std::string getRuleset(RESPONSE_CALLBACK_ARGS)
{
    std::string &argument = request.argument;
    int *status_code = &response.status_code;
    /// type: 1 for Surge, 2 for Quantumult X, 3 for Clash domain rule-provider, 4 for Clash ipcidr rule-provider, 5 for Surge DOMAIN-SET, 6 for Clash classical ruleset
    std::string url = urlSafeBase64Decode(getUrlArg(argument, "url")), type = getUrlArg(argument, "type"), group = urlSafeBase64Decode(getUrlArg(argument, "group"));
    std::string output_content, dummy;
    int type_int = to_int(type, 0);

    if(!url.size() || !type.size() || (type_int == 2 && !group.size()) || (type_int < 1 || type_int > 6))
    {
        *status_code = 400;
        return "Invalid request!";
    }

    std::string proxy = parseProxy(global.proxyRuleset);
    string_array vArray = split(url, "|");
    for(std::string &x : vArray)
        x.insert(0, "ruleset,");
    std::vector<RulesetContent> rca;
    RulesetConfigs confs = INIBinding::from<RulesetConfig>::from_ini(vArray);
    refreshRulesets(confs, rca);
    for(RulesetContent &x : rca)
    {
        std::string content = x.rule_content.get();
        output_content += convertRuleset(content, x.rule_type);
    }

    if(!output_content.size())
    {
        *status_code = 400;
        return "Invalid request!";
    }

    std::string strLine;
    std::stringstream ss;
    const std::string rule_match_regex = "^(.*?,.*?)(,.*)(,.*)$";

    ss << output_content;
    char delimiter = getLineBreak(output_content);
    std::string::size_type lineSize, posb, pose;
    auto filterLine = [&]()
    {
        posb = 0;
        pose = strLine.find(',');
        if(pose == strLine.npos)
            return 1;
        posb = pose + 1;
        pose = strLine.find(',', posb);
        if(pose == strLine.npos)
        {
            pose = strLine.size();
            if(strLine[pose - 1] == '\r')
                pose--;
        }
        pose -= posb;
        return 0;
    };

    lineSize = output_content.size();
    output_content.clear();
    output_content.reserve(lineSize);

    if(type_int == 3 || type_int == 4 || type_int == 6)
        output_content = "payload:\n";

    while(getline(ss, strLine, delimiter))
    {
        if(strFind(strLine, "//"))
        {
            strLine.erase(strLine.find("//"));
            strLine = trimWhitespace(strLine);
        }
        switch(type_int)
        {
        case 2:
            if(!std::any_of(QuanXRuleTypes.begin(), QuanXRuleTypes.end(), [&strLine](std::string type){return startsWith(strLine, type);}))
                continue;
            break;
        case 1:
            if(!std::any_of(SurgeRuleTypes.begin(), SurgeRuleTypes.end(), [&strLine](std::string type){return startsWith(strLine, type);}))
                continue;
            break;
        case 3:
            if(!startsWith(strLine, "DOMAIN-SUFFIX,") && !startsWith(strLine, "DOMAIN,"))
                continue;
            if(filterLine())
                continue;
            output_content += "  - '";
            if(strLine[posb - 2] == 'X')
                output_content += "+.";
            output_content += strLine.substr(posb, pose);
            output_content += "'\n";
            continue;
        case 4:
            if(!startsWith(strLine, "IP-CIDR,") && !startsWith(strLine, "IP-CIDR6,"))
                continue;
            if(filterLine())
                continue;
            output_content += "  - '";
            output_content += strLine.substr(posb, pose);
            output_content += "'\n";
            continue;
        case 5:
            if(!startsWith(strLine, "DOMAIN-SUFFIX,") && !startsWith(strLine, "DOMAIN,"))
                continue;
            if(filterLine())
                continue;
            output_content += strLine.substr(posb, pose);
            output_content += '\n';
            continue;
        case 6:
            if(!std::any_of(ClashRuleTypes.begin(), ClashRuleTypes.end(), [&strLine](std::string type){return startsWith(strLine, type);}))
                continue;
            output_content += "  - ";
        }

        lineSize = strLine.size();
        if(lineSize && strLine[lineSize - 1] == '\r') //remove line break
            strLine.erase(--lineSize);

        if(!strLine.empty() && (strLine[0] != ';' && strLine[0] != '#' && !(lineSize >= 2 && strLine[0] == '/' && strLine[1] == '/')))
        {
            if(type_int == 2)
            {
                if(startsWith(strLine, "IP-CIDR6"))
                    strLine.replace(0, 8, "IP6-CIDR");
                strLine += "," + group;
                if(count_least(strLine, ',', 3) && regReplace(strLine, rule_match_regex, "$2") == ",no-resolve")
                    strLine = regReplace(strLine, rule_match_regex, "$1$3$2");
                else
                    strLine = regReplace(strLine, rule_match_regex, "$1$3");
            }
        }
        output_content += strLine;
        output_content += '\n';
    }

    if(output_content == "payload:\n")
    {
        switch(type_int)
        {
        case 3:
            output_content += "  - '--placeholder--'";
            break;
        case 4:
            output_content += "  - '0.0.0.0/32'";
            break;
        case 6:
            output_content += "  - 'DOMAIN,--placeholder--'";
            break;
        }
    }
    return output_content;
}