Add a separate tools command for building nightly and remove the old fastlane one.

Tools/Sources/Commands/CI/CI.swift

@@ -6,7 +6,8 @@ struct CI: ParsableCommand {
     static let configuration = CommandConfiguration(abstract: "CI workflow commands that can be run both locally and in CI environments.",
                                                     subcommands: [
                                                         UnitTests.self,
-                                                        RunTests.self
+                                                        RunTests.self,
+                                                        ConfigureNightly.self
                                                     ])
     
     static let testOutputDirectory = "test_output"

Tools/Sources/Commands/CI/ConfigureNightly.swift

@@ -0,0 +1,63 @@
+import ArgumentParser
+import CommandLineTools
+import Foundation
+import Yams
+
+struct ConfigureNightly: AsyncParsableCommand {
+    static let configuration = CommandConfiguration(abstract: "Configures the project for a Nightly build.",
+                                                    discussion: "Adds the Nightly variant to project.yml, updates secrets, runs xcodegen, and generates the app icon banner.")
+
+    @Option(help: "The build number to display on the app icon banner.")
+    var buildNumber: String
+
+    func run() async throws {
+        guard !buildNumber.isEmpty else {
+            throw ValidationError("Invalid build number.")
+        }
+
+        try addNightlyVariant()
+        
+        try Zsh.run(command: "swift run pipeline update-foss-secrets")
+        try Zsh.run(command: "xcodegen")
+
+        let releaseVersion = try readMarketingVersion()
+        try await generateAppIconBanner(version: releaseVersion, buildNumber: buildNumber)
+    }
+
+    /// Adds the Nightly variant include path to `project.yml` if it isn't already present.
+    private func addNightlyVariant() throws {
+        let projectURL = URL.projectDirectory.appending(component: "project.yml")
+        let projectString = try String(contentsOf: projectURL)
+        guard var projectConfig = try Yams.compose(yaml: projectString) else {
+            throw ValidationError("Failed to parse project.yml.")
+        }
+        
+        // Check if the nightly variant is already included
+        if projectConfig["include"]?.sequence?.contains(where: { $0.mapping?["path"] == "Variants/Nightly/nightly.yml" }) == false {
+            projectConfig["include"]?.sequence?.append(["path": "Variants/Nightly/nightly.yml"])
+        }
+
+        let updatedYAMLString = try Yams.serialize(node: projectConfig)
+        try updatedYAMLString.write(to: projectURL, atomically: true, encoding: .utf8)
+    }
+
+    /// Reads the MARKETING_VERSION from `project.yml`.
+    private func readMarketingVersion() throws -> String {
+        let projectURL = URL.projectDirectory.appending(component: "project.yml")
+        let projectString = try String(contentsOf: projectURL)
+
+        let marketingVersionRegex = /MARKETING_VERSION:\s*([^\s]+)/
+        guard let match = projectString.firstMatch(of: marketingVersionRegex) else {
+            throw ValidationError("Could not find MARKETING_VERSION in project.yml.")
+        }
+
+        return String(match.1)
+    }
+
+    /// Generates the app icon banner with version and build number.
+    private func generateAppIconBanner(version: String, buildNumber: String) async throws {
+        let bannerText = "\(version) (\(buildNumber))"
+        let iconPath = "Variants/Nightly/Resources/NightlyAppIcon.icon/Assets/Version.png"
+        try await AppIconBanner.parse([iconPath, "--banner-text", bannerText]).run()
+    }
+}