refactor api server around rpc services

pkg/rpc/registry.go

@@ -0,0 +1,56 @@
+package rpc
+
+import (
+	"context"
+	"encoding/json"
+	"strings"
+)
+
+type MethodHandler func(context.Context, json.RawMessage) (interface{}, *Error)
+
+type Registry struct {
+	methods map[string]MethodHandler
+}
+
+func NewRegistry() *Registry {
+	return &Registry{methods: map[string]MethodHandler{}}
+}
+
+func (r *Registry) Register(method string, handler MethodHandler) {
+	if r == nil || handler == nil {
+		return
+	}
+	method = strings.ToLower(strings.TrimSpace(method))
+	if method == "" {
+		return
+	}
+	r.methods[method] = handler
+}
+
+func (r *Registry) Handle(ctx context.Context, req Request) (interface{}, *Error) {
+	if r == nil {
+		return nil, &Error{Code: "internal", Message: "rpc registry unavailable"}
+	}
+	handler := r.methods[req.NormalizedMethod()]
+	if handler == nil {
+		return nil, &Error{
+			Code:    "invalid_argument",
+			Message: "unknown method",
+			Details: map[string]interface{}{"method": strings.TrimSpace(req.Method)},
+		}
+	}
+	return handler(ctx, req.Params)
+}
+
+func RegisterJSON[T any](r *Registry, method string, handler func(context.Context, T) (interface{}, *Error)) {
+	if r == nil || handler == nil {
+		return
+	}
+	r.Register(method, func(ctx context.Context, raw json.RawMessage) (interface{}, *Error) {
+		var params T
+		if err := DecodeParams(raw, &params); err != nil {
+			return nil, &Error{Code: "invalid_argument", Message: err.Error()}
+		}
+		return handler(ctx, params)
+	})
+}