Add --monorepo-config CLI mode for unified multi-package generation

Sources/swift-gtk-gen/Main.swift

@@ -17,6 +17,51 @@ struct SwiftGtkGenCLI {
             return
         }
 
+        if !args.monorepoConfigTOML.isEmpty {
+            guard FileManager.default.fileExists(atPath: args.monorepoConfigTOML) else {
+                print("Error: monorepo config file not found: \(args.monorepoConfigTOML)")
+                exit(1)
+            }
+            do {
+                let tomlContent = try String(contentsOfFile: args.monorepoConfigTOML, encoding: .utf8)
+                let toml = try TOMLReader.parse(tomlContent)
+                let monorepoConfig = try MonorepoConfig.from(toml: toml, defaultOutputDir: args.output)
+                let monorepoAnalyzer = MultiPackageAnalyzer(config: monorepoConfig)
+                let analysis = try monorepoAnalyzer.analyze()
+
+                let generator = CodeGenerator(config: GenerationConfig(
+                    library: "", version: "", girsDirectories: [],
+                    targetDirectory: "", externalLibraries: [],
+                    generate: [], manual: [], ignore: [], objects: []
+                ))
+                let outputs = try generator.generateMonorepo(analysis: analysis)
+
+                for (moduleName, sourceFiles) in outputs {
+                    let sourcesDir = URL(fileURLWithPath: monorepoConfig.outputDir)
+                        .appendingPathComponent("Sources/\(moduleName)/Generated")
+                    try FileManager.default.createDirectory(at: sourcesDir, withIntermediateDirectories: true)
+                    for (fileName, content) in sourceFiles.sorted(by: { $0.key < $1.key }) {
+                        let fileURL = sourcesDir.appendingPathComponent(fileName)
+                        try content.write(to: fileURL, atomically: true, encoding: .utf8)
+                        print("Generated \(fileURL.path)")
+                    }
+                }
+
+                let scaffolding = CodeGenerator.generateMonorepoScaffolding(analysis: analysis)
+                let outputRoot = URL(fileURLWithPath: monorepoConfig.outputDir)
+                for (relativePath, content) in scaffolding.sorted(by: { $0.key < $1.key }) {
+                    let fileURL = outputRoot.appendingPathComponent(relativePath)
+                    try FileManager.default.createDirectory(at: fileURL.deletingLastPathComponent(), withIntermediateDirectories: true)
+                    try content.write(to: fileURL, atomically: true, encoding: .utf8)
+                    print("Generated \(fileURL.path)")
+                }
+            } catch {
+                print("Error: \(error)")
+                exit(1)
+            }
+            return
+        }
+
         guard !args.girFile.isEmpty else {
             print("Error: --gir-file is required")
             exit(1)
@@ -133,6 +178,7 @@ struct SwiftGtkGenCLI {
         var generateAll: Bool = false
         var manual: [String] = []
         var ignore: [String] = []
+        var monorepoConfigTOML: String = ""
     }
 
     /// Parses command-line arguments.
@@ -191,6 +237,9 @@ struct SwiftGtkGenCLI {
             case "--ignore":
                 guard let val = nextArg(&args, for: flag) else { return CLIArgs(showHelp: true, girFile: "") }
                 cli.ignore = val.components(separatedBy: ",")
+            case "--monorepo-config":
+                guard let val = nextArg(&args, for: flag) else { return CLIArgs(showHelp: true, girFile: "") }
+                cli.monorepoConfigTOML = val
             default:
                 break
             }
@@ -292,6 +341,7 @@ struct SwiftGtkGenCLI {
         print("  --manual TYPES        Comma-separated types to mark manual")
         print("  --ignore TYPES        Comma-separated types to ignore")
         print("  --emit-single-file    Emit a single file instead of per-type files")
+        print("  --monorepo-config PATH  Generate a monorepo using this TOML config")
         print("  --help, -h            Show this help")
     }
 }