MatrixRequest and Response protocol

Signed-off-by: Finn Behrens <me@kloenk.dev>

3 files changed, 105 insertions, 5 deletions

diff --git a/Sources/MatrixClient/HomeServer.swift b/Sources/MatrixClient/API/HomeServer.swift
index 64b44b0..db8a853 100644
--- a/Sources/MatrixClient/HomeServer.swift
+++ b/Sources/MatrixClient/API/HomeServer.swift
@@ -21,9 +21,29 @@ public struct MatrixHomeserver: Codable {
         
         self.url = components
     }
+    
+    public func path(_ path: String) -> URLComponents {
+        var components = url
+        components.path = path
+        return components;
+    }
+}
+
+public struct MatrixServerInfoRequest: MatrixRequest {
+    public typealias Response = MatrixServerInfo
+    
+    public typealias URLParameters = ()
+    
+    public func path(with parameters: ()) -> String {
+        return "/_matrix/client/versions"
+    }
+    
+    public static var httpMethod = "GET"
+    
+    public static var requiresAuth = false
 }
 
-public struct MatrixServerInfo: Codable {
+public struct MatrixServerInfo: MatrixResponse {
     /// The supported versions.
     public var versions: [String]
     
@@ -37,7 +57,21 @@ public struct MatrixServerInfo: Codable {
     }
 }
 
-public struct MatrixWellKnown {
+public struct MatrixWellKnownRequest: MatrixRequest {
+    public typealias Response = MatrixWellKnown
+    
+    public typealias URLParameters = ()
+    
+    public func path(with parameters: ()) -> String {
+        return "/.well-known/matrix/client"
+    }
+    
+    public static var httpMethod = "GET"
+    
+    public static var requiresAuth = false
+}
+
+public struct MatrixWellKnown: MatrixResponse {
     /// Used by clients to discover homeserver information.
     public var homeserver: ServerInformation?
     
@@ -67,7 +101,6 @@ public struct MatrixWellKnown {
     }
 }
 
-// TODO: encode for extraInfos
 extension MatrixWellKnown: Codable {
     private enum KnownCodingKeys: String, CodingKey, CaseIterable {
         case homeserver = "m.homeserver"
diff --git a/Sources/MatrixClient/API/Request.swift b/Sources/MatrixClient/API/Request.swift
new file mode 100644
index 0000000..1f2cc0d
--- /dev/null
+++ b/Sources/MatrixClient/API/Request.swift
@@ -0,0 +1,67 @@
+//
+//  File.swift
+//  File
+//
+//  Created by Finn Behrens on 29.09.21.
+//
+
+import Foundation
+
+public protocol MatrixRequest: Codable {
+    associatedtype Response: MatrixResponse
+    
+    associatedtype URLParameters
+    func path(with parameters: URLParameters) -> String
+    
+    static var httpMethod: String { get }
+    static var requiresAuth: Bool { get }
+    // TODO: rate limited property?
+}
+
+public extension MatrixRequest {
+    func request(on homeserver: MatrixHomeserver, withToken token: String? = nil, with parameters: URLParameters) throws -> URLRequest {
+        let components = homeserver.path(self.path(with: parameters))
+        // components.queryItems = self.queryParameters
+        
+        var urlRequest = URLRequest(url: components.url!)
+        
+        if Self.requiresAuth {
+            guard let token = token else {
+                throw MatrixError.Forbidden
+            }
+            urlRequest.addValue("Bearer \(token)", forHTTPHeaderField: "Authorization")
+        }
+        
+        urlRequest.httpMethod = Self.httpMethod
+        if ["POST", "PUT", "PATCH"].contains(Self.httpMethod) {
+            urlRequest.httpBody = try? JSONEncoder().encode(self)
+        }
+        
+        return urlRequest
+    }
+    
+    func repsonse(on homeserver: MatrixHomeserver, withToken token: String? = nil, with parameters: URLParameters, withUrlSession urlSession: URLSession = URLSession.shared) async throws -> Response {
+        let request = try request(on: homeserver, withToken: token, with: parameters)
+        
+        let (data, urlResponse) = try await urlSession.data(for: request)
+        
+        guard let response = urlResponse as? HTTPURLResponse else {
+            throw MatrixError.Unknown
+        }
+        guard response.statusCode == 200 else {
+            throw try MatrixServerError(json: data, code: response.statusCode)
+        }
+        
+        return try Response(fromMatrixRequestData: data)
+    }
+}
+
+public protocol MatrixResponse: Codable {
+}
+
+public extension MatrixResponse {
+    init(fromMatrixRequestData data: Data) throws {
+        let decoder = JSONDecoder()
+        self = try decoder.decode(Self.self, from: data)
+    }
+}
diff --git a/Sources/MatrixClient/MatrixClient.swift b/Sources/MatrixClient/MatrixClient.swift
index 9e0a493..32bcd8b 100644
--- a/Sources/MatrixClient/MatrixClient.swift
+++ b/Sources/MatrixClient/MatrixClient.swift
@@ -33,7 +33,7 @@ public struct MatrixClient {
     ///    Requires auth:   No.
     /// ```
     public func getVersions() async throws -> MatrixServerInfo {
-        return try await request("/_matrix/client/versions", withAuthorization: false, forType: MatrixServerInfo.self)
+        return try await MatrixServerInfoRequest().repsonse(on: homeserver, with: (), withUrlSession: urlSession)
     }
     
     /// Gets discovery information about the domain. The file may include additional keys, which MUST follow the Java package naming convention,
@@ -46,7 +46,7 @@ public struct MatrixClient {
     ///    Requires auth:   No.
     ///```
     public func getWellKnown() async throws -> MatrixWellKnown {
-        return try await request("/.well-known/matrix/client", withAuthorization: false, forType: MatrixWellKnown.self)
+        return try await MatrixWellKnownRequest().repsonse(on: homeserver, with: (), withUrlSession: urlSession)
     }
     
     /// Gets the homeserver's supported login types to authenticate users. Clients should pick one of these and supply it as the type when logging in.