Support new Mastodon instance configuration

Pachyderm/Model/Instance.swift

@@ -18,12 +18,21 @@ public class Instance: Decodable {
     public let thumbnail: URL?
     public let languages: [String]?
     public let stats: Stats?
+    public let configuration: Configuration?
 
     // pleroma doesn't currently implement these
     public let contactAccount: Account?
     
-    // MARK: Unofficial additions to the Mastodon API.
-    public let maxStatusCharacters: Int?
+    // superseded by mastodon's configuration.statuses.max_characters, still used by older instances & pleroma
+    let maxTootCharacters: Int?
+    let pollLimits: PollsConfiguration?
+    
+    public var maxStatusCharacters: Int? {
+        configuration?.statuses.maxCharacters ?? maxTootCharacters
+    }
+    public var pollsConfiguration: PollsConfiguration? {
+        configuration?.polls ?? pollLimits
+    }
     
     // we need a custom decoder, because all API-compatible implementations don't return some data in the same format
     public required init(from decoder: Decoder) throws {
@@ -44,14 +53,18 @@ public class Instance: Decodable {
         
         self.stats = try? container.decodeIfPresent(Stats.self, forKey: .stats)
         self.thumbnail = try? container.decodeIfPresent(URL.self, forKey: .thumbnail)
-        if let maxStatusCharacters = try? container.decodeIfPresent(Int.self, forKey: .maxStatusCharacters) {
-            self.maxStatusCharacters = maxStatusCharacters
-        } else if let str = try? container.decodeIfPresent(String.self, forKey: .maxStatusCharacters),
-            let maxStatusCharacters = Int(str, radix: 10) {
-            self.maxStatusCharacters = maxStatusCharacters
+        
+        self.configuration = try? container.decodeIfPresent(Configuration.self, forKey: .configuration)
+        
+        if let maxTootCharacters = try? container.decodeIfPresent(Int.self, forKey: .maxTootCharacters) {
+            self.maxTootCharacters = maxTootCharacters
+        } else if let str = try? container.decodeIfPresent(String.self, forKey: .maxTootCharacters),
+            let maxTootCharacters = Int(str, radix: 10) {
+            self.maxTootCharacters = maxTootCharacters
         } else {
-            self.maxStatusCharacters = nil
+            self.maxTootCharacters = nil
         }
+        self.pollLimits = try? container.decodeIfPresent(PollsConfiguration.self, forKey: .pollLimits)
         
     }
     
@@ -65,15 +78,16 @@ public class Instance: Decodable {
         case thumbnail
         case languages
         case stats
-        
+        case configuration
         case contactAccount = "contact_account"
         
-        case maxStatusCharacters = "max_toot_chars"
+        case maxTootCharacters = "max_toot_chars"
+        case pollLimits = "poll_limits"
     }
 }
 
 extension Instance {
-    public class Stats: Decodable {
+    public struct Stats: Decodable {
         public let domainCount: Int?
         public let statusCount: Int?
         public let userCount: Int?
@@ -85,3 +99,68 @@ extension Instance {
         }
     }
 }
+
+extension Instance {
+    public struct Configuration: Decodable {
+        public let statuses: StatusesConfiguration
+        public let mediaAttachments: MediaAttachmentsConfiguration
+        /// Use Instance.pollsConfiguration to support older instance that don't have this nested
+        let polls: PollsConfiguration
+        
+        private enum CodingKeys: String, CodingKey {
+            case statuses
+            case mediaAttachments = "media_attachments"
+            case polls
+        }
+    }
+}
+
+extension Instance {
+    public struct StatusesConfiguration: Decodable {
+        public let maxCharacters: Int
+        public let maxMediaAttachments: Int
+        public let charactersReservedPerURL: Int
+        
+        private enum CodingKeys: String, CodingKey {
+            case maxCharacters = "max_characters"
+            case maxMediaAttachments = "max_media_attachments"
+            case charactersReservedPerURL = "characters_reserved_per_url"
+        }
+    }
+}
+
+extension Instance {
+    public struct MediaAttachmentsConfiguration: Decodable {
+        public let supportedMIMETypes: [String]
+        public let imageSizeLimit: Int
+        public let imageMatrixLimit: Int
+        public let videoSizeLimit: Int
+        public let videoFrameRateLimit: Int
+        public let videoMatrixLimit: Int
+        
+        private enum CodingKeys: String, CodingKey {
+            case supportedMIMETypes = "supported_mime_types"
+            case imageSizeLimit = "image_size_limit"
+            case imageMatrixLimit = "image_matrix_limit"
+            case videoSizeLimit = "video_size_limit"
+            case videoFrameRateLimit = "video_frame_rate_limit"
+            case videoMatrixLimit = "video_matrix_limit"
+        }
+    }
+}
+
+extension Instance {
+    public struct PollsConfiguration: Decodable {
+        public let maxOptions: Int
+        public let maxCharactersPerOption: Int
+        public let minExpiration: TimeInterval
+        public let maxExpiration: TimeInterval
+        
+        private enum CodingKeys: String, CodingKey {
+            case maxOptions = "max_options"
+            case maxCharactersPerOption = "max_characters_per_option"
+            case minExpiration = "min_expiration"
+            case maxExpiration = "max_expiration"
+        }
+    }
+}