File impl

src/crypto/Crypto.java

@@ -1,10 +1,112 @@
 package crypto;
 
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.sql.SQLOutput;
+import java.util.Arrays;
+import java.util.List;
 import java.util.Scanner;
 
 public class Crypto {
     public static void main(String[] args) {
+        final String MODE = "-mode";
+        final String KEY= "-key";
+        final String DATA= "-data";
+        final String IN = "-in";
+        final String OUT = "-out";
+
         Scanner scanner = new Scanner(System.in);
-	// write your code here
+
+        String target;
+        String message = null;
+        String processed = null;
+        int offset;
+        int index = -1;
+        List argsList = Arrays.asList(args);
+
+        /*Mode*/
+        index = argsList.indexOf(MODE);
+        if(index != -1){
+            target = args[index+1];
+        } else{
+            target = "enc";
+        }
+
+        /*Input*/
+        index = argsList.indexOf(IN);
+        if(index != -1){
+            try {
+                message = new String(Files.readAllBytes(Paths.get(args[index + 1])));
+            } catch (IOException e) {
+                System.out.println("Not found file " + args[index + 1]);
+            }
+        } else{
+            index = argsList.indexOf(DATA);
+            if(index != -1 && message != null){
+                message = args[index + 1];
+            } else{
+                System.out.println("Enter data:");
+                message = scanner.nextLine();
+            }
+        }
+
+        /*Key*/
+        index = argsList.indexOf(KEY);
+        if(index != -1){
+            offset = Integer.parseInt(args[index+1]);
+        } else{
+            System.out.println("Enter key:");
+            offset = scanner.nextInt();
+
+        }
+
+        if(target.equals("enc")){
+            processed = enc(message, offset);
+        } else if(target.equals("dec")){
+            processed = dec(message, offset);
+        }
+
+        /*Output*/
+        index = argsList.indexOf(OUT);
+        if(index != -1){
+            File outputFile = new File(args[index + 1]);
+            try (FileWriter writer = new FileWriter(outputFile)) {
+                writer.write(processed);
+            } catch (IOException e) {
+                System.out.println("Cannot write output message to file");
+            }
+        } else{
+            System.out.println(processed);
+        }
+    }
+
+    public Crypto() {
+    }
+
+    public static String enc(String originalStr, int offset){
+        return offsetAll(originalStr, offset);
+    }
+
+    public static String dec(String originalStr, int offset){
+        return offsetAll(originalStr, -offset);
+    }
+    public static String offsetAll(String originalStr, int offset){
+        final int lettersStar = 97;
+        final int lettersAmount = 26;
+
+        StringBuilder out = new StringBuilder();
+        char[] letters = new char[originalStr.length()];
+        originalStr.getChars(0, originalStr.length(), letters, 0  );
+
+        for (int letter : letters){
+            letter = (letter + offset);
+            out.append((char)letter);
+        }
+
+        return out.toString();
     }
 }