android/app/src/main/java/com/fabledsword/thoughtsync/AppUpdate.kt

@@ -5,6 +5,7 @@ import android.content.Intent
 import android.content.IntentSender
 import android.content.pm.PackageInstaller
 import android.net.ConnectivityManager
+import android.net.NetworkCapabilities
 import android.net.Uri
 import android.os.Build
 import android.provider.Settings
@@ -64,19 +65,25 @@ object AppUpdate {
             .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
 
     /**
-     * Whether this is a network to spend fifty-odd megabytes on without being asked.
+     * Whether this is wifi somebody is not paying by the megabyte for.
      *
-     * The update fetches itself in the background once one is found, and doing that
-     * over mobile data is a bill nobody agreed to. On a metered link the update is
-     * still FOUND and still nags — pressing Install downloads it then, which is a
-     * choice rather than a surprise.
+     * The app fetches its own update in the background, and fifty-odd megabytes over
+     * mobile data is a bill nobody agreed to. Anywhere else it simply waits — the
+     * update is found, nothing is downloaded, and nothing is said until it can be.
      *
-     * A missing ConnectivityManager reads as metered: the cautious answer is the one
-     * that costs nothing.
+     * BOTH conditions, deliberately. Wifi alone would still download over a tethered
+     * hotspot, which is mobile data wearing a different hat and the exact bill this
+     * avoids. Unmetered alone would download over an unmetered cellular plan, which
+     * is not what "on wifi" means to the person who asked for it.
+     *
+     * Every uncertain answer is `false`: the cautious one costs nothing.
      */
-    fun onUnmeteredNetwork(context: Context): Boolean {
+    fun onWifi(context: Context): Boolean {
         val manager = context.getSystemService(ConnectivityManager::class.java) ?: return false
-        return !manager.isActiveNetworkMetered
+        val active = manager.activeNetwork ?: return false
+        val caps = manager.getNetworkCapabilities(active) ?: return false
+        return caps.hasTransport(NetworkCapabilities.TRANSPORT_WIFI) &&
+            caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED)
     }
 
     /** Where a download goes: app-private, so no storage permission is involved. */

android/app/src/main/java/com/fabledsword/thoughtsync/MainActivity.kt

@@ -229,7 +229,6 @@ private fun App(
                         ?.let {
                             BoardUpdate(
                                 version = it.version,
-                                ready = update.state.ready,
                                 busy = update.state.busy,
                                 onInstall = update::downloadAndInstall,
                                 onDismiss = update::dismissNag,

android/app/src/main/java/com/fabledsword/thoughtsync/ui/BoardScreen.kt

@@ -124,7 +124,6 @@ fun BoardScreen(
                 update?.let {
                     UpdateBanner(
                         version = it.version,
-                        ready = it.ready,
                         busy = it.busy,
                         onInstall = it.onInstall,
                         onDismiss = it.onDismiss,
@@ -207,14 +206,13 @@ data class BoardSync(
  * `version` and a pair of booleans as positional arguments could be swapped with
  * nothing to catch it.
  *
- * Null covers every reason there is nothing to show — unlinked, up to date, already
- * dismissed for this sitting, mid-install — so the board never has to know which.
+ * Null covers every reason there is nothing to show — unlinked, up to date, found but
+ * not yet downloaded, dismissed for this sitting — so the board never has to know
+ * which.
  */
 data class BoardUpdate(
     val version: String,
-    /** Already fetched, so Install is one tap rather than a wait. */
-    val ready: Boolean,
-    /** A check, fetch or install is in flight. */
+    /** An install is in flight — the banner stays and reports it. */
     val busy: Boolean,
     val onInstall: () -> Unit,
     val onDismiss: () -> Unit,

android/app/src/main/java/com/fabledsword/thoughtsync/ui/UpdateCard.kt

@@ -129,14 +129,17 @@ fun UpdateCard(
  * screen and press Check — so the updates that got installed were the ones somebody
  * went looking for, and the rest were simply never found.
  *
+ * Only ever shown once the build is DOWNLOADED, so the offer is a single tap rather
+ * than the start of a wait — and so nothing is said at all until the app has been on
+ * wifi, which is where the fetch happens.
+ *
  * Dismissible, but not permanently. "Later" clears it for this sitting; the next time
- * the app comes forward the background check finds the same build and says so again.
- * That is the difference between a reminder and a notice you can lose.
+ * the app comes forward it says so again. That is the difference between a reminder
+ * and a notice you can lose.
  */
 @Composable
 fun UpdateBanner(
     version: String,
-    ready: Boolean,
     busy: Boolean,
     onInstall: () -> Unit,
     onDismiss: () -> Unit,
@@ -155,13 +158,7 @@ fun UpdateBanner(
         verticalAlignment = Alignment.CenterVertically,
     ) {
         Text(
-            // Two sentences for two states: fetched already, or waiting to be. The
-            // button is the same either way — the difference is how long it takes.
-            text =
-                stringResource(
-                    if (ready) R.string.update_banner_ready else R.string.update_banner_available,
-                    version,
-                ),
+            text = stringResource(R.string.update_banner_ready, version),
             style = MaterialTheme.typography.bodyMedium,
             modifier = Modifier.weight(1f),
         )

android/app/src/main/java/com/fabledsword/thoughtsync/ui/UpdateViewModel.kt

@@ -37,10 +37,15 @@ data class UpdateState(
     /**
      * Worth interrupting the board for.
      *
-     * Not gated on [ready]: on a metered connection nothing is downloaded in advance,
-     * and an update nobody is told about is worse than one that costs a tap to fetch.
+     * Gated on [ready], so the banner never appears until the bytes are on disk. An
+     * update that has been FOUND is not news anyone can act on quickly — offering it
+     * off wifi would turn one tap into a download somebody did not plan.
+     *
+     * Deliberately still true while [working]: the install is the one moment the
+     * banner has something to report, and hiding it there would look like the tap
+     * did nothing.
      */
-    val nagging: Boolean get() = available != null && !nagDismissed && !working
+    val nagging: Boolean get() = ready && available != null && !nagDismissed
 }
 
 /**
@@ -83,8 +88,28 @@ class UpdateViewModel(
      * when one ran recently: flicking between two apps is not a request to re-check.
      */
     fun checkInBackground() {
+        if (state.busy) return
+
+        // Already fetched and waved away — say so again. "Later" is for that sitting,
+        // not forever, and without this the early return below would mean a single
+        // dismissal silenced the update permanently. Which is precisely the "lost"
+        // this whole path exists to prevent.
+        if (state.ready) {
+            if (state.nagDismissed) state = state.copy(nagDismissed = false)
+            return
+        }
+
+        // Already found one and never fetched it — almost always because the last look
+        // happened on mobile data. Retry the FETCH rather than the check, and ignore
+        // the interval: this is what makes an update found on the train arrive when
+        // the person gets home, instead of waiting out six hours first.
+        if (state.available != null) {
+            if (AppUpdate.onWifi(context)) viewModelScope.launch { download() }
+            return
+        }
+
         val now = System.currentTimeMillis()
-        if (state.busy || state.ready || now - lastCheckAt < CHECK_INTERVAL_MS) return
+        if (now - lastCheckAt < CHECK_INTERVAL_MS) return
         lastCheckAt = now
         runCheck(fetch = true)
     }
@@ -109,10 +134,10 @@ class UpdateViewModel(
                     // be read, and a failed check must not take the screen down.
                     state.copy(checking = false, error = e.message ?: FALLBACK)
                 }
-            // Fetched in advance so the nag is a one-tap install rather than the start
-            // of a wait. Not over mobile data: fifty-odd megabytes is a bill nobody
-            // agreed to, and on a metered link the Install button downloads instead.
-            if (fetch && state.available != null && AppUpdate.onUnmeteredNetwork(context)) {
+            // Fetched before anything is said, so the banner is a one-tap install
+            // rather than the start of a wait. Off wifi this simply does not happen
+            // and the app stays quiet — the next foreground on wifi picks it up.
+            if (fetch && state.available != null && AppUpdate.onWifi(context)) {
                 download()
             }
         }
@@ -130,7 +155,7 @@ class UpdateViewModel(
             }
     }
 
-    /** Stop nagging until the app next comes forward and finds it again. */
+    /** Stop nagging for this sitting. The next trip to the foreground says it again. */
     fun dismissNag() {
         state = state.copy(nagDismissed = true)
     }

android/app/src/main/res/values/strings.xml

@@ -121,7 +121,6 @@
     <string name="update_check">Check for an update</string>
     <string name="update_install">Update</string>
     <string name="update_banner_ready">Build %1$s is downloaded and ready.</string>
-    <string name="update_banner_available">Build %1$s is available.</string>
     <string name="update_later">Later</string>
     <string name="update_failed_title">The update didn\'t install</string>
     <string name="update_permission_title">Android needs your permission</string>