Removes redundancy between the encrypt command and the group encrypt command

src/main/java/net/knarcraft/bookswithoutborders/command/CommandEncrypt.java

@@ -10,8 +10,6 @@ import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.BookMeta;
 
-import java.util.Objects;
-
 /**
  * Command executor for the encrypt command
  */
@@ -25,39 +23,67 @@ public class CommandEncrypt implements CommandExecutor {
 
     @Override
     public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
+        if (performPreChecks(sender, args, 1, "You must specify a key to encrypt a book!") == null) {
+            return false;
+        }
+
+        EncryptionStyle encryptionStyle = args.length == 2 ? EncryptionStyle.getFromString(args[1]) : EncryptionStyle.SUBSTITUTION;
+        return encryptBook(encryptionStyle, (Player) sender, args[0], "");
+    }
+
+    /**
+     * Performs necessary pre-checks before going through with the encryption
+     * @param sender <p>The sender trying to encrypt a book</p>
+     * @param args <p>The arguments given</p>
+     * @param necessaryArguments <p>How many arguments is the minimum requirement</p>
+     * @param missingArgumentsError <p>The error to show if a required argument is missing</p>
+     * @return <p>The metadata of the book to encrypt, or null if any checks fail</p>
+     */
+    BookMeta performPreChecks(CommandSender sender, String[] args, int necessaryArguments, String missingArgumentsError) {
         if (!(sender instanceof Player player)) {
             BooksWithoutBorders.sendErrorMessage(sender, "This command can only be used by a player!");
-            return false;
+            return null;
         }
 
-        if (InventoryHelper.notHoldingOneWrittenBookCheck(player, "You must be holding a written book to encrypt it!",
+        if (InventoryHelper.notHoldingOneWrittenBookCheck(player,
+                "You must be holding a written book to encrypt it!",
                 "You cannot encrypt two books at once!")) {
-            return false;
+            return null;
         }
 
-        if (args.length < 1) {
+        int argumentCount = args.length;
-            BooksWithoutBorders.sendErrorMessage(player, "You must specify a key to encrypt a book!");
+        if (argumentCount < necessaryArguments) {
-            return false;
+            BooksWithoutBorders.sendErrorMessage(player, missingArgumentsError);
+            return null;
         }
-        if (args.length > 2) {
+        if (argumentCount > necessaryArguments + 1) {
             BooksWithoutBorders.sendErrorMessage(player, "Too many command options specified!");
-            return false;
+            return null;
         }
 
         ItemStack heldBook = InventoryHelper.getHeldBook(player, true);
-
+        BookMeta bookMetadata = (BookMeta) heldBook.getItemMeta();
-        if (!((BookMeta) Objects.requireNonNull(heldBook.getItemMeta())).hasPages()) {
+        if (bookMetadata == null) {
+            BooksWithoutBorders.sendErrorMessage(player, "Your book seems to be corrupt!");
+            return null;
+        }
+        if (!bookMetadata.hasPages()) {
             BooksWithoutBorders.sendErrorMessage(player, "Book must have contents to encrypt!");
-            return false;
+            return null;
         }
+        return bookMetadata;
+    }
 
-        ItemStack encryptedBook;
+    /**
-
+     * Encrypts the given book
-        if (args.length == 2) {
+     * @param encryptionStyle <p>The encryption style to use</p>
-            encryptedBook = booksWithoutBorders.encryptBook(player, true, args[0], EncryptionStyle.getFromString(args[1]), "");
+     * @param player <p>The player encrypting the book</p>
-        } else {
+     * @param key <p>The encryption key to use</p>
-            encryptedBook = booksWithoutBorders.encryptBook(player, true, args[0], EncryptionStyle.SUBSTITUTION, "");
+     * @param group <p>The group to encrypt for</p>
-        }
+     * @return <p>True if the book was encrypted successfully</p>
+     */
+    boolean encryptBook(EncryptionStyle encryptionStyle, Player player, String key, String group) {
+        ItemStack encryptedBook = booksWithoutBorders.encryptBook(player, true, key, encryptionStyle, group);
 
         if (encryptedBook != null) {
             InventoryHelper.setHeldWrittenBook(player, encryptedBook);
@@ -66,4 +92,5 @@ public class CommandEncrypt implements CommandExecutor {
             return false;
         }
     }
+
 }

src/main/java/net/knarcraft/bookswithoutborders/command/CommandGroupEncrypt.java

@@ -2,12 +2,10 @@ package net.knarcraft.bookswithoutborders.command;
 
 import net.knarcraft.bookswithoutborders.BooksWithoutBorders;
 import net.knarcraft.bookswithoutborders.state.EncryptionStyle;
-import net.knarcraft.bookswithoutborders.utility.InventoryHelper;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandExecutor;
 import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
-import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.BookMeta;
 
 import java.util.List;
@@ -15,69 +13,30 @@ import java.util.List;
 /**
  * Command executor for the group encrypt command
  */
-public class CommandGroupEncrypt implements CommandExecutor {
+public class CommandGroupEncrypt extends CommandEncrypt implements CommandExecutor {
-
-    private final BooksWithoutBorders booksWithoutBorders;
 
     public CommandGroupEncrypt(BooksWithoutBorders booksWithoutBorders) {
-        this.booksWithoutBorders = booksWithoutBorders;
+        super(booksWithoutBorders);
     }
 
     @Override
     public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
-        if (!(sender instanceof Player player)) {
+        BookMeta bookMetadata = performPreChecks(sender, args, 2,
-            BooksWithoutBorders.sendErrorMessage(sender, "This command can only be used by a player!");
+                "You must specify a group name and key to encrypt a book!");
-            return false;
-        }
-
-        if (InventoryHelper.notHoldingOneWrittenBookCheck(player,
-                "You must be holding a written book to encrypt it!",
-                "You cannot encrypt two books at once!")) {
-            return false;
-        }
-
-        if (args.length < 2) {
-            BooksWithoutBorders.sendErrorMessage(player, "You must specify a group name and key to encrypt a book!");
-            return false;
-        }
-        if (args.length > 3) {
-            BooksWithoutBorders.sendErrorMessage(player, "Too many command options specified!");
-            return false;
-        }
-
-        ItemStack heldBook = InventoryHelper.getHeldBook(player, true);
-        BookMeta bookMetadata = (BookMeta) heldBook.getItemMeta();
 
         if (bookMetadata == null) {
-            BooksWithoutBorders.sendErrorMessage(player, "Your book seems to be corrupt!");
-            return false;
-        }
-
-        if (!bookMetadata.hasPages()) {
-            BooksWithoutBorders.sendErrorMessage(player, "Book must have contents to encrypt!");
             return false;
         }
 
+        //Check if book is already group encrypted
         List<String> lore = bookMetadata.getLore();
         if (bookMetadata.hasLore() && lore != null && lore.get(0).contains(" encrypted]")) {
-            BooksWithoutBorders.sendErrorMessage(player, "Book is already group encrypted!");
+            BooksWithoutBorders.sendErrorMessage(sender, "Book is already group encrypted!");
             return false;
         }
 
-        ItemStack eBook;
+        EncryptionStyle encryptionStyle = args.length == 3 ? EncryptionStyle.getFromString(args[2]) : EncryptionStyle.SUBSTITUTION;
-
+        return encryptBook(encryptionStyle, (Player) sender, args[1], args[0]);
-        if (args.length == 3) {
-            eBook = booksWithoutBorders.encryptBook(player, true, args[1], EncryptionStyle.getFromString(args[2]), args[0]);
-        } else {
-            eBook = booksWithoutBorders.encryptBook(player, true, args[1], EncryptionStyle.SUBSTITUTION, args[0]);
-        }
-
-        if (eBook != null) {
-            InventoryHelper.setHeldWrittenBook(player, eBook);
-            return true;
-        } else {
-            return false;
-        }
     }
 
 }