function invoke(action, version, params = {}) {
    return new Promise((resolve, reject) => {
        const xhr = new XMLHttpRequest();
        xhr.addEventListener('error', () => reject('failed to issue request'));
        xhr.addEventListener('load', () => {
            try {
                const response = JSON.parse(xhr.responseText);
                if (Object.getOwnPropertyNames(response).length != 2) {
                    throw 'response has an unexpected number of fields';
                }
                if (!response.hasOwnProperty('error')) {
                    throw 'response is missing required error field';
                }
                if (!response.hasOwnProperty('result')) {
                    throw 'response is missing required result field';
                }
                if (response.error) {
                    throw response.error;
                }
                resolve(response.result);
            } catch (e) {
                reject(e);
            }
        });

        xhr.open('POST', 'http://127.0.0.1:8765');
        xhr.send(JSON.stringify({ action, version, params }));
    });
}

await invoke('requestPermission', 6);


await invoke('guiAddCards', 6, {
    "note": {
        "deckName": "Default",
        "modelName": "Cloze",
        "fields": {
            "Text": "The capital of Romania is {{c1::Bucharest}}",
            "Extra": "Romania is a country in Europe"
        },
        "options": {
            "closeAfterAdding": true
        },
        "tags": [
          "countries"
        ],
        "picture": [{
            "url": "https://upload.wikimedia.org/wikipedia/commons/thumb/1/13/EU-Romania.svg/285px-EU-Romania.svg.png",
            "filename": "romania.png",
            "fields": [
                "Extra"
            ]
        }]
    }
});