refactor: use new protoc plugin for api v2 (#5798)

* refactor: use new protoc plugin for api v2

* simplify code

internal/protoc/protoc-gen-zitadel/main.go

@@ -0,0 +1,147 @@
+package main
+
+import (
+	"bytes"
+	_ "embed"
+	"fmt"
+	"io"
+	"os"
+	"text/template"
+
+	"google.golang.org/protobuf/compiler/protogen"
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/types/descriptorpb"
+	"google.golang.org/protobuf/types/pluginpb"
+
+	protoc_gen_zitadel "github.com/zitadel/zitadel/pkg/grpc/protoc/v2"
+)
+
+var (
+	//go:embed zitadel.pb.go.tmpl
+	zitadelTemplate []byte
+)
+
+type authMethods struct {
+	GoPackageName       string
+	ProtoPackageName    string
+	ServiceName         string
+	AuthOptions         []authOption
+	AuthContext         []authContext
+	CustomHTTPResponses []httpResponse
+}
+
+type authOption struct {
+	Name           string
+	Permission     string
+	CheckFieldName string
+}
+
+type authContext struct {
+	Name      string
+	OrgMethod string
+}
+
+type httpResponse struct {
+	Name string
+	Code int32
+}
+
+func main() {
+	input, _ := io.ReadAll(os.Stdin)
+	var req pluginpb.CodeGeneratorRequest
+	err := proto.Unmarshal(input, &req)
+	if err != nil {
+		panic(err)
+	}
+
+	opts := protogen.Options{}
+	plugin, err := opts.New(&req)
+	if err != nil {
+		panic(err)
+	}
+	plugin.SupportedFeatures = uint64(pluginpb.CodeGeneratorResponse_FEATURE_PROTO3_OPTIONAL)
+
+	tmpl := loadTemplate(zitadelTemplate)
+
+	for _, file := range plugin.Files {
+		methods := new(authMethods)
+		for _, service := range file.Services {
+			methods.ServiceName = service.GoName
+			methods.GoPackageName = string(file.GoPackageName)
+			methods.ProtoPackageName = *file.Proto.Package
+			for _, method := range service.Methods {
+				options := method.Desc.Options().(*descriptorpb.MethodOptions)
+				if options == nil {
+					continue
+				}
+				ext := proto.GetExtension(options, protoc_gen_zitadel.E_Options).(*protoc_gen_zitadel.Options)
+				if ext == nil {
+					continue
+				}
+				if ext.AuthOption != nil {
+					generateAuthOption(methods, ext.AuthOption, method)
+				}
+				if ext.HttpResponse != nil {
+					methods.CustomHTTPResponses = append(methods.CustomHTTPResponses, httpResponse{Name: string(method.Output.Desc.Name()), Code: ext.HttpResponse.SuccessCode})
+				}
+			}
+		}
+		if len(methods.AuthOptions) > 0 {
+			generateFile(tmpl, methods, file, plugin)
+		}
+	}
+
+	// Generate a response from our plugin and marshall as protobuf
+	stdout := plugin.Response()
+	out, err := proto.Marshal(stdout)
+	if err != nil {
+		panic(err)
+	}
+
+	// Write the response to stdout, to be picked up by protoc
+	_, err = fmt.Fprint(os.Stdout, string(out))
+	if err != nil {
+		panic(err)
+	}
+}
+
+func generateAuthOption(methods *authMethods, protoAuthOption *protoc_gen_zitadel.AuthOption, method *protogen.Method) {
+	methods.AuthOptions = append(methods.AuthOptions, authOption{Name: string(method.Desc.Name()), Permission: protoAuthOption.Permission})
+	if protoAuthOption.OrgField == "" {
+		return
+	}
+	orgMethod := buildAuthContextField(method.Input.Fields, protoAuthOption.OrgField)
+	if orgMethod != "" {
+		methods.AuthContext = append(methods.AuthContext, authContext{Name: string(method.Input.Desc.Name()), OrgMethod: orgMethod})
+	}
+}
+
+func generateFile(tmpl *template.Template, methods *authMethods, protoFile *protogen.File, plugin *protogen.Plugin) {
+	var buffer bytes.Buffer
+	err := tmpl.Execute(&buffer, &methods)
+	if err != nil {
+		panic(err)
+	}
+
+	filename := protoFile.GeneratedFilenamePrefix + ".pb.zitadel.go"
+	file := plugin.NewGeneratedFile(filename, ".")
+
+	_, err = file.Write(buffer.Bytes())
+	if err != nil {
+		panic(err)
+	}
+}
+
+func loadTemplate(templateData []byte) *template.Template {
+	return template.Must(template.New("").
+		Parse(string(templateData)))
+}
+
+func buildAuthContextField(fields []*protogen.Field, fieldName string) string {
+	for _, field := range fields {
+		if string(field.Desc.Name()) == fieldName {
+			return ".Get" + field.GoName + "()"
+		}
+	}
+	return ""
+}

internal/protoc/protoc-gen-zitadel/zitadel.pb.go.tmpl

@@ -0,0 +1,29 @@
+// Code generated by protoc-gen-zitadel. DO NOT EDIT.
+
+package {{.GoPackageName}}
+
+import (
+	"github.com/zitadel/zitadel/internal/api/authz"
+    {{if .AuthContext}}"github.com/zitadel/zitadel/pkg/grpc/object/v2alpha"{{end}}
+)
+
+var {{.ServiceName}}_AuthMethods = authz.MethodMapping {
+    {{ range $m := .AuthOptions}}
+        {{$.ServiceName}}_{{$m.Name}}_FullMethodName: authz.Option{
+            Permission: "{{$m.Permission}}",
+            CheckParam: "{{$m.CheckFieldName}}",
+        },
+    {{ end}}
+}
+
+{{ range $m := .AuthContext}}
+func (r *{{ $m.Name }}) OrganisationFromRequest() *object.Organisation {
+    return r{{$m.OrgMethod}}
+}
+{{ end }}
+
+{{ range $resp := .CustomHTTPResponses}}
+func (r *{{ $resp.Name }}) CustomHTTPCode() int {
+    return {{$resp.Code}}
+}
+{{ end }}