function myPreviewRender (text) {
    text = text.replace(/[\u00A0-\u9999<>\&]/gim, function(i) {
        return '&#'+i.charCodeAt(0)+';';
    });
    text = SimpleMDE.prototype.markdown(text);
    text = DOMPurify.sanitize(text);

    return text;
};

function MDEWrapper(textarea, enableButton, disableButton) {
    this.element = textarea;
    this.enableButton = enableButton;
    this.disableButton = disableButton;
    this.simplemde = null;

    var wrapper = this;

    if (this.enableButton) {
        this.enableButton.on('click', function() {wrapper.enable()});
    }
    if (this.disableButton) {
        this.disableButton.on('click', function() {wrapper.disable()});
    }
}

MDEWrapper.prototype.enable = function() {
    var wrapper = this;
    if (this.simplemde == null) {
        this.simplemde = new SimpleMDE({
            element: wrapper.element,
            forceSync: true,
            status: true,
            previewRender: myPreviewRender,
            spellChecker: false,
            promptURLs: true,
            autoDownloadFontAwesome: false
        });
        if (this.enableButton) {
            this.enableButton.addClass('active');
        }
        if (this.disableButton) {
            this.disableButton.removeClass('active');
        }
    }
}

MDEWrapper.prototype.disable = function() {
    if (this.simplemde != null) {
        this.simplemde.toTextArea();
        this.simplemde = null;
        if (this.disableButton) {
            this.disableButton.addClass('active');
        }
        if (this.enableButton) {
            this.enableButton.removeClass('active');
        }
    }
}

MDEWrapper.prototype.isEnabled = function() {
    return this.simplemde != null;
}