<?php

/**
 * imap_search.php
 *
 * IMAP asearch routines
 *
 * Subfolder search idea from Patch #806075 by Thomas Pohl xraven at users.sourceforge.net. Thanks Thomas!
 *
 * @author Alex Lemaresquier - Brainstorm <alex at brainstorm.fr>
 * @copyright &copy; 1999-2006 The SquirrelMail Project Team
 * @license http://opensource.org/licenses/gpl-license.php GNU Public License
 * @version $Id: imap_asearch.php,v 1.47 2006/01/29 10:36:06 stekkel Exp $
 * @package squirrelmail
 * @subpackage imap
 * @see search.php
 * @link http://www.ietf.org/rfc/rfc3501.txt
 */

/** This functionality requires the IMAP and date functions
 */
require_once(SM_PATH . 'functions/imap_general.php');
require_once(SM_PATH . 'functions/date.php');

/** Set to TRUE to dump the IMAP dialogue
 * @global bool $imap_asearch_debug_dump
 */
$imap_asearch_debug_dump = FALSE;

/** IMAP SEARCH keys
 * @global array $imap_asearch_opcodes
 */
global $imap_asearch_opcodes;
$imap_asearch_opcodes = array(
/* <sequence-set> => 'asequence', */    // Special handling, @see sqimap_asearch_build_criteria()
/*'ALL' is binary operator */
    'ANSWERED' => '',
    'BCC' => 'astring',
    'BEFORE' => 'adate',
    'BODY' => 'astring',
    'CC' => 'astring',
    'DELETED' => '',
    'DRAFT' => '',
    'FLAGGED' => '',
    'FROM' => 'astring',
    'HEADER' => 'afield',    // Special syntax for this one, @see sqimap_asearch_build_criteria()
    'KEYWORD' => 'akeyword',
    'LARGER' => 'anum',
    'NEW' => '',
/*'NOT' is unary operator */
    'OLD' => '',
    'ON' => 'adate',
/*'OR' is binary operator */
    'RECENT' => '',
    'SEEN' => '',
    'SENTBEFORE' => 'adate',
    'SENTON' => 'adate',
    'SENTSINCE' => 'adate',
    'SINCE' => 'adate',
    'SMALLER' => 'anum',
    'SUBJECT' => 'astring',
    'TEXT' => 'astring',
    'TO' => 'astring',
    'UID' => 'asequence',
    'UNANSWERED' => '',
    'UNDELETED' => '',
    'UNDRAFT' => '',
    'UNFLAGGED' => '',
    'UNKEYWORD' => 'akeyword',
    'UNSEEN' => ''
);

/** IMAP SEARCH month names encoding
 * @global array $imap_asearch_months
 */
$imap_asearch_months = array(
    '01' => 'jan',
    '02' => 'feb',
    '03' => 'mar',
    '04' => 'apr',
    '05' => 'may',
    '06' => 'jun',
    '07' => 'jul',
    '08' => 'aug',
    '09' => 'sep',
    '10' => 'oct',
    '11' => 'nov',
    '12' => 'dec'
);

/**
 * Function to display an error related to an IMAP query.
 * We need to do our own error management since we may receive NO responses on purpose (even BAD with SORT or THREAD)
 * so we call sqimap_error_box() if the function exists (sm >= 1.5) or use our own embedded code
 * @global array imap_error_titles
 * @param string $response the imap server response code
 * @param string $query the failed query
 * @param string $message an optional error message
 * @param string $link an optional link to try again
 */
//@global array color sm colors array
function sqimap_asearch_error_box($response, $query, $message, $link = '')
{
    global $color;
    // Error message titles according to IMAP server returned code
    $imap_error_titles = array(
        'OK' => '',
        'NO' => _("ERROR: Could not complete request."),
        'BAD' => _("ERROR: Bad or malformed request."),
        'BYE' => _("ERROR: IMAP server closed the connection."),
        '' => _("ERROR: Connection dropped by IMAP server.")
    );


    if (!array_key_exists($response, $imap_error_titles))
        $title = _("ERROR: Unknown IMAP response.");
    else
        $title = $imap_error_titles[$response];
    if ($link == '')
        $message_title = _("Reason Given:");
    else
        $message_title = _("Possible reason:");
    $message_title .= ' ';
    sqimap_error_box($title, $query, $message_title, $message, $link);
}

/**
 * This is a convenient way to avoid spreading if (isset(... all over the code
 * @param mixed $var any variable (reference)
 * @param mixed $def default value to return if unset (default is zls (''), pass 0 or array() when appropriate)
 * @return mixed $def if $var is unset, otherwise $var
 */
function asearch_nz(&$var, $def = '')
{
    if (isset($var))
        return $var;
    return $def;
}

/**
 * This should give the same results as PHP 4 >= 4.3.0's html_entity_decode(),
 * except it doesn't handle hex constructs
 * @param string $string string to unhtmlentity()
 * @return string decoded string
 */
function asearch_unhtmlentities($string) {
    $trans_tbl = array_flip(get_html_translation_table(HTML_ENTITIES));
    for ($i=127; $i<255; $i++)    /* Add &#<dec>; entities */
        $trans_tbl['&#' . $i . ';'] = chr($i);
    return strtr($string, $trans_tbl);
/* I think the one above is quicker, though it should be benchmarked
    $string = strtr($string, array_flip(get_html_translation_table(HTML_ENTITIES)));
    return preg_replace("/&#([0-9]+);/E", "chr('\\1')", $string);
 */
}

/** Encode a string to quoted or literal as defined in rfc 3501
 *
 * -  4.3 String:
 *        A quoted string is a sequence of zero or more 7-bit characters,
 *         excluding CR and LF, with double quote (<">) characters at each end.
 * -  9. Formal Syntax:
 *        quoted-specials = DQUOTE / "\"
 * @param string $what string to encode
 * @param string $charset search charset used
 * @return string encoded string
 */
function sqimap_asearch_encode_string($what, $charset)
{
    if (strtoupper($charset) == 'ISO-2022-JP')    // This should be now handled in imap_utf7_local?
        $what = mb_convert_encoding($what, 'JIS', 'auto');
    if (preg_match('/["\\\\\r\n\x80-\xff]/', $what))
        return '{' . strlen($what) . "}\r\n" . $what;    // 4.3 literal form
    return '"' . $what . '"';    // 4.3 quoted string form
}

/**
 * Parses a user date string into an rfc 3501 date string
 * Handles space, slash, backslash, dot and comma as separators (and dash of course ;=)
 * @global array imap_asearch_months
 * @param string user date
 * @return array a preg_match-style array:
 *  - [0] = fully formatted rfc 3501 date string (<day number>-<US month TLA>-<4 digit year>)
 *  - [1] = day
 *  - [2] = month
 *  - [3] = year
 */
function sqimap_asearch_parse_date($what)
{
    global $imap_asearch_months;

    $what = trim($what);
    $what = ereg_replace('[ /\\.,]+', '-', $what);
    if ($what) {
        preg_match('/^([0-9]+)-+([^\-]+)-+([0-9]+)$/', $what, $what_parts);
        if (count($what_parts) == 4) {
            $what_month = strtolower(asearch_unhtmlentities($what_parts[2]));
/*                if (!in_array($what_month, $imap_asearch_months)) {*/
                foreach ($imap_asearch_months as $month_number => $month_code) {
                    if (($what_month == $month_number)
                    || ($what_month == $month_code)
                    || ($what_month == strtolower(asearch_unhtmlentities(getMonthName($month_number))))
                    || ($what_month == strtolower(asearch_unhtmlentities(getMonthAbrv($month_number))))
                    ) {
                        $what_parts[2] = $month_number;
                        $what_parts[0] = $what_parts[1] . '-' . $month_code . '-' . $what_parts[3];
                        break;
                    }
                }
/*                }*/
        }
    }
    else
        $what_parts = array();
    return $what_parts;
}

/**
 * Build one criteria sequence
 * @global array imap_asearch_opcodes
 * @param string $opcode search opcode
 * @param string $what opcode argument
 * @param string $charset search charset
 * @return string one full criteria sequence
 */
function sqimap_asearch_build_criteria($opcode, $what, $charset)
{
    global $imap_asearch_opcodes;

    $criteria = '';
    switch ($imap_asearch_opcodes[$opcode]) {
        default:
        case 'anum':
            $what = str_replace(' ', '', $what);
            $what = ereg_replace('[^0-9]+[^KMG]$', '', strtoupper($what));
            if ($what != '') {
                switch (substr($what, -1)) {
                    case 'G':
                        $what = substr($what, 0, -1) << 30;
                    break;
                    case 'M':
                        $what = substr($what, 0, -1) << 20;
                    break;
                    case 'K':
                        $what = substr($what, 0, -1) << 10;
                    break;
                }
                $criteria = $opcode . ' ' . $what . ' ';
            }
        break;
        case '':    //aflag
            $criteria = $opcode . ' ';
        break;
        case 'afield':    /* HEADER field-name: field-body */
            preg_match('/^([^:]+):(.*)$/', $what, $what_parts);
            if (count($what_parts) == 3)
                $criteria = $opcode . ' ' .
                    sqimap_asearch_encode_string($what_parts[1], $charset) . ' ' .
                    sqimap_asearch_encode_string($what_parts[2], $charset) . ' ';
        break;
        case 'adate':
            $what_parts = sqimap_asearch_parse_date($what);
            if (isset($what_parts[0]))
                $criteria = $opcode . ' ' . $what_parts[0] . ' ';
        break;
        case 'akeyword':
        case 'astring':
            $criteria = $opcode . ' ' . sqimap_asearch_encode_string($what, $charset) . ' ';
        break;
        case 'asequence':
            $what = ereg_replace('[^0-9:\(\)]+', '', $what);
            if ($what != '')
                $criteria = $opcode . ' ' . $what . ' ';
        break;
    }
    return $criteria;
}

/**
 * Another way to do array_values(array_unique(array_merge($to, $from)));
 * @param array $to to array (reference)
 * @param array $from from array
 * @return array uniquely merged array
 */
function sqimap_array_merge_unique(&$to, $from)
{
    if (empty($to))
        return $from;
    $count = count($from);
    for ($i = 0; $i < $count; $i++) {
        if (!in_array($from[$i], $to))
            $to[] = $from[$i];
    }
    return $to;
}

/**
 * Run the IMAP SEARCH command as defined in rfc 3501
 * @link http://www.ietf.org/rfc/rfc3501.txt
 * @param resource $imapConnection the current imap stream
 * @param string $search_string the full search expression eg "ALL RECENT"
 * @param string $search_charset charset to use or zls ('')
 * @return array an IDs or UIDs array of matching messages or an empty array
 * @since 1.5.0
 */
function sqimap_run_search($imapConnection, $search_string, $search_charset)
{
    //For some reason, this seems to happen and forbids searching servers not allowing OPTIONAL [CHARSET]
    if (strtoupper($search_charset) == 'US-ASCII')
        $search_charset = '';
    /* 6.4.4 try OPTIONAL [CHARSET] specification first */
    if ($search_charset != '')
        $query = 'SEARCH CHARSET "' . strtoupper($search_charset) . '" ' . $search_string;
    else
        $query = 'SEARCH ' . $search_string;
    $readin = sqimap_run_command_list($imapConnection, $query, false, $response, $message, TRUE);

    /* 6.4.4 try US-ASCII charset if we tried an OPTIONAL [CHARSET] and received a tagged NO response (SHOULD be [BADCHARSET]) */
    if (($search_charset != '')  && (strtoupper($response) == 'NO')) {
        $query = 'SEARCH CHARSET US-ASCII ' . $search_string;
        $readin = sqimap_run_command_list($imapConnection, $query, false, $response, $message, TRUE);
    }
    if (strtoupper($response) != 'OK') {
        sqimap_asearch_error_box($response, $query, $message);
        return array();
    }
    $messagelist = parseUidList($readin,'SEARCH');

    if (empty($messagelist))    //Empty search response, ie '* SEARCH'
        return array();

    $cnt = count($messagelist);
    for ($q = 0; $q < $cnt; $q++)
        $id[$q] = trim($messagelist[$q]);
    return $id;
}

/**
 * @global bool allow_charset_search user setting
 * @global array languages sm languages array
 * @global string squirrelmail_language user language setting
 * @return string the user defined charset if $allow_charset_search is TRUE else zls ('')
 */
function sqimap_asearch_get_charset()
{
    global $allow_charset_search, $languages, $squirrelmail_language;

    if ($allow_charset_search)
        return $languages[$squirrelmail_language]['CHARSET'];
    return '';
}

/**
 * Convert SquirrelMail internal sort to IMAP sort taking care of:
 * - user defined date sorting (ARRIVAL vs DATE)
 * - if the searched mailbox is the sent folder then TO is being used instead of FROM
 * - reverse order by using REVERSE
 * @param string $mailbox mailbox name to sort
 * @param integer $sort_by sm sort criteria index
 * @global bool internal_date_sort sort by arrival date instead of message date
 * @global string sent_folder sent folder name
 * @return string imap sort criteria
 */
function sqimap_asearch_get_sort_criteria($mailbox, $sort_by)
{
    global $internal_date_sort, $sent_folder;

    $sort_opcodes = array ('DATE', 'FROM', 'SUBJECT', 'SIZE');
    if ($internal_date_sort == true)
        $sort_opcodes[0] = 'ARRIVAL';
//        if (handleAsSent($mailbox))
//        if (isSentFolder($mailbox))
    if ($mailbox == $sent_folder)
        $sort_opcodes[1] = 'TO';
    return (($sort_by % 2) ? '' : 'REVERSE ') . $sort_opcodes[($sort_by >> 1) & 3];
}

/**
 * @param string $cur_mailbox unformatted mailbox name
 * @param array $boxes_unformatted selectable mailbox unformatted names array (reference)
 * @return array sub mailboxes unformatted names
 */
function sqimap_asearch_get_sub_mailboxes($cur_mailbox, &$mboxes_array)
{
    $sub_mboxes_array = array();
    $boxcount = count($mboxes_array);
    for ($boxnum=0; $boxnum < $boxcount; $boxnum++) {
        if (isBoxBelow($mboxes_array[$boxnum], $cur_mailbox))
            $sub_mboxes_array[] = $mboxes_array[$boxnum];
    }
    return $sub_mboxes_array;
}

/**
 * Create the search query strings for all given criteria and merge results for every mailbox
 * @param resource $imapConnection
 * @param array $mailbox_array (reference)
 * @param array $biop_array (reference)
 * @param array $unop_array (reference)
 * @param array $where_array (reference)
 * @param array $what_array (reference)
 * @param array $exclude_array (reference)
 * @param array $sub_array (reference)
 * @param array $mboxes_array selectable unformatted mailboxes names (reference)
 * @return array array(mailbox => array(UIDs))
 */
function sqimap_asearch($imapConnection, &$mailbox_array, &$biop_array, &$unop_array, &$where_array, &$what_array, &$exclude_array, &$sub_array, &$mboxes_array)
{

    $search_charset = sqimap_asearch_get_charset();
    $mbox_search = array();
    $search_string = '';
    $cur_mailbox = $mailbox_array[0];
    $cur_biop = '';    /* Start with ALL */
    /* We loop one more time than the real array count, so the last search gets fired */
    for ($cur_crit=0,$iCnt=count($where_array); $cur_crit <= $iCnt; ++$cur_crit) {
        if (empty($exclude_array[$cur_crit])) {
            $next_mailbox = (isset($mailbox_array[$cur_crit])) ? $mailbox_array[$cur_crit] : false;
            if ($next_mailbox != $cur_mailbox) {
                $search_string = trim($search_string);    /* Trim out last space */
                if ($cur_mailbox == 'All Folders')
                    $search_mboxes = $mboxes_array;
                else if ((!empty($sub_array[$cur_crit - 1])) || (!in_array($cur_mailbox, $mboxes_array)))
                    $search_mboxes = sqimap_asearch_get_sub_mailboxes($cur_mailbox, $mboxes_array);
                else
                    $search_mboxes = array($cur_mailbox);
                foreach ($search_mboxes as $cur_mailbox) {
                    if (isset($mbox_search[$cur_mailbox])) {
                        $mbox_search[$cur_mailbox]['search'] .= ' ' . $search_string;
                    } else {
                        $mbox_search[$cur_mailbox]['search'] = $search_string;
                    }
                    $mbox_search[$cur_mailbox]['charset'] = $search_charset;
                }
                $cur_mailbox = $next_mailbox;
                $search_string = '';
            }
            if (isset($where_array[$cur_crit]) && empty($exclude_array[$cur_crit])) {
                $aCriteria = array();
                for ($crit = $cur_crit; $crit < count($where_array); $crit++) {
                    $criteria = trim(sqimap_asearch_build_criteria($where_array[$crit], $what_array[$crit], $search_charset));
                    if (!empty($criteria) && empty($exclude_array[$crit])) {
                        if (asearch_nz($mailbox_array[$crit]) == $cur_mailbox) {
                            $unop = $unop_array[$crit];
                            if (!empty($unop)) {
                                $criteria = $unop . ' ' . $criteria;
                            }
                            $aCriteria[] = array($biop_array[$crit], $criteria);
                        }
                    }
                    // unset something
                    $exclude_array[$crit] = true;
                }
                $aSearch = array();
                for($i=0,$iCnt=count($aCriteria);$i<$iCnt;++$i) {
                    $cur_biop = $aCriteria[$i][0];
                    $next_biop = (isset($aCriteria[$i+1][0])) ? $aCriteria[$i+1][0] : false;
                    if ($next_biop != $cur_biop && $next_biop == 'OR') {
                        $aSearch[] = 'OR '.$aCriteria[$i][1];
                    } else if ($cur_biop != 'OR') {
                        $aSearch[] = 'ALL '.$aCriteria[$i][1];
                    } else { // OR only supports 2 search keys so we need to create a parenthesized list
                        $prev_biop = (isset($aCriteria[$i-1][0])) ? $aCriteria[$i-1][0] : false;
                        if ($prev_biop == $cur_biop) {
                            $last = $aSearch[$i-1];
                            if (!substr($last,-1) == ')') {
                                $aSearch[$i-1] = "(OR $last";
                                $aSearch[] = $aCriteria[$i][1].')';
                            } else {
                                $sEnd = '';
                                while ($last && substr($last,-1) == ')') {
                                    $last = substr($last,0,-1);
                                    $sEnd .= ')';
                                }
                                $aSearch[$i-1] = "(OR $last";
                                $aSearch[] = $aCriteria[$i][1].$sEnd.')';
                            }
                        } else {
                            $aSearch[] = $aCriteria[$i][1];
                        }
                    }
                }
                $search_string .= implode(' ',$aSearch);
            }
        }
    }
    return ($mbox_search);
}

?>
