Add API key validation, secure DB key storage, input field padding, scroll fixes

app/src/main/java/com/mistral/chat/data/ChatDatabase.kt

@@ -4,6 +4,8 @@ import android.content.Context
 import androidx.room.Database
 import androidx.room.Room
 import androidx.room.RoomDatabase
+import androidx.security.crypto.EncryptedSharedPreferences
+import androidx.security.crypto.MasterKey
 import net.sqlcipher.database.SupportFactory
 
 @Database(
@@ -44,14 +46,25 @@ abstract class ChatDatabase : RoomDatabase() {
         }
         
         private fun getOrCreatePassphrase(context: Context): ByteArray {
-            val prefs = context.getSharedPreferences("db_prefs", Context.MODE_PRIVATE)
+            val masterKey = MasterKey.Builder(context)
-            val existingKey = prefs.getString("db_key", null)
+                .setKeyScheme(MasterKey.KeyScheme.AES256_GCM)
+                .build()
+            
+            val securePrefs = EncryptedSharedPreferences.create(
+                context,
+                "db_prefs",
+                masterKey,
+                EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
+                EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM
+            )
+            
+            val existingKey = securePrefs.getString("db_key", null)
             
             return if (existingKey != null) {
                 existingKey.toByteArray(Charsets.UTF_8)
             } else {
                 val newKey = generateSecureKey()
-                prefs.edit().putString("db_key", newKey).apply()
+                securePrefs.edit().putString("db_key", newKey).apply()
                 newKey.toByteArray(Charsets.UTF_8)
             }
         }

app/src/main/java/com/mistral/chat/ui/MainActivity.kt

@@ -83,6 +83,9 @@ class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelecte
     private var userMessageCount = 0
     private var titleGenerationJob: kotlinx.coroutines.Job? = null
     private var isFirstLoad = true
+    private var userScrolledAfterSend = false
+    private var lastUserMessagePosition = -1
+    private var apiKeyDialog: AlertDialog? = null
 
     companion object {
         private const val PREFS_NAME = "mistral_chat_prefs"
@@ -599,16 +602,25 @@ class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelecte
             stackFromEnd = true
         }
         recyclerView.adapter = adapter
+        
+        recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
+            override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
+                super.onScrolled(recyclerView, dx, dy)
+                val layoutManager = recyclerView.layoutManager as LinearLayoutManager
+                val lastVisible = layoutManager.findLastVisibleItemPosition()
+                val totalItems = layoutManager.itemCount
+                
+                if (lastVisible < totalItems - 2) {
+                    userScrolledAfterSend = true
+                }
+            }
+        })
     }
 
     private fun setupInput() {
         sendButton.setOnClickListener {
-            if (currentJob?.isActive == true) {
-                cancelRequest()
-            } else {
             sendInput()
         }
-        }
         
         inputField.setOnEditorActionListener { _, actionId, event ->
             if (actionId == EditorInfo.IME_ACTION_SEND || actionId == EditorInfo.IME_ACTION_GO || actionId == EditorInfo.IME_ACTION_DONE || (event?.keyCode == KeyEvent.KEYCODE_ENTER && event.action == KeyEvent.ACTION_DOWN)) {
@@ -624,6 +636,13 @@ class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelecte
         val userInput = inputField.text?.toString()?.trim()
         if (userInput.isNullOrEmpty()) return
 
+        val apiKey = getApiKey()
+        if (apiKey.isEmpty() || apiKey.length < 32 || !apiKey.matches(Regex("^[a-zA-Z0-9]+$"))) {
+            Toast.makeText(this, getString(R.string.api_key_required), Toast.LENGTH_SHORT).show()
+            showApiKeyDialog()
+            return
+        }
+
         if (currentSessionId == null) {
             createNewSessionAndSend(userInput)
             return
@@ -632,6 +651,14 @@ class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelecte
         addMessage(Message(content = userInput, isUser = true, senderName = getCurrentProfileName()))
         
         inputField.text?.clear()
+        
+        userScrolledAfterSend = false
+        lastUserMessagePosition = messages.size - 1
+        
+        recyclerView.postDelayed({
+            recyclerView.scrollToPosition(lastUserMessagePosition)
+        }, 100)
+        
         sendMessage(userInput)
     }
 
@@ -741,10 +768,11 @@ class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelecte
         messages.add(message)
         adapter.notifyItemInserted(newPosition)
         
-        // Scroll to show new AI response
+        if (!message.isUser && !userScrolledAfterSend) {
-        if (!message.isUser) {
             recyclerView.postDelayed({
+                if (!userScrolledAfterSend) {
                     recyclerView.scrollToPosition(newPosition)
+                }
             }, 150)
         }
         
@@ -821,7 +849,14 @@ class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelecte
             .setPositiveButton(R.string.save) { _, _ ->
                 val newKey = inputField.text?.toString()?.trim()
                 if (!newKey.isNullOrEmpty()) {
+                    if (newKey.length < 32 || !newKey.matches(Regex("^[a-zA-Z0-9]+$"))) {
+                        Toast.makeText(this, "Неверный формат API ключа (минимум 32 символа, только a-z, A-Z, 0-9)", Toast.LENGTH_LONG).show()
+                        return@setPositiveButton
+                    }
+                    
                     saveApiKey(newKey)
+                    client = MistralClient(newKey)
+                    apiKeyDialog?.dismiss()
                     Toast.makeText(this, getString(R.string.api_key_saved), Toast.LENGTH_SHORT).show()
                 } else {
                     Toast.makeText(this, getString(R.string.enter_api_key), Toast.LENGTH_SHORT).show()
@@ -829,13 +864,17 @@ class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelecte
             }
             .apply {
                 if (hasCustomKey) {
-                    setNegativeButton(R.string.cancel, null)
+                    setNegativeButton(R.string.cancel) { dialog, _ ->
+                        dialog.dismiss()
+                    }
                     setNeutralButton(R.string.delete) { _, _ ->
                         deleteApiKey()
                     }
                 }
             }
             .setCancelable(false)
+            .create()
+            .also { apiKeyDialog = it }
             .show()
     }
 
@@ -843,7 +882,6 @@ class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelecte
         val selectedModel = selectedModelName
         
         sendButton.isEnabled = false
-        sendButton.setImageResource(R.drawable.ic_stop)
         progressIndicator.isVisible = true
 
         currentJob = lifecycleScope.launch {
@@ -889,35 +927,22 @@ class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelecte
                 }
                 
                 sendButton.isEnabled = true
-                sendButton.setImageResource(R.drawable.ic_mistral_logo)
                 progressIndicator.isVisible = false
             } catch (e: kotlinx.coroutines.CancellationException) {
                 if (!isActive) return@launch
                 addMessage(Message(content = "Запрос отменён", isUser = false, senderName = "System"))
                 sendButton.isEnabled = true
-                sendButton.setImageResource(R.drawable.ic_mistral_logo)
                 progressIndicator.isVisible = false
             } catch (e: Exception) {
                 if (!isActive) return@launch
                 val userFriendlyMessage = getUserFriendlyError(e.message ?: "Unknown error")
                 addMessage(Message(content = userFriendlyMessage, isUser = false, senderName = "Error"))
                 sendButton.isEnabled = true
-                sendButton.setImageResource(R.drawable.ic_mistral_logo)
                 progressIndicator.isVisible = false
             }
         }
     }
 
-    private fun cancelRequest() {
-        currentJob?.cancel()
-        titleGenerationJob?.cancel()
-        client?.cancelRequest()
-        
-        sendButton.isEnabled = true
-        sendButton.setImageResource(R.drawable.ic_mistral_logo)
-        progressIndicator.isVisible = false
-    }
-
     private fun getSelectedProfileContext(): String {
         if (currentProfileId == null) return ""
         

app/src/main/res/layout/activity_main.xml

@@ -109,8 +109,8 @@
                     android:layout_height="wrap_content"
                     android:gravity="center_vertical"
                     android:orientation="horizontal"
-                    android:paddingStart="4dp"
+                    android:paddingStart="8dp"
-                    android:paddingEnd="0dp"
+                    android:paddingEnd="8dp"
                     android:paddingTop="4dp"
                     android:paddingBottom="4dp">
 
@@ -125,8 +125,8 @@
                         android:inputType="textMultiLine|textCapSentences"
                         android:maxLines="5"
                         android:minHeight="56dp"
-                        android:paddingStart="8dp"
+                        android:paddingStart="12dp"
-                        android:paddingEnd="8dp"
+                        android:paddingEnd="12dp"
                         android:paddingTop="12dp"
                         android:paddingBottom="12dp" />
 
@@ -134,6 +134,7 @@
                         android:id="@+id/sendButton"
                         android:layout_width="40dp"
                         android:layout_height="40dp"
+                        android:layout_marginStart="4dp"
                         android:padding="8dp"
                         android:src="@drawable/ic_mistral_logo"
                         android:background="@drawable/bg_send_button"

app/src/main/res/layout/dialog_api_key.xml

@@ -19,6 +19,8 @@
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:inputType="textPassword"
+            android:digits="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
+            android:maxLength="64"
             android:maxLines="1" />
 
     </com.google.android.material.textfield.TextInputLayout>