function parseSimpleXml(raw) {
    const result = {};
    const reg = /<([A-Za-z0-9_]+)>(?:<!\[CDATA\[([\s\S]*?)\]\]>|([\s\S]*?))<\/\1>/g;
    let match;
    while ((match = reg.exec(raw)) !== null) {
        const key = match[1];
        if (key === 'xml')
            continue;
        result[key] = match[2] !== undefined ? match[2] : String(match[3] || '').trim();
    }
    return result;
}

function readRawBody(req) {
    return new Promise((resolve, reject) => {
        const chunks = [];
        req.on('data', chunk => chunks.push(chunk));
        req.on('end', () => resolve(Buffer.concat(chunks).toString('utf8')));
        req.on('error', reject);
    });
}

export default function xmlBodyParser() {
    return async (ctx, next) => {
        const contentType = String(ctx.request.headers['content-type'] || '').toLowerCase();
        if (!contentType.includes('xml')) {
            await next();
            return;
        }

        const rawBody = await readRawBody(ctx.req);
        ctx.request.body = {
            xml: parseSimpleXml(rawBody),
            rawBody,
        };
        await next();
    };
}