document.addEventListener("DOMContentLoaded", () => {
    document.querySelector('#json-file').addEventListener('change', async function () {
        const rawFile = await readFileAsync(this.files[0]);
        const json = JSON.parse(arrayBufferToString(rawFile));
        document.querySelector('#json-file-loader').style.display = 'none';
        document.querySelector('#map').style.display = 'block';
        document.querySelector('#json-export').addEventListener('click', () => exportJson(json));
        setupMap(json);
    })
});

function readFileAsync(file) {
    return new Promise((resolve, reject) => {
        let reader = new FileReader();
        reader.onload = () => resolve(reader.result);
        reader.onerror = reject;
        reader.readAsArrayBuffer(file);
    });
}

function arrayBufferToString(arrayBuffer) {
    return new TextDecoder('utf-8').decode(arrayBuffer);
}