Sub2API v1.0 - AI API 网关（二开初始版本，基于上游 Wei-Shaw/sub2api）

backend/internal/service/http_upstream_profile.go

@@ -0,0 +1,56 @@
+package service
+
+import "context"
+
+// HTTPUpstreamProfile marks HTTP upstream requests that need provider-specific
+// transport policy.
+type HTTPUpstreamProfile string
+
+const (
+	HTTPUpstreamProfileDefault HTTPUpstreamProfile = ""
+	HTTPUpstreamProfileOpenAI  HTTPUpstreamProfile = "openai"
+)
+
+type httpUpstreamProfileContextKey struct{}
+type httpUpstreamDisableRedirectsContextKey struct{}
+
+// WithHTTPUpstreamProfile injects an upstream transport profile into ctx.
+func WithHTTPUpstreamProfile(ctx context.Context, profile HTTPUpstreamProfile) context.Context {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	if profile == HTTPUpstreamProfileDefault {
+		return ctx
+	}
+	return context.WithValue(ctx, httpUpstreamProfileContextKey{}, profile)
+}
+
+// HTTPUpstreamProfileFromContext resolves the upstream transport profile from ctx.
+func HTTPUpstreamProfileFromContext(ctx context.Context) HTTPUpstreamProfile {
+	if ctx == nil {
+		return HTTPUpstreamProfileDefault
+	}
+	profile, ok := ctx.Value(httpUpstreamProfileContextKey{}).(HTTPUpstreamProfile)
+	if !ok {
+		return HTTPUpstreamProfileDefault
+	}
+	switch profile {
+	case HTTPUpstreamProfileOpenAI:
+		return profile
+	default:
+		return HTTPUpstreamProfileDefault
+	}
+}
+
+// WithHTTPUpstreamRedirectsDisabled prevents credential-bearing probes from
+// following redirects through the shared upstream client.
+func WithHTTPUpstreamRedirectsDisabled(ctx context.Context) context.Context {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	return context.WithValue(ctx, httpUpstreamDisableRedirectsContextKey{}, true)
+}
+
+func HTTPUpstreamRedirectsDisabled(ctx context.Context) bool {
+	return ctx != nil && ctx.Value(httpUpstreamDisableRedirectsContextKey{}) == true
+}