package cleaner;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;

import javax.swing.JFileChooser;

public class Main {
	
	public static void main(String[] args) throws Exception {
		String rutaRepo = (args.length > 0)?args[0]:null;
		cleanInvalidJARs(rutaRepo);
	}
	
	private static void cleanInvalidJARs(String rutaRepo) {
		File mavenRepo = null;
		if(rutaRepo != null) {
			mavenRepo = new File(rutaRepo);
		} else {
			JFileChooser chooser = new JFileChooser();
			chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
			int op = chooser.showOpenDialog(null);
			if(op == JFileChooser.APPROVE_OPTION) {
				mavenRepo = chooser.getSelectedFile();
			}
		}
		
		if(mavenRepo != null) {
			List<File> invalidJARs = detectInvalidJARs(mavenRepo);
			for(File jar:invalidJARs) {
				System.out.println("Invalid JAR found at: "+jar.getAbsolutePath());
			}
			Scanner sc =  new  Scanner(System.in);
			if(invalidJARs.isEmpty()) {
				System.out.println("No invalid JARs found");
			} else {
				System.out.print("Do you want to delete them <Y/N>? ");
				String action = sc.nextLine();
				if(action.equals("Y")) {
					System.out.print("Do you want to delete the entire folders (includes the POM and other files) <Y/N>? ");
					action = sc.nextLine();
					deleteJARs(invalidJARs, action.equals("Y"));
				}
			}
			sc.close();
		}
	}
	
	private static void deleteJARs(List<File> jarList) {
		deleteJARs(jarList, true);
	}
	
	private static void deleteJARs(List<File> jarList, boolean deleteParent) {
		for(File f:jarList) {
			if(deleteParent) {
				System.out.println("Deleting "+f.getParentFile().getAbsolutePath());
				deleteDir(f.getParentFile());
			} else {
				System.out.println("Deleting "+f.getAbsolutePath());
				f.delete();
			}
		}
	}
	
	private static void deleteDir(File currentDir) {
		if(currentDir.listFiles().length == 0) {
			currentDir.delete();
		} else {
			for(File f:currentDir.listFiles()) {
				if(f.isDirectory()) {
					deleteDir(f);
				} else {
					f.delete();
				}
			}
		}
	}
	
	private static List<File> detectInvalidJARs(File currentDir) {
		List<File> invalidJARs = new ArrayList<>();
		for(File file:currentDir.listFiles()) {
			if(file.isDirectory()) {
				invalidJARs.addAll(detectInvalidJARs(file));
			} else {
				if(file.getName().endsWith(".jar")) {
					if(!validateJAR(file)) {
						invalidJARs.add(file);
					}
				}
			}
		}
		return invalidJARs;
	}
	
	private static boolean validateJAR(File jarFile) {
		boolean valid = false;
		byte[] buffer = new byte[4];
		byte[] jarSignature = new byte[]{0x50, 0x4B, 0x03, 0x04};
		try {
			FileInputStream fis = new FileInputStream(jarFile);
			if(fis.read(buffer) == 4) {
				valid = Arrays.equals(buffer, jarSignature);
			}
			fis.close();
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return valid;
	}
}