Register eagle0:// URL scheme on Windows for OAuth deep links (#5609)

* Register eagle0:// URL scheme on Windows for OAuth deep links

The Windows installer now registers the eagle0:// URL scheme in the
registry (HKEY_CURRENT_USER\Software\Classes\eagle0) pointing to the
game executable. This allows OAuth callbacks to redirect back to the
app automatically.

Also updated OAuthManager to check command line arguments for deep
links since Windows passes URL scheme launches as command line args.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Add golang.org/x/sys dependency for Windows registry access

The Windows installer uses golang.org/x/sys/windows/registry to register
the eagle0:// URL scheme. This adds the required dependency to go.mod,
go.sum, and MODULE.bazel.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

MODULE.bazel

@@ -122,6 +122,7 @@ use_repo(
     "com_github_webview_webview_go",
     "org_golang_google_grpc",
     "org_golang_google_protobuf",
+    "org_golang_x_sys",
 )
 
 #

go.mod

@@ -12,6 +12,7 @@ require (
 	github.com/golang-jwt/jwt/v5 v5.2.1
 	github.com/google/uuid v1.6.0
 	github.com/webview/webview_go v0.0.0-20240831120633-6173450d4dd6
+	golang.org/x/sys v0.28.0
 	google.golang.org/grpc v1.68.0
 	google.golang.org/protobuf v1.36.3
 )

go.sum

@@ -43,6 +43,8 @@ github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/webview/webview_go v0.0.0-20240831120633-6173450d4dd6 h1:VQpB2SpK88C6B5lPHTuSZKb2Qee1QWwiFlC5CKY4AW0=
 github.com/webview/webview_go v0.0.0-20240831120633-6173450d4dd6/go.mod h1:yE65LFCeWf4kyWD5re+h4XNvOHJEXOCOuJZ4v8l5sgk=
+golang.org/x/sys v0.28.0 h1:Fksou7UEQUWlKvIdsqzJmUmCX3cZuD2+P3XyyzwMhlA=
+golang.org/x/sys v0.28.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/text v0.25.0 h1:qVyWApTSYLk/drJRO5mDlNYskwQznZmkpV2c8q9zls4=
 golang.org/x/text v0.25.0/go.mod h1:WEdwpYrmk1qmdHvhkSTNPm3app7v4rsT8F2UD6+VHIA=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

src/main/csharp/net/eagle0/clients/unity/eagle0/Assets/Auth/OAuthManager.cs

@@ -53,6 +53,21 @@ namespace Auth {
             if (!string.IsNullOrEmpty(Application.absoluteURL)) {
                 OnDeepLinkActivated(Application.absoluteURL);
             }
+
+            // On Windows, URL scheme launches pass the URL as a command line argument
+            CheckCommandLineForDeepLink();
+        }
+
+        private void CheckCommandLineForDeepLink() {
+            var args = System.Environment.GetCommandLineArgs();
+            // Args[0] is the executable path, check remaining args for eagle0:// URLs
+            for (int i = 1; i < args.Length; i++) {
+                if (args[i].StartsWith("eagle0://")) {
+                    Debug.Log($"[OAuthManager] Found deep link in command line: {args[i]}");
+                    OnDeepLinkActivated(args[i]);
+                    break;
+                }
+            }
         }
 
         private void OnDeepLinkActivated(string url) {

src/main/go/net/eagle0/clients/win/installer/BUILD.bazel

@@ -11,12 +11,15 @@ go_library(
         "ui_webview_stub.go",
         "ui_webview_windows.go",
         "updater.go",
+        "urlscheme_stub.go",
+        "urlscheme_windows.go",
     ],
     importpath = "github.com/nolen777/eagle0/src/main/go/net/eagle0/clients/win/installer",
     visibility = ["//visibility:private"],
     deps = select({
         "@io_bazel_rules_go//go/platform:windows": [
             "@com_github_webview_webview_go//:webview_go",
+            "@org_golang_x_sys//windows/registry",
         ],
         "//conditions:default": [],
     }),
@@ -50,6 +53,7 @@ genrule(
         "ui_interface.go",
         "ui_webview_windows.go",
         "updater.go",
+        "urlscheme_windows.go",
         "resource_windows_amd64.syso",
         "@llvm_mingw//:all_files",
         "@go_default_sdk//:files",
@@ -130,12 +134,17 @@ module github.com/nolen777/eagle0/src/main/go/net/eagle0/clients/win/installer
 
 go 1.23
 
-require github.com/webview/webview_go v0.0.0-20240831120633-6173450d4dd6
+require (
+	github.com/webview/webview_go v0.0.0-20240831120633-6173450d4dd6
+	golang.org/x/sys v0.28.0
+)
 GOMOD
 
         cat > go.sum << 'GOSUM'
 github.com/webview/webview_go v0.0.0-20240831120633-6173450d4dd6 h1:VQpB2SpK88C6B5lPHTuSZKb2Qee1QWwiFlC5CKY4AW0=
 github.com/webview/webview_go v0.0.0-20240831120633-6173450d4dd6/go.mod h1:yE65LFCeWf4kyWD5re+h4XNvOHJEXOCOuJZ4v8l5sgk=
+golang.org/x/sys v0.28.0 h1:Fksou7UEQUWlKvIdsqzJmUmCX3cZuD2+P3XyyzwMhlA=
+golang.org/x/sys v0.28.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 GOSUM
 
         # Copy source files from Bazel sandbox (exclude Go SDK and llvm files)

src/main/go/net/eagle0/clients/win/installer/main.go

@@ -154,6 +154,12 @@ func runInstallerLogic(invitationCode string) error {
 			saveInvitationCode(invitationCode)
 		}
 
+		// Register eagle0:// URL scheme for OAuth deep links
+		if err := RegisterURLScheme(exeLocation); err != nil {
+			ui.ShowWarning(fmt.Sprintf("Failed to register URL scheme: %v", err))
+			// Continue anyway - URL scheme is nice to have but not critical
+		}
+
 		ui.UpdateStatus("Launching Eagle0...")
 		cmd := exec.Command(exeLocation)
 		if err := cmd.Start(); err != nil {

src/main/go/net/eagle0/clients/win/installer/urlscheme_stub.go

@@ -0,0 +1,8 @@
+//go:build !windows
+
+package main
+
+// RegisterURLScheme is a no-op on non-Windows platforms
+func RegisterURLScheme(exePath string) error {
+	return nil
+}

src/main/go/net/eagle0/clients/win/installer/urlscheme_windows.go

@@ -0,0 +1,60 @@
+//go:build windows
+
+package main
+
+import (
+	"fmt"
+
+	"golang.org/x/sys/windows/registry"
+)
+
+const urlScheme = "eagle0"
+
+// RegisterURLScheme registers the eagle0:// URL scheme in the Windows registry.
+// This allows the browser to open the Eagle0 app when navigating to eagle0:// URLs.
+// The URL scheme points to the game executable, which will handle the deep link.
+func RegisterURLScheme(exePath string) error {
+	// Create the URL scheme key under HKEY_CURRENT_USER (doesn't require admin)
+	// Structure:
+	// HKEY_CURRENT_USER\Software\Classes\eagle0
+	//   (Default) = "URL:Eagle0 Protocol"
+	//   URL Protocol = ""
+	//   shell\open\command
+	//     (Default) = "\"C:\path\to\eagle0.exe\" \"%1\""
+
+	keyPath := `Software\Classes\` + urlScheme
+
+	// Create or open the main key
+	key, _, err := registry.CreateKey(registry.CURRENT_USER, keyPath, registry.ALL_ACCESS)
+	if err != nil {
+		return fmt.Errorf("failed to create registry key %s: %w", keyPath, err)
+	}
+	defer key.Close()
+
+	// Set the default value (description)
+	if err := key.SetStringValue("", "URL:Eagle0 Protocol"); err != nil {
+		return fmt.Errorf("failed to set default value: %w", err)
+	}
+
+	// Set URL Protocol (empty string indicates this is a URL protocol handler)
+	if err := key.SetStringValue("URL Protocol", ""); err != nil {
+		return fmt.Errorf("failed to set URL Protocol: %w", err)
+	}
+
+	// Create shell\open\command subkey
+	cmdKeyPath := keyPath + `\shell\open\command`
+	cmdKey, _, err := registry.CreateKey(registry.CURRENT_USER, cmdKeyPath, registry.ALL_ACCESS)
+	if err != nil {
+		return fmt.Errorf("failed to create registry key %s: %w", cmdKeyPath, err)
+	}
+	defer cmdKey.Close()
+
+	// Set the command to launch the game with the URL as argument
+	// The %1 will be replaced with the full URL (e.g., eagle0://auth/complete)
+	command := fmt.Sprintf(`"%s" "%%1"`, exePath)
+	if err := cmdKey.SetStringValue("", command); err != nil {
+		return fmt.Errorf("failed to set command: %w", err)
+	}
+
+	return nil
+}