HarshvardhanCn01/Voice-Assistant

1const conversions = require('./conversions');2 3/*4	This function routes a model to all other models.5 6	all functions that are routed have a property `.conversion` attached7	to the returned synthetic function. This property is an array8	of strings, each with the steps in between the 'from' and 'to'9	color models (inclusive).10 11	conversions that are not possible simply are not included.12*/13 14function buildGraph() {15	const graph = {};16	// https://jsperf.com/object-keys-vs-for-in-with-closure/317	const models = Object.keys(conversions);18 19	for (let len = models.length, i = 0; i < len; i++) {20		graph[models[i]] = {21			// http://jsperf.com/1-vs-infinity22			// micro-opt, but this is simple.23			distance: -1,24			parent: null25		};26	}27 28	return graph;29}30 31// https://en.wikipedia.org/wiki/Breadth-first_search32function deriveBFS(fromModel) {33	const graph = buildGraph();34	const queue = [fromModel]; // Unshift -> queue -> pop35 36	graph[fromModel].distance = 0;37 38	while (queue.length) {39		const current = queue.pop();40		const adjacents = Object.keys(conversions[current]);41 42		for (let len = adjacents.length, i = 0; i < len; i++) {43			const adjacent = adjacents[i];44			const node = graph[adjacent];45 46			if (node.distance === -1) {47				node.distance = graph[current].distance + 1;48				node.parent = current;49				queue.unshift(adjacent);50			}51		}52	}53 54	return graph;55}56 57function link(from, to) {58	return function (args) {59		return to(from(args));60	};61}62 63function wrapConversion(toModel, graph) {64	const path = [graph[toModel].parent, toModel];65	let fn = conversions[graph[toModel].parent][toModel];66 67	let cur = graph[toModel].parent;68	while (graph[cur].parent) {69		path.unshift(graph[cur].parent);70		fn = link(conversions[graph[cur].parent][cur], fn);71		cur = graph[cur].parent;72	}73 74	fn.conversion = path;75	return fn;76}77 78module.exports = function (fromModel) {79	const graph = deriveBFS(fromModel);80	const conversion = {};81 82	const models = Object.keys(graph);83	for (let len = models.length, i = 0; i < len; i++) {84		const toModel = models[i];85		const node = graph[toModel];86 87		if (node.parent === null) {88			// No possible conversion, or this node is the source model.89			continue;90		}91 92		conversion[toModel] = wrapConversion(toModel, graph);93	}94 95	return conversion;96};97 98