Add plus-minus feature to location notes (± 1 grid) (#821)

Expands location notes coverage to include 8 neighboring geohash cells,
creating a 3×3 grid around the user's current building-level location.

Changes:
- Add Geohash.neighbors() method to calculate 8 surrounding cells
- Update LocationNotesManager to subscribe to center + neighbors (9 cells total)
- Add NostrFilter.geohashNotes([String]) overload for multi-cell subscriptions
- Display '± 1' indicator in LocationNotesView header

Coverage:
- Single cell: ~38m × 19m
- 3×3 grid: ~114m × 57m total area
- Better discovery of nearby activity

Behavior:
- Subscribe: Fetches notes from all 9 cells (single efficient subscription)
- Post: Still uses center geohash only (correct privacy-preserving behavior)
- UI: Shows 'geohash ± 1' to indicate expanded coverage

Co-authored-by: jack <jackjackbits@users.noreply.github.com>

bitchat/Nostr/NostrRelayManager.swift

@@ -906,6 +906,16 @@ struct NostrFilter: Encodable {
         filter.limit = limit
         return filter
     }
+
+    // For location notes with neighbors: subscribe to multiple geohashes (center + neighbors)
+    static func geohashNotes(_ geohashes: [String], since: Date? = nil, limit: Int = 200) -> NostrFilter {
+        var filter = NostrFilter()
+        filter.kinds = [1]
+        filter.since = since?.timeIntervalSince1970.toInt()
+        filter.tagFilters = ["g": geohashes]
+        filter.limit = limit
+        return filter
+    }
 }
 
 // Dynamic coding key for tag filters

bitchat/Protocols/Geohash.swift

@@ -119,4 +119,57 @@ enum Geohash {
         }
         return (latInterval.0, latInterval.1, lonInterval.0, lonInterval.1)
     }
+
+    /// Returns all 8 neighboring geohash cells at the same precision.
+    /// - Parameter geohash: Base32 geohash string.
+    /// - Returns: Array of 8 neighboring geohashes (N, NE, E, SE, S, SW, W, NW order).
+    static func neighbors(of geohash: String) -> [String] {
+        guard !geohash.isEmpty else { return [] }
+
+        let precision = geohash.count
+        let bounds = decodeBounds(geohash)
+        let center = decodeCenter(geohash)
+
+        // Calculate cell dimensions
+        let latHeight = bounds.latMax - bounds.latMin
+        let lonWidth = bounds.lonMax - bounds.lonMin
+
+        // Helper to wrap longitude around ±180
+        func wrapLongitude(_ lon: Double) -> Double {
+            var wrapped = lon
+            while wrapped > 180.0 { wrapped -= 360.0 }
+            while wrapped < -180.0 { wrapped += 360.0 }
+            return wrapped
+        }
+
+        // Helper to clamp latitude to ±90
+        func clampLatitude(_ lat: Double) -> Double {
+            return max(-90.0, min(90.0, lat))
+        }
+
+        // Calculate 8 neighbor centers
+        let neighbors: [(lat: Double, lon: Double)] = [
+            (center.lat + latHeight, center.lon),                    // N
+            (center.lat + latHeight, center.lon + lonWidth),         // NE
+            (center.lat, center.lon + lonWidth),                     // E
+            (center.lat - latHeight, center.lon + lonWidth),         // SE
+            (center.lat - latHeight, center.lon),                    // S
+            (center.lat - latHeight, center.lon - lonWidth),         // SW
+            (center.lat, center.lon - lonWidth),                     // W
+            (center.lat + latHeight, center.lon - lonWidth)          // NW
+        ]
+
+        // Encode each neighbor, handling boundary conditions
+        return neighbors.compactMap { neighbor in
+            let lat = clampLatitude(neighbor.lat)
+            let lon = wrapLongitude(neighbor.lon)
+
+            // Skip if we've crossed a pole (latitude clamped to boundary)
+            if (neighbor.lat > 90.0 || neighbor.lat < -90.0) {
+                return nil
+            }
+
+            return encode(latitude: lat, longitude: lon, precision: precision)
+        }
+    }
 }

bitchat/Services/LocationNotesCounter.swift

@@ -1,104 +0,0 @@
-import BitLogger
-import Foundation
-
-struct LocationNotesCounterDependencies {
-    typealias RelayLookup = @MainActor (_ geohash: String, _ count: Int) -> [String]
-    typealias Subscribe = @MainActor (_ filter: NostrFilter, _ id: String, _ relays: [String], _ handler: @escaping (NostrEvent) -> Void, _ onEOSE: (() -> Void)?) -> Void
-    typealias Unsubscribe = @MainActor (_ id: String) -> Void
-
-    var relayLookup: RelayLookup
-    var subscribe: Subscribe
-    var unsubscribe: Unsubscribe
-
-    static let live = LocationNotesCounterDependencies(
-        relayLookup: { geohash, count in
-            GeoRelayDirectory.shared.closestRelays(toGeohash: geohash, count: count)
-        },
-        subscribe: { filter, id, relays, handler, onEOSE in
-            NostrRelayManager.shared.subscribe(
-                filter: filter,
-                id: id,
-                relayUrls: relays,
-                handler: handler,
-                onEOSE: onEOSE
-            )
-        },
-        unsubscribe: { id in
-            NostrRelayManager.shared.unsubscribe(id: id)
-        }
-    )
-}
-
-/// Lightweight background counter for location notes (kind 1) at building-level geohash (8 chars).
-@MainActor
-final class LocationNotesCounter: ObservableObject {
-    static let shared = LocationNotesCounter()
-
-    @Published private(set) var geohash: String? = nil
-    @Published private(set) var count: Int? = 0
-    @Published private(set) var initialLoadComplete: Bool = false
-    @Published private(set) var relayAvailable: Bool = true
-
-    private var subscriptionID: String? = nil
-    private var noteIDs = Set<String>()
-    private let dependencies: LocationNotesCounterDependencies
-
-    private init(dependencies: LocationNotesCounterDependencies = .live) {
-        self.dependencies = dependencies
-    }
-
-    init(testDependencies: LocationNotesCounterDependencies) {
-        self.dependencies = testDependencies
-    }
-
-    func subscribe(geohash gh: String) {
-        let norm = gh.lowercased()
-        if geohash == norm, subscriptionID != nil { return }
-        // Validate geohash (building-level precision: 8 chars)
-        guard Geohash.isValidBuildingGeohash(norm) else {
-            SecureLogger.warning("LocationNotesCounter: rejecting invalid geohash '\(norm)' (expected 8 valid base32 chars)", category: .session)
-            return
-        }
-        // Unsubscribe previous without clearing count to avoid flicker
-        if let sub = subscriptionID { dependencies.unsubscribe(sub) }
-        subscriptionID = nil
-        geohash = norm
-        noteIDs.removeAll()
-        initialLoadComplete = false
-        relayAvailable = true
-
-        // Subscribe only to the building geohash (precision 8)
-        let subID = "locnotes-count-\(norm)-\(UUID().uuidString.prefix(6))"
-        let relays = dependencies.relayLookup(norm, TransportConfig.nostrGeoRelayCount)
-        guard !relays.isEmpty else {
-            relayAvailable = false
-            initialLoadComplete = true
-            count = 0
-            SecureLogger.warning("LocationNotesCounter: no geo relays for geohash=\(norm)", category: .session)
-            return
-        }
-
-        subscriptionID = subID
-        let filter = NostrFilter.geohashNotes(norm, since: nil, limit: 200)
-        dependencies.subscribe(filter, subID, relays, { [weak self] event in
-            guard let self = self else { return }
-            guard event.kind == NostrProtocol.EventKind.textNote.rawValue else { return }
-            guard event.tags.contains(where: { $0.count >= 2 && $0[0].lowercased() == "g" && $0[1].lowercased() == norm }) else { return }
-            if !self.noteIDs.contains(event.id) {
-                self.noteIDs.insert(event.id)
-                self.count = self.noteIDs.count
-            }
-        }, { [weak self] in
-            self?.initialLoadComplete = true
-        })
-    }
-
-    func cancel() {
-        if let sub = subscriptionID { dependencies.unsubscribe(sub) }
-        subscriptionID = nil
-        geohash = nil
-        count = 0
-        noteIDs.removeAll()
-        relayAvailable = true
-    }
-}

bitchat/Services/LocationNotesManager.swift

@@ -163,14 +163,22 @@ final class LocationNotesManager: ObservableObject {
 
         subscriptionID = subID
         initialLoadComplete = false
-        // For persistent notes, allow relays to return recent history without an aggressive time cutoff
-        let filter = NostrFilter.geohashNotes(geohash, since: nil, limit: 200)
+
+        // Subscribe to center + 8 neighbors (± 1 grid)
+        let neighbors = Geohash.neighbors(of: geohash)
+        let allGeohashes = [geohash] + neighbors
+        let filter = NostrFilter.geohashNotes(allGeohashes, since: nil, limit: 200)
+
+        // Build a set of valid geohashes for tag matching (includes all 9 cells)
+        let validGeohashes = Set(allGeohashes.map { $0.lowercased() })
 
         dependencies.subscribe(filter, subID, relays, { [weak self] event in
             guard let self = self else { return }
             guard event.kind == NostrProtocol.EventKind.textNote.rawValue else { return }
-            // Ensure matching tag
-            guard event.tags.contains(where: { $0.count >= 2 && $0[0].lowercased() == "g" && $0[1].lowercased() == self.geohash }) else { return }
+            // Ensure matching tag - accept any of our 9 geohashes
+            guard event.tags.contains(where: { tag in
+                tag.count >= 2 && tag[0].lowercased() == "g" && validGeohashes.contains(tag[1].lowercased())
+            }) else { return }
             guard !self.noteIDs.contains(event.id) else { return }
             self.noteIDs.insert(event.id)
             let nick = event.tags.first(where: { $0.first?.lowercased() == "n" && $0.count >= 2 })?.dropFirst().first

bitchat/Views/ContentView.swift

@@ -25,7 +25,6 @@ struct ContentView: View {
     @EnvironmentObject var viewModel: ChatViewModel
     @ObservedObject private var locationManager = LocationChannelManager.shared
     @ObservedObject private var bookmarks = GeohashBookmarksStore.shared
-    @ObservedObject private var notesCounter = LocationNotesCounter.shared
     @State private var messageText = ""
     @State private var textFieldSelection: NSRange? = nil
     @FocusState private var isTextFieldFocused: Bool
@@ -51,7 +50,6 @@ struct ContentView: View {
     @State private var expandedMessageIDs: Set<String> = []
     @State private var showLocationNotes = false
     @State private var notesGeohash: String? = nil
-    @State private var sheetNotesCount: Int = 0
     @ScaledMetric(relativeTo: .body) private var headerHeight: CGFloat = 44
     @ScaledMetric(relativeTo: .subheadline) private var headerPeerIconSize: CGFloat = 11
     @ScaledMetric(relativeTo: .subheadline) private var headerPeerCountFontSize: CGFloat = 12
@@ -1287,10 +1285,9 @@ struct ContentView: View {
                         showLocationNotes = true
                     }) {
                         HStack(alignment: .center, spacing: 4) {
-                            let hasNotes = (notesCounter.count ?? 0) > 0
-                            Image(systemName: "long.text.page.and.pencil")
+                            Image(systemName: "note.text")
                                 .font(.bitchatSystem(size: 12))
-                                .foregroundColor(hasNotes ? textColor : Color.gray)
+                                .foregroundColor(Color.orange.opacity(0.8))
                                 .padding(.top, 1)
                         }
                         .fixedSize(horizontal: true, vertical: false)
@@ -1392,7 +1389,7 @@ struct ContentView: View {
         }) {
             Group {
                 if let gh = notesGeohash ?? LocationChannelManager.shared.availableChannels.first(where: { $0.level == .building })?.geohash {
-                    LocationNotesView(geohash: gh, onNotesCountChanged: { cnt in sheetNotesCount = cnt })
+                    LocationNotesView(geohash: gh)
                         .environmentObject(viewModel)
                 } else {
                     VStack(spacing: 12) {
@@ -1449,7 +1446,6 @@ struct ContentView: View {
             }
         }
         .onAppear {
-            updateNotesCounterSubscription()
             if case .mesh = locationManager.selectedChannel,
                locationManager.permissionState == .authorized,
                LocationChannelManager.shared.availableChannels.isEmpty {
@@ -1457,16 +1453,13 @@ struct ContentView: View {
             }
         }
         .onChange(of: locationManager.selectedChannel) { _ in
-            updateNotesCounterSubscription()
             if case .mesh = locationManager.selectedChannel,
                locationManager.permissionState == .authorized,
                LocationChannelManager.shared.availableChannels.isEmpty {
                 LocationChannelManager.shared.refreshChannels()
             }
         }
-        .onChange(of: locationManager.availableChannels) { _ in updateNotesCounterSubscription() }
         .onChange(of: locationManager.permissionState) { _ in
-            updateNotesCounterSubscription()
             if case .mesh = locationManager.selectedChannel,
                locationManager.permissionState == .authorized,
                LocationChannelManager.shared.availableChannels.isEmpty {
@@ -1482,31 +1475,3 @@ struct ContentView: View {
     }
 
 }
-
-// MARK: - Notes Counter Subscription Helper
-extension ContentView {
-    private func updateNotesCounterSubscription() {
-        switch locationManager.selectedChannel {
-        case .mesh:
-            // Ensure we have a fresh one-shot location fix so building geohash is current
-            if locationManager.permissionState == .authorized {
-                LocationChannelManager.shared.refreshChannels()
-            }
-            if locationManager.permissionState == .authorized {
-                if let building = LocationChannelManager.shared.availableChannels.first(where: { $0.level == .building })?.geohash {
-                    LocationNotesCounter.shared.subscribe(geohash: building)
-                } else {
-                    // Keep existing subscription if we had one to avoid flicker
-                    // Only cancel if we have no known geohash
-                    if LocationNotesCounter.shared.geohash == nil {
-                        LocationNotesCounter.shared.cancel()
-                    }
-                }
-            } else {
-                LocationNotesCounter.shared.cancel()
-            }
-        case .location:
-            LocationNotesCounter.shared.cancel()
-        }
-    }
-}

bitchat/Views/LocationNotesView.swift

@@ -141,7 +141,7 @@ struct LocationNotesView: View {
         String(
             format: String(localized: "location_notes.header", comment: "Header displaying the geohash and localized note count"),
             locale: .current,
-            geohash, count
+            "\(geohash) ± 1", count
         )
     }
 

bitchatTests/LocationNotesManagerTests.swift

@@ -91,61 +91,3 @@ struct LocationNotesManagerTests {
         case shouldNotDerive
     }
 }
-
-@MainActor
-struct LocationNotesCounterTests {
-    @Test func subscribeWithoutRelaysMarksUnavailable() {
-        var subscribeCalled = false
-        let deps = LocationNotesCounterDependencies(
-            relayLookup: { _, _ in [] },
-            subscribe: { _, _, _, _, _ in subscribeCalled = true },
-            unsubscribe: { _ in }
-        )
-
-        let counter = LocationNotesCounter(testDependencies: deps)
-        counter.subscribe(geohash: "u4pruydq")
-
-        #expect(!subscribeCalled)
-        #expect(!counter.relayAvailable)
-        #expect(counter.initialLoadComplete)
-        #expect(counter.count == 0)
-    }
-
-    @Test func subscribeCountsUniqueNotes() {
-        var storedHandler: ((NostrEvent) -> Void)?
-        var storedEOSE: (() -> Void)?
-        let deps = LocationNotesCounterDependencies(
-            relayLookup: { _, _ in ["wss://relay.geo"] },
-            subscribe: { filter, id, relays, handler, eose in
-                #expect(relays == ["wss://relay.geo"])
-                #expect(filter.kinds == [1])
-                #expect(!id.isEmpty)
-                storedHandler = handler
-                storedEOSE = eose
-            },
-            unsubscribe: { _ in }
-        )
-
-        let counter = LocationNotesCounter(testDependencies: deps)
-        counter.subscribe(geohash: "u4pruydq")
-
-        var first = NostrEvent(
-            pubkey: "pub",
-            createdAt: Date(),
-            kind: .textNote,
-            tags: [["g", "u4pruydq"]],
-            content: "a"
-        )
-        first.id = "eventA"
-        storedHandler?(first)
-
-        let duplicate = first
-        storedHandler?(duplicate)
-
-        storedEOSE?()
-
-        #expect(counter.relayAvailable)
-        #expect(counter.count == 1)
-        #expect(counter.initialLoadComplete)
-    }
-}