Extract BLE and chat architecture policies (#1324)

Co-authored-by: jack <jackjackbits@users.noreply.github.com>
2026-07-25 05:45:18 +00:00 · 2026-06-02 09:01:59 +02:00
parent 193cfdc06a
commit 3eb4f2bd72
46 changed files with 3286 additions and 786 deletions
@@ -0,0 +1,87 @@
+import BitFoundation
+import Foundation
+
+struct BLEOutboundLinkPlan: Equatable {
+    let directedPeerHint: PeerID?
+    let fragmentChunkSize: Int?
+    let selectedLinks: BLEFanoutSelection
+    let shouldSpoolDirectedPacket: Bool
+}
+
+enum BLEOutboundLinkPlanner {
+    static func plan(
+        packet: BitchatPacket,
+        dataCount: Int,
+        peripheralIDs: [String],
+        peripheralWriteLimits: [Int],
+        centralIDs: [String],
+        centralNotifyLimits: [Int],
+        ingressRecord: BLEIngressLinkRecord?,
+        excludedLinks: Set<BLEIngressLinkID>,
+        directedOnlyPeer: PeerID?
+    ) -> BLEOutboundLinkPlan {
+        if let minLimit = minimumLinkLimit(
+            peripheralWriteLimits: peripheralWriteLimits,
+            centralNotifyLimits: centralNotifyLimits
+        ), packet.type != MessageType.fragment.rawValue,
+           dataCount > minLimit {
+            return BLEOutboundLinkPlan(
+                directedPeerHint: directedPeerHint(for: packet, explicitPeer: directedOnlyPeer),
+                fragmentChunkSize: BLEOutboundPacketPolicy.fragmentChunkSize(forLinkLimit: minLimit),
+                selectedLinks: BLEFanoutSelection(peripheralIDs: [], centralIDs: []),
+                shouldSpoolDirectedPacket: false
+            )
+        }
+
+        let directedPeerHint = directedPeerHint(for: packet, explicitPeer: directedOnlyPeer)
+        let selectedLinks = BLEFanoutSelector.selectLinks(
+            peripheralIDs: peripheralIDs,
+            centralIDs: centralIDs,
+            ingressLink: ingressRecord?.link,
+            excludedLinks: excludedLinks,
+            directedPeerHint: directedPeerHint,
+            packetType: packet.type,
+            messageID: BLEOutboundPacketPolicy.messageID(for: packet)
+        )
+
+        return BLEOutboundLinkPlan(
+            directedPeerHint: directedPeerHint,
+            fragmentChunkSize: nil,
+            selectedLinks: selectedLinks,
+            shouldSpoolDirectedPacket: shouldSpoolDirectedPacket(
+                directedPeerHint: directedPeerHint,
+                selectedLinks: selectedLinks,
+                packetType: packet.type
+            )
+        )
+    }
+
+    static func directedPeerHint(for packet: BitchatPacket, explicitPeer: PeerID?) -> PeerID? {
+        if let explicitPeer { return explicitPeer }
+        if let recipient = PeerID(str: packet.recipientID?.hexEncodedString()), !recipient.isEmpty {
+            return recipient
+        }
+        return nil
+    }
+
+    static func minimumLinkLimit(peripheralWriteLimits: [Int], centralNotifyLimits: [Int]) -> Int? {
+        [peripheralWriteLimits.min(), centralNotifyLimits.min()]
+            .compactMap { $0 }
+            .min()
+    }
+
+    static func shouldSpoolDirectedPacket(
+        directedPeerHint: PeerID?,
+        selectedLinks: BLEFanoutSelection,
+        packetType: UInt8
+    ) -> Bool {
+        guard directedPeerHint != nil,
+              selectedLinks.peripheralIDs.isEmpty,
+              selectedLinks.centralIDs.isEmpty else {
+            return false
+        }
+
+        return packetType == MessageType.noiseEncrypted.rawValue ||
+            packetType == MessageType.noiseHandshake.rawValue
+    }
+}