// navigation starts to work right now

let onSwipe = require('client/onSwipe');

let ctrlOrAlt = ~navigator.userAgent.toLowerCase().indexOf("mac os x") ? 'ctrl' : 'alt';

function onKeyDown(event) {

// don't react on Ctrl-> <- if in text

if (document.activeElement) {

if (~['INPUT', 'TEXTAREA', 'SELECT'].indexOf(document.activeElement.tagName)) return;

}

if (!event[ctrlOrAlt + 'Key']) return;

let rel = null;

switch (event.keyCode) {

case 0x25:

rel = 'prev';

break;

case 0x27:

rel = 'next';

break;

default:

return;

}

let link = document.querySelector('link[rel="' + rel + '"]');

if (!link) return;

document.location = link.href;

event.preventDefault();

}

function showHotKeys() {

let keyDesc = ctrlOrAlt[0].toUpperCase() + ctrlOrAlt.slice(1);

let shortcut;

let next = document.querySelector('link[rel="next"]');

if (next) {

shortcut = document.querySelector('a[href="' + next.getAttribute('href') + '"] .page__nav-text-shortcut');

shortcut.innerHTML = keyDesc + ' + <span class="page__nav-text-arr">→</span>';

}

let prev = document.querySelector('link[rel="prev"]');

if (prev) {

shortcut = document.querySelector('a[href="' + prev.getAttribute('href') + '"] .page__nav-text-shortcut');

shortcut.innerHTML = keyDesc + ' + <span class="page__nav-text-arr">←</span>';

}

}

onSwipe(document, {

onRight: function() {

let link = document.querySelector('link[rel="prev"]');

if (link) document.location = link.href;

},

onLeft: function() {

let link = document.querySelector('link[rel="next"]');

if (link) document.location = link.href;

}

});

document.addEventListener('keydown', onKeyDown);

document.addEventListener('DOMContentLoaded', showHotKeys);