add swift api client with model types, json decoding

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

clients/macos/MagnumOpus/Services/APIClient.swift

@@ -0,0 +1,82 @@
+import Foundation
+
+struct ThreadSummary: Codable, Identifiable {
+	let threadId: String
+	let subject: String
+	let authors: String
+	let totalMessages: Int
+	let tags: String
+	let timestamp: Int
+	let accountId: String
+
+	var id: String { threadId }
+
+	var tagList: [String] {
+		tags.split(separator: ",").map(String.init)
+	}
+
+	var isUnread: Bool {
+		tagList.contains("unread")
+	}
+
+	var date: Date {
+		Date(timeIntervalSince1970: TimeInterval(timestamp))
+	}
+}
+
+struct EmailMessage: Codable, Identifiable {
+	let messageId: String
+	let threadId: String
+	let fromHeader: String
+	let toHeader: String
+	let subject: String
+	let date: String
+	let inReplyTo: String
+	let body: String
+	let tags: String
+	let timestamp: Int
+	let accountId: String
+
+	var id: String { messageId }
+
+	var senderName: String {
+		if let range = fromHeader.range(of: " <") {
+			return String(fromHeader[..<range.lowerBound])
+		}
+		return fromHeader
+	}
+}
+
+struct ThreadListResponse: Codable {
+	let threads: [ThreadSummary]
+}
+
+struct MessageListResponse: Codable {
+	let messages: [EmailMessage]
+}
+
+@Observable
+final class APIClient {
+	private let baseURL: URL
+
+	init(baseURL: URL) {
+		self.baseURL = baseURL
+	}
+
+	func fetchThreads(accountId: String) async throws -> [ThreadSummary] {
+		var components = URLComponents(
+			url: baseURL.appendingPathComponent("api/threads"),
+			resolvingAgainstBaseURL: false
+		)!
+		components.queryItems = [URLQueryItem(name: "accountId", value: accountId)]
+
+		let (data, _) = try await URLSession.shared.data(from: components.url!)
+		return try JSONDecoder().decode(ThreadListResponse.self, from: data).threads
+	}
+
+	func fetchMessages(threadId: String) async throws -> [EmailMessage] {
+		let url = baseURL.appendingPathComponent("api/threads/\(threadId)/messages")
+		let (data, _) = try await URLSession.shared.data(from: url)
+		return try JSONDecoder().decode(MessageListResponse.self, from: data).messages
+	}
+}

clients/macos/MagnumOpusTests/APIClientTests.swift

@@ -0,0 +1,55 @@
+import Testing
+@testable import MagnumOpus
+
+@Suite("APIClient")
+struct APIClientTests {
+	@Test("decodes thread list from JSON")
+	func decodesThreadList() throws {
+		let json = """
+		{
+			"threads": [
+				{
+					"threadId": "t001",
+					"subject": "Q1 Planning",
+					"authors": "Alice, Bob",
+					"totalMessages": 3,
+					"tags": "inbox,unread",
+					"timestamp": 1709884532,
+					"accountId": "personal"
+				}
+			]
+		}
+		""".data(using: .utf8)!
+
+		let response = try JSONDecoder().decode(ThreadListResponse.self, from: json)
+		#expect(response.threads.count == 1)
+		#expect(response.threads[0].subject == "Q1 Planning")
+	}
+
+	@Test("decodes message list from JSON")
+	func decodesMessageList() throws {
+		let json = """
+		{
+			"messages": [
+				{
+					"messageId": "msg001@example.com",
+					"threadId": "t001",
+					"fromHeader": "Alice <alice@example.com>",
+					"toHeader": "user@example.com",
+					"subject": "Q1 Planning",
+					"date": "2024-03-08T10:15:32+01:00",
+					"inReplyTo": "",
+					"body": "Hey, let's plan Q1.",
+					"tags": "inbox,unread",
+					"timestamp": 1709884532,
+					"accountId": "personal"
+				}
+			]
+		}
+		""".data(using: .utf8)!
+
+		let response = try JSONDecoder().decode(MessageListResponse.self, from: json)
+		#expect(response.messages.count == 1)
+		#expect(response.messages[0].body == "Hey, let's plan Q1.")
+	}
+}