<?php

function sphinx_execute(string $sql) {
    $link = _sphinxql_link();

    if (func_num_args() > 1) {
        $mark_count = substr_count($sql, '?');
        $positions = array();
        $last_pos = -1;
        for ($i = 0; $i < $mark_count; $i++) {
            $last_pos = strpos($sql, '?', $last_pos + 1);
            $positions[] = $last_pos;
        }
        for ($i = $mark_count - 1; $i >= 0; $i--) {
            $arg = func_get_arg($i + 1);
            if (is_string($arg))
                $arg = _sphinx_normalize($arg);
            $v = '\''.$link->real_escape_string($arg).'\'';
            $sql = substr_replace($sql, $v, $positions[$i], 1);
        }
    }

    $q = $link->query($sql);

    $error = sphinx_error();
    if ($error)
        logError(__FUNCTION__, $error);

    return $q;
}

function sphinx_error() {
    $link = _sphinxql_link(auto_create: false);
    return $link?->error;
}

function sphinx_mkquery($q, array $opts = []) {
    $defaults = [
        'any_word' => false,
        'star' => false,
        'and' => false,
        'exact_first' => false
    ];
    $opts = array_merge($defaults, $opts);
    $q = preg_replace('/\s+/', ' ', $q);
    $q = _sphinx_normalize($q);
    $q = trim($q);
    $q = sphinx_client()->escapeString($q);
    if ($opts['star']) {
        $words = explode(' ', $q);
        $words = array_map(fn($word) => $word.'*', $words);
        $q = implode(' ', $words);
    }
    if ($opts['any_word']) {
        $q = str_replace(' ', ' | ', $q);
    } else if ($opts['and']) {
        $q = str_replace(' ', ' AND ', $q);
    }
    if ($opts['exact_first']) {
        $q = '"^'.$q.'$" | "'.$q.'" | ('.$q.')';
    }
    return $q;
}

function sphinx_client(): Sphinx\SphinxClient {
    static $cl = null;
    if (!is_null($cl))
        return $cl;
    return $cl = new Sphinx\SphinxClient;
}

function _sphinx_normalize(string $origstr): string {
    $buf = preg_replace('/[Ёё]/iu', 'е', $origstr);
    if (!pcre_check_error($buf, no_error: true)) {
        $origstr = mb_convert_encoding($origstr, 'UTF-8', 'UTF-8');
        $buf = preg_replace('/[Ёё]/iu', 'е', $origstr);
        pcre_check_error($buf);
    }
    if ($buf === null) {
        logError(__METHOD__.': preg_replace() failed with error: '.preg_last_error().': '.preg_last_error_msg());
        $buf = $origstr;
    }
    return preg_replace('/[!\?]/', '', $buf);
}

function _sphinxql_link($auto_create = true) {
    global $config;

    /** @var ?mysqli $link */
    static $link = null;
    if (!is_null($link) || !$auto_create)
        return $link;

    $link = new mysqli();
    $link->real_connect(
        $config['sphinx']['host'],
        ini_get('mysql.default_user'),
        ini_get('mysql.default_password'),
        null,
        9306);
    $link->set_charset('utf8');

    return $link;
}