Updated on 2026-08-14

core/analytics/models/src/main/java/com/tangem/core/analytics/models/AnalyticsParam.kt

@@ -1,5 +1,7 @@
 package com.tangem.core.analytics.models
 
+const val IS_NOT_HTTP_ERROR = "Is not http error"
+
 sealed class AnalyticsParam {
 
     sealed class CardBalanceState(val value: String) {

data/markets/src/main/java/com/tangem/data/markets/analytics/MarketsDataAnalyticsEvent.kt

@@ -2,6 +2,7 @@ package com.tangem.data.markets.analytics
 
 import com.tangem.core.analytics.models.AnalyticsEvent
 import com.tangem.core.analytics.models.AnalyticsParam
+import com.tangem.core.analytics.models.IS_NOT_HTTP_ERROR
 
 sealed interface MarketsDataAnalyticsEvent {
 
@@ -82,8 +83,4 @@ sealed interface MarketsDataAnalyticsEvent {
         Custom("Custom"),
         Unknown("Unknown"),
     }
-
-    private companion object {
-        const val IS_NOT_HTTP_ERROR = "Is not http error"
-    }
 }

data/news/src/main/java/com/tangem/data/news/repository/DefaultNewsRepository.kt

@@ -1,5 +1,9 @@
 package com.tangem.data.news.repository
 
+import arrow.core.Either
+import arrow.core.flatten
+import arrow.core.left
+import arrow.core.right
 import com.tangem.datasource.api.common.response.ApiResponse
 import com.tangem.datasource.api.common.response.ApiResponseError
 import com.tangem.datasource.api.common.response.fold
@@ -90,7 +94,7 @@ internal class DefaultNewsRepository(
             .combine(newsLikedStore.getAll()) { articles, likedFlags ->
                 articles.map { article ->
                     article.copy(
-                        isLiked = isNewsLiked(article.id),
+                        isLiked = likedFlags[article.id] == true,
                     )
                 }
             }
@@ -99,9 +103,10 @@ internal class DefaultNewsRepository(
             }
     }
 
-    override suspend fun fetchDetailedArticles(newsIds: Collection<Int>, language: String?) {
+    override suspend fun fetchDetailedArticles(
-        fetchDetailedArticlesInternal(newsIds = newsIds, language = language)
+        newsIds: Collection<Int>,
-    }
+        language: String?,
+    ): Either<Map<Int, Throwable>, Unit> = fetchDetailedArticlesInternal(newsIds = newsIds, language = language)
 
     override suspend fun fetchTrendingNews(limit: Int, language: String?) {
         fetchAndStoreTrendingNews(limit = limit, language = language)
@@ -145,10 +150,9 @@ internal class DefaultNewsRepository(
         return newsLikedStore.getSync()[articleId] == true
     }
 
-    override suspend fun toggleNewsLiked(articleId: Int): Boolean = withContext(dispatchers.io) {
+    override suspend fun toggleNewsLiked(articleId: Int) = withContext(dispatchers.io) {
         val isNewsLikedValue = !isNewsLiked(articleId)
         newsLikedStore.updateLiked(listOf(articleId), isNewsLikedValue)
-        isNewsLikedValue
     }
 
     private fun updateViewedStatusForNewsBatch(
@@ -162,9 +166,12 @@ internal class DefaultNewsRepository(
         )
     }
 
-    private suspend fun fetchDetailedArticlesInternal(newsIds: Collection<Int>, language: String?) =
+    private suspend fun fetchDetailedArticlesInternal(
+        newsIds: Collection<Int>,
+        language: String?,
+    ): Either<Map<Int, Throwable>, Unit> = Either.catch {
         withContext(dispatchers.io) {
-            if (newsIds.isEmpty()) return@withContext
+            if (newsIds.isEmpty()) return@withContext Unit.right()
 
             val uniqueIds = newsIds.distinct()
             val idsToFetch = buildList {
@@ -174,26 +181,42 @@ internal class DefaultNewsRepository(
                 }
             }
 
-            if (idsToFetch.isEmpty()) return@withContext
+            if (idsToFetch.isEmpty()) return@withContext Unit.right()
 
             val fetchedArticles = supervisorScope {
                 idsToFetch.map { newsId ->
                     async {
-                        newsApi.getNewsDetails(newsId = newsId, language = language)
+                        Either.catch {
-                            .getOrThrow()
+                            newsApi.getNewsDetails(newsId = newsId, language = language)
-                            .toDomainDetailedArticle(
+                                .getOrThrow()
-                                isLiked = isNewsLiked(newsId),
+                                .toDomainDetailedArticle(
-                            )
+                                    isLiked = isNewsLiked(newsId),
+                                )
+                        }.mapLeft {
+                            newsId to it
+                        }
                     }
                 }.awaitAll()
             }
 
-            if (fetchedArticles.isNotEmpty()) {
+            fetchedArticles
-                newsDetailsStore.store(
+                .filterIsInstance<Either.Right<DetailedArticle>>()
-                    articles = fetchedArticles.associateBy(DetailedArticle::id),
+                .map { it.value }
-                )
+                .let { articles ->
-            }
+                    if (articles.isNotEmpty()) {
+                        newsDetailsStore.store(
+                            articles = articles.associateBy(DetailedArticle::id),
+                        )
+                    }
+                }
+
+            val errors = fetchedArticles
+                .filterIsInstance<Either.Left<Pair<Int, Throwable>>>()
+                .associate { it.value.first to it.value.second }
+
+            if (errors.isEmpty()) Unit.right() else errors.left()
         }
+    }.mapLeft { t -> mapOf(GLOBAL_ERROR_ID to t) }.flatten()
 
     private suspend fun fetchAndStoreTrendingNews(limit: Int, language: String?) {
         return withContext(dispatchers.io) {
@@ -378,5 +401,6 @@ internal class DefaultNewsRepository(
         private const val INITIAL_BATCH_KEY = 0
         private const val FIRST_PAGE = 1
         private const val TRENDING_NEWS_KEY = "trending_news"
+        private const val GLOBAL_ERROR_ID = -1
     }
 }

domain/news/src/main/java/com/tangem/domain/news/repository/NewsRepository.kt

@@ -1,5 +1,6 @@
 package com.tangem.domain.news.repository
 
+import arrow.core.Either
 import com.tangem.domain.models.news.ArticleCategory
 import com.tangem.domain.models.news.DetailedArticle
 import com.tangem.domain.models.news.ShortArticle
@@ -37,7 +38,7 @@ interface NewsRepository {
     /**
      * Fetches and caches detailed articles for provided ids in parallel.
      */
-    suspend fun fetchDetailedArticles(newsIds: Collection<Int>, language: String?)
+    suspend fun fetchDetailedArticles(newsIds: Collection<Int>, language: String?): Either<Map<Int, Throwable>, Unit>
 
     /**
      * Fetch list of trending news by limit and with correct locale and store it in runtime data store.
@@ -64,7 +65,6 @@ interface NewsRepository {
 
     /**
      * Toggle news liked state
-     * @return an actual liked state of the article
      */
-    suspend fun toggleNewsLiked(articleId: Int): Boolean
+    suspend fun toggleNewsLiked(articleId: Int)
 }

domain/news/src/main/java/com/tangem/domain/news/usecase/ObserveNewsDetailsUseCase.kt

@@ -24,7 +24,6 @@ class ObserveNewsDetailsUseCase(
     /**
      * Prefetches the given article ids (can be called with current + next ids for pager preloading).
      */
-    suspend fun prefetch(newsIds: Collection<Int>, language: String?): Either<Throwable, Unit> = Either.catch {
+    suspend fun prefetch(newsIds: Collection<Int>, language: String?): Either<Map<Int, Throwable>, Unit> =
         repository.fetchDetailedArticles(newsIds, language)
-    }
 }

domain/news/src/main/java/com/tangem/domain/news/usecase/ToggleArticleLikedUseCase.kt

@@ -1,5 +1,6 @@
 package com.tangem.domain.news.usecase
 
+import arrow.core.Either
 import com.tangem.domain.news.repository.NewsRepository
 
 class ToggleArticleLikedUseCase(private val repository: NewsRepository) {
@@ -7,7 +8,7 @@ class ToggleArticleLikedUseCase(private val repository: NewsRepository) {
     /**
      * Toggle an article liked state.
      */
-    suspend fun toggleLiked(articleId: Int): Boolean {
+    suspend fun toggleLiked(articleId: Int) = Either.catch {
-        return repository.toggleNewsLiked(articleId)
+        repository.toggleNewsLiked(articleId)
     }
 }

features/feed/impl/src/main/kotlin/com/tangem/features/feed/components/market/details/analytics/MarketTokenAnalyticsEvent.kt

@@ -0,0 +1,47 @@
+package com.tangem.features.feed.components.market.details.analytics
+
+import com.tangem.core.analytics.models.AnalyticsEvent
+import com.tangem.core.analytics.models.AnalyticsParam
+import com.tangem.core.analytics.models.AnalyticsParam.Key.ERROR_CODE
+import com.tangem.core.analytics.models.AnalyticsParam.Key.ERROR_MESSAGE
+import com.tangem.core.analytics.models.IS_NOT_HTTP_ERROR
+import com.tangem.core.analytics.models.OneTimePerSessionEvent
+
+internal sealed class MarketTokenAnalyticsEvent(
+    event: String,
+    params: Map<String, String> = emptyMap(),
+) : AnalyticsEvent(category = "CoinPage", event = event, params = params) {
+
+    data class TokenNewsViewed(
+        private val token: String,
+    ) : MarketTokenAnalyticsEvent(
+        event = "Token News Viewed",
+        params = mapOf(
+            AnalyticsParam.TOKEN_PARAM to token,
+        ),
+    ), OneTimePerSessionEvent {
+        override val oneTimeEventId: String = event + token
+    }
+
+    data class TokenNewsCarouselScrolled(
+        private val token: String,
+    ) : MarketTokenAnalyticsEvent(
+        event = "Token News Carousel Scrolled",
+        params = mapOf(
+            AnalyticsParam.TOKEN_PARAM to token,
+        ),
+    ), OneTimePerSessionEvent {
+        override val oneTimeEventId: String = event + token
+    }
+
+    data class TokenNewsLoadError(
+        private val code: Int?,
+        private val message: String,
+    ) : MarketTokenAnalyticsEvent(
+        event = "Token News Load Error",
+        params = mapOf(
+            ERROR_CODE to (code ?: IS_NOT_HTTP_ERROR).toString(),
+            ERROR_MESSAGE to message,
+        ),
+    )
+}

features/feed/impl/src/main/kotlin/com/tangem/features/feed/model/feed/analytics/FeedAnalyticsEvent.kt

@@ -5,6 +5,7 @@ import com.tangem.core.analytics.models.AnalyticsParam
 import com.tangem.core.analytics.models.AnalyticsParam.Key.ERROR_CODE
 import com.tangem.core.analytics.models.AnalyticsParam.Key.ERROR_MESSAGE
 import com.tangem.core.analytics.models.AnalyticsParam.Key.SOURCE
+import com.tangem.core.analytics.models.IS_NOT_HTTP_ERROR
 import com.tangem.core.analytics.models.OneTimePerSessionEvent
 
 internal sealed class FeedAnalyticsEvent(
@@ -89,8 +90,4 @@ internal sealed class FeedAnalyticsEvent(
     )
 
     class TokenSearchedClicked : FeedAnalyticsEvent(event = "Token Searched Clicked")
-
-    private companion object {
-        const val IS_NOT_HTTP_ERROR = "Is not http error"
-    }
 }

features/feed/impl/src/main/kotlin/com/tangem/features/feed/model/market/details/MarketsTokenDetailsModel.kt

@@ -22,6 +22,7 @@ import com.tangem.core.ui.format.bigdecimal.fiat
 import com.tangem.core.ui.format.bigdecimal.format
 import com.tangem.core.ui.format.bigdecimal.percent
 import com.tangem.core.ui.format.bigdecimal.price
+import com.tangem.datasource.api.common.response.ApiResponseError
 import com.tangem.domain.appcurrency.GetSelectedAppCurrencyUseCase
 import com.tangem.domain.appcurrency.model.AppCurrency
 import com.tangem.domain.card.common.extensions.hotWalletExcludedBlockchains
@@ -36,6 +37,7 @@ import com.tangem.domain.settings.usercountry.models.UserCountry
 import com.tangem.domain.settings.usercountry.models.needApplyFCARestrictions
 import com.tangem.domain.wallets.usecase.GetWalletsUseCase
 import com.tangem.features.feed.components.market.details.DefaultMarketsTokenDetailsComponent
+import com.tangem.features.feed.components.market.details.analytics.MarketTokenAnalyticsEvent
 import com.tangem.features.feed.impl.R
 import com.tangem.features.feed.model.market.details.analytics.MarketDetailsAnalyticsEvent
 import com.tangem.features.feed.model.market.details.converter.DescriptionConverter
@@ -242,6 +244,8 @@ internal class MarketsTokenDetailsModel @Inject constructor(
             relatedNews = MarketsTokenDetailsUM.RelatedNews(
                 articles = persistentListOf(),
                 onArticledClicked = {},
+                onFirstVisible = {},
+                onScroll = {},
             ),
         ),
     )
@@ -322,10 +326,36 @@ internal class MarketsTokenDetailsModel @Inject constructor(
                                         /* preselectedIds */ relatedNews.map { it.id },
                                     )
                                 },
+                                onFirstVisible = {
+                                    analyticsEventHandler.send(
+                                        MarketTokenAnalyticsEvent.TokenNewsViewed(
+                                            token = params.token.symbol,
+                                        ),
+                                    )
+                                },
+                                onScroll = {
+                                    analyticsEventHandler.send(
+                                        MarketTokenAnalyticsEvent.TokenNewsCarouselScrolled(
+                                            token = params.token.symbol,
+                                        ),
+                                    )
+                                },
                             ),
                         )
                     }
                 }
+            }.onLeft { throwable ->
+                val (code, message) = if (throwable is ApiResponseError.HttpException) {
+                    throwable.code.numericCode to throwable.message.orEmpty()
+                } else {
+                    null to ""
+                }
+                analyticsEventHandler.send(
+                    MarketTokenAnalyticsEvent.TokenNewsLoadError(
+                        code = code,
+                        message = message,
+                    ),
+                )
             }
         }
     }

features/feed/impl/src/main/kotlin/com/tangem/features/feed/model/news/details/NewsDetailsModel.kt

@@ -3,11 +3,13 @@ package com.tangem.features.feed.model.news.details
 import androidx.compose.runtime.Stable
 import arrow.core.getOrElse
 import com.tangem.core.analytics.api.AnalyticsEventHandler
+import com.tangem.core.analytics.models.AnalyticsParam
 import com.tangem.core.decompose.di.ModelScoped
 import com.tangem.core.decompose.model.Model
 import com.tangem.core.decompose.model.ParamsContainer
 import com.tangem.core.navigation.share.ShareManager
 import com.tangem.core.navigation.url.UrlOpener
+import com.tangem.datasource.api.common.response.ApiResponseError
 import com.tangem.domain.appcurrency.GetSelectedAppCurrencyUseCase
 import com.tangem.domain.appcurrency.model.AppCurrency
 import com.tangem.domain.markets.GetTokenMarketInfoUseCase
@@ -33,6 +35,7 @@ import kotlinx.collections.immutable.persistentListOf
 import kotlinx.collections.immutable.toImmutableList
 import kotlinx.coroutines.flow.*
 import kotlinx.coroutines.launch
+import timber.log.Timber
 import java.util.Locale
 import javax.inject.Inject
 
@@ -129,7 +132,9 @@ internal class NewsDetailsModel @Inject constructor(
 
     private fun onLikeClick(articleId: Int) {
         modelScope.launch {
-            toggleArticleLikedUseCase.toggleLiked(articleId)
+            toggleArticleLikedUseCase
+                .toggleLiked(articleId)
+                .onLeft { Timber.e(it) }
             analyticsEventHandler.send(NewsDetailsAnalyticsEvent.NewsLikeClicked(articleId))
         }
     }
@@ -202,7 +207,35 @@ internal class NewsDetailsModel @Inject constructor(
         observeNewsDetailsUseCase.prefetch(
             newsIds = params.preselectedArticlesId,
             language = currentLanguage,
-        ).mapLeft {
+        ).onLeft { errors ->
+            errors.onEach { (newsId, throwable) ->
+                when {
+                    // an article is opened from deeplink and is not found
+                    params.screenSource == AnalyticsParam.ScreensSources.NewsLink.value &&
+                        newsId == params.articleId &&
+                        throwable is ApiResponseError.HttpException &&
+                        throwable.code == ApiResponseError.HttpException.Code.NOT_FOUND
+                    -> {
+                        analyticsEventHandler.send(
+                            NewsDetailsAnalyticsEvent.NewsLinkMismatch(
+                                newsId = params.articleId,
+                            ),
+                        )
+                    }
+                    // global request executing error
+                    newsId < 0 -> {
+                        Timber.e(throwable)
+                    }
+                    else -> {
+                        analyticsEventHandler.send(
+                            NewsDetailsAnalyticsEvent.NewsArticleLoadError(
+                                newsId = newsId,
+                            ),
+                        )
+                    }
+                }
+            }
+        }.mapLeft {
             stateFactory.createErrorState()
         }
     }

features/feed/impl/src/main/kotlin/com/tangem/features/feed/model/news/details/analytics/NewsDetailsAnalyticsEvent.kt

@@ -41,4 +41,22 @@ internal sealed class NewsDetailsAnalyticsEvent(
     ), OneTimePerSessionEvent {
         override val oneTimeEventId: String = event + newsId
     }
+
+    data class NewsArticleLoadError(
+        private val newsId: Int,
+    ) : NewsDetailsAnalyticsEvent(
+        event = "News Article Load Error",
+        params = mapOf(
+            "News Id" to newsId.toString(),
+        ),
+    )
+
+    data class NewsLinkMismatch(
+        private val newsId: Int,
+    ) : NewsDetailsAnalyticsEvent(
+        event = "News Link Mismatch",
+        params = mapOf(
+            "News Id" to newsId.toString(),
+        ),
+    )
 }

features/feed/impl/src/main/kotlin/com/tangem/features/feed/model/news/list/analytics/NewsListAnalyticsEvent.kt

@@ -3,6 +3,7 @@ package com.tangem.features.feed.model.news.list.analytics
 import com.tangem.core.analytics.models.AnalyticsEvent
 import com.tangem.core.analytics.models.AnalyticsParam.Key.ERROR_CODE
 import com.tangem.core.analytics.models.AnalyticsParam.Key.ERROR_MESSAGE
+import com.tangem.core.analytics.models.IS_NOT_HTTP_ERROR
 
 internal sealed class NewsListAnalyticsEvent(
     event: String,
@@ -28,8 +29,4 @@ internal sealed class NewsListAnalyticsEvent(
             "Selected Categories" to categoryId.toString(),
         ),
     )
-
-    private companion object {
-        const val IS_NOT_HTTP_ERROR = "Is not http error"
-    }
 }

features/feed/impl/src/main/kotlin/com/tangem/features/feed/ui/market/detailed/components/TokenMarketDetailsBody.kt

@@ -3,7 +3,7 @@ package com.tangem.features.feed.ui.market.detailed.components
 import androidx.compose.foundation.layout.*
 import androidx.compose.foundation.lazy.LazyListScope
 import androidx.compose.foundation.lazy.LazyRow
-import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.lazy.itemsIndexed
 import androidx.compose.foundation.lazy.rememberLazyListState
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
@@ -11,9 +11,9 @@ import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.layout.onFirstVisible
 import androidx.compose.ui.unit.dp
 import com.tangem.common.ui.news.ArticleCard
-import com.tangem.common.ui.news.ArticleConfigUM
 import com.tangem.core.ui.components.UnableToLoadData
 import com.tangem.core.ui.components.block.TangemBlockCardColors
 import com.tangem.core.ui.components.items.DescriptionItem
@@ -24,6 +24,8 @@ import com.tangem.features.feed.impl.R
 import com.tangem.features.feed.ui.market.detailed.state.MarketsTokenDetailsUM
 import com.tangem.features.feed.ui.market.detailed.state.MarketsTokenDetailsUM.RelatedNews
 
+private const val FOURTH_ITEM_INDEX = 3
+
 @Suppress("CanBeNonNullable") // TODO will be removed after [REDACTED_JIRA]
 internal fun LazyListScope.tokenMarketDetailsBody(
     state: MarketsTokenDetailsUM.Body,
@@ -215,7 +217,11 @@ private fun LazyListScope.relatedNews(relatedNews: RelatedNews) {
         Column(
             modifier = Modifier
                 .fillMaxWidth()
-                .padding(bottom = 32.dp, top = 20.dp),
+                .padding(bottom = 32.dp, top = 20.dp)
+                .onFirstVisible(
+                    minFractionVisible = 0.5f,
+                    callback = relatedNews.onFirstVisible,
+                ),
             verticalArrangement = Arrangement.spacedBy(12.dp),
         ) {
             Text(
@@ -231,14 +237,23 @@ private fun LazyListScope.relatedNews(relatedNews: RelatedNews) {
                 horizontalArrangement = Arrangement.spacedBy(12.dp),
                 state = listState,
             ) {
-                items(
+                itemsIndexed(
                     items = relatedNews.articles,
-                    key = ArticleConfigUM::id,
+                    key = { index, article -> article.id },
-                ) { article ->
+                ) { index, article ->
+                    val articleModifier = if (index == FOURTH_ITEM_INDEX) {
+                        Modifier.onFirstVisible(
+                            minFractionVisible = 0.5f,
+                            callback = relatedNews.onScroll,
+                        )
+                    } else {
+                        Modifier
+                    }
+
                     ArticleCard(
                         articleConfigUM = article,
                         onArticleClick = { relatedNews.onArticledClicked(article.id) },
-                        modifier = Modifier
+                        modifier = articleModifier
                             .height(164.dp)
                             .width(216.dp),
                         colors = TangemBlockCardColors.copy(containerColor = TangemTheme.colors.background.action),

features/feed/impl/src/main/kotlin/com/tangem/features/feed/ui/market/detailed/preview/MarketsTokenDetailsPreview.kt

@@ -46,6 +46,8 @@ internal object MarketsTokenDetailsPreview {
         relatedNews = MarketsTokenDetailsUM.RelatedNews(
             articles = persistentListOf(),
             onArticledClicked = {},
+            onFirstVisible = {},
+            onScroll = {},
         ),
     )
 
@@ -136,6 +138,8 @@ internal object MarketsTokenDetailsPreview {
         relatedNews = MarketsTokenDetailsUM.RelatedNews(
             articles = persistentListOf(),
             onArticledClicked = {},
+            onFirstVisible = {},
+            onScroll = {},
         ),
     )
 }

features/feed/impl/src/main/kotlin/com/tangem/features/feed/ui/market/detailed/state/MarketsTokenDetailsUM.kt

@@ -76,5 +76,7 @@ internal data class MarketsTokenDetailsUM(
     data class RelatedNews(
         val articles: ImmutableList<ArticleConfigUM>,
         val onArticledClicked: (id: Int) -> Unit,
+        val onFirstVisible: () -> Unit,
+        val onScroll: () -> Unit,
     )
 }