/* Apply before paint; preference is local to this browser and site. */
(function () {
    'use strict';
    var key = 'convoa-night-shift';
    var root = document.documentElement;
    var enabled = false;
    try { enabled = window.localStorage.getItem(key) === 'night'; } catch (error) {}
    function apply(value) {
        enabled = value;
        root.classList.toggle('convoa-night', enabled);
        var button = document.getElementById('convoa-night-toggle');
        if (!button) { return; }
        var label = enabled ? 'Switch to day view' : 'Enable night shift view';
        button.setAttribute('aria-pressed', String(enabled));
        button.setAttribute('aria-label', label);
        button.title = label;
        button.querySelector('i').className = 'icon ' + (enabled ? 'fa-sun-o' : 'fa-moon-o');
    }
    apply(enabled);
    function initialise() {
        var button = document.getElementById('convoa-night-toggle');
        if (!button) { return; }
        if (button.getAttribute('data-night-ready') === 'true') { return; }
        button.setAttribute('data-night-ready', 'true');
        apply(enabled);
        button.addEventListener('click', function () {
            apply(!enabled);
            try { window.localStorage.setItem(key, enabled ? 'night' : 'day'); } catch (error) {}
        });
    }
    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', initialise);
    } else {
        initialise();
    }
    window.addEventListener('storage', function (event) {
        if (event.key === key || event.key === null) { apply(event.newValue === 'night'); }
    });
}());

/* SVG filtering leaves smiley interiors and animated source GIFs intact. */
(function () {
    function installEdgeFilter() {
        if (document.getElementById('convoa-edge')) { return; }
        var holder = document.createElement('div');
        holder.setAttribute('aria-hidden', 'true');
        holder.style.cssText = 'position:absolute;width:0;height:0;overflow:hidden;pointer-events:none';
        holder.innerHTML = "<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"0\" height=\"0\"><defs><filter id=\"convoa-edge\" x=\"0\" y=\"0\" width=\"100%\" height=\"100%\" color-interpolation-filters=\"sRGB\"><feMorphology in=\"SourceAlpha\" operator=\"erode\" radius=\"1\" result=\"interior\"/><feComposite in=\"SourceAlpha\" in2=\"interior\" operator=\"out\" result=\"edge\"/><feColorMatrix in=\"SourceGraphic\" type=\"matrix\" values=\"0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3.3333 3.3333 3.3333 0 -8.5\" result=\"light\"/><feComposite in=\"light\" in2=\"edge\" operator=\"in\" result=\"fringe\"/><feComposite in=\"SourceGraphic\" in2=\"fringe\" operator=\"out\"/></filter></defs></svg>";
        document.body.appendChild(holder);
    }
    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', installEdgeFilter);
    } else { installEdgeFilter(); }
}());