feat(rust): a Rust server's next wipe (module-rust phase 16, M18)

RustServerDto gains nextWipe { at, source }, null both when the operator
set no schedule and against a module older than phase 16. The server
list row and the server screen's header read "Next wipe Thu 1 Oct,
19:00 · in 6 days" in the phone's own zone, and "(rescheduled)" for a
one-off date the operator set.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E14m6SuuY6i1vASFeGDBeY

app/src/main/java/com/runicgateway/app/data/api/dto/RustDto.kt

@@ -68,6 +68,24 @@ data class RustServerDto(
     /** When this module last wrote the row — a failed poll moves it too. */
     val updatedAt: String? = null,
     val stale: Boolean = false,
+    /**
+     * When the server wipes next (module-rust phase 16, D130), or null. Null
+     * both when the operator set no schedule and against a module older than
+     * phase 16, which does not send the field — either way nothing is drawn.
+     */
+    val nextWipe: RustNextWipeDto? = null,
+)
+
+/**
+ * The next wipe, as the module computed it from the operator's schedule on this
+ * read. [source] is `forced` (Facepunch's monthly forced wipe), `rule` (the
+ * server's own weekly or biweekly day) or `once` (a one-off date the operator
+ * set — a delayed or an extra wipe). An unknown word is shown like `rule`.
+ */
+@Serializable
+data class RustNextWipeDto(
+    val at: String? = null,
+    val source: String? = null,
 )
 
 /**

app/src/main/java/com/runicgateway/app/ui/rust/RustFormat.kt

@@ -67,6 +67,29 @@ fun wipeDay(
         .format(at.atZone(zone))
 }
 
+/**
+ * The next wipe (module-rust phase 16), as `Thu 1 Oct, 19:00 · in 6 days` in
+ * the PHONE's zone — or null when there is no instant to show.
+ *
+ * The module computes the instant from the operator's rule in the operator's
+ * zone; the phone only says it the reader's way, which is the same split the
+ * website's `nextWipe()` makes. The `(rescheduled)` mark for a one-off date is
+ * the caller's, from a string resource.
+ */
+fun nextWipeWhen(
+    value: String?,
+    now: Instant = Instant.now(),
+    zone: ZoneId = ZoneId.systemDefault(),
+    locale: Locale = Locale.getDefault(),
+): String? {
+    val at = parseWireInstant(value) ?: return null
+    val local = at.atZone(zone)
+    val date = DateTimeFormatter.ofPattern("EEE d MMM", locale).format(local)
+    val time = DateTimeFormatter.ofLocalizedTime(FormatStyle.SHORT).withLocale(locale).format(local)
+    val distance = rustAgo(value, now) ?: return "$date, $time"
+    return "$date, $time · $distance"
+}
+
 /**
  * "3 minutes ago", for a "last reported" line.
  *

app/src/main/java/com/runicgateway/app/ui/rust/RustServerScreen.kt

@@ -186,6 +186,15 @@ private fun ServerHeader(
             )
         }
 
+        nextWipeLine(server)?.let {
+            Text(
+                text = it,
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.padding(top = 2.dp),
+            )
+        }
+
         Row(
             modifier = Modifier.fillMaxWidth().padding(top = 8.dp),
             horizontalArrangement = Arrangement.spacedBy(12.dp),

app/src/main/java/com/runicgateway/app/ui/rust/RustServersScreen.kt

@@ -142,6 +142,15 @@ private fun ServerRow(server: RustServerDto, onOpen: () -> Unit) {
             )
         }
 
+        nextWipeLine(server)?.let {
+            Text(
+                text = it,
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.padding(top = 2.dp),
+            )
+        }
+
         Text(
             text = lastReported(server),
             style = MaterialTheme.typography.bodySmall,
@@ -170,6 +179,22 @@ internal fun describeWorld(server: RustServerDto): String? {
     return parts.takeIf { it.isNotEmpty() }?.joinToString(" · ")
 }
 
+/**
+ * "Next wipe Thu 1 Oct, 19:00 · in 6 days", with "(rescheduled)" for a one-off
+ * date — or null, and the caller draws no line, when the server has no schedule
+ * or the module predates phase 16 and sends no field.
+ */
+@Composable
+internal fun nextWipeLine(server: RustServerDto): String? {
+    val next = server.nextWipe ?: return null
+    val whenText = nextWipeWhen(next.at) ?: return null
+    return if (next.source == "once") {
+        stringResource(R.string.rust_next_wipe_rescheduled, whenText)
+    } else {
+        stringResource(R.string.rust_next_wipe, whenText)
+    }
+}
+
 /**
  * "last reported 3 minutes ago".
  *

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

@@ -578,6 +578,8 @@
     <string name="rust_world_size">size %1$d</string>
     <string name="rust_world_seed">seed %1$d</string>
     <string name="rust_wiped_on">wiped %1$s</string>
+    <string name="rust_next_wipe">Next wipe %1$s</string>
+    <string name="rust_next_wipe_rescheduled">Next wipe %1$s (rescheduled)</string>
     <string name="rust_refresh_failed">Could not refresh just now. This is the last thing the site heard.</string>
     <string name="rust_no_such_server">No such server</string>
     <string name="rust_no_such_server_detail">This address does not name a server this site follows.</string>