Binance UX: fiat precision, lot size info & network error handling

accbot-android/app/src/main/java/com/accbot/dca/MainActivity.kt

@@ -337,7 +337,7 @@ fun AccBotApp(
             )
         }
 
-        // Main screens — HorizontalPager with bottom nav / nav rail
+        // Main screens – HorizontalPager with bottom nav / nav rail
         composable("main") {
             var isChartTouching by remember { mutableStateOf(false) }
 
@@ -429,6 +429,9 @@ fun AccBotApp(
                 },
                 onNavigateToHistory = { crypto, fiat ->
                     navController.navigate(Screen.History.createRoute(crypto, fiat))
+                },
+                onNavigateToTransactionDetails = { transactionId ->
+                    navController.navigate(Screen.TransactionDetails.createRoute(transactionId))
                 }
             )
         }

accbot-android/app/src/main/java/com/accbot/dca/data/local/BackupDataRestorer.kt

@@ -155,7 +155,7 @@ class BackupDataRestorer @Inject constructor(
         val restoredNext = nextExecutionAt?.let { Instant.ofEpochMilli(it) }
 
         val effectiveNext = if (restoredNext != null && restoredNext.isAfter(now)) {
-            restoredNext // still in the future — keep it
+            restoredNext // still in the future – keep it
         } else if (cronExpression != null) {
             CronUtils.getNextExecution(cronExpression, now)
                 ?: now.plus(Duration.ofMinutes(freq.intervalMinutes.takeIf { it > 0 } ?: 1440))

accbot-android/app/src/main/java/com/accbot/dca/data/local/Daos.kt

@@ -66,6 +66,22 @@ interface DcaPlanDao {
 
     @Query("SELECT * FROM dca_plans ORDER BY createdAt DESC")
     suspend fun getAllPlansOnce(): List<DcaPlanEntity>
+
+    @Query("UPDATE dca_plans SET networkRetryCount = networkRetryCount + 1, nextNetworkRetryAt = :nextRetryAt, originalScheduledAt = CASE WHEN originalScheduledAt IS NULL THEN :originalScheduledAt ELSE originalScheduledAt END WHERE id = :planId")
+    suspend fun incrementNetworkRetry(planId: Long, nextRetryAt: Instant, originalScheduledAt: Instant)
+
+    @Query("UPDATE dca_plans SET networkRetryCount = networkRetryCount + 1, nextNetworkRetryAt = :nextRetryAt, originalScheduledAt = CASE WHEN originalScheduledAt IS NULL THEN :originalScheduledAt ELSE originalScheduledAt END WHERE id = :planId")
+    fun incrementNetworkRetrySync(planId: Long, nextRetryAt: Instant, originalScheduledAt: Instant)
+
+    @Query("UPDATE dca_plans SET networkRetryCount = 0, nextNetworkRetryAt = NULL, originalScheduledAt = NULL WHERE id = :planId")
+    suspend fun resetNetworkRetry(planId: Long)
+
+    @Query("UPDATE dca_plans SET missedPurchaseCount = :count WHERE id = :planId")
+    suspend fun setMissedPurchaseCount(planId: Long, count: Int)
+
+    @Query("UPDATE dca_plans SET missedPurchaseCount = 0 WHERE id = :planId")
+    suspend fun resetMissedPurchaseCount(planId: Long)
+
 }
 
 @Dao
@@ -418,6 +434,7 @@ interface NotificationDao {
 
     @Query("SELECT * FROM notifications ORDER BY createdAt DESC")
     suspend fun getAllNotificationsOnce(): List<NotificationEntity>
+
 }
 
 @Dao

accbot-android/app/src/main/java/com/accbot/dca/data/local/DcaDatabase.kt

@@ -19,7 +19,7 @@ import androidx.sqlite.db.SupportSQLiteDatabase
         NotificationEntity::class,
         WithdrawalThresholdEntity::class
     ],
-    version = 15,
+    version = 18,
     exportSchema = true
 )
 @TypeConverters(Converters::class)
@@ -193,6 +193,28 @@ abstract class DcaDatabase : RoomDatabase() {
             }
         }
 
+        // Migration from version 15 to 16: Add network retry tracking columns to dca_plans
+        private val MIGRATION_15_16 = object : Migration(15, 16) {
+            override fun migrate(database: SupportSQLiteDatabase) {
+                database.execSQL("ALTER TABLE dca_plans ADD COLUMN networkRetryCount INTEGER NOT NULL DEFAULT 0")
+                database.execSQL("ALTER TABLE dca_plans ADD COLUMN nextNetworkRetryAt INTEGER DEFAULT NULL")
+            }
+        }
+
+        // Migration from version 16 to 17: Add originalScheduledAt for delay tracking across retries
+        private val MIGRATION_16_17 = object : Migration(16, 17) {
+            override fun migrate(database: SupportSQLiteDatabase) {
+                database.execSQL("ALTER TABLE dca_plans ADD COLUMN originalScheduledAt INTEGER DEFAULT NULL")
+            }
+        }
+
+        // Migration from version 17 to 18: Add missedPurchaseCount for offline recovery
+        private val MIGRATION_17_18 = object : Migration(17, 18) {
+            override fun migrate(database: SupportSQLiteDatabase) {
+                database.execSQL("ALTER TABLE dca_plans ADD COLUMN missedPurchaseCount INTEGER NOT NULL DEFAULT 0")
+            }
+        }
+
         // Migration from version 9 to 10: Add notifications and withdrawal_thresholds tables
         private val MIGRATION_9_10 = object : Migration(9, 10) {
             override fun migrate(database: SupportSQLiteDatabase) {
@@ -295,7 +317,7 @@ abstract class DcaDatabase : RoomDatabase() {
                 DcaDatabase::class.java,
                 databaseName
             )
-                .addMigrations(MIGRATION_1_2, MIGRATION_2_3, MIGRATION_3_4, MIGRATION_4_5, MIGRATION_5_6, MIGRATION_6_7, MIGRATION_7_8, MIGRATION_8_9, MIGRATION_9_10, MIGRATION_10_11, MIGRATION_11_12, MIGRATION_12_13, MIGRATION_13_14, MIGRATION_14_15)
+                .addMigrations(MIGRATION_1_2, MIGRATION_2_3, MIGRATION_3_4, MIGRATION_4_5, MIGRATION_5_6, MIGRATION_6_7, MIGRATION_7_8, MIGRATION_8_9, MIGRATION_9_10, MIGRATION_10_11, MIGRATION_11_12, MIGRATION_12_13, MIGRATION_13_14, MIGRATION_14_15, MIGRATION_15_16, MIGRATION_16_17, MIGRATION_17_18)
                 // Only allow destructive migration on app downgrade, never on failed upgrade
                 // This protects user's transaction history from accidental deletion
                 .fallbackToDestructiveMigrationOnDowngrade()

accbot-android/app/src/main/java/com/accbot/dca/data/local/Entities.kt

@@ -17,7 +17,7 @@ import java.time.Instant
 /**
  * Notification type for in-app notification history
  */
-enum class NotificationType { PURCHASE, ERROR, LOW_BALANCE, WITHDRAWAL_THRESHOLD }
+enum class NotificationType { PURCHASE, ERROR, LOW_BALANCE, WITHDRAWAL_THRESHOLD, NETWORK_RETRY, MISSED_PURCHASES }
 
 /**
  * Room type converters
@@ -130,7 +130,11 @@ data class DcaPlanEntity(
     val createdAt: Instant = Instant.now(),
     val lastExecutedAt: Instant? = null,
     val nextExecutionAt: Instant? = null,
-    val targetAmount: BigDecimal? = null
+    val targetAmount: BigDecimal? = null,
+    val networkRetryCount: Int = 0,
+    val nextNetworkRetryAt: Instant? = null,
+    val originalScheduledAt: Instant? = null,
+    val missedPurchaseCount: Int = 0
 )
 
 /**

accbot-android/app/src/main/java/com/accbot/dca/data/local/NotificationTemplateArgs.kt

@@ -4,7 +4,7 @@ import org.json.JSONObject
 
 /**
  * Structured arguments for notification templates.
- * Stored as JSON in the `templateArgs` column — text is rendered at display time
+ * Stored as JSON in the `templateArgs` column – text is rendered at display time
  * using the current locale, so language switches re-render old notifications.
  *
  * Numbers are stored as raw strings (BigDecimal.toPlainString()) and formatted
@@ -20,7 +20,9 @@ sealed class NotificationTemplateArgs {
         val crypto: String,
         val fiatAmount: String,
         val fiat: String,
-        val price: String
+        val price: String,
+        val scheduledAtEpochMs: Long? = null,
+        val executedAtEpochMs: Long? = null
     ) : NotificationTemplateArgs() {
         override fun toJson(): String = JSONObject().apply {
             put(KEY_TYPE, TYPE_PURCHASE)
@@ -29,6 +31,8 @@ sealed class NotificationTemplateArgs {
             put("fiatAmount", fiatAmount)
             put("fiat", fiat)
             put("price", price)
+            if (scheduledAtEpochMs != null) put("scheduledAtEpochMs", scheduledAtEpochMs)
+            if (executedAtEpochMs != null) put("executedAtEpochMs", executedAtEpochMs)
         }.toString()
     }
 
@@ -37,14 +41,18 @@ sealed class NotificationTemplateArgs {
         val fiatAmount: String,
         val fiat: String,
         val crypto: String,
-        val price: String
+        val price: String,
+        val scheduledAtEpochMs: Long? = null,
+        val executedAtEpochMs: Long? = null
     ) : NotificationTemplateArgs() {
         override fun toJson(): String = JSONObject().apply {
             put(KEY_TYPE, TYPE_PURCHASE_PENDING)
             put("fiatAmount", fiatAmount)
             put("fiat", fiat)
             put("crypto", crypto)
             put("price", price)
+            if (scheduledAtEpochMs != null) put("scheduledAtEpochMs", scheduledAtEpochMs)
+            if (executedAtEpochMs != null) put("executedAtEpochMs", executedAtEpochMs)
         }.toString()
     }
 
@@ -88,7 +96,7 @@ sealed class NotificationTemplateArgs {
         }.toString()
     }
 
-    /** Target accumulation reached — plan auto-disabled. */
+    /** Target accumulation reached – plan auto-disabled. */
     data class TargetReached(
         val targetAmount: String,
         val crypto: String
@@ -116,6 +124,42 @@ sealed class NotificationTemplateArgs {
         }.toString()
     }
 
+    /** Network error – purchase will be retried. */
+    data class NetworkRetry(
+        val crypto: String,
+        val exchangeName: String,
+        val errorMessage: String,
+        val nextRetryAtEpochMs: Long,
+        val attemptCount: Int,
+        val planId: Long
+    ) : NotificationTemplateArgs() {
+        override fun toJson(): String = JSONObject().apply {
+            put(KEY_TYPE, TYPE_NETWORK_RETRY)
+            put("crypto", crypto)
+            put("exchangeName", exchangeName)
+            put("errorMessage", errorMessage)
+            put("nextRetryAtEpochMs", nextRetryAtEpochMs)
+            put("attemptCount", attemptCount)
+            put("planId", planId)
+        }.toString()
+    }
+
+    /** Missed purchases due to prolonged offline period. */
+    data class MissedPurchases(
+        val crypto: String,
+        val exchangeName: String,
+        val missedCount: Int,
+        val planId: Long
+    ) : NotificationTemplateArgs() {
+        override fun toJson(): String = JSONObject().apply {
+            put(KEY_TYPE, TYPE_MISSED_PURCHASES)
+            put("crypto", crypto)
+            put("exchangeName", exchangeName)
+            put("missedCount", missedCount)
+            put("planId", planId)
+        }.toString()
+    }
+
     companion object {
         private const val KEY_TYPE = "type"
         private const val TYPE_PURCHASE = "purchase"
@@ -125,6 +169,8 @@ sealed class NotificationTemplateArgs {
         private const val TYPE_WITHDRAWAL_THRESHOLD = "withdrawal_threshold"
         private const val TYPE_TARGET_REACHED = "target_reached"
         private const val TYPE_BELOW_MINIMUM = "below_minimum"
+        private const val TYPE_NETWORK_RETRY = "network_retry"
+        private const val TYPE_MISSED_PURCHASES = "missed_purchases"
 
         fun fromJson(json: String): NotificationTemplateArgs? = try {
             val obj = JSONObject(json)
@@ -134,13 +180,17 @@ sealed class NotificationTemplateArgs {
                     crypto = obj.getString("crypto"),
                     fiatAmount = obj.getString("fiatAmount"),
                     fiat = obj.getString("fiat"),
-                    price = obj.getString("price")
+                    price = obj.getString("price"),
+                    scheduledAtEpochMs = obj.optLong("scheduledAtEpochMs", 0L).takeIf { it > 0 },
+                    executedAtEpochMs = obj.optLong("executedAtEpochMs", 0L).takeIf { it > 0 }
                 )
                 TYPE_PURCHASE_PENDING -> PurchasePending(
                     fiatAmount = obj.getString("fiatAmount"),
                     fiat = obj.getString("fiat"),
                     crypto = obj.getString("crypto"),
-                    price = obj.getString("price")
+                    price = obj.getString("price"),
+                    scheduledAtEpochMs = obj.optLong("scheduledAtEpochMs", 0L).takeIf { it > 0 },
+                    executedAtEpochMs = obj.optLong("executedAtEpochMs", 0L).takeIf { it > 0 }
                 )
                 TYPE_ERROR -> Error(
                     crypto = obj.getString("crypto"),
@@ -166,6 +216,20 @@ sealed class NotificationTemplateArgs {
                     fiat = obj.getString("fiat"),
                     minOrderSize = obj.getString("minOrderSize")
                 )
+                TYPE_MISSED_PURCHASES -> MissedPurchases(
+                    crypto = obj.getString("crypto"),
+                    exchangeName = obj.getString("exchangeName"),
+                    missedCount = obj.getInt("missedCount"),
+                    planId = obj.optLong("planId", 0)
+                )
+                TYPE_NETWORK_RETRY -> NetworkRetry(
+                    crypto = obj.getString("crypto"),
+                    exchangeName = obj.getString("exchangeName"),
+                    errorMessage = obj.getString("errorMessage"),
+                    nextRetryAtEpochMs = obj.getLong("nextRetryAtEpochMs"),
+                    attemptCount = obj.optInt("attemptCount", 1),
+                    planId = obj.optLong("planId", 0)
+                )
                 else -> null
             }
         } catch (_: Exception) {

accbot-android/app/src/main/java/com/accbot/dca/data/local/UserPreferences.kt

@@ -34,7 +34,7 @@ class UserPreferences @Inject constructor(
 
     private val _appThemeFlow = MutableStateFlow(readAppTheme())
 
-    /** Observable theme state — emits immediately when theme changes. */
+    /** Observable theme state – emits immediately when theme changes. */
     val appThemeFlow: StateFlow<AppTheme> = _appThemeFlow.asStateFlow()
 
     private fun readAppTheme(): AppTheme {

accbot-android/app/src/main/java/com/accbot/dca/data/remote/MarketDataService.kt

@@ -238,7 +238,7 @@ class MarketDataService @Inject constructor(
     /**
      * Get daily price history for a date range using CryptoCompare histoday endpoint.
      * Free tier supports full historical data (up to 2000 data points per call).
-     * Used for historical backfill — fetches data ending at [toDate] going back [limit] days.
+     * Used for historical backfill – fetches data ending at [toDate] going back [limit] days.
      * Returns list of (LocalDate, BigDecimal) pairs ordered by date ascending.
      */
     suspend fun getDailyPriceHistoryRange(

accbot-android/app/src/main/java/com/accbot/dca/domain/model/BackupModels.kt

@@ -3,7 +3,7 @@ package com.accbot.dca.domain.model
 import java.time.Instant
 
 /**
- * Backup envelope — the top-level structure of a backup file (always plaintext JSON).
+ * Backup envelope – the top-level structure of a backup file (always plaintext JSON).
  */
 data class BackupEnvelope(
     val format: String = FORMAT_IDENTIFIER,
@@ -24,7 +24,7 @@ data class BackupEnvelope(
 }
 
 /**
- * Backup payload — the actual data after decryption/decompression.
+ * Backup payload – the actual data after decryption/decompression.
  */
 data class BackupPayload(
     val plans: List<BackupPlan> = emptyList(),

accbot-android/app/src/main/java/com/accbot/dca/domain/model/Models.kt

@@ -82,7 +82,19 @@ enum class Exchange(
         supportedCryptos = listOf("BTC", "ETH", "SOL", "ADA"),
         minOrderSize = mapOf("EUR" to BigDecimal("1"), "USD" to BigDecimal("1")),
         sandboxSupport = SandboxSupport.FULL
-    )
+    );
+
+    companion object {
+        /** Binance LOT_SIZE step sizes per crypto (from /api/v3/exchangeInfo). */
+        val binanceLotStepSize = mapOf(
+            "BTC" to "0.00001",
+            "ETH" to "0.0001",
+            "BNB" to "0.001",
+            "SOL" to "0.001",
+            "ADA" to "0.1",
+            "DOT" to "0.01"
+        )
+    }
 }
 
 /**

accbot-android/app/src/main/java/com/accbot/dca/domain/usecase/CalculateChartDataUseCase.kt

@@ -209,7 +209,7 @@ class CalculateChartDataUseCase @Inject constructor(
                         YearMonth.from(currentDate).let { it.year * 100 + it.monthValue }
                     }
                     if (pendingBucketKey != null && bucketKey != pendingBucketKey) {
-                        // Bucket boundary crossed — emit the pending snapshot
+                        // Bucket boundary crossed – emit the pending snapshot
                         pendingPrice?.let { pp ->
                             result.add(buildChartDataPoint(
                                 pendingEpochDay, pendingCrypto, pendingInvested, pp
@@ -223,7 +223,7 @@ class CalculateChartDataUseCase @Inject constructor(
                     pendingPrice = price
                     pendingBucketKey = bucketKey
                 } else {
-                    // Daily emission — build point directly
+                    // Daily emission – build point directly
                     result.add(buildChartDataPoint(
                         epochDay, cumulativeCrypto, cumulativeInvested, price
                     ))
@@ -356,7 +356,7 @@ class CalculateChartDataUseCase @Inject constructor(
                         YearMonth.from(currentDate).let { it.year * 100 + it.monthValue }
                     }
                     if (pendingBucketKey != null && bucketKey != pendingBucketKey && hasPendingData) {
-                        // Bucket boundary crossed — emit previous snapshot
+                        // Bucket boundary crossed – emit previous snapshot
                         result.add(buildAggregatePoint(pendingEpochDay, pendingValue, pendingInvested))
                     }
                     pendingEpochDay = epochDay

accbot-android/app/src/main/java/com/accbot/dca/domain/usecase/ImportTradeHistoryUseCase.kt

@@ -36,7 +36,7 @@ class ImportTradeHistoryUseCase @Inject constructor(
         sinceDate: Instant? = null
     ): Flow<ApiImportProgress> = flow {
         try {
-            // Fetch all pages — from sinceDate if provided, otherwise from the beginning.
+            // Fetch all pages – from sinceDate if provided, otherwise from the beginning.
             // Deduplication by exchangeOrderId prevents duplicates, so there's no need
             // for a timestamp cursor which can skip historical trades when the only
             // existing transactions are from auto-buy (not from a prior API import).

accbot-android/app/src/main/java/com/accbot/dca/domain/usecase/SyncDailyPricesUseCase.kt

@@ -12,10 +12,10 @@ import javax.inject.Inject
 
 /**
  * Orchestrates two-phase daily price sync:
- * 1. Forward sync (every sync): CoinGecko — fills the small gap between latest cached date and today
- * 2. Historical backfill (one-time per pair): CryptoCompare — fetches older data in ≤2000-day chunks backwards
+ * 1. Forward sync (every sync): CoinGecko – fills the small gap between latest cached date and today
+ * 2. Historical backfill (one-time per pair): CryptoCompare – fetches older data in ≤2000-day chunks backwards
  *
- * Historical prices are immutable — once fetched, they never need re-fetching.
+ * Historical prices are immutable – once fetched, they never need re-fetching.
  * After the one-time backfill, subsequent syncs only run phase 1 (0-2 API calls total).
  */
 class SyncDailyPricesUseCase @Inject constructor(
@@ -62,7 +62,7 @@ class SyncDailyPricesUseCase @Inject constructor(
                 val latestDate = latestDay?.let { LocalDate.ofEpochDay(it) }
 
                 if (latestDate == null) {
-                    // Brand new pair — bootstrap with last 365 days via CoinGecko
+                    // Brand new pair – bootstrap with last 365 days via CoinGecko
                     Log.d(TAG, "[$crypto/$fiat] Bootstrap: fetching last 365 days")
                     val prices = marketDataService.getDailyPriceHistory(crypto, fiat, 365)
                     if (prices != null && prices.isNotEmpty()) {