
     */
    void logCreateUser(ClientBasic* client,
                       const UserName& username,
                       bool password,
                       const BSONObj* customData,
                       const std::vector<RoleName>& roles);

    /**
     * Logs the result of a dropUser command.
     */
    void logDropUser(ClientBasic* client,
                     const UserName& username);

    /**
     * Logs the result of a dropAllUsersFromDatabase command.
     */
    void logDropAllUsersFromDatabase(ClientBasic* client,
                                     const StringData& dbname);

    /**
     * Logs the result of a updateUser command.
     */
    void logUpdateUser(ClientBasic* client,
                       const UserName& username,
                       bool password,
                       const BSONObj* customData,
                       const std::vector<RoleName>* roles);

    /**
     * Logs the result of a grantRolesToUser command.
     */
    void logGrantRolesToUser(ClientBasic* client,
                             const UserName& username,
                             const std::vector<RoleName>& roles);

    /**
     * Logs the result of a revokeRolesFromUser command.
     */
    void logRevokeRolesFromUser(ClientBasic* client,
                                const UserName& username,
                                const std::vector<RoleName>& roles);

    /**
     * Logs the result of a createRole command.
     */
    void logCreateRole(ClientBasic* client,
                       const RoleName& role,
                       const std::vector<RoleName>& roles,
                       const PrivilegeVector& privileges);

    /**
     * Logs the result of a updateRole command.
     */
    void logUpdateRole(ClientBasic* client,
                       const RoleName& role,
                       const std::vector<RoleName>* roles,
                       const PrivilegeVector* privileges);

    /**
     * Logs the result of a dropRole command.
     */
    void logDropRole(ClientBasic* client,
                     const RoleName& role);

    /**
     * Logs the result of a dropAllRolesForDatabase command.
     */
    void logDropAllRolesFromDatabase(ClientBasic* client,
                                     const StringData& dbname);

    /**
     * Logs the result of a grantRolesToRole command.
     */
    void logGrantRolesToRole(ClientBasic* client,
                             const RoleName& role,
                             const std::vector<RoleName>& roles);

    /**
     * Logs the result of a revokeRolesFromRole command.
     */
    void logRevokeRolesFromRole(ClientBasic* client,
                                const RoleName& role,
                                const std::vector<RoleName>& roles);

    /**
     * Logs the result of a grantPrivilegesToRole command.
     */
    void logGrantPrivilegesToRole(ClientBasic* client,
                                  const RoleName& role,
                                  const PrivilegeVector& privileges);

    /**
     * Logs the result of a revokePrivilegesFromRole command.
     */
    void logRevokePrivilegesFromRole(ClientBasic* client,
                                     const RoleName& role,
                                     const PrivilegeVector& privileges);

    /**
     * Logs the result of a replSet(Re)config command.
     */
    void logReplSetReconfig(ClientBasic* client,
                            const BSONObj* oldConfig,
                            const BSONObj* newConfig);

    /**
     * Logs the result of an ApplicationMessage command.
     */
    void logApplicationMessage(ClientBasic* client,
                               const StringData& msg);

    /**
     * Logs the result of a shutdown command.
     */
    void logShutdown(ClientBasic* client);

    /**
     * Logs the result of a createIndex command.
     */
    void logCreateIndex(ClientBasic* client,
                        const BSONObj* indexSpec,
                        const StringData& indexname,
                        const StringData& nsname);

    /**
     * Logs the result of a createCollection command.
     */
    void logCreateCollection(ClientBasic* client,
                             const StringData& nsname);

    /**
     * Logs the result of a createDatabase command.
     */
    void logCreateDatabase(ClientBasic* client,
                           const StringData& dbname);


    /**
     * Logs the result of a dropIndex command.
     */
    void logDropIndex(ClientBasic* client,
                      const StringData& indexname,
                      const StringData& nsname);

    /**
     * Logs the result of a dropCollection command.
     */
    void logDropCollection(ClientBasic* client,
                           const StringData& nsname);

    /**
     * Logs the result of a dropDatabase command.
     */
    void logDropDatabase(ClientBasic* client,
                         const StringData& dbname);

    /**
     * Logs a collection rename event.
     */
    void logRenameCollection(ClientBasic* client,
                             const StringData& source,
                             const StringData& target);

    /**
     * Logs the result of a enableSharding command.
     */
    void logEnableSharding(ClientBasic* client,
                           const StringData& dbname);

    /**
     * Logs the result of a addShard command.
     */
    void logAddShard(ClientBasic* client,
                     const StringData& name,
                     const std::string& servers,
                     long long maxSize);

    /**
     * Logs the result of a removeShard command.
     */
    void logRemoveShard(ClientBasic* client,
                        const StringData& shardname);

    /**
     * Logs the result of a shardCollection command.
     */
    void logShardCollection(ClientBasic* client,
                            const StringData& ns,
                            const BSONObj& keyPattern,
                            bool unique);


    /* 
     * Appends an array of user/db pairs to the provided Document.
     * The users are extracted from the current client.  They are to be the
     * impersonated users for a Command run by an internal user.
     */
    void appendImpersonatedUsers(BSONObjBuilder* cmd);
    const char cmdOptionImpersonatedUsers[] = "impersonatedUsers";

    /* 
     * Looks for an 'impersonatedUsers' field.  This field is used by mongos to
     * transmit the usernames of the currently authenticated user when it runs commands
     * on a shard using internal user authentication.  Auditing uses this information
     * to properly ascribe users to actions.  This is necessary only for implicit actions that
     * mongos cannot properly audit itself; examples are implicit collection and database creation.
     * This function requires that the field is the last field in the bson object; it edits the
     * command BSON to efficiently remove the field before returning.
     *
     * cmdObj [in, out]: If any impersonated users field exists, it will be parsed and removed.
     * authSession [in]: current authorization session
     * parsedUserNames [out]: populated with parsed usernames
     * fieldIsPresent [out]: true if impersonatedUsers field was present in the object
     */ 
    void parseAndRemoveImpersonatedUserField(BSONObj cmdObj, 
                                             AuthorizationSession* authSession,
                                             std::vector<UserName>* parsedUserNames,
                                             bool* fieldIsPresent);

}  // namespace audit
}  // namespace mongo