Coverage Summary for Class: SyncEvent (com.georgeci.moneysurfer.feature.settings.sync)

 package com.georgeci.moneysurfer.feature.settings.sync
 
 import co.touchlab.kermit.Logger
 import com.georgeci.moneysurfer.domain.auth.SessionPointers
 import com.georgeci.moneysurfer.domain.config.SyncSettings
 import com.georgeci.moneysurfer.domain.primitives.WorkspaceId
 import com.georgeci.moneysurfer.sync.api.LastSyncOutcome
 import com.georgeci.moneysurfer.sync.api.SyncError
 import com.georgeci.moneysurfer.sync.api.SyncReason
 import com.georgeci.moneysurfer.sync.api.SyncStep
 import com.georgeci.moneysurfer.sync.api.SyncSummary
 import com.georgeci.moneysurfer.sync.coordinator.SyncCoordinator
 import com.georgeci.moneysurfer.sync.repository.PendingMutation
 import com.georgeci.moneysurfer.sync.repository.PendingMutationQueue
 import com.georgeci.moneysurfer.sync.repository.SyncMeta
 import com.georgeci.moneysurfer.sync.repository.SyncMetaRepository
 import com.georgeci.moneysurfer.utils.MviViewModel
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.flatMapLatest
 import kotlinx.coroutines.flow.flowOf
 import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.withTimeoutOrNull
 import org.koin.core.annotation.KoinViewModel
 import kotlin.time.Instant
 import com.georgeci.moneysurfer.sync.api.SyncState as LiveSyncState
 
 /**
  * Read model for the sync diagnostics screen.
  *
  * Every piece was already exposed as a flow somewhere — live coordinator state, the persisted last
  * outcome, the outbox, the per-collection cursors — but nothing put them on one screen, so the
  * question "why did the pull bring nothing back" had to be answered from logs. The cursors answer
  * it directly (see docs/architecture/cloud-login-hydration.md and issue #356), which is why they
  * are here rather than in a debug-only panel.
  *
  * The screen only reads and re-renders; the two write actions are a manual sync and a cursor reset.
  */
 @OptIn(ExperimentalCoroutinesApi::class)
 @KoinViewModel
 class SyncViewModel(
     private val syncCoordinator: SyncCoordinator,
     private val syncSettings: SyncSettings,
     private val pendingMutationQueue: PendingMutationQueue,
     private val syncMetaRepository: SyncMetaRepository,
     private val session: SessionPointers,
 ) : MviViewModel<SyncState, SyncEvent, SyncEffect>(
     initialState = SyncState(),
 ) {
 
     private val log = Logger.withTag(TAG)
 
     init {
         observeCoordinator()
         observeOutbox()
         observeCursors()
     }
 
     override fun onEvent(event: SyncEvent) {
         when (event) {
             SyncEvent.OnBackClick -> postSideEffect(SyncEffect.NavigateBack)
             SyncEvent.OnSyncClick -> sync()
             SyncEvent.OnResetCursorsClick -> updateState { copy(showResetCursorsConfirm = true) }
             SyncEvent.OnResetCursorsDismissed -> updateState { copy(showResetCursorsConfirm = false) }
             SyncEvent.OnResetCursorsConfirmed -> {
                 updateState { copy(showResetCursorsConfirm = false) }
                 resetCursors()
             }
         }
     }
 
     private fun observeCoordinator() {
         launch {
             combine(syncCoordinator.state, syncCoordinator.lastOutcome, ::Pair)
                 .onEach { (live, outcome) -> updateState { copy(live = live, lastOutcome = outcome) } }
                 .collect()
         }
     }
 
     private fun observeOutbox() {
         // Sync off → the outbox can't drain and nothing on this screen can act on it, so don't hold
         // the Flow open. `flatMapLatest` rather than an early return because the server kill switch
         // can retract mid-session — same shape as SettingsViewModel's badge. The screen renders the
         // resulting empty list as "not read" rather than "nothing queued": rows survive the switch
         // flipping, so reporting an empty outbox here would be reporting a fact nobody checked.
         launch {
             syncSettings.isEnabled
                 .onEach { enabled -> updateState { copy(syncEnabled = enabled) } }
                 .flatMapLatest { enabled ->
                     // One row past the render limit, so "there are more" is something the screen
                     // observes rather than infers from a full page.
                     if (enabled) pendingMutationQueue.observeOutbox(OUTBOX_QUERY_LIMIT) else flowOf(emptyList())
                 }
                 .onEach { rows -> updateState { copy(outbox = rows) } }
                 .collect()
         }
     }
 
     private fun observeCursors() {
         launch {
             session.currentWorkspaceId
                 .onEach { workspaceId -> updateState { copy(workspaceId = workspaceId) } }
                 .flatMapLatest { workspaceId ->
                     if (workspaceId == null) flowOf(emptyList()) else syncMetaRepository.observe(workspaceId.value)
                 }
                 .onEach { rows -> updateState { copy(cursors = rows.sortedBy { it.collection }) } }
                 .collect()
         }
     }
 
     private fun sync() {
         launch {
             // Defensive: SettingsScreen no longer surfaces a way here when sync is off, but the
             // navigation entry stays registered — bail out so a deep link or a stale back stack
             // can't trigger an actual sync against Firestore.
             if (!syncSettings.isEnabled.first()) {
                 log.i { "[sync] disabled — ignoring manual sync request" }
                 return@launch
             }
             log.i { "[sync] requesting MANUAL sync via coordinator" }
             // Fire and forget: the coordinator's own `state` / `lastOutcome` flows are what this
             // screen renders, so awaiting the handle here would only duplicate them — and would
             // drop the result if the screen left composition mid-sync.
             syncCoordinator.requestSync(reason = SyncReason.MANUAL)
         }
     }
 
     /**
      * Drops every `lastPulledAt` for the active workspace and immediately re-syncs. Without the
      * sync the reset looks like a no-op — the cursors are only re-read on the next pull, and it is
      * that full re-pull, not the empty cursor table, that the user came here for.
      *
      * The wipe has to wait for the coordinator to go idle first. A pull in flight writes
      * `setCursor(now)` per collection as it finishes each one, and a request made now would queue
      * *behind* that pull rather than merge into it — so clearing immediately would have the running
      * sync restore fresh cursors and the queued "full" re-pull would then filter on them and bring
      * nothing back. Cancelling and waiting is what makes the action mean what it says.
      */
     private fun resetCursors() {
         val workspaceId = currentState.workspaceId
         if (workspaceId == null) {
             log.w { "[sync] no active workspace — ignoring cursor reset" }
             return
         }
         launch {
             syncCoordinator.cancelAll()
             val idle = withTimeoutOrNull(IDLE_WAIT_MS) {
                 syncCoordinator.state.first { it is LiveSyncState.Idle }
             }
             if (idle == null) {
                 // Cancellation is cooperative: an SDK call already in flight finishes first. Going
                 // ahead is still better than dropping the user's action — worst case the reset is
                 // partly overwritten, which is exactly the state they will retry from.
                 log.w { "[sync] coordinator still busy after ${IDLE_WAIT_MS}ms — clearing cursors anyway" }
             }
             log.i { "[sync] clearing pull cursors for workspace ${workspaceId.value}" }
             syncMetaRepository.clearScope(workspaceId.value)
             if (syncSettings.isEnabled.first()) {
                 syncCoordinator.requestSync(reason = SyncReason.MANUAL)
             }
         }
     }
 
     private companion object {
         const val TAG = "SyncVM"
 
         /** How long a cursor reset waits for a cancelled sync to actually stop. */
         const val IDLE_WAIT_MS = 5_000L
 
         /** One past what the screen renders — the extra row is how truncation is detected. */
         const val OUTBOX_QUERY_LIMIT = PendingMutationQueue.DEFAULT_OUTBOX_LIMIT + 1
     }
 }
 
 data class SyncState(
     val live: LiveSyncState = LiveSyncState.Idle,
     val lastOutcome: LastSyncOutcome = LastSyncOutcome.None,
     val outbox: List<PendingMutation> = emptyList(),
     val cursors: List<SyncMeta> = emptyList(),
     val workspaceId: WorkspaceId? = null,
     val syncEnabled: Boolean = false,
     val showResetCursorsConfirm: Boolean = false,
 ) {
 
     /**
      * Hero summary, derived rather than stored. Precedence is live activity, then a missing
      * workspace, then the last terminal outcome: a sync in flight is the most useful thing to say,
      * but once nothing is running, "no active workspace" outranks any earlier result — the actions
      * below are inert without one, and a hero reading "Up to date" from a sync that happened before
      * the workspace went away would leave that unexplained.
      *
      * Cancelled reads as [SyncStatus.Idle] on purpose: the user cancelled, so there is no result to
      * report back to them.
      */
     val syncStatus: SyncStatus
         get() = when (val current = live) {
             is LiveSyncState.Running -> SyncStatus.Running(current.currentStep)
             is LiveSyncState.Queued -> SyncStatus.Queued(current.count)
             LiveSyncState.Idle -> when {
                 workspaceId == null -> SyncStatus.NoWorkspace
                 else -> when (val outcome = lastOutcome) {
                     LastSyncOutcome.None -> SyncStatus.Idle
                     is LastSyncOutcome.Success -> SyncStatus.Done(outcome.summary, outcome.at)
                     is LastSyncOutcome.Failed -> SyncStatus.Failed(outcome.error, outcome.at)
                     is LastSyncOutcome.Cancelled -> SyncStatus.Idle
                 }
             }
         }
 
     /** The cursor reset needs a workspace to scope the wipe to; a manual sync does not. */
     val canResetCursors: Boolean get() = workspaceId != null
 
     /** Rows the outbox section renders; anything past this is reported as truncated. */
     val visibleOutbox: List<PendingMutation>
         get() = outbox.take(PendingMutationQueue.DEFAULT_OUTBOX_LIMIT)
 
     /** True only when the queue actually held more rows than [visibleOutbox] shows. */
     val outboxTruncated: Boolean
         get() = outbox.size > PendingMutationQueue.DEFAULT_OUTBOX_LIMIT
 }
 
 sealed interface SyncStatus {
     data object Idle : SyncStatus
     data object NoWorkspace : SyncStatus
     data class Queued(val count: Int) : SyncStatus
     data class Running(val step: SyncStep) : SyncStatus
     data class Done(val summary: SyncSummary, val at: Instant) : SyncStatus
     data class Failed(val error: SyncError, val at: Instant) : SyncStatus
 }
 
 sealed interface SyncEvent {
     data object OnBackClick : SyncEvent
     data object OnSyncClick : SyncEvent
     data object OnResetCursorsClick : SyncEvent
     data object OnResetCursorsDismissed : SyncEvent
     data object OnResetCursorsConfirmed : SyncEvent
 }
 
 sealed interface SyncEffect {
     data object NavigateBack : SyncEffect
 }