Updated on 2026-08-14

data/common/src/main/kotlin/com/tangem/data/common/cache/etag/DefaultETagsStore.kt

@@ -0,0 +1,40 @@
+package com.tangem.data.common.cache.etag
+
+import androidx.datastore.preferences.core.Preferences
+import androidx.datastore.preferences.core.stringPreferencesKey
+import com.tangem.datasource.local.preferences.AppPreferencesStore
+import com.tangem.datasource.local.preferences.utils.getSyncOrNull
+import com.tangem.datasource.local.preferences.utils.store
+import com.tangem.domain.models.wallet.UserWalletId
+import timber.log.Timber
+
+/**
+ * Default implementation of the [ETagsStore] interface for managing ETag values
+ *
+ * @property appPreferencesStore the preferences store used for saving and retrieving ETag values
+ */
+internal class DefaultETagsStore(
+    private val appPreferencesStore: AppPreferencesStore,
+) : ETagsStore {
+
+    override suspend fun getSyncOrNull(userWalletId: UserWalletId, key: ETagsStore.Key): String? {
+        val key = getAccountsETagKey(userWalletId = userWalletId, key = key)
+
+        return appPreferencesStore.getSyncOrNull(key = key)
+    }
+
+    override suspend fun store(userWalletId: UserWalletId, key: ETagsStore.Key, value: String) {
+        if (value.isBlank()) {
+            Timber.e("ETag value is blank, not storing it. userWalletId: $userWalletId, key: $key")
+            return
+        }
+
+        val key = getAccountsETagKey(userWalletId = userWalletId, key = key)
+
+        appPreferencesStore.store(key = key, value = value)
+    }
+
+    private fun getAccountsETagKey(userWalletId: UserWalletId, key: ETagsStore.Key): Preferences.Key<String> {
+        return stringPreferencesKey(name = "etag_${key}_${userWalletId.stringValue}")
+    }
+}

data/common/src/main/kotlin/com/tangem/data/common/cache/etag/ETagsStore.kt

@@ -0,0 +1,34 @@
+package com.tangem.data.common.cache.etag
+
+import com.tangem.domain.models.wallet.UserWalletId
+
+/**
+ * Interface for working with ETag (Entity Tag), which is used for data caching and validation.
+ *
+[REDACTED_AUTHOR]
+ */
+interface ETagsStore {
+
+    /**
+     * Retrieves the stored ETag value for the specified wallet and key
+     *
+     * @param userWalletId identifier of the user wallet
+     * @param key          the key for which to get the ETag value
+     */
+    suspend fun getSyncOrNull(userWalletId: UserWalletId, key: Key): String?
+
+    /**
+     * Stores the ETag value for the specified wallet and key
+     *
+     * @param userWalletId identifier of the user wallet
+     * @param key          the key for which to get the ETag value
+     */
+    suspend fun store(userWalletId: UserWalletId, key: Key, value: String)
+
+    /** Enumeration of possible keys for storing ETag values */
+    enum class Key {
+        WalletAccounts,
+        UserTokens,
+        ;
+    }
+}

data/common/src/main/kotlin/com/tangem/data/common/currency/UserTokensResponseAccountIdEnricher.kt

@@ -50,9 +50,9 @@ object UserTokensResponseAccountIdEnricher {
 
         if (enrichedTokens.isEmpty()) return tokens
 
+        val enrichedTokenMap = enrichedTokens.associateBy { it }
         return tokens.map { token ->
-            val enrichedToken = enrichedTokens.firstOrNull { it == token }
-            enrichedToken ?: token
+            enrichedTokenMap[token] ?: token
         }
     }
 

data/common/src/main/kotlin/com/tangem/data/common/di/DataCommonModule.kt

@@ -1,10 +1,13 @@
 package com.tangem.data.common.di
 
 import com.tangem.blockchainsdk.utils.ExcludedBlockchains
+import com.tangem.data.common.cache.etag.DefaultETagsStore
+import com.tangem.data.common.cache.etag.ETagsStore
 import com.tangem.data.common.currency.*
 import com.tangem.data.common.quote.DefaultQuotesFetcher
 import com.tangem.data.common.quote.QuotesFetcher
 import com.tangem.datasource.api.tangemTech.TangemTechApi
+import com.tangem.datasource.local.preferences.AppPreferencesStore
 import com.tangem.datasource.local.token.UserTokensResponseStore
 import com.tangem.datasource.local.userwallet.UserWalletsStore
 import com.tangem.domain.account.featuretoggle.AccountsFeatureToggles
@@ -76,4 +79,10 @@ internal object DataCommonModule {
     fun provideQuotesFetcher(tangemTechApi: TangemTechApi, dispatchers: CoroutineDispatcherProvider): QuotesFetcher {
         return DefaultQuotesFetcher(tangemTechApi = tangemTechApi, dispatchers = dispatchers)
     }
+
+    @Provides
+    @Singleton
+    fun provideETagsStore(appPreferencesStore: AppPreferencesStore): ETagsStore {
+        return DefaultETagsStore(appPreferencesStore = appPreferencesStore)
+    }
 }