function findInputNode()

in seriously.js [1510:1552]
36 lines of code
22 McCabe index (conditional complexity)

		function findInputNode(hook, source, options) {
			var node, i;

			if (typeof hook !== 'string' || !source && source !== 0) {
				if (!options || typeof options !== 'object') {
					options = source;
				}
				source = hook;
			}

			if (typeof hook !== 'string' || !seriousSources[hook]) {
				hook = null;
			}

			if (source instanceof SourceNode ||
					source instanceof EffectNode ||
					source instanceof TransformNode) {
				node = source;
			} else if (source instanceof Effect ||
					source instanceof Source ||
					source instanceof Transform) {
				node = nodesById[source.id];

				if (!node) {
					throw new Error('Cannot connect a foreign node');
				}
			} else {
				if (typeof source === 'string' && isNaN(source)) {
					source = getElement(source, ['canvas', 'img', 'video']);
				}

				for (i = 0; i < sources.length; i++) {
					node = sources[i];
					if ((!hook || hook === node.hook) && node.compare && node.compare(source, options)) {
						return node;
					}
				}

				node = new SourceNode(hook, source, options);
			}

			return node;
		}