import crawlers.ConcurrentCrawler;

import crawlers.Crawler;

import crawlers.SimpleCrawler;

import java.net.MalformedURLException;

import java.net.URL;

import java.util.Set;

public class Main {

public static void main(String[] args) {

final String ERROR_MSG =

"USAGE: "

+ "java -jar crawler.jar {'-c'/'-s'} [Start URL] [Number of URLs to find] \n"

+ "\tUse options '-c' and '-s' to run the concurrent and sequential crawlers"

+ " respectively.";

if (args.length != 3) {

System.out.println(ERROR_MSG);

return;

}

String startUrl = args[1];

try {

new URL(startUrl);

} catch (MalformedURLException e) {

System.out.println(startUrl + " is not a valid URL.");

return;

}

int limit;

try {

limit = Integer.parseInt(args[2]);

} catch (NumberFormatException e) {

System.out.println("Limit needs to be a valid Integer.");

return;

}

Crawler crawler;

if (args[0].equals("-c")) {

crawler = new ConcurrentCrawler(limit, "ConcurrentCrawler");

} else if (args[0].equals("-s")) {

crawler = new SimpleCrawler(limit, "SequentialCrawler");

} else {

System.out.println(ERROR_MSG);

return;

}

Set<String> results = crawler.crawlFrom(startUrl);

results.forEach(System.out::println);

}

}