Updated on 2026-08-14

core/ui/src/main/java/com/tangem/core/ui/extensions/String.kt

@@ -80,4 +80,29 @@ fun String.capitalize(): String = replaceFirstChar { if (it.isLowerCase()) it.ti
 
 fun String.orMaskWithStars(maskWithStars: Boolean): String {
     return if (maskWithStars) THREE_STARS else this
+}
+
+/**
+ * Returns a masked representation of the string for safe display.
+ *
+ * Rules:
+ * - empty string: returned unchanged
+ * - length <= 2: all characters are replaced with '*'
+ * - length <= 4: keep the first and last characters, mask the middle
+ * - length > 4: keep the first two and last two characters, mask the middle with "**"
+ *
+ * @return masked string according to the rules above
+ */
+@Suppress("MagicNumber")
+fun String.mask(): String {
+    return when {
+        this.isEmpty() -> this
+        this.length <= 2 -> "*".repeat(this.length) // mask all if too short
+        this.length <= 4 -> this.first() + "*".repeat(this.length - 2) + this.last()
+        else -> {
+            val prefix = this.take(2)
+            val suffix = this.takeLast(2)
+            "$prefix**$suffix"
+        }
+    }
 }

core/ui/src/main/java/com/tangem/core/ui/message/EventMessage.kt

@@ -147,6 +147,8 @@ data class DialogMessage(
     }
 }
 
+data class GlobalLoadingMessage(val isShow: Boolean) : EventMessage
+
 /**
  * Shows a bottom sheet.
  *

core/ui/src/main/java/com/tangem/core/ui/message/EventMessageEffect.kt

@@ -2,13 +2,23 @@ package com.tangem.core.ui.message
 
 import android.content.Context
 import android.widget.Toast
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.SnackbarDuration
 import androidx.compose.material3.SnackbarHostState
 import androidx.compose.material3.SnackbarResult
 import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.window.Dialog
+import androidx.compose.ui.window.DialogProperties
 import com.tangem.core.ui.components.BasicDialog
 import com.tangem.core.ui.components.DialogButtonUM
+import com.tangem.core.ui.components.SpacerHMax
 import com.tangem.core.ui.components.bottomsheets.TangemBottomSheetConfig
 import com.tangem.core.ui.components.bottomsheets.message.MessageBottomSheet
 import com.tangem.core.ui.components.bottomsheets.message.MessageBottomSheetUM
@@ -17,6 +27,7 @@ import com.tangem.core.ui.event.EventEffect
 import com.tangem.core.ui.extensions.resolveReference
 import com.tangem.core.ui.res.LocalEventMessageHandler
 import com.tangem.core.ui.res.LocalSnackbarHostState
+import com.tangem.core.ui.res.TangemTheme
 
 @Composable
 fun EventMessageEffect(
@@ -33,6 +44,7 @@ fun EventMessageEffect(
     var dialogMessage: DialogMessage? by remember { mutableStateOf(value = null) }
     var bottomSheetMessage: BottomSheetMessage? by remember { mutableStateOf(value = null) }
     var bottomSheetMessageV2: BottomSheetMessageV2? by remember { mutableStateOf(value = null) }
+    var loadingMessage: GlobalLoadingMessage? by remember { mutableStateOf(value = null) }
 
     EventEffect(event = messageEvent) { message ->
         when (message) {
@@ -51,6 +63,13 @@ fun EventMessageEffect(
             is ToastMessage -> {
                 onShowToast(message, context)
             }
+            is GlobalLoadingMessage -> {
+                loadingMessage = if (message.isShow) {
+                    message
+                } else {
+                    null
+                }
+            }
         }
     }
 
@@ -80,6 +99,34 @@ fun EventMessageEffect(
             onDismissRequest = { bottomSheetMessageV2 = null },
         )
     }
+
+    loadingMessage?.let {
+        LoadingDialog()
+    }
+}
+
+@Composable
+private fun LoadingDialog() {
+    Dialog(
+        onDismissRequest = {},
+        properties = DialogProperties(
+            dismissOnBackPress = false,
+            dismissOnClickOutside = false,
+        ),
+    ) {
+        Column(
+            modifier = Modifier
+                .fillMaxSize(),
+            verticalArrangement = Arrangement.spacedBy(16.dp),
+        ) {
+            SpacerHMax()
+            CircularProgressIndicator(
+                modifier = Modifier.align(Alignment.CenterHorizontally),
+                color = TangemTheme.colors.icon.primary1,
+            )
+            SpacerHMax()
+        }
+    }
 }
 
 @Composable

core/ui/src/test/java/com/tangem/core/ui/extensions/StringMaskTest.kt

@@ -0,0 +1,91 @@
+package com.tangem.core.ui.extensions
+
+import com.google.common.truth.Truth.assertThat
+import org.junit.Test
+
+class StringMaskTest {
+
+    @Test
+    fun GIVEN_empty_string_WHEN_mask_THEN_returns_empty_string() {
+        // GIVEN
+        val input = ""
+
+        // WHEN
+        val actual = input.mask()
+
+        // THEN
+        assertThat(actual).isEqualTo("")
+    }
+
+    @Test
+    fun GIVEN_one_char_WHEN_mask_THEN_returns_asterisk() {
+        // GIVEN
+        val input = "a"
+
+        // WHEN
+        val actual = input.mask()
+
+        // THEN
+        assertThat(actual).isEqualTo("*")
+    }
+
+    @Test
+    fun GIVEN_two_chars_WHEN_mask_THEN_returns_two_asterisks() {
+        // GIVEN
+        val input = "ab"
+
+        // WHEN
+        val actual = input.mask()
+
+        // THEN
+        assertThat(actual).isEqualTo("**")
+    }
+
+    @Test
+    fun GIVEN_three_chars_WHEN_mask_THEN_masks_middle_only() {
+        // GIVEN
+        val input = "abc"
+
+        // WHEN
+        val actual = input.mask()
+
+        // THEN
+        assertThat(actual).isEqualTo("a*c")
+    }
+
+    @Test
+    fun GIVEN_four_chars_WHEN_mask_THEN_masks_middle_two() {
+        // GIVEN
+        val input = "abcd"
+
+        // WHEN
+        val actual = input.mask()
+
+        // THEN
+        assertThat(actual).isEqualTo("a**d")
+    }
+
+    @Test
+    fun GIVEN_five_chars_WHEN_mask_THEN_keeps_edges_and_two_stars_in_middle() {
+        // GIVEN
+        val input = "abcde"
+
+        // WHEN
+        val actual = input.mask()
+
+        // THEN
+        assertThat(actual).isEqualTo("ab**de")
+    }
+
+    @Test
+    fun GIVEN_seven_chars_WHEN_mask_THEN_keeps_two_on_each_side_and_two_stars() {
+        // GIVEN
+        val input = "abcdefg"
+
+        // WHEN
+        val actual = input.mask()
+
+        // THEN
+        assertThat(actual).isEqualTo("ab**fg")
+    }
+}