feat: add history sync worker

app/src/main/java/com/bitcointxoko/gudariwallet/sync/HistoricalSyncWorker.kt

@@ -0,0 +1,77 @@
+package com.bitcointxoko.gudariwallet.sync
+
+import android.content.Context
+import android.util.Log
+import androidx.work.CoroutineWorker
+import androidx.work.WorkerParameters
+import androidx.work.workDataOf
+import com.bitcointxoko.gudariwallet.data.HistoricalSyncStore
+import com.bitcointxoko.gudariwallet.data.PaymentCacheRepository
+import com.bitcointxoko.gudariwallet.data.WalletRepository
+import com.bitcointxoko.gudariwallet.util.NotificationHelper
+
+private const val TAG       = "HistoricalSyncWorker"
+private const val PAGE_SIZE = 100
+
+class HistoricalSyncWorker(
+    appContext   : Context,
+    params       : WorkerParameters,
+    private val repo         : WalletRepository,
+    private val paymentCache : PaymentCacheRepository,
+    private val syncStore    : HistoricalSyncStore
+) : CoroutineWorker(appContext, params) {
+
+    companion object {
+        const val KEY_FETCHED = "fetched"
+        const val KEY_TOTAL   = "total"
+    }
+
+    override suspend fun doWork(): Result {
+        // Guard: already completed — safe if WorkManager ever retries a success
+        if (syncStore.isComplete()) {
+            Log.d(TAG, "Already complete — skipping")
+            return Result.success()
+        }
+
+        Log.d(TAG, "Starting historical payment sync")
+        var offset = 0
+        var total  = -1
+
+        while (true) {
+            val page = runCatching {
+                repo.getPaymentsPaginated(offset = offset, limit = PAGE_SIZE)
+            }.getOrElse { e ->
+                Log.w(TAG, "Network error on offset=$offset: ${e.message} — scheduling retry")
+                return Result.retry()  // WorkManager applies exponential backoff automatically
+            }
+
+            // First page: learn the real total from the server
+            if (total == -1) {
+                total = page.total
+                Log.d(TAG, "Server reports $total total payments")
+                if (total == 0) {
+                    syncStore.markComplete()
+                    return Result.success()
+                }
+            }
+
+            // Full overwrite — mergePayments uses INSERT OR REPLACE, no skip logic
+            paymentCache.mergePayments(page.data)
+            offset += page.data.size
+
+            Log.d(TAG, "Progress: $offset / $total")
+            setProgress(workDataOf(
+                KEY_FETCHED to offset,
+                KEY_TOTAL   to total
+            ))
+
+            // Stop if server returned a short page (end of data) or we've reached total
+            if (page.data.size < PAGE_SIZE || offset >= total) break
+        }
+
+        syncStore.markComplete()
+        Log.d(TAG, "Historical sync complete — $offset payments stored")
+        NotificationHelper.notifySyncComplete(applicationContext, offset)
+        return Result.success()
+    }
+}

app/src/main/java/com/bitcointxoko/gudariwallet/sync/HistoricalSyncWorkerFactory.kt

@@ -0,0 +1,26 @@
+package com.bitcointxoko.gudariwallet.sync
+
+import android.content.Context
+import androidx.work.ListenableWorker
+import androidx.work.WorkerFactory
+import androidx.work.WorkerParameters
+import com.bitcointxoko.gudariwallet.data.HistoricalSyncStore
+import com.bitcointxoko.gudariwallet.data.PaymentCacheRepository
+import com.bitcointxoko.gudariwallet.data.WalletRepository
+
+class HistoricalSyncWorkerFactory(
+    private val repo         : WalletRepository,
+    private val paymentCache : PaymentCacheRepository,
+    private val syncStore    : HistoricalSyncStore
+) : WorkerFactory() {
+
+    override fun createWorker(
+        appContext       : Context,
+        workerClassName  : String,
+        workerParameters : WorkerParameters
+    ): ListenableWorker? =
+        if (workerClassName == HistoricalSyncWorker::class.java.name)
+            HistoricalSyncWorker(appContext, workerParameters, repo, paymentCache, syncStore)
+        else
+            null  // return null to delegate to the next factory in the chain
+}