Add binary file handling with hash-based storage and retrieval

Introduced hash-based storage for binary files in `RequestHandler`, with subdirectory organization. Added methods for creating hashes, saving, and retrieving files. Enabled binary file transmission via WebSocket commands. Updated `Settings` to support configurable data directory.

src/jvmMain/kotlin/nl/astraeus/vst/base/Settings.kt

@@ -8,10 +8,11 @@ object Settings {
   var port = 9004
   var connectionTimeout = 30000
   var jdbcStatsPort = 6001
+  var dataDir = "data"
 
   var jdbcDriver = "nl.astraeus.jdbc.Driver"
   val jdbcConnectionUrl
-    get() = "jdbc:stat:webServerPort=$jdbcStatsPort:jdbc:sqlite:data/vst.db"
+    get() = "jdbc:stat:webServerPort=$jdbcStatsPort:jdbc:sqlite:$dataDir/vst.db"
   var jdbcUser = "sa"
   var jdbcPassword = ""
 
@@ -35,6 +36,8 @@ object Settings {
 
     port = properties.getProperty("port", port.toString()).toInt()
     jdbcStatsPort = properties.getProperty("jdbcStatsPort", jdbcStatsPort.toString()).toInt()
+    dataDir = properties.getProperty("dataDir", dataDir)
+
     connectionTimeout =
       properties.getProperty("connectionTimeout", connectionTimeout.toString()).toInt()
     jdbcDriver = properties.getProperty("jdbcDriver", jdbcDriver)

src/jvmMain/kotlin/nl/astraeus/vst/base/web/RequestHandler.kt

@@ -17,10 +17,14 @@ import io.undertow.websockets.core.BufferedTextMessage
 import io.undertow.websockets.core.WebSocketChannel
 import io.undertow.websockets.core.WebSockets
 import io.undertow.websockets.spi.WebSocketHttpExchange
+import nl.astraeus.vst.base.Settings
 import nl.astraeus.vst.base.db.Database
 import nl.astraeus.vst.base.db.PatchDao
 import nl.astraeus.vst.base.db.PatchEntity
+import java.io.File
+import java.nio.ByteBuffer
 import java.nio.file.Paths
+import java.security.MessageDigest
 
 object VstSessionConfig {
   val config = SessionCookieConfig()
@@ -34,6 +38,57 @@ class WebsocketHandler(
   val session: Session?
 ) : AbstractReceiveListener(), WebSocketConnectionCallback {
 
+  companion object {
+    // Ensure the data directory exists
+    private val dataDir = File(Settings.dataDir).apply {
+      if (!exists()) {
+        mkdirs()
+      }
+    }
+
+    fun fileExists(hash: String): Boolean {
+      check(hash.length == 64) { "Hash must be 64 characters long" }
+
+      var currentDir = dataDir
+      var remaining = hash
+      while(remaining.length > 8) {
+        val subDir = remaining.substring(0, 8)
+        currentDir = File(currentDir, subDir)
+        if (!currentDir.exists()) {
+          return false
+        }
+        remaining = remaining.substring(8)
+      }
+
+      return File(currentDir, remaining).exists()
+    }
+
+    // Get file from hash, using subdirectories based on hash
+    fun getFileFromHash(hash: String): File {
+      check(hash.length == 64) { "Hash must be 64 characters long" }
+
+      var currentDir = dataDir
+      var remaining = hash
+      while(remaining.length > 8) {
+        val subDir = remaining.substring(0, 8)
+        currentDir = File(currentDir, subDir)
+        if (!currentDir.exists()) {
+          currentDir.mkdirs()
+        }
+        remaining = remaining.substring(8)
+      }
+
+      return File(currentDir, remaining)
+    }
+
+    // Create SHA-1 hash from binary data
+    fun createHashFromBytes(bytes: ByteArray): String {
+      val md = MessageDigest.getInstance("SHA-256")
+      val digest = md.digest(bytes)
+      return digest.joinToString("") { "%02x".format(it) }
+    }
+  }
+
   override fun onConnect(exchange: WebSocketHttpExchange, channel: WebSocketChannel) {
     channel.receiveSetter.set(this)
     channel.resumeReceives()
@@ -78,16 +133,51 @@ class WebsocketHandler(
           }
         }
 
-        // todo: add LOAD_BINARY command which expects a hash,
-        // find the file in the data/files/ directory and send it as binary
+        "LOAD_BINARY" -> {
+          val hash = value.trim()
+          if (hash.isNotEmpty()) {
+            if (fileExists(hash)) {
+              val file = getFileFromHash(hash)
+              if (file.exists() && file.isFile) {
+                val bytes = file.readBytes()
+                WebSockets.sendBinary(ByteBuffer.wrap(bytes), channel, null)
+              }
+            }
+          }
+        }
       }
     }
   }
 
   override fun onFullBinaryMessage(channel: WebSocketChannel?, message: BufferedBinaryMessage?) {
-    // todo: create hash from binary, save file in data/files/ directory,
+    // Process binary message: create hash from binary, save file in data/files/ directory,
     // sub directories are 5 characters of the hash per directory
+    if (channel != null && message != null) {
+      try {
+        // Get the binary data
+        val pooled = message.data
+        val buffer = pooled.resource[0] // Get the first ByteBuffer
 
+        // Convert ByteBuffer to ByteArray
+        val bytes = ByteArray(buffer.remaining())
+        buffer.get(bytes)
+
+        // Free the pooled resource
+        pooled.free()
+
+        // Create hash from binary data
+        val hash = createHashFromBytes(bytes)
+
+        // Save file in data/files/ directory with subdirectories
+        val file = getFileFromHash(hash)
+        file.writeBytes(bytes)
+
+        // Send the hash back to the client
+        WebSockets.sendText("BINARY_SAVED\n$hash", channel, null)
+      } catch (e: Exception) {
+        WebSockets.sendText("ERROR\n${e.message}", channel, null)
+      }
+    }
   }
 }