/**
 * @file llmail.h
 * @brief smtp helper functions.
 *
 * $LicenseInfo:firstyear=2001&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#ifndef LL_LLMAIL_H
#define LL_LLMAIL_H

typedef struct apr_pool_t apr_pool_t;

#include "llsd.h"

class LLMail
{
public:
    // if hostname is NULL, then the host is resolved as 'mail'
    static void init(const std::string& hostname, apr_pool_t* pool);

    // Allow all email transmission to be disabled/enabled.
    static void enable(bool mail_enabled);

    /**
     * @brief send an email
     * @param from_name The name of the email sender
     * @param from_address The email address for the sender
     * @param to_name The name of the email recipient
     * @param to_address The email recipient address
     * @param subject The subject of the email
     * @param headers optional X-Foo headers in an llsd map.
     * @return Returns true if the call succeeds, false otherwise.
     *
     * Results in:
     * From: "from_name" <from_address>
     * To:   "to_name" <to_address>
     * Subject: subject
     *
     * message
     */
    static bool send(
        const char* from_name,
        const char* from_address,
        const char* to_name,
        const char* to_address,
        const char* subject,
        const char* message,
        const LLSD& headers = LLSD());

    /**
     * @brief build the complete smtp transaction & header for use in an
     * mail.
     *
     * @param from_name The name of the email sender
     * @param from_address The email address for the sender
     * @param to_name The name of the email recipient
     * @param to_address The email recipient address
     * @param subject The subject of the email
     * @param headers optional X-Foo headers in an llsd map.
     * @return Returns the complete SMTP transaction mail header.
     */
    static std::string buildSMTPTransaction(
        const char* from_name,
        const char* from_address,
        const char* to_name,
        const char* to_address,
        const char* subject,
        const LLSD& headers = LLSD());

    /**
    * @brief send an email with header and body.
    *
    * @param header The email header. Use build_mail_header().
    * @param message The unescaped email message.
    * @param from_address Used for debugging
    * @param to_address Used for debugging
    * @return Returns true if the message could be sent.
    */
    static bool send(
        const std::string& header,
        const std::string& message,
        const char* from_address,
        const char* to_address);

    // IM-to-email sessions use a "session id" based on an encrypted
    // combination of from agent_id, to agent_id, and timestamp.  When
    // a user replies to an email we use the from_id to determine the
    // sender's name and the to_id to route the message.  The address
    // is encrypted to prevent users from building addresses to spoof
    // IMs from other users.  The timestamps allow the "sessions" to
    // expire, in case one of the sessions is stolen/hijacked.
    //
    // indra/tools/mailglue is responsible for parsing the inbound mail.
    //
    // secret: binary blob passed to blowfish, max length 56 bytes
    // secret_size: length of blob, in bytes
    //
    // Returns: "base64" encoded email local-part, with _ and - as the
    // non-alphanumeric characters.  This allows better compatibility
    // with email systems than the default / and + extra chars.  JC
    static std::string encryptIMEmailAddress(
        const LLUUID& from_agent_id,
        const LLUUID& to_agent_id,
        U32 time,
        const U8* secret,
        size_t secret_size);
};

extern const size_t LL_MAX_KNOWN_GOOD_MAIL_SIZE;

#endif