const _richText_text_styles_ = ['bold', 'underline', 'italic', 'danger', 'sup', 'sub'];

function renderRichText(body) {
    let sections = body.sections || [];
    let nodes = [];
    sections.forEach(section => {
        nodes.push(renderSection(section));
    });
    return nodes;
}

function renderSection(section) {
    let blocks = section.blocks || [];
    let inline = blocks.length > 1;
    let node = document.createElement('p');
    blocks.forEach(block => {
        node.appendChild(renderBlock(block, inline));
    });
    return node;
}

function renderBlock(block, inline) {
    let container = document.createElement('span');
    let type = '';
    if (block.type === 'text') {
        type = 'text';
        if (block.param != undefined) {
            _richText_text_styles_.forEach(style => {
                if (block.param[style] === true) {
                    type += ' ' + style;
                }
            })
        }
        container.textContent = block.value;
    } else if (block.type === 'image') {
        type = 'image loading';
        if (inline === true) {
            type += ' inline';
        }
        let img = container.appendChild(new Image());
        img.src = block.value;
        img.onload = function () {
            this.parentNode.className = this.parentNode.className.replace(/loading/g, '');
        }
    } else if (block.type === 'audio') {
        type = 'audio';
        let audio = container.appendChild(new Audio());
        audio.src = block.value;
        audio.controls = true;
        audio.setAttribute("type", "audio/mpeg");
    }
    container.className = type;
    return container;
}