From 1e42792d2adf919e57a657aaf1031ba0c8ac5f1b Mon Sep 17 00:00:00 2001
From: Sam Deane <sam@elegantchaos.com>
Date: Fri, 6 Dec 2024 10:47:01 +0000
Subject: [PATCH] experimenting with @Signal macro

---
 Sources/SwiftGodot/MacroDefs.swift            |  4 +
 .../SwiftGodotMacroLibrary/MacroGodot.swift   |  1 +
 .../NuSignalMacro.swift                       | 91 +++++++++++++++++++
 Tests/SwiftGodotTests/SignalTests.swift       | 16 +++-
 4 files changed, 111 insertions(+), 1 deletion(-)

diff --git a/Sources/SwiftGodot/MacroDefs.swift b/Sources/SwiftGodot/MacroDefs.swift
index 7d80e0637..11d7f273b 100644
--- a/Sources/SwiftGodot/MacroDefs.swift
+++ b/Sources/SwiftGodot/MacroDefs.swift
@@ -248,4 +248,8 @@ public macro signal(_ signalName: String, arguments: Dictionary<String, Any.Type
 @freestanding(declaration, names: arbitrary)
 public macro nusignal(_ signalName: String, arguments: [String: Any.Type] = [:]) = #externalMacro(module: "SwiftGodotMacroLibrary", type: "NuSignalMacro")
 
+@attached(accessor)
+public macro Signal() = #externalMacro(module: "SwiftGodotMacroLibrary", type: "NuSignalMacro2")
+
+
 #endif
diff --git a/Sources/SwiftGodotMacroLibrary/MacroGodot.swift b/Sources/SwiftGodotMacroLibrary/MacroGodot.swift
index 12769a755..8ec031107 100644
--- a/Sources/SwiftGodotMacroLibrary/MacroGodot.swift
+++ b/Sources/SwiftGodotMacroLibrary/MacroGodot.swift
@@ -647,6 +647,7 @@ struct godotMacrosPlugin: CompilerPlugin {
         Texture2DLiteralMacro.self,
         SignalMacro.self,
         NuSignalMacro.self,
+        NuSignalMacro2.self,
     ]
 }
 
diff --git a/Sources/SwiftGodotMacroLibrary/NuSignalMacro.swift b/Sources/SwiftGodotMacroLibrary/NuSignalMacro.swift
index 3d61e6878..8aad16b38 100644
--- a/Sources/SwiftGodotMacroLibrary/NuSignalMacro.swift
+++ b/Sources/SwiftGodotMacroLibrary/NuSignalMacro.swift
@@ -90,3 +90,94 @@ public struct NuSignalMacro: DeclarationMacro {
     }
 
 }
+
+
+public struct NuSignalMacro2: AccessorMacro {
+    
+    enum ProviderDiagnostic: Error, DiagnosticMessage {
+        case invalidDeclaration
+        case missingTypeAnnotation
+
+        var severity: DiagnosticSeverity { .error }
+        
+        var message: String {
+            switch self {
+                case .invalidDeclaration:
+                    "Signal can only be applied to stored properties"
+                case .missingTypeAnnotation:
+                    "SceneTree requires an explicit type declaration"
+            }
+        }
+        
+        var diagnosticID: MessageID {
+            MessageID(domain: "SwiftGodotMacros", id: message)
+        }
+    }
+    
+    public static func expansion(of node: AttributeSyntax,
+                                 providingAccessorsOf declaration: some DeclSyntaxProtocol,
+                                 in context: some MacroExpansionContext) throws -> [AccessorDeclSyntax]
+    {
+        guard let varDecl = declaration.as(VariableDeclSyntax.self) else {
+            let invalidUsageErr = Diagnostic(node: node.root, message: ProviderDiagnostic.invalidDeclaration)
+            context.diagnose(invalidUsageErr)
+            return []
+        }
+
+        guard let signalType = varDecl.bindings.first?.typeAnnotation?.type else {
+            let missingAnnotationErr = Diagnostic(node: node.root, message: ProviderDiagnostic.missingTypeAnnotation)
+            context.diagnose(missingAnnotationErr)
+            return []
+        }
+
+        guard let nodeIdentifier = varDecl.bindings.first?.pattern.as(IdentifierPatternSyntax.self)?.identifier else {
+            fatalError("No identifier for this expression could be found.")
+        }
+
+        var signalName = SignalName(godotName: nodeIdentifier.text.camelCaseToSnakeCase(), swiftName: nodeIdentifier.text)
+        var arguments = [(name: String, type: String)]()
+        
+//        for (index, argument) in node.arguments {
+//            if index == 0 {
+//                signalName = argument.expression.signalName()
+//            }
+//            if index == 1 {
+//                if argument.expression.description == ".init()" {
+//                    // its an empty dictionary, so no arguments
+//                    continue
+//                }
+//                
+//                guard let dictSyntax = DictionaryExprSyntax(argument.expression) else {
+//                    throw ProviderDiagnostic.argumentsInUnexpectedSyntax
+//                }
+//                
+//                if case .colon = dictSyntax.content {
+//                    // its an empty dictionary, so no arguments
+//                    continue
+//                }
+//                
+//                guard let pairList = DictionaryElementListSyntax(dictSyntax.content) else {
+//                    throw ProviderDiagnostic.argumentsInUnexpectedSyntax
+//                }
+//                
+//                for pair in pairList {
+//                    guard let typeName = pair.value.typeName() else {
+//                        throw ProviderDiagnostic.argumentsInUnexpectedSyntax
+//                    }
+//                    arguments.append((pair.key.description, typeName))
+//                }
+//            }
+//        }
+        
+//        let genericTypeList = arguments.map { $0.type }.joined(separator: ", ")
+//        
+//        let signalWrapperType = arguments.isEmpty ? "GenericSignal< /* no args */ >" : "GenericSignal<\(genericTypeList)>"
+        
+        return [
+            """
+            get { \(raw: signalType)(target: self, signalName: \"\(raw: signalName.godotName)\") }
+            """
+        ]
+    }
+    
+}
diff --git a/Tests/SwiftGodotTests/SignalTests.swift b/Tests/SwiftGodotTests/SignalTests.swift
index 42d44167c..7cbf66371 100644
--- a/Tests/SwiftGodotTests/SignalTests.swift
+++ b/Tests/SwiftGodotTests/SignalTests.swift
@@ -6,6 +6,7 @@ import SwiftGodotTestability
 private class TestSignalNode: Node {
     #signal("mySignal", arguments: ["age": Int.self, "name": String.self])
     #nusignal("nuSignal", arguments: ["age": Int.self, "name": String.self])
+    @Signal var anotherSignal: GenericSignal< /* no args */ >
     var receivedInt: Int? = nil
     var receivedString: String? = nil
     
@@ -32,7 +33,7 @@ final class SignalTests: GodotTestCase {
     }
 
     func testNuSignal() {
-        let node = TestNode()
+        let node = TestSignalNode()
         var signalReceived = false
 
         node.nuSignal.connect { age, name in
@@ -44,6 +45,19 @@ final class SignalTests: GodotTestCase {
         XCTAssertTrue (signalReceived, "signal should have been received")
     }
 
+    func testNuSignal2() {
+        let node = TestSignalNode()
+        var signalReceived = false
+        
+        node.nuSignal.connect { age, name in
+            XCTAssertEqual (age, 22)
+            XCTAssertEqual (name, "Sam")
+            signalReceived = true
+        }
+        node.nuSignal.emit(22, "Sam")
+        XCTAssertTrue (signalReceived, "signal should have been received")
+    }
+
     func testBuiltInSignalWithNoArgument() {
         let node = Node()
         var signalReceived = false