update to MVVM

app/src/main/java/com/mob/utsmyanmar/ui/password_input/PasswordInput.kt

@@ -25,15 +25,15 @@ import androidx.compose.material3.Icon
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
-import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.remember
-import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import androidx.lifecycle.viewmodel.compose.viewModel
 import com.mob.utsmyanmar.ui.components.NumericKeypad
 import com.mob.utsmyanmar.ui.components.appbar.AppBar
 import com.mob.utsmyanmar.ui.preview.P2Preview
@@ -52,8 +52,6 @@ private val passwords = mapOf(
     PasswordType.SETTLEMENT to "123456"
 )
 
-private const val PASSWORD_LENGTH = 6
-
 private val passwordKeys = listOf(
     listOf("1", "2", "3"),
     listOf("4", "5", "6"),
@@ -65,11 +63,13 @@ private val passwordKeys = listOf(
 fun InputPassword(
     passwordType: String,
     onBack: () -> Unit = {},
-    onPasswordCorrect: () -> Unit = {}
+    onPasswordCorrect: () -> Unit = {},
+    viewModel: PasswordInputViewModel = viewModel()
 ) {
     val expectedPassword = passwords[passwordType] ?: passwords[PasswordType.SETTING]!!
-    var input by remember { mutableStateOf("") }
-    var errorMessage by remember { mutableStateOf<String?>(null) }
+    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+
+    LaunchedEffect(Unit) { viewModel.reset() }
 
     Scaffold(
         topBar = {
@@ -85,6 +85,7 @@ fun InputPassword(
         ) {
             Spacer(Modifier.height(8.dp))
 
+            // Display area
             Box(
                 modifier = Modifier
                     .fillMaxSize()
@@ -92,11 +93,8 @@ fun InputPassword(
             ) {
                 Card(
                     modifier = Modifier
-                        .align(Alignment.CenterEnd)
-                        .clickable(enabled = input.isNotEmpty()) {
-                            input = input.dropLast(1)
-                            errorMessage = null
-                        },
+                        .align(Alignment.TopEnd)
+                        .clickable(enabled = uiState.canDelete, onClick = viewModel::onDelete),
                     shape = RoundedCornerShape(18.dp),
                     colors = CardDefaults.cardColors(containerColor = Color.White),
                     elevation = CardDefaults.cardElevation(defaultElevation = 6.dp)
@@ -104,7 +102,7 @@ fun InputPassword(
                     Icon(
                         imageVector = Icons.Rounded.Backspace,
                         contentDescription = "Delete",
-                        tint = if (input.isNotEmpty()) Color.LegacyRed else Color.Gray,
+                        tint = if (uiState.canDelete) Color.LegacyRed else Color.Gray,
                         modifier = Modifier.padding(horizontal = 14.dp, vertical = 12.dp)
                     )
                 }
@@ -114,23 +112,19 @@ fun InputPassword(
                     verticalArrangement = Arrangement.Center,
                     horizontalAlignment = Alignment.CenterHorizontally
                 ) {
-                    Text(
-                        text = "Enter Password",
-                        color = Color.Gray,
-                        fontSize = 18.sp
-                    )
+                    Text(text = "Enter Password", color = Color.Gray, fontSize = 18.sp)
                     Spacer(Modifier.height(16.dp))
-                    PasswordDots(filledCount = input.length, totalCount = PASSWORD_LENGTH)
+                    PasswordDots(filledCount = uiState.input.length, totalCount = PASSWORD_LENGTH)
                     Spacer(Modifier.height(8.dp))
                     Text(
-                        text = errorMessage ?: "",
+                        text = uiState.errorMessage ?: "",
                         color = Color.LegacyRed,
                         fontSize = 14.sp
                     )
                 }
             }
 
-            // Keypad — mirrors InputAmountScreen weight(3f) section
+            // Keypad — stable lambda: viewModel::onKey never changes between recompositions
             Column(
                 modifier = Modifier
                     .fillMaxWidth()
@@ -140,18 +134,13 @@ fun InputPassword(
                 NumericKeypad(
                     keys = passwordKeys,
                     modifier = Modifier.fillMaxSize(),
-                    onKeyClick = { digit ->
-                        if (input.length < PASSWORD_LENGTH) {
-                            input += digit
-                            errorMessage = null
-                        }
-                    }
+                    onKeyClick = viewModel::onKey
                 )
             }
 
             Spacer(Modifier.height(16.dp))
 
-            // Action buttons — mirrors InputAmountScreen weight(0.5f) section
+            // Action buttons
             Box(
                 modifier = Modifier
                     .fillMaxWidth()
@@ -174,16 +163,9 @@ fun InputPassword(
                     }
 
                     Button(
-                        onClick = {
-                            if (input == expectedPassword) {
-                                onPasswordCorrect()
-                            } else {
-                                errorMessage = "Incorrect password"
-                                input = ""
-                            }
-                        },
+                        onClick = { viewModel.validate(expectedPassword, onPasswordCorrect) },
                         modifier = Modifier.weight(1f).height(56.dp),
-                        enabled = input.length == PASSWORD_LENGTH,
+                        enabled = uiState.isConfirmEnabled,
                         shape = RoundedCornerShape(8.dp),
                         colors = ButtonDefaults.buttonColors(
                             containerColor = Color.LegacyRed,

app/src/main/java/com/mob/utsmyanmar/ui/password_input/PasswordInputUiState.kt

@@ -0,0 +1,11 @@
+package com.mob.utsmyanmar.ui.password_input
+
+internal const val PASSWORD_LENGTH = 6
+
+data class PasswordInputUiState(
+    val input: String = "",
+    val errorMessage: String? = null
+) {
+    val isConfirmEnabled: Boolean get() = input.length == PASSWORD_LENGTH
+    val canDelete: Boolean get() = input.isNotEmpty()
+}

app/src/main/java/com/mob/utsmyanmar/ui/password_input/PasswordInputViewModel.kt

@@ -0,0 +1,40 @@
+package com.mob.utsmyanmar.ui.password_input
+
+import androidx.lifecycle.ViewModel
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.update
+
+class PasswordInputViewModel : ViewModel() {
+
+    private val _uiState = MutableStateFlow(PasswordInputUiState())
+    val uiState: StateFlow<PasswordInputUiState> = _uiState.asStateFlow()
+
+    fun onKey(digit: String) {
+        _uiState.update { state ->
+            if (state.input.length < PASSWORD_LENGTH)
+                state.copy(input = state.input + digit, errorMessage = null)
+            else
+                state
+        }
+    }
+
+    fun onDelete() {
+        _uiState.update { state ->
+            state.copy(input = state.input.dropLast(1), errorMessage = null)
+        }
+    }
+
+    fun validate(expectedPassword: String, onCorrect: () -> Unit) {
+        if (_uiState.value.input == expectedPassword) {
+            onCorrect()
+        } else {
+            _uiState.update { it.copy(errorMessage = "Incorrect password", input = "") }
+        }
+    }
+
+    fun reset() {
+        _uiState.value = PasswordInputUiState()
+    }
+}