require('dotenv').config();

const ALLOWED_EXT = ['jpg', 'jpeg', 'png'];

function extFromUrl(url) {
    const m = /\.([a-z0-9]+)(\?|$)/i.exec(String(url || ''));
    return m ? m[1].toLowerCase() : null;
}

// Portiert aus adapters/media.lua IsAllowedExternalUrl
function isAllowedExternalUrl(url) {
    url = String(url || '');
    if (!/^https:\/\//i.test(url)) return { ok: false, reason: 'url_must_be_https' };
    if (/^https:\/\/i\.ibb\.co\//i.test(url) || /^https:\/\/ibb\.co\//i.test(url)) return { ok: true };
    const ext = extFromUrl(url);
    if (ext && ALLOWED_EXT.includes(ext)) return { ok: true };
    return { ok: false, reason: 'unsupported_image_url' };
}

// Upload eines Buffers zu imgbb -> { url }
async function uploadToImgbb(buffer, filename) {
    const key = process.env.IMGBB_KEY;
    if (!key) throw new Error('imgbb_key_missing');
    const form = new FormData();
    form.append('image', buffer.toString('base64'));
    if (filename) form.append('name', filename.replace(/\.[^.]+$/, ''));

    const resp = await fetch(`https://api.imgbb.com/1/upload?key=${encodeURIComponent(key)}`, {
        method: 'POST',
        body: form,
    });
    const data = await resp.json();
    if (!data || !data.success || !data.data || !data.data.url) {
        throw new Error('imgbb_upload_failed');
    }
    return { url: data.data.url };
}

module.exports = { isAllowedExternalUrl, uploadToImgbb, ALLOWED_EXT };