Yattee v2 rewrite

Yattee/Utilities/AvatarURLBuilder.swift

@@ -0,0 +1,79 @@
+//
+//  AvatarURLBuilder.swift
+//  Yattee
+//
+//  Utility for constructing channel avatar URLs with Yattee Server fallback.
+//
+
+import Foundation
+import Nuke
+
+/// Utility for constructing channel avatar URLs with Yattee Server fallback
+enum AvatarURLBuilder {
+    
+    /// Available avatar sizes on Yattee Server
+    private static let availableSizes = [32, 48, 76, 100, 176, 512]
+    
+    /// Constructs the effective avatar URL for a channel
+    /// - Parameters:
+    ///   - channelID: The channel ID
+    ///   - directURL: Direct avatar URL if available (from API response)
+    ///   - serverURL: Yattee Server base URL
+    ///   - size: Desired size in points (will be doubled for retina and rounded to nearest available)
+    /// - Returns: URL to use for avatar, or nil if unavailable
+    static func avatarURL(
+        channelID: String,
+        directURL: URL?,
+        serverURL: URL?,
+        size: Int
+    ) -> URL? {
+        // Check if this is a YouTube channel (UC prefix or @handle)
+        let isYouTubeChannel = channelID.hasPrefix("UC") || channelID.hasPrefix("@")
+
+        // Priority 1: For YouTube channels, prefer Yattee Server (more reliable, avoids stale URLs from iCloud sync)
+        if isYouTubeChannel, let serverURL = serverURL {
+            return buildServerAvatarURL(serverURL: serverURL, channelID: channelID, size: size)
+        }
+
+        // Priority 2: Use direct URL for non-YouTube channels or when server unavailable
+        if let directURL = directURL {
+            return directURL
+        }
+
+        // Priority 3: Try server as last resort (for YouTube without direct URL)
+        if let serverURL = serverURL {
+            return buildServerAvatarURL(serverURL: serverURL, channelID: channelID, size: size)
+        }
+
+        return nil
+    }
+
+    /// Builds the Yattee Server avatar URL for a channel
+    private static func buildServerAvatarURL(serverURL: URL, channelID: String, size: Int) -> URL {
+        // Calculate retina size and round to nearest available
+        let retinaSize = size * 2
+        let roundedSize = availableSizes
+            .min { abs($0 - retinaSize) < abs($1 - retinaSize) } ?? 176
+
+        return serverURL
+            .appendingPathComponent("api/v1/channels")
+            .appendingPathComponent(channelID)
+            .appendingPathComponent("avatar")
+            .appendingPathComponent("\(roundedSize).jpg")
+    }
+
+    /// Creates an ImageRequest with auth header for Yattee Server avatar URLs
+    /// - Parameters:
+    ///   - url: The avatar URL
+    ///   - authHeader: Optional Basic Auth header for Yattee Server
+    /// - Returns: ImageRequest configured with auth if needed, or nil if URL is nil
+    static func imageRequest(url: URL?, authHeader: String?) -> ImageRequest? {
+        guard let url else { return nil }
+        var request = URLRequest(url: url)
+        // Only add auth header for Yattee Server avatar URLs
+        if let authHeader, url.path.contains("/api/v1/channels/") && url.path.contains("/avatar/") {
+            request.setValue(authHeader, forHTTPHeaderField: "Authorization")
+        }
+        return ImageRequest(urlRequest: request)
+    }
+}