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

backend/internal/service/openai_image_intent_hint.go

@@ -0,0 +1,59 @@
+package service
+
+import "github.com/gin-gonic/gin"
+
+// 请求级 hint 仅限 HTTP：缺失表示 unknown，false/true 都表示已完成 canonical 判定。
+const openAIImageIntentHintContextKey = "openai_image_intent_hint"
+
+type openAIImageIntentClassifier func(endpoint string, requestedModel string, body []byte) bool
+
+// SetOpenAIImageIntentHint 只写入请求级 canonical 判定，不记录 attempt-local 结果。
+func SetOpenAIImageIntentHint(c *gin.Context, imageIntent bool) {
+	if c == nil || GetOpenAIClientTransport(c) != OpenAIClientTransportHTTP {
+		return
+	}
+	c.Set(openAIImageIntentHintContextKey, imageIntent)
+}
+
+func getOpenAIImageIntentHint(c *gin.Context) (imageIntent bool, known bool) {
+	if c == nil || GetOpenAIClientTransport(c) != OpenAIClientTransportHTTP {
+		return false, false
+	}
+	value, ok := c.Get(openAIImageIntentHintContextKey)
+	if !ok {
+		return false, false
+	}
+	imageIntent, ok = value.(bool)
+	return imageIntent, ok
+}
+
+func resolveOpenAIImageIntentHint(
+	c *gin.Context,
+	requestedModel string,
+	canonicalBody []byte,
+	classify openAIImageIntentClassifier,
+) bool {
+	if imageIntent, known := getOpenAIImageIntentHint(c); known {
+		return imageIntent
+	}
+	imageIntent := classify(openAIResponsesEndpoint, requestedModel, canonicalBody)
+	SetOpenAIImageIntentHint(c, imageIntent)
+	return imageIntent
+}
+
+func resolveOpenAIPassthroughImageIntent(
+	c *gin.Context,
+	canonicalRequestedModel string,
+	canonicalBody []byte,
+	attemptRequestedModel string,
+	attemptBody []byte,
+	attemptInvalidated bool,
+	classify openAIImageIntentClassifier,
+) bool {
+	imageIntent := resolveOpenAIImageIntentHint(c, canonicalRequestedModel, canonicalBody, classify)
+	if attemptInvalidated {
+		// strip/compact 改写只重算当前 attempt，不得把变换后的结果写回请求级 canonical hint。
+		imageIntent = classify(openAIResponsesEndpoint, attemptRequestedModel, attemptBody)
+	}
+	return imageIntent
+}