Refactor: Extract types from BitchatProtocol (#611)

* Extract BitchatMessage into a separate file * Convert `fromBinaryPayload` to `convenience init?` * Extract message dedup into an extension * Remove dead `formatMessageContent` * Minor refactor of timestamp and username formatting * Remove dead `getSenderColor` * Extract MessagePadding into a separate file * Extract BitchatPacket into a separate file * Extract ReadReceipt into a separate file * Extract NoisePayload into a separate file * Remove unnecessary import
2026-07-25 23:25:20 +00:00 · 2025-09-15 15:21:03 +02:00
parent ea8d51a36b
commit 6a6504c6f2
5 changed files with 288 additions and 270 deletions
@@ -0,0 +1,91 @@
+//
+// BitchatPacket.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import Foundation
+
+/// The core packet structure for all BitChat protocol messages.
+/// Encapsulates all data needed for routing through the mesh network,
+/// including TTL for hop limiting and optional encryption.
+/// - Note: Packets larger than BLE MTU (512 bytes) are automatically fragmented
+struct BitchatPacket: Codable {
+    let version: UInt8
+    let type: UInt8
+    let senderID: Data
+    let recipientID: Data?
+    let timestamp: UInt64
+    let payload: Data
+    var signature: Data?
+    var ttl: UInt8
+    
+    init(type: UInt8, senderID: Data, recipientID: Data?, timestamp: UInt64, payload: Data, signature: Data?, ttl: UInt8) {
+        self.version = 1
+        self.type = type
+        self.senderID = senderID
+        self.recipientID = recipientID
+        self.timestamp = timestamp
+        self.payload = payload
+        self.signature = signature
+        self.ttl = ttl
+    }
+    
+    // Convenience initializer for new binary format
+    init(type: UInt8, ttl: UInt8, senderID: String, payload: Data) {
+        self.version = 1
+        self.type = type
+        // Convert hex string peer ID to binary data (8 bytes)
+        var senderData = Data()
+        var tempID = senderID
+        while tempID.count >= 2 {
+            let hexByte = String(tempID.prefix(2))
+            if let byte = UInt8(hexByte, radix: 16) {
+                senderData.append(byte)
+            }
+            tempID = String(tempID.dropFirst(2))
+        }
+        self.senderID = senderData
+        self.recipientID = nil
+        self.timestamp = UInt64(Date().timeIntervalSince1970 * 1000) // milliseconds
+        self.payload = payload
+        self.signature = nil
+        self.ttl = ttl
+    }
+    
+    var data: Data? {
+        BinaryProtocol.encode(self)
+    }
+    
+    func toBinaryData(padding: Bool = true) -> Data? {
+        BinaryProtocol.encode(self, padding: padding)
+    }
+
+    // Backward-compatible helper (defaults to padded encoding)
+    func toBinaryData() -> Data? {
+        toBinaryData(padding: true)
+    }
+    
+    /// Create binary representation for signing (without signature and TTL fields)
+    /// TTL is excluded because it changes during packet relay operations
+    func toBinaryDataForSigning() -> Data? {
+        // Create a copy without signature and with fixed TTL for signing
+        // TTL must be excluded because it changes during relay
+        let unsignedPacket = BitchatPacket(
+            type: type,
+            senderID: senderID,
+            recipientID: recipientID,
+            timestamp: timestamp,
+            payload: payload,
+            signature: nil, // Remove signature for signing
+            ttl: 0 // Use fixed TTL=0 for signing to ensure relay compatibility
+        )
+        return BinaryProtocol.encode(unsignedPacket)
+    }
+    
+    static func from(_ data: Data) -> BitchatPacket? {
+        BinaryProtocol.decode(data)
+    }
+}