const chalk = require('chalk');
const minimist = require('minimist');
const out = require('./console-out');
const globalPkg = require('../package.json');
const args = process.argv.slice(2);
const argv = minimist(args);

module.exports = {getBypassAndGenerator, handleArgFlags};

/**
 * Parses the user input to identify the generator to run and any bypass data
 * @param plop - The plop context
 */
function getBypassAndGenerator(plop) {
	// See if there are args to pass to generator
	const eoaIndex = args.indexOf('--');
	const {plopArgV, eoaArg} = (eoaIndex === -1
		? {plopArgV: []}
		: {
			plopArgV: minimist(args.slice(eoaIndex + 1, args.length)),
			eoaArg: args[eoaIndex + 1]
		}
	);

  // locate the generator name based on input and take the rest of the
	// user's input as prompt bypass data to be passed into the generator
	let generatorName = '';
	let bypassArr = [];

	const generatorNames = plop.getGeneratorList().map(v => v.name);
	for (let i=0; i < argv._.length; i++) {
		const nameTest = (generatorName.length ? generatorName + ' ' : '') + argv._[i];
		if (listHasOptionThatStartsWith(generatorNames, nameTest)) {
			generatorName = nameTest;
		} else {
			let index = argv._.findIndex(arg => arg === eoaArg);
			// If can't find index, slice until the very end - allowing all `_` to be passed
			index = index !== -1 ? index : argv._.length;
			// Force `'_'` to become undefined in nameless bypassArr
			bypassArr = argv._.slice(i, index).map(arg => (/^_+$/).test(arg) ? undefined : arg);
			break;
		}
	}

  return {generatorName, bypassArr, plopArgV};
}

function listHasOptionThatStartsWith(list, prefix) {
	return list.some(function (txt) {
		return txt.indexOf(prefix) === 0;
	});
}

/**
 * Handles all basic argument flags
 * @param env - Values parsed by Liftoff
 */
function handleArgFlags(env) {
	// Make sure that we're not overwritting `help`, `init,` or `version` args in generators
	if (argv._.length === 0) {
		// handle request for usage and options
		if (argv.help || argv.h) {
			out.displayHelpScreen();
			process.exit(0);
		}

		// handle request for initializing a new plopfile
		if (argv.init || argv.i) {
			return out.createInitPlopfile(env.cwd, function (err) {
				if (err) {
					console.log(err);
					process.exit(1);
				}
				process.exit(0);
			});
		}

		// handle request for version number
		if (argv.version || argv.v) {

			const localVersion = env.modulePackage.version;
			if (localVersion !== globalPkg.version && localVersion != null) {
				console.log(chalk.yellow('CLI version'), globalPkg.version);
				console.log(chalk.yellow('Local version'), localVersion);
			} else {
				console.log(globalPkg.version);
			}
			process.exit(0);
		}
	}

	// abort if there's no plopfile found
	if (env.configPath == null) {
		console.error(chalk.red('[PLOP] ') + 'No plopfile found');
		out.displayHelpScreen();
		process.exit(1);
	}
}