Fix oopsie

Also fixes an exception that occurs when a negative PID is sent through Memory Link.

src/main/java/entralinked/Configuration.java

@@ -6,9 +6,7 @@ import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 public record Configuration(
         String hostName,
         boolean clearPlayerDreamInfoOnWake,
-        boolean allowOverwritingPlayerDreamInfo,
-        boolean allowPlayerGameVersionMismatch,
         boolean allowWfcRegistrationThroughLogin) {
     
-    public static final Configuration DEFAULT = new Configuration("local", true, false, false, true);
+    public static final Configuration DEFAULT = new Configuration("local", true, true);
 }

src/main/java/entralinked/gui/view/MainView.java

@@ -7,10 +7,15 @@ import java.awt.Dimension;
 import java.awt.Font;
 import java.awt.event.WindowAdapter;
 import java.awt.event.WindowEvent;
+import java.io.File;
+import java.io.FileInputStream;
 import java.io.IOException;
 import java.net.URISyntaxException;
 import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.StandardCopyOption;
 import java.util.List;
+import java.util.Objects;
 import java.util.concurrent.CompletableFuture;
 
 import javax.swing.BorderFactory;
@@ -19,6 +24,7 @@ import javax.swing.JFrame;
 import javax.swing.JLabel;
 import javax.swing.JMenu;
 import javax.swing.JMenuBar;
+import javax.swing.JOptionPane;
 import javax.swing.JPanel;
 import javax.swing.JScrollPane;
 import javax.swing.JTabbedPane;
@@ -38,8 +44,14 @@ import com.formdev.flatlaf.intellijthemes.FlatOneDarkIJTheme;
 import com.formdev.flatlaf.util.ColorFunctions;
 
 import entralinked.Entralinked;
+import entralinked.GameVersion;
+import entralinked.gui.FileChooser;
 import entralinked.gui.panels.DashboardPanel;
+import entralinked.model.player.Player;
+import entralinked.model.player.PlayerManager;
 import entralinked.utility.ConsumerAppender;
+import entralinked.utility.GsidUtility;
+import entralinked.utility.LEInputStream;
 import entralinked.utility.SwingUtility;
 
 /**
@@ -52,9 +64,13 @@ public class MainView {
     public static final Color TEXT_COLOR_ERROR = Color.RED.darker();
     private final StyleContext styleContext = StyleContext.getDefaultStyleContext();
     private final AttributeSet fontAttribute = styleContext.addAttribute(SimpleAttributeSet.EMPTY, StyleConstants.FontFamily, "Consolas");
+    private final Entralinked entralinked;
+    private final JFrame frame;
     private final JLabel statusLabel;
     
     public MainView(Entralinked entralinked) {
+        this.entralinked = entralinked;
+        
         // Set look and feel
         FlatOneDarkIJTheme.setup();
         UIManager.getDefaults().put("Component.focusedBorderColor", UIManager.get("Component.borderColor"));
@@ -112,10 +128,15 @@ public class MainView {
         tabbedPane.addTab("Dashboard", new DashboardPanel(entralinked));
         
         // Create window
-        JFrame frame = new JFrame("Entralinked");
+        frame = new JFrame("Entralinked");
         
         // Create menu bar
         JMenuBar menuBar = new JMenuBar();
+        JMenu toolsMenu = new JMenu("Tools");
+        toolsMenu.add(SwingUtility.createAction("Import save file (Memory Link)", () -> FileChooser.showFileOpenDialog(frame, selection -> {
+            importSaveFile(selection.file());
+        })));
+        menuBar.add(toolsMenu);
         JMenu helpMenu = new JMenu("Help");
         helpMenu.add(SwingUtility.createAction("Update PID (Error 60000)", () -> new PidToolDialog(entralinked, frame)));
         helpMenu.add(SwingUtility.createAction("GitHub", () -> {
@@ -159,4 +180,77 @@ public class MainView {
     public void setStatusLabelText(String text) {
         statusLabel.setText(text);
     }
+    
+    private void importSaveFile(File file) {
+        // Check file size
+        if(file.length() != 524288) {
+            JOptionPane.showMessageDialog(frame, "Invalid file length.\n"
+                    + "Expected 524288 bytes, got %s.".formatted(file.length()), "Attention", JOptionPane.WARNING_MESSAGE);
+            return;
+        }
+        
+        PlayerManager playerManager = entralinked.getPlayerManager();
+        Player player = null;
+        GameVersion version = null;
+        
+        try(LEInputStream inputStream = new LEInputStream(new FileInputStream(file))) {
+            inputStream.skipNBytes(0x19400); // Skip to trainer info
+            inputStream.skipNBytes(0x4);
+            String name = inputStream.readUTF16(7);
+            inputStream.skipNBytes(0x2);
+            int trainerId = inputStream.readInt();
+            int profileId = inputStream.readInt();
+            inputStream.skipNBytes(0x2);
+            int language = inputStream.read();
+            int romCode = inputStream.read();
+            version = GameVersion.lookup(romCode, language);
+            
+            // Check game version
+            if(version == null || version.isVersion2()) {
+                JOptionPane.showMessageDialog(frame, "This is not a Black & White save file.", "Attention", JOptionPane.WARNING_MESSAGE);
+                return;
+            }
+            
+            String gameSyncId = GsidUtility.stringifyGameSyncId(profileId == 0 ? Objects.hash(name, trainerId) & 0x7FFFFFFF : profileId);
+            player = playerManager.doesPlayerExist(gameSyncId) ? playerManager.getPlayer(gameSyncId) : playerManager.registerPlayer(gameSyncId, version);
+        } catch(Exception e) {
+            SwingUtility.showExceptionInfo(frame, "Failed to read save data.", e);
+            return;
+        }
+        
+        // Check if player exists
+        if(player == null) {
+            JOptionPane.showMessageDialog(frame, "Failed to create player data.", "Attention", JOptionPane.WARNING_MESSAGE);
+            return;
+        }
+        
+        // Check version mismatch
+        if(player.getGameVersion() != version) {
+            if(!SwingUtility.showIgnorableConfirmDialog(frame,
+                "The game version stored in the profile data does not match.\n"
+                + "Do you want to overwrite it and import the save file anyway?", "Attention")) {
+                return;
+            }
+            
+            player.setGameVersion(version);
+            
+            // Try to save player data
+            if(!playerManager.savePlayer(player)) {
+                JOptionPane.showMessageDialog(frame, "Failed to save player data.", "Attention", JOptionPane.WARNING_MESSAGE);
+                return;
+            }
+        }
+        
+        // Copy save file
+        try {
+            Files.copy(file.toPath(), player.getSaveFile().toPath(), StandardCopyOption.REPLACE_EXISTING);
+        } catch(Exception e) {
+            SwingUtility.showExceptionInfo(frame, "Failed to import save data.", e);
+            return;
+        }
+        
+        JOptionPane.showMessageDialog(frame, "Save file has been imported successfully!\n"
+                + "You can now use Memory Link with the following Game Sync ID:\n\n%s".formatted(player.getGameSyncId()),
+                "Attention", JOptionPane.INFORMATION_MESSAGE);
+    }
 }

src/main/java/entralinked/model/player/PlayerManager.java

@@ -18,6 +18,7 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
 
 import entralinked.GameVersion;
+import entralinked.utility.GsidUtility;
 
 /**
  * Manager class for managing {@link Player} information (Global Link users)
@@ -117,9 +118,14 @@ public class PlayerManager {
             Player player = mapper.readValue(inputFile, PlayerDto.class).toPlayer();
             String gameSyncId = player.getGameSyncId();
             
+            // Check if Game Sync ID is valid
+            if(!GsidUtility.isValidGameSyncId(gameSyncId)) {
+                throw new IOException("Invalid Game Sync ID: %s".formatted(gameSyncId));
+            }
+            
             // Check for duplicate Game Sync ID
             if(doesPlayerExist(gameSyncId)) {
-                throw new IOException("Duplicate Game Sync ID %s".formatted(gameSyncId));
+                throw new IOException("Duplicate Game Sync ID: %s".formatted(gameSyncId));
             }
             
             player.setDataDirectory(inputFile.getParentFile());
@@ -180,7 +186,13 @@ public class PlayerManager {
     public Player registerPlayer(String gameSyncId, GameVersion version) {
         // Check for duplicate Game Sync ID
         if(playerMap.containsKey(gameSyncId)) {
-            logger.warn("Attempted to register duplicate player {}", gameSyncId);
+            logger.warn("Attempted to register duplicate Game Sync ID: {}", gameSyncId);
+            return null;
+        }
+        
+        // Check if Game Sync ID is valid
+        if(!GsidUtility.isValidGameSyncId(gameSyncId)) {
+            logger.warn("Attempted to register invalid Game Sync ID: {}", gameSyncId);
             return null;
         }
         

src/main/java/entralinked/network/http/dls/DlsHandler.java

@@ -124,7 +124,7 @@ public class DlsHandler implements HttpHandler {
      */
     private String getDlcGameCode(String gameCode) {
         return switch(gameCode) {
-            case "IRAJ" -> "IRAO";
+            case "IRAJ", "IRAK" -> "IRAO";
             default -> gameCode;
         };
     }

src/main/java/entralinked/network/http/pgl/PglHandler.java

@@ -321,6 +321,13 @@ public class PglHandler implements HttpHandler {
      */
     private void handleMemoryLink(PglRequest request, Context ctx) throws IOException {
         LEOutputStream outputStream = new LEOutputStream(ctx.outputStream());
+        
+        // Check if Game Sync ID is valid
+        if(!GsidUtility.isValidGameSyncId(request.gameSyncId())) {
+            writeStatusCode(outputStream, 8); // Invalid Game Sync ID
+            return;
+        }
+        
         Player player = playerManager.getPlayer(request.gameSyncId());
         User user = ctx.attribute("user");
         
@@ -413,11 +420,8 @@ public class PglHandler implements HttpHandler {
         LEOutputStream outputStream = new LEOutputStream(ctx.outputStream());
         Player player = playerManager.getPlayer(request.gameSyncId());
         
-        // Check if the player exists, has no Pokémon tucked in already and uses the same game version
-        if(player == null
-                || (!configuration.allowOverwritingPlayerDreamInfo() && player.getStatus() != PlayerStatus.AWAKE)
-                || (!configuration.allowPlayerGameVersionMismatch() && player.getGameVersion() != null 
-                        && request.gameVersion() != player.getGameVersion())) {
+        // Check if the player exists
+        if(player == null) {
             // Skip everything
             ServletInputStream inputStream = ctx.req().getInputStream();
             
@@ -432,6 +436,18 @@ public class PglHandler implements HttpHandler {
         
         logger.info("Player {} is uploading save data", player.getGameSyncId());
         
+        // Warn if player's current status is unexpected
+        if(player.getStatus() != PlayerStatus.AWAKE)
+        {
+            logger.warn("Player {} is not AWAKE -- existing dream information will be overwritten!", player.getGameSyncId());
+        }
+        
+        // Warn if player's game version changed
+        if(player.getGameVersion() != null && request.gameVersion() != player.getGameVersion())
+        {
+            logger.warn("Player {}'s game version changed from {} to {}", player.getGameSyncId(), player.getGameVersion(), request.gameVersion());
+        }
+                
         // Try to store save data
         if(!playerManager.storePlayerGameSaveFile(player, ctx.bodyInputStream())) {
             writeStatusCode(outputStream, 4); // Game save data IO error
@@ -472,9 +488,9 @@ public class PglHandler implements HttpHandler {
         // Prepare response
         LEOutputStream outputStream = new LEOutputStream(ctx.outputStream());
         
-        // Make sure Game Sync ID is present
-        if(request.gameSyncId() == null) {
-            writeStatusCode(outputStream, 1); // Unauthorized
+        // Check if Game Sync ID is valid
+        if(!GsidUtility.isValidGameSyncId(request.gameSyncId())) {
+            writeStatusCode(outputStream, 8); // Invalid Game Sync ID
             return;
         }
         
@@ -511,6 +527,13 @@ public class PglHandler implements HttpHandler {
         LEOutputStream outputStream = new LEOutputStream(ctx.outputStream());
         String gameSyncId = GsidUtility.stringifyGameSyncId(Integer.parseInt(ctx.body().replace("\u0000", ""))); // So quirky
         
+        // Check if Game Sync ID is valid
+        if(!GsidUtility.isValidGameSyncId(gameSyncId)) {
+            logger.debug("[account.createdata] Rejecting invalid Game Sync ID: {} ({})", gameSyncId, ctx.body());
+            writeStatusCode(outputStream, 8); // Invalid Game Sync ID
+            return;
+        }
+        
         // Check if player doesn't exist already
         if(playerManager.doesPlayerExist(gameSyncId)) {
             writeStatusCode(outputStream, 2); // Duplicate Game Sync ID

src/main/java/entralinked/serialization/GsidDeserializer.java

@@ -25,12 +25,6 @@ public class GsidDeserializer extends StdDeserializer<String> {
     
     @Override
     public String deserialize(JsonParser parser, DeserializationContext context) throws IOException {
-        int gsid = parser.getIntValue();
-        
-        if(gsid < 0) {
-            throw new IOException("Game Sync ID cannot be a negative number.");
-        }
-        
-        return GsidUtility.stringifyGameSyncId(gsid);
+        return GsidUtility.stringifyGameSyncId(parser.getValueAsInt(-1));
     }
 }

src/main/java/entralinked/utility/GsidUtility.java

@@ -2,40 +2,87 @@ package entralinked.utility;
 
 import java.util.regex.Pattern;
 
+/**
+ * Game Sync ID generation process:
+ *
+ * Let's take example PID "1231499195".
+ * Start by storing both the PID and its checksum (35497) in working variable "ugsid".
+ * We do this by simply shifting the checksum 32 bits to the left: ugsid = pid | (checksum << 32) = 0x8AA949672FBB
+ * 
+ * Calculating each character is pretty straightforward.
+ * We just use the 5 least significant bits of ugsid as the index for the character table.
+ * Character 1: 0x8AA949672FBB & 0x1F = 27 = '5'
+ * 
+ * After each character, we shift ugsid 5 bits to the right. Since ugsid contains 48 bits of data,
+ * taking the 5 least significant bits each time gives us enough indexes for (if we round up) exactly 10 characters.
+ * If we take a look at the full value of ugsid (0x8AA949672FBB) in binary and split it into sections of 5 bits,
+ * we'll actually already be able to see the entire Game Sync ID in reverse:
+ * 
+ * Character:        'E'   'L'   'X'   'F'   'E'   'Y'   'Q'   'M'   '7'   '5'
+ * Chartable index:   4    10    21     5     4    22    14    11    29    27
+ * Binary:          XX100 01010 10101 00101 00100 10110 01110 01011 11101 11011
+ *                                           
+ * Adding all of the characters together gets us the Game Sync ID "57MQYEFXLE".
+ * 
+ * Reversing this process to retrieve the PID and checksum is very straightforward.
+ * Simply go through each character, find the index of it in the character table & left shift the total value 5 bits each time.
+ * If we do this with the Game Sync ID we just created, then it should give us back the value of ugsid: 0x8AA949672FBB
+ * To then retrieve the PID, simply do: ugsid & 0xFFFFFFFF = 1231499195
+ * To retrieve the checksum, simply do: (ugsid >> 32) & 0xFFFF = 35497
+ * We can then validate the Game Sync ID if we want to by comparing the checksums.
+ */
 public class GsidUtility {
     
     public static final String GSID_CHARTABLE = "ABCDEFGHJKLMNPQRSTUVWXYZ23456789";
     public static final Pattern GSID_PATTERN = Pattern.compile("[A-HJ-NP-Z2-9]{10}");
     
     /**
-     * Stringifies the specified numerical Game Sync ID
+     * Stringifies the specified numerical Game Sync ID.
      * 
      * Black 2 - {@code sub_21B480C} (overlay #199)
      */
     public static String stringifyGameSyncId(int gsid) {
         char[] output = new char[10];
-        int index = 0;
+        long checksum = Crc16.calc(gsid);
+        long ugsid = gsid | (checksum << 32);
         
-        // v12 = gsid
-        // v5 = sub_204405C(gsid, 4u)
-        // v8 = v5 + __CFSHR__(v12, 31) + (v12 >> 31)
-        
-        // uses unsigned ints for bitshift operations
-        long ugsid = gsid;
-        long checksum = Crc16.calc(gsid); // + __CFSHR__(v12, 31) + (v12 >> 31); ??
-        
-        // do while v4 < 10
         for(int i = 0; i < output.length; i++) {
-            index = (int)((ugsid & 0x1F) & 0x1FFFF); // chartable string is unicode, so normally multiplies by 2
-            ugsid = (ugsid >> 5) | (checksum << 27);
-            checksum >>= 5;
-            output[i] = GSID_CHARTABLE.charAt(index); // sub_2048734(v4, chartable + index)
+            int index = (int)((ugsid >> (5 * i)) & 0x1F);
+            output[i] = GSID_CHARTABLE.charAt(index);
         }
         
         return new String(output);
     }
     
+    /**
+     * Determines if a Game Sync ID is valid by checking its length, characters & checksum.
+     * 
+     * @return {@code true} if the Game Sync ID is valid, otherwise {@code false}.
+     */
     public static boolean isValidGameSyncId(String gsid) {
-        return GSID_PATTERN.matcher(gsid).matches();
+        if(gsid == null) {
+            return false;
+        }
+        
+        int length = gsid.length();
+        long ugsid = 0;
+        
+        if(length != 10) {
+            return false;
+        }
+                
+        for(int i = 0; i < length; i++) {
+            int index = GSID_CHARTABLE.indexOf(gsid.charAt(i));
+            
+            if(index == -1) {
+                return false;
+            }
+            
+            ugsid |= (long)index << (5 * i);
+        }
+        
+        int output = (int)(ugsid & 0xFFFFFFFF);
+        int checksum = (int)((ugsid >> 32) & 0xFFFF);
+        return output >= 0 && Crc16.calc(output) == checksum;
     }
 }

src/main/java/entralinked/utility/LEInputStream.java

@@ -48,4 +48,23 @@ public class LEInputStream extends FilterInputStream {
     public double readDouble() throws IOException {
         return Double.longBitsToDouble(readLong());
     }
+    
+    public String readUTF16(int length) throws IOException {
+        char[] charBuffer = new char[length];
+        int read = 0;
+        
+        for(int i = 0; i < charBuffer.length; i++) {
+            int c = readShort() & 0xFFFF;
+            
+            if(c == 0xFFFF) {
+                break;
+            }
+            
+            charBuffer[i] = (char)c;
+            read++;
+        }
+        
+        skipNBytes((length - (read + 1)) * 2);
+        return new String(charBuffer, 0, read);
+    }
 }

src/test/java/entralinked/utility/GsidUtilityTest.java

@@ -31,6 +31,20 @@ public class GsidUtilityTest {
         // Illegal length (should be 10)
         assertFalse(GsidUtility.isValidGameSyncId("Y67UEN38K"));
         assertFalse(GsidUtility.isValidGameSyncId("3ER5K8MBN4C"));
+        
+        // Invalid checksum
+        assertFalse(GsidUtility.isValidGameSyncId("VFWM2Q2ADH"));
+        assertFalse(GsidUtility.isValidGameSyncId("44DAWDA4SH"));
+        assertFalse(GsidUtility.isValidGameSyncId("J6F55U7FUE"));
+        assertFalse(GsidUtility.isValidGameSyncId("8FAB4ZF6JF"));
+        assertFalse(GsidUtility.isValidGameSyncId("HWLNS77HWD"));
+        
+        // Negative PID
+        assertFalse(GsidUtility.isValidGameSyncId("VYSBC78999"));
+        assertFalse(GsidUtility.isValidGameSyncId("2UD7GJ8999"));
+        assertFalse(GsidUtility.isValidGameSyncId("BTULWN8999"));
+        assertFalse(GsidUtility.isValidGameSyncId("ZW3JBQ9999"));
+        assertFalse(GsidUtility.isValidGameSyncId("MNTNWB9999"));
     }
     
     @Test
@@ -38,8 +52,8 @@ public class GsidUtilityTest {
     void testValidGameSyncIds() {
         assertTrue(GsidUtility.isValidGameSyncId("VFWM2QAXNF"));
         assertTrue(GsidUtility.isValidGameSyncId("44DAWDJKJ8"));
-        assertTrue(GsidUtility.isValidGameSyncId("J6F55UB2X9"));
-        assertTrue(GsidUtility.isValidGameSyncId("8FAB4Z3EN9"));
+        assertTrue(GsidUtility.isValidGameSyncId("J6F55UB2XD"));
+        assertTrue(GsidUtility.isValidGameSyncId("8FAB4Z3END"));
         assertTrue(GsidUtility.isValidGameSyncId("HWLNS7BTNB"));
     }
 }