Update lexicon models, methods to latest changes

Sources/ATProtoKit/Models/Lexicons/app.bsky/Actor/AppBskyActorDefs.swift

@@ -379,6 +379,12 @@ extension AppBskyLexicon.Actor {
         /// A URI which indicates the user is being followed by the requesting account.
         public let followedByURI: String?
 
+        /// An array of mutual followers. Optional.
+        ///
+        /// - Note: According to the AT Protocol specifications: "The subject's followers whom you
+        /// also follow."
+        public let knownFollowers: KnownFollowers
+
         enum CodingKeys: String, CodingKey {
             case isMuted = "muted"
             case mutedByArray = "mutedByList"
@@ -387,6 +393,33 @@ extension AppBskyLexicon.Actor {
             case blockingByArray = "blockingByList"
             case followingURI = "following"
             case followedByURI = "followedBy"
+            case knownFollowers
+        }
+    }
+
+    /// A definition model for mutual followers.
+    ///
+    /// - Note: According to the AT Protocol specifications: "The subject's followers whom you
+    /// also follow."
+    ///
+    /// - SeeAlso: This is based on the [`app.bsky.actor.defs`][github] lexicon.
+    ///
+    /// [github]: https://github.com/bluesky-social/atproto/blob/main/lexicons/app/bsky/actor/defs.json
+    public struct KnownFollowers: Codable {
+
+        /// The number of mutual followers related to the parent structure's specifications.
+        public let count: Int
+
+        /// An array of user accounts that follow the viewer.
+        public let followers: [ProfileViewBasicDefinition]
+
+        public func encode(to encoder: any Encoder) throws {
+            var container = encoder.container(keyedBy: CodingKeys.self)
+
+            try container.encode(self.count, forKey: .count)
+
+            // Truncate `displayName` to 5 items before encoding
+            try truncatedEncode(self.followers, withContainer: &container, forKey: .followers, upToLength: 5)
         }
     }
 

Sources/ATProtoKit/Models/Lexicons/app.bsky/Graph/AppBskyGraphGetKnownFollowers.swift

@@ -0,0 +1,31 @@
+//
+//  AppBskyGraphGetKnownFollowers.swift
+//
+//
+//  Created by Christopher Jr Riley on 2024-06-12.
+//
+
+import Foundation
+
+extension AppBskyLexicon.Graph {
+
+    /// An output model for identifying mutual followers.
+    ///
+    /// - Note: According to the AT Protocol specifications: "Enumerates accounts which follow a
+    /// specified account (actor) and are followed by the viewer."
+    ///
+    /// - SeeAlso: This is based on the [`app.bsky.graph.getKnownFollowers`][github] lexicon.
+    ///
+    /// [github]: https://github.com/bluesky-social/atproto/blob/main/lexicons/app/bsky/graph/getKnownFollowers.json
+    public struct GetKnownFollowersOutput: Codable {
+
+        /// The user account that mutually follows ``followers``.
+        public let subject: AppBskyLexicon.Actor.ProfileViewDefinition
+
+        /// The number of the last successful message decoded. Optional.
+        public let cursor: String?
+
+        /// An array of mutual followers.
+        public let followers: [AppBskyLexicon.Actor.ProfileViewDefinition]
+    }
+}

Sources/ATProtoKit/Networking/PlatformAPI/GetKnownFollowers.swift

@@ -0,0 +1,77 @@
+//
+//  GetKnownFollowers.swift
+//
+//
+//  Created by Christopher Jr Riley on 2024-06-12.
+//
+
+import Foundation
+
+extension ATProtoKit {
+
+    /// Identifies mutual followers.
+    /// 
+    /// - Note: According to the AT Protocol specifications: "Enumerates accounts which follow a
+    /// specified account (actor) and are followed by the viewer."
+    /// 
+    /// - SeeAlso: This is based on the [`app.bsky.graph.getKnownFollowers`][github] lexicon.
+    /// 
+    /// [github]: https://github.com/bluesky-social/atproto/blob/main/lexicons/app/bsky/graph/getKnownFollowers.json
+    /// 
+    /// - Parameters:
+    ///   - actor: The user account to check for mutual followers.
+    ///   - limit: The number of items the list will hold. Optional. Defaults to `50`.
+    ///   - cursor: The mark used to indicate the starting point for the next set of
+    ///   result. Optional.
+    /// - Returns: A `Result`, containing either a
+    /// ``AppBskyLexicon/Graph/GetKnownFollowersOutput``
+    /// if successful, or an `Error` if not.
+    public func getKnownFollowers(
+        from actor: String,
+        limit: Int? = 50,
+        cursor: String? = nil
+    ) async throws -> Result<AppBskyLexicon.Graph.GetKnownFollowersOutput, Error> {
+        guard session != nil,
+              let accessToken = session?.accessToken else {
+            return .failure(ATRequestPrepareError.missingActiveSession)
+        }
+
+        guard let sessionURL = session?.pdsURL,
+              let requestURL = URL(string: "\(sessionURL)/xrpc/app.bsky.graph.getKnownFollowers") else {
+            return .failure(ATRequestPrepareError.invalidRequestURL)
+        }
+
+        var queryItems = [(String, String)]()
+
+        if let limit {
+            let finalLimit = max(1, min(limit, 100))
+            queryItems.append(("limit", "\(finalLimit)"))
+        }
+
+        if let cursor {
+            queryItems.append(("cursor", cursor))
+        }
+
+        let queryURL: URL
+
+        do {
+            queryURL = try APIClientService.setQueryItems(
+                for: requestURL,
+                with: queryItems
+            )
+
+            let request = APIClientService.createRequest(forRequest: queryURL,
+                                                         andMethod: .get,
+                                                         acceptValue: "application/json",
+                                                         contentTypeValue: nil,
+                                                         authorizationValue: "Bearer \(accessToken)")
+            let response = try await APIClientService.sendRequest(request,
+                                                                  decodeTo: AppBskyLexicon.Graph.GetKnownFollowersOutput.self)
+
+            return .success(response)
+
+        } catch {
+            return .failure(error)
+        }
+    }
+}