Extract BLE and chat architecture policies (#1324)

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

bitchatTests/Services/BLEAnnounceThrottleTests.swift

@@ -0,0 +1,52 @@
+import Foundation
+import Testing
+@testable import bitchat
+
+struct BLEAnnounceThrottleTests {
+    @Test
+    func firstAnnounceIsAllowed() {
+        var throttle = BLEAnnounceThrottle(normalMinimumInterval: 10, forcedMinimumInterval: 2)
+
+        let shouldSend = throttle.shouldSend(force: false, now: Date(timeIntervalSince1970: 100))
+
+        #expect(shouldSend)
+    }
+
+    @Test
+    func regularAnnounceUsesNormalMinimumInterval() {
+        let now = Date(timeIntervalSince1970: 100)
+        var throttle = BLEAnnounceThrottle(normalMinimumInterval: 10, forcedMinimumInterval: 2)
+
+        let first = throttle.shouldSend(force: false, now: now)
+        let suppressed = throttle.shouldSend(force: false, now: now.addingTimeInterval(9.9))
+        let afterInterval = throttle.shouldSend(force: false, now: now.addingTimeInterval(10))
+
+        #expect(first)
+        #expect(!suppressed)
+        #expect(afterInterval)
+    }
+
+    @Test
+    func forcedAnnounceUsesShorterMinimumInterval() {
+        let now = Date(timeIntervalSince1970: 100)
+        var throttle = BLEAnnounceThrottle(normalMinimumInterval: 10, forcedMinimumInterval: 2)
+
+        let first = throttle.shouldSend(force: false, now: now)
+        let suppressed = throttle.shouldSend(force: true, now: now.addingTimeInterval(1.9))
+        let afterInterval = throttle.shouldSend(force: true, now: now.addingTimeInterval(2))
+
+        #expect(first)
+        #expect(!suppressed)
+        #expect(afterInterval)
+    }
+
+    @Test
+    func elapsedReportsTimeSinceAcceptedSend() {
+        let now = Date(timeIntervalSince1970: 100)
+        var throttle = BLEAnnounceThrottle(normalMinimumInterval: 10, forcedMinimumInterval: 2)
+
+        throttle.shouldSend(force: false, now: now)
+
+        #expect(throttle.elapsed(since: now.addingTimeInterval(3)) == 3)
+    }
+}