From 0c89ed98e4bfc53e28d1752e63a33b670dfb0ce3 Mon Sep 17 00:00:00 2001
From: Terry Yiu <963907+tyiu@users.noreply.github.com>
Date: Sat, 5 Oct 2024 15:19:41 -0400
Subject: [PATCH] Add AuthenticationEvent.Builder to deprecate equivalent
 function in EventCreating (#183)

---
 .../NostrSDK/Events/AuthenticationEvent.swift | 31 +++++++++++++++----
 .../Events/AuthenticationEventTests.swift     | 14 +++++++++
 2 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/Sources/NostrSDK/Events/AuthenticationEvent.swift b/Sources/NostrSDK/Events/AuthenticationEvent.swift
index 964899c..3306ec2 100644
--- a/Sources/NostrSDK/Events/AuthenticationEvent.swift
+++ b/Sources/NostrSDK/Events/AuthenticationEvent.swift
@@ -52,14 +52,33 @@ public final class AuthenticationEvent: NostrEvent, RelayProviding {
 
 public extension EventCreating {
 
+    @available(*, deprecated, message: "Deprecated in favor of AuthenticationEvent.Builder.")
     func authenticate(relayURL: URL, challenge: String, signedBy keypair: Keypair) throws -> AuthenticationEvent {
-        let validatedRelayURL = try RelayURLValidator.shared.validateRelayURL(relayURL)
+        try AuthenticationEvent.Builder()
+            .relayURL(relayURL)
+            .challenge(challenge)
+            .build(signedBy: keypair)
+    }
+}
+
+public extension AuthenticationEvent {
+    /// Builder of a ``AuthenticationEvent``.
+    final class Builder: NostrEvent.Builder<AuthenticationEvent> {
+        public init() {
+            super.init(kind: .authentication)
+        }
 
-        let tags: [Tag] = [
-            Tag(name: "relay", value: validatedRelayURL.absoluteString),
-            Tag(name: "challenge", value: challenge)
-        ]
+        /// The relay URL this event authenticates to.
+        @discardableResult
+        public final func relayURL(_ relayURL: URL) throws -> Self {
+            let validatedRelayURL = try RelayURLValidator.shared.validateRelayURL(relayURL)
+            return appendTags(Tag(name: "relay", value: validatedRelayURL.absoluteString))
+        }
 
-        return try AuthenticationEvent(content: "", tags: tags, signedBy: keypair)
+        /// The challenge string as received from the relay.
+        @discardableResult
+        public final func challenge(_ challenge: String) throws -> Self {
+            appendTags(Tag(name: "challenge", value: challenge))
+        }
     }
 }
diff --git a/Tests/NostrSDKTests/Events/AuthenticationEventTests.swift b/Tests/NostrSDKTests/Events/AuthenticationEventTests.swift
index fc7116d..9195c35 100644
--- a/Tests/NostrSDKTests/Events/AuthenticationEventTests.swift
+++ b/Tests/NostrSDKTests/Events/AuthenticationEventTests.swift
@@ -11,6 +11,20 @@ import XCTest
 final class AuthenticationEventTests: XCTestCase, EventCreating, EventVerifying, FixtureLoading {
 
     func testCreateAuthenticationEvent() throws {
+        let relayURL = try XCTUnwrap(URL(string: "wss://relay.example.com/"))
+        let event = try AuthenticationEvent.Builder()
+            .relayURL(relayURL)
+            .challenge("some-challenge-string")
+            .build(signedBy: Keypair.test)
+
+        XCTAssertEqual(event.kind, .authentication)
+        XCTAssertEqual(event.relayURL, relayURL)
+        XCTAssertEqual(event.challenge, "some-challenge-string")
+
+        try verifyEvent(event)
+    }
+
+    func testCreateAuthenticationEventDeprecated() throws {
         let relayURL = try XCTUnwrap(URL(string: "wss://relay.example.com/"))
         let event = try authenticate(relayURL: relayURL, challenge: "some-challenge-string", signedBy: Keypair.test)