SyncViewModel.kt

1package com.peachpasswords.ui.sync23import android.content.Context4import androidx.lifecycle.ViewModel5import androidx.lifecycle.viewModelScope6import com.peachpasswords.sync.BackgroundSyncCoordinator7import com.peachpasswords.sync.BackgroundSyncPreference8import com.peachpasswords.sync.SyncVaultAdapter9import com.peachpasswords.sync.PairedDevice10import com.peachpasswords.sync.PairedDeviceStore11import com.peachpasswords.sync.PendingVouchedDevice12import com.peachpasswords.sync.PendingVouchedDeviceStore13import com.peachpasswords.sync.hexToPubkey14import com.peachpasswords.sync.PeachSyncService15import com.peachpasswords.sync.RelayDecision16import com.peachpasswords.sync.RelaySettingsStore17import com.peachpasswords.sync.SyncMode18import com.peachpasswords.sync.SyncAlertStore19import com.peachpasswords.sync.SyncOutcomeReason20import com.peachpasswords.sync.SyncOutcomeStore21import com.peachpasswords.sync.SyncOutcomeSummary22import com.peachpasswords.sync.VaultSyncAdapter23import com.peachpasswords.sync.buildLocalIdentity24import com.peachpasswords.sync.deriveLocalSyncKeypair25import com.peachpasswords.sync.getOrCreateDeviceId26import com.peachpasswords.vault.VaultCrypto27import com.peachpasswords.vault.VaultRepository28import dagger.hilt.android.lifecycle.HiltViewModel29import dagger.hilt.android.qualifiers.ApplicationContext30import kotlinx.coroutines.flow.MutableStateFlow31import kotlinx.coroutines.flow.SharingStarted32import kotlinx.coroutines.flow.StateFlow33import kotlinx.coroutines.flow.asStateFlow34import kotlinx.coroutines.flow.stateIn35import kotlinx.coroutines.delay36import kotlinx.coroutines.Job37import kotlinx.coroutines.launch38import javax.inject.Inject3940/**41 * Backs the Sync settings card: relay mode, the paired-device list, and the42 * manual sync control.43 *44 * Sync itself runs in [PeachSyncService], which holds a socket in each paired45 * peer's rendezvous room. Which side opens the conversation there depends on46 * the peer: we wait for a browser extension, because an extension can only47 * dial, and for another phone the lower long-term key dials. So48 * "sync now" makes sure the service is up and asks it to re-read the device49 * list — the work happens there, not here. See docs/sync-lan-retirement.md.50 */51@HiltViewModel52class SyncViewModel @Inject constructor(53    @ApplicationContext private val context: Context,54    private val vault: VaultRepository,55    private val deviceStore: PairedDeviceStore,56    private val pendingVouchedStore: PendingVouchedDeviceStore,57    private val syncAlertStore: SyncAlertStore,58    private val backgroundSync: BackgroundSyncPreference,59    private val relaySettings: RelaySettingsStore,60    private val syncOutcomes: SyncOutcomeStore,61) : ViewModel() {6263    /** The last sync attempt, whatever it was. Survives process death. */64    val status: StateFlow<SyncOutcomeSummary> = syncOutcomes.summary6566    val backgroundSyncEnabled: StateFlow<Boolean> = backgroundSync.enabled6768    /**69     * Decides when the sync service actually runs for the background-sync70     * preference. The service's own locked-handling is the gate — refusing to71     * start here while locked used to leave the preference on with no72     * notification, which was exactly the v2.5.13 "no peer answered" symptom.73     */74    private val backgroundSyncCoordinator = BackgroundSyncCoordinator(75        start = { PeachSyncService.start(context) },76        stop = { PeachSyncService.stop(context) },77        isUnlocked = vault.isUnlocked,78        preferenceEnabled = backgroundSync.enabled,79    )8081    init {82        // Catches the lock-then-unlock case: the user enables the setting while83        // locked, then unlocks — the service should come up the moment a sync84        // identity exists. StateFlow.collect fires the current value85        // immediately, so the already-unlocked case is covered too.86        backgroundSyncCoordinator.observe(viewModelScope)87    }8889    fun setBackgroundSyncEnabled(enabled: Boolean) {90        backgroundSync.setEnabled(enabled)91        backgroundSyncCoordinator.setEnabled(enabled)92    }9394    /** Blank while no private relay is configured, so the field stays honest. */95    private val _privateRelayUrl = MutableStateFlow(relaySettings.privateRelayUrl())96    val privateRelayUrl: StateFlow<String> = _privateRelayUrl.asStateFlow()979899    private val _syncMode = MutableStateFlow(relaySettings.syncMode())100    val syncMode: StateFlow<SyncMode> = _syncMode.asStateFlow()101102    fun setSyncMode(mode: SyncMode) {103        relaySettings.setSyncMode(mode)104        _syncMode.value = relaySettings.syncMode()105        _privateRelayUrl.value = relaySettings.privateRelayUrl()106    }107108    /** A custom URL implies private mode. Returns false on an invalid URL. */109    fun setRelayUrl(input: String): Boolean = runCatching {110        relaySettings.setRelayUrl(input)111        _privateRelayUrl.value = relaySettings.privateRelayUrl()112        _syncMode.value = relaySettings.syncMode()113        true114    }.getOrDefault(false)115116117    /** Live list of trusted peers, backing the Sync settings card device list (C7). */118    val pairedDevices: StateFlow<List<PairedDevice>> =119        deviceStore.observeAll()120            .stateIn(viewModelScope, SharingStarted.WhileSubscribed(5_000), emptyList())121122    val pendingVouched: StateFlow<List<PendingVouchedDevice>> =123        pendingVouchedStore.observeAll()124            .stateIn(viewModelScope, SharingStarted.WhileSubscribed(5_000), emptyList())125126    /**127     * Revoke a paired device. Removing it REVOKES rather than just dropping the128     * local row: a plain removal is undone the moment any other peer vouches it129     * back through a manifest, which is exactly what the relay makes easy.130     */131    fun unpairDevice(id: String) = viewModelScope.launch {132        deviceStore.revoke(id, getOrCreateDeviceId(context))133    }134135    fun confirmVouchedDevice(id: String) = viewModelScope.launch {136        val pending = pendingVouchedStore.get(id) ?: return@launch137        // Last gate before a vouched device becomes a sync peer. A queue entry138        // can predate the revocation that names it, so revocation is re-checked139        // here rather than trusted to have swept the queue.140        if (deviceStore.isRevoked(pending.deviceId, pending.longTermPublicKeyHex)) {141            pendingVouchedStore.remove(id)142            return@launch143        }144        deviceStore.upsert(145            PairedDevice(146                deviceId = pending.deviceId,147                deviceName = pending.deviceName,148                deviceType = pending.deviceType,149                longTermPublicKeyHex = pending.longTermPublicKeyHex,150                signingPublicKeyHex = pending.signingPublicKeyHex,151                trustSource = "vouched",152                wsPort = pending.wsPort,153                pairedAt = pending.pairedAt,154            ),155        )156        pendingVouchedStore.remove(id)157    }158159    fun rejectVouchedDevice(id: String) = viewModelScope.launch {160        pendingVouchedStore.remove(id)161    }162163    /** Browser-style nuclear recovery path: re-key sync and forget every peer. */164    suspend fun rotateSyncIdentity(): Boolean {165        val ok = vault.rotateSyncIdentity()166        if (ok) {167            deviceStore.clear()168            syncOutcomes.reset()169        }170        return ok171    }172173    /** Adapter over the live vault; null while the vault is locked. */174    fun buildAdapter(): SyncVaultAdapter? {175        if (!vault.isUnlocked.value) return null176        return VaultSyncAdapter(177            repo = vault,178            ourDeviceId = getOrCreateDeviceId(context),179            pairedDevices = deviceStore,180            pendingVouched = pendingVouchedStore,181            syncAlerts = syncAlertStore,182        )183    }184185    /**186     * Manual trigger, and the one place a sync attempt is started on purpose.187     *188     * It used to claim a completed sync the instant the service was189     * asked to start, which is a success it had not earned — the service only190     * re-reads the device list, and the sync itself happens later in a191     * rendezvous room or not at all. Now the attempt goes busy and the outcome192     * comes from whoever actually finishes it.193     */194    fun syncNow() {195        val decision = relaySettings.relayInForce()196        if (decision is RelayDecision.Refuse) {197            syncOutcomes.report(SyncOutcomeSummary(reason = decision.reason))198            return199        }200        if (!vault.isUnlocked.value) {201            syncOutcomes.report(SyncOutcomeSummary(reason = SyncOutcomeReason.VAULT_LOCKED))202            return203        }204        // Read the store, not `pairedDevices.value`: that flow only holds a real205        // list while something is collecting it, so pull-to-refresh on the vault206        // list — which collects `status` and nothing else — always saw an empty207        // list and reported "no devices paired" against a fully paired phone.208        val devices = deviceStore.getAll()209        if (devices.isEmpty()) {210            syncOutcomes.report(SyncOutcomeSummary(reason = SyncOutcomeReason.NO_PAIRED_DEVICES))211            return212        }213        // The same filter CloudRelayReconnectListener applies when it decides214        // which rooms to hold — a peer with no rendezvous secret is skipped215        // there in silence, which is precisely the case that must not look like216        // a successful no-op.217        if (devices.none { it.rendezvousSecretHex != null }) {218            syncOutcomes.report(219                SyncOutcomeSummary(220                    reason = SyncOutcomeReason.NO_ELIGIBLE_HOST,221                    detail = devices.joinToString("; ") {222                        "${it.deviceName ?: it.deviceId} [type=${it.deviceType ?: "unset"}, trust=${it.trustSource ?: "unset"}]"223                    },224                ),225            )226            return227        }228229        syncOutcomes.begin()230        PeachSyncService.start(context)231        // Nothing else can close this attempt: the phone usually WAITS to be232        // dialled, so if no peer turns up there is no session to report a233        // failure from and the light would pulse for ever. Deliberately shorter234        // than the dialler's own bound: this one answers the person holding the235        // phone, and a session still running will report over it.236        attemptTimeout?.cancel()237        attemptTimeout = viewModelScope.launch {238            delay(SYNC_ATTEMPT_TIMEOUT_MS)239            if (syncOutcomes.summary.value.syncing) {240                syncOutcomes.report(241                    SyncOutcomeSummary(242                        reason = SyncOutcomeReason.RELAY_UNREACHABLE,243                        detail = "no peer answered within ${SYNC_ATTEMPT_TIMEOUT_MS / 1000}s",244                    ),245                )246            }247        }248    }249250    /**251     * Legacy manual / discovery trigger kept for existing callers; now routes252     * through [syncNow] so a populated device store actually dials peers.253     */254    fun triggerSync() = syncNow()255256    private var attemptTimeout: Job? = null257258    private companion object {259        const val SYNC_ATTEMPT_TIMEOUT_MS = 20_000L260    }261}