(function () {
	if (typeof self === 'undefined' || !self.Prism || !self.document || !document.querySelector) {
		return;
	}

	self.Prism.fileHighlight = function() {

		var Extensions = {
			'js': 'javascript',
			'html': 'markup',
			'svg': 'markup',
			'xml': 'markup',
			'py': 'python',
			'rb': 'ruby',
			'ps1': 'powershell',
			'psm1': 'powershell'
		};

		if(Array.prototype.forEach) { // Check to prevent error in IE8
			Array.prototype.slice.call(document.querySelectorAll('pre[data-src]')).forEach(function (pre) {
				var src = pre.getAttribute('data-src');

				var language, parent = pre;
				var lang = /\blang(?:uage)?-(?!\*)(\w+)\b/i;
				while (parent && !lang.test(parent.className)) {
					parent = parent.parentNode;
				}

				if (parent) {
					language = (pre.className.match(lang) || [, ''])[1];
				}

				if (!language) {
					var extension = (src.match(/\.(\w+)$/) || [, ''])[1];
					language = Extensions[extension] || extension;
				}

				var code = document.createElement('code');
				code.className = 'language-' + language;

				pre.textContent = '';

				code.textContent = 'Loading…';

				pre.appendChild(code);

				var xhr = new XMLHttpRequest();

				xhr.open('GET', src, true);

				xhr.onreadystatechange = function () {
					if (xhr.readyState == 4) {

						if (xhr.status < 400 && xhr.responseText) {
							code.textContent = xhr.responseText;

							Prism.highlightElement(code);
						}
						else if (xhr.status >= 400) {
							code.textContent = '✖ Error ' + xhr.status + ' while fetching file: ' + xhr.statusText;
						}
						else {
							code.textContent = '✖ Error: File does not exist or is empty';
						}
					}
				};

				xhr.send(null);
			});
		}

	};

	document.addEventListener('DOMContentLoaded', self.Prism.fileHighlight);

})();
