Add router export and type schema generation; add Codec.Name()

pkg/codec/codec.go

@@ -7,6 +7,9 @@ import "net/http"
 // response data. This allows for different data formats (e.g., JSON, Protocol Buffers).
 // The framework includes implementations for JSON and Protocol Buffers in the codec package.
 type Codec[T any, U any] interface {
+	// Name returns codec identifier for metadata export ("json", "proto", ...).
+	Name() string
+
 	// NewRequest creates a new zero-value instance of the request type T.
 	// This is used by the framework to get an instance for decoding, avoiding reflection.
 	NewRequest() T

pkg/codec/json.go

@@ -14,6 +14,11 @@ type JSONCodec[T any, U any] struct {
 	// For example, custom field naming strategies, etc.
 }
 
+// Name returns codec identifier.
+func (c *JSONCodec[T, U]) Name() string {
+	return "json"
+}
+
 // NewRequest creates a new zero-value instance of the request type T.
 // This method is required by the Codec interface and is used internally
 // by the framework to get an instance for decoding without using reflection.

pkg/codec/proto.go

@@ -15,6 +15,11 @@ type ProtoCodec[T proto.Message, U proto.Message] struct {
 	newRequest func() T
 }
 
+// Name returns codec identifier.
+func (c *ProtoCodec[T, U]) Name() string {
+	return "proto"
+}
+
 // NewProtoCodec creates a new ProtoCodec instance for protobuf request/response types.
 // It infers the underlying message type from T and allocates fresh zero-value messages
 // without reflection by using Go's new(expr) support.

pkg/router/cors_test.go

@@ -24,6 +24,10 @@ type genericCORSTestResponse struct {
 // genericCORSTestCodec implements the Codec interface for testing generic routes with CORS.
 type genericCORSTestCodec struct{}
 
+func (c *genericCORSTestCodec) Name() string {
+	return "json"
+}
+
 func (c *genericCORSTestCodec) NewRequest() genericCORSTestRequest {
 	return genericCORSTestRequest{}
 }

pkg/router/export.go

@@ -0,0 +1,238 @@
+package router
+
+import (
+	"encoding/json"
+	"io"
+	"os"
+	"time"
+
+	"github.com/Suhaibinator/SRouter/pkg/common"
+)
+
+const exportSpecVersion = "1.0"
+
+// ExportSpec describes the exported router metadata document.
+type ExportSpec struct {
+	Version    string          `json:"version" yaml:"version"`
+	ExportedAt string          `json:"exportedAt" yaml:"exportedAt"`
+	Service    ServiceMetadata `json:"service" yaml:"service"`
+	Routes     []RouteMetadata `json:"routes" yaml:"routes"`
+}
+
+// ServiceMetadata captures service-wide router configuration.
+type ServiceMetadata struct {
+	Name            string             `json:"name" yaml:"name"`
+	GlobalTimeout   string             `json:"globalTimeout,omitempty" yaml:"globalTimeout,omitempty"`
+	GlobalMaxBody   int64              `json:"globalMaxBodySize,omitempty" yaml:"globalMaxBodySize,omitempty"`
+	GlobalRateLimit *RateLimitMetadata `json:"globalRateLimit,omitempty" yaml:"globalRateLimit,omitempty"`
+	CORS            *CORSMetadata      `json:"cors,omitempty" yaml:"cors,omitempty"`
+	TraceIDEnabled  bool               `json:"traceIdEnabled" yaml:"traceIdEnabled"`
+}
+
+// CORSMetadata captures CORS settings.
+type CORSMetadata struct {
+	Origins          []string `json:"origins" yaml:"origins"`
+	Methods          []string `json:"methods" yaml:"methods"`
+	Headers          []string `json:"headers" yaml:"headers"`
+	ExposeHeaders    []string `json:"exposeHeaders,omitempty" yaml:"exposeHeaders,omitempty"`
+	AllowCredentials bool     `json:"allowCredentials" yaml:"allowCredentials"`
+	MaxAge           string   `json:"maxAge,omitempty" yaml:"maxAge,omitempty"`
+}
+
+// RouteMetadata describes a registered route.
+type RouteMetadata struct {
+	Path           string             `json:"path" yaml:"path"`
+	Methods        []string           `json:"methods" yaml:"methods"`
+	AuthLevel      string             `json:"authLevel" yaml:"authLevel"`
+	Request        *RequestSchema     `json:"request,omitempty" yaml:"request,omitempty"`
+	Response       *TypeSchema        `json:"response,omitempty" yaml:"response,omitempty"`
+	Timeout        string             `json:"timeout,omitempty" yaml:"timeout,omitempty"`
+	MaxBodySize    int64              `json:"maxBodySize,omitempty" yaml:"maxBodySize,omitempty"`
+	RateLimit      *RateLimitMetadata `json:"rateLimit,omitempty" yaml:"rateLimit,omitempty"`
+	AuthToken      *AuthTokenMetadata `json:"authToken,omitempty" yaml:"authToken,omitempty"`
+	SubRouter      string             `json:"subRouter,omitempty" yaml:"subRouter,omitempty"`
+	DisableTimeout bool               `json:"disableTimeout,omitempty" yaml:"disableTimeout,omitempty"`
+}
+
+// RequestSchema describes generic route request extraction and shape.
+type RequestSchema struct {
+	Source       string      `json:"source" yaml:"source"`
+	SourceKey    string      `json:"sourceKey,omitempty" yaml:"sourceKey,omitempty"`
+	Codec        string      `json:"codec" yaml:"codec"`
+	Schema       *TypeSchema `json:"schema" yaml:"schema"`
+	HasSanitizer bool        `json:"hasSanitizer,omitempty" yaml:"hasSanitizer,omitempty"`
+}
+
+// TypeSchema describes a Go type tree.
+type TypeSchema struct {
+	TypeName string        `json:"typeName" yaml:"typeName"`
+	Package  string        `json:"package,omitempty" yaml:"package,omitempty"`
+	Kind     string        `json:"kind" yaml:"kind"`
+	Fields   []FieldSchema `json:"fields,omitempty" yaml:"fields,omitempty"`
+}
+
+// FieldSchema describes a reflected struct field.
+type FieldSchema struct {
+	Name     string      `json:"name" yaml:"name"`
+	JSONName string      `json:"jsonName,omitempty" yaml:"jsonName,omitempty"`
+	Type     string      `json:"type" yaml:"type"`
+	Required bool        `json:"required,omitempty" yaml:"required,omitempty"`
+	Schema   *TypeSchema `json:"schema,omitempty" yaml:"schema,omitempty"`
+}
+
+// RateLimitMetadata describes exported rate limiting config.
+type RateLimitMetadata struct {
+	BucketName string `json:"bucketName,omitempty" yaml:"bucketName,omitempty"`
+	Limit      int    `json:"limit" yaml:"limit"`
+	Window     string `json:"window" yaml:"window"`
+	Strategy   string `json:"strategy" yaml:"strategy"`
+}
+
+// AuthTokenMetadata describes auth token extraction settings.
+type AuthTokenMetadata struct {
+	Source     string `json:"source" yaml:"source"`
+	HeaderName string `json:"headerName,omitempty" yaml:"headerName,omitempty"`
+	CookieName string `json:"cookieName,omitempty" yaml:"cookieName,omitempty"`
+}
+
+// ExportSpec returns a snapshot export document for the router.
+func (r *Router[T, U]) ExportSpec() *ExportSpec {
+	service := ServiceMetadata{
+		Name:            r.config.ServiceName,
+		GlobalTimeout:   durationString(r.config.GlobalTimeout),
+		GlobalMaxBody:   r.config.GlobalMaxBodySize,
+		GlobalRateLimit: rateLimitMetadataFromConfig(r.config.GlobalRateLimit),
+		TraceIDEnabled:  r.config.TraceIDBufferSize > 0,
+	}
+	if r.config.CORSConfig != nil {
+		service.CORS = &CORSMetadata{
+			Origins:          append([]string(nil), r.config.CORSConfig.Origins...),
+			Methods:          append([]string(nil), r.config.CORSConfig.Methods...),
+			Headers:          append([]string(nil), r.config.CORSConfig.Headers...),
+			ExposeHeaders:    append([]string(nil), r.config.CORSConfig.ExposeHeaders...),
+			AllowCredentials: r.config.CORSConfig.AllowCredentials,
+			MaxAge:           durationString(r.config.CORSConfig.MaxAge),
+		}
+	}
+
+	r.metadataMu.RLock()
+	routes := append([]RouteMetadata(nil), r.routeMetadata...)
+	r.metadataMu.RUnlock()
+
+	return &ExportSpec{
+		Version:    exportSpecVersion,
+		ExportedAt: time.Now().UTC().Format(time.RFC3339),
+		Service:    service,
+		Routes:     routes,
+	}
+}
+
+// ExportJSON writes the spec as indented JSON.
+func (r *Router[T, U]) ExportJSON(w io.Writer) error {
+	enc := json.NewEncoder(w)
+	enc.SetIndent("", "  ")
+	return enc.Encode(r.ExportSpec())
+}
+
+// ExportJSONFile writes the spec to a file path as indented JSON.
+func (r *Router[T, U]) ExportJSONFile(path string) error {
+	f, err := os.Create(path)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	return r.ExportJSON(f)
+}
+
+func (r *Router[T, U]) appendRouteMetadata(metadata RouteMetadata) {
+	r.metadataMu.Lock()
+	r.routeMetadata = append(r.routeMetadata, metadata)
+	r.metadataMu.Unlock()
+}
+
+func durationString(d time.Duration) string {
+	if d <= 0 {
+		return ""
+	}
+	return d.String()
+}
+
+func authLevelString(level *AuthLevel) string {
+	if level == nil {
+		return "none"
+	}
+	switch *level {
+	case AuthRequired:
+		return "required"
+	case AuthOptional:
+		return "optional"
+	default:
+		return "none"
+	}
+}
+
+func sourceTypeString(source SourceType) string {
+	switch source {
+	case Body:
+		return "body"
+	case Base64QueryParameter:
+		return "base64_query"
+	case Base62QueryParameter:
+		return "base62_query"
+	case Base64PathParameter:
+		return "base64_path"
+	case Base62PathParameter:
+		return "base62_path"
+	case Empty:
+		return "empty"
+	default:
+		return "unknown"
+	}
+}
+
+func rateLimitStrategyString(strategy common.RateLimitStrategy) string {
+	switch strategy {
+	case common.StrategyUser:
+		return "user"
+	case common.StrategyCustom:
+		return "custom"
+	default:
+		return "ip"
+	}
+}
+
+func rateLimitMetadataFromConfig(config *common.RateLimitConfig[any, any]) *RateLimitMetadata {
+	if config == nil {
+		return nil
+	}
+	return &RateLimitMetadata{
+		BucketName: config.BucketName,
+		Limit:      config.Limit,
+		Window:     durationString(config.Window),
+		Strategy:   rateLimitStrategyString(config.Strategy),
+	}
+}
+
+func rateLimitMetadataFromRuntimeConfig[T comparable, U any](config *common.RateLimitConfig[T, U]) *RateLimitMetadata {
+	if config == nil {
+		return nil
+	}
+	return &RateLimitMetadata{
+		BucketName: config.BucketName,
+		Limit:      config.Limit,
+		Window:     durationString(config.Window),
+		Strategy:   rateLimitStrategyString(config.Strategy),
+	}
+}
+
+func authTokenMetadataFromConfig(config common.AuthTokenConfig) *AuthTokenMetadata {
+	source := "header"
+	if config.Source == common.AuthTokenSourceCookie {
+		source = "cookie"
+	}
+	return &AuthTokenMetadata{
+		Source:     source,
+		HeaderName: config.HeaderName,
+		CookieName: config.CookieName,
+	}
+}