/** You'll need lodash since I'm using hints of FP */
const _ = require('lodash');

/**
 * Generates pairings bases on the base array provided
 * @param  {Array} base Array of strings for generating pairings
 * @return {Array} Array containing nested groups of pairings, each representing
 *   every possible grouping.
 */
function generateArrayOfPairs(base) {
	const modBase = _.clone(base);

	// push extra (nobody) to array if uneven number
	if (modBase.length % 2 !== 0) modBase.push('nobody');

	const [group1, group2] = _.chunk(modBase, modBase.length / 2);
	const output = [];

	let i = modBase.length;
	while (i--) {
		// some shifting because I'm too lazy for linked lists
		group1.unshift(group2.shift());
		group2.push(group1.pop());
		// combine each array into 2-indexed pairs
		output.push(_.zip(group1, group2));
	}

	return output;
}

/**
 * Converts raw name string to readable form
 */
const wrapName = name => {
	const names = _.startCase(name).split(' ');
	return `**${_.head(names)} ${_.last(names)[0]}.**`;
}

/**
 * Mapping function for converting
 * @param  {Array} group The group of pairings to use (mapped value)
 * @param  {Number} index Group index
 * @return {String} The presentable string for a specific group
 */
const mapToReadable = (group, index) => `## Week ${index + 1}
${group
	.map(name => name
		.map(wrapName)
		.join(' meets with ')
	).join('\n')
}`

// start output
console.log(_.flow(
	// split string literal to array without null values
	names => names
		.split('\n')
		// remove any empty values
		.filter(name => name !== ''),
	// generate raw pairings
	generateArrayOfPairs,
	// format as presentable string
	pairs => pairs
		.map(mapToReadable)
		.join('\n\n')
// the below is case in-sensitve
)(`Name 1
Name 2
Name 3`));