Refactor 1/n: ChatViewModel's Message Sending section (#613)

* 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

* Extract peer-seed color calculation out

* Extract `handleDeliveredReadReceipt` to a new function

* Extract `handlePrivateMessage` to a new function

* Separate `delivered` and `readReceipt` functions

* Extract `handleGiftWrap` into a function

* Extract `subscribeToGeoChat` into a function

* Minor cleanup

* Extract `handleNostrEvent` into a function

* Minor cleanup

* Create `sendGeohash` function + minor cleanup

* Extract sending geohash dm into a function

* Check for blocks before trying to send a DM

bitchat/Utils/Color+Peer.swift

@@ -0,0 +1,37 @@
+//
+// Color+Peer.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import SwiftUI
+
+extension Color {
+    private static var peerColorCache: [String: Color] = [:]
+    
+    init(peerSeed: String, isDark: Bool) {
+        let cacheKey = peerSeed + (isDark ? "|dark" : "|light")
+        if let cached = Self.peerColorCache[cacheKey] {
+            self = cached
+        }
+        let h = peerSeed.djb2()
+        var hue = Double(h % 1000) / 1000.0
+        let orange = 30.0 / 360.0
+        if abs(hue - orange) < TransportConfig.uiColorHueAvoidanceDelta {
+            hue = fmod(hue + TransportConfig.uiColorHueOffset, 1.0)
+        }
+        let sRand = Double((h >> 17) & 0x3FF) / 1023.0
+        let bRand = Double((h >> 27) & 0x3FF) / 1023.0
+        let sBase: Double = isDark ? 0.80 : 0.70
+        let sRange: Double = 0.20
+        let bBase: Double = isDark ? 0.75 : 0.45
+        let bRange: Double = isDark ? 0.16 : 0.14
+        let saturation = min(1.0, max(0.50, sBase + (sRand - 0.5) * sRange))
+        let brightness = min(1.0, max(0.35, bBase + (bRand - 0.5) * bRange))
+        let c = Color(hue: hue, saturation: saturation, brightness: brightness)
+        Self.peerColorCache[cacheKey] = c
+        self = c
+    }
+}

bitchat/Utils/String+DJB2.swift

@@ -0,0 +1,17 @@
+//
+// String+DJB2.swift
+// bitchat
+//
+// This is free and unencumbered software released into the public domain.
+// For more information, see <https://unlicense.org>
+//
+
+import Foundation
+
+extension String {
+    func djb2() -> UInt64 {
+        var hash: UInt64 = 5381
+        for b in utf8 { hash = ((hash << 5) &+ hash) &+ UInt64(b) }
+        return hash
+    }
+}