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

backend/internal/handler/gateway_key_billing.go

@@ -0,0 +1,108 @@
+package handler
+
+import (
+	"net/http"
+	"time"
+
+	"github.com/Wei-Shaw/sub2api/internal/config"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/timezone"
+	middleware2 "github.com/Wei-Shaw/sub2api/internal/server/middleware"
+	"github.com/Wei-Shaw/sub2api/internal/service"
+	"github.com/gin-gonic/gin"
+)
+
+const keyBillingInfoSchemaVersion = 1
+
+type keyBillingInfoResponse struct {
+	Object                  string    `json:"object"`
+	SchemaVersion           int       `json:"schema_version"`
+	BillingScope            string    `json:"billing_scope"`
+	GroupRateMultiplier     float64   `json:"group_rate_multiplier"`
+	UserRateMultiplier      *float64  `json:"user_rate_multiplier,omitempty"`
+	ResolvedRateMultiplier  float64   `json:"resolved_rate_multiplier"`
+	PeakRateEnabled         bool      `json:"peak_rate_enabled"`
+	PeakStart               *string   `json:"peak_start,omitempty"`
+	PeakEnd                 *string   `json:"peak_end,omitempty"`
+	PeakRateMultiplier      *float64  `json:"peak_rate_multiplier,omitempty"`
+	AppliedPeakMultiplier   *float64  `json:"applied_peak_multiplier,omitempty"`
+	EffectiveRateMultiplier float64   `json:"effective_rate_multiplier"`
+	Timezone                *string   `json:"timezone,omitempty"`
+	ObservedAt              time.Time `json:"observed_at"`
+}
+
+// KeyBillingInfo returns the token billing multiplier effective for the authenticated API key.
+// GET /v1/sub2api/billing
+func (h *GatewayHandler) KeyBillingInfo(c *gin.Context) {
+	apiKey, ok := middleware2.GetAPIKeyFromContext(c)
+	if !ok {
+		h.errorResponse(c, http.StatusUnauthorized, "authentication_error", "Invalid API key")
+		return
+	}
+	if h.cfg != nil && h.cfg.RunMode == config.RunModeSimple {
+		h.errorResponse(c, http.StatusNotFound, "not_found_error", "Billing information is not supported in simple mode")
+		return
+	}
+	if apiKey.GroupID == nil {
+		h.errorResponse(c, http.StatusForbidden, "permission_error", "API key is not assigned to a group")
+		return
+	}
+	if apiKey.Group == nil {
+		h.errorResponse(c, http.StatusInternalServerError, "api_error", "Billing information is unavailable")
+		return
+	}
+
+	resolvedRate, ok := h.resolveKeyBillingRate(c, apiKey)
+	if !ok {
+		h.errorResponse(c, http.StatusInternalServerError, "api_error", "Billing information is unavailable")
+		return
+	}
+
+	c.Header("Cache-Control", "no-store")
+	c.JSON(http.StatusOK, buildKeyBillingInfo(apiKey, resolvedRate, timezone.Now()))
+}
+
+func (h *GatewayHandler) resolveKeyBillingRate(c *gin.Context, apiKey *service.APIKey) (float64, bool) {
+	groupRate := apiKey.Group.RateMultiplier
+	switch apiKey.Group.Platform {
+	case service.PlatformOpenAI, service.PlatformGrok:
+		if h.openAIGatewayService == nil {
+			return 0, false
+		}
+		return h.openAIGatewayService.ResolveUserGroupRateMultiplier(c.Request.Context(), apiKey.UserID, *apiKey.GroupID, groupRate), true
+	default:
+		if h.gatewayService == nil {
+			return 0, false
+		}
+		return h.gatewayService.ResolveUserGroupRateMultiplier(c.Request.Context(), apiKey.UserID, *apiKey.GroupID, groupRate), true
+	}
+}
+
+func buildKeyBillingInfo(apiKey *service.APIKey, resolvedRate float64, now time.Time) keyBillingInfoResponse {
+	groupRate := apiKey.Group.RateMultiplier
+	var userRate *float64
+	if resolvedRate != groupRate {
+		userRate = &resolvedRate
+	}
+	appliedPeak := apiKey.Group.PeakMultiplierAt(now)
+
+	response := keyBillingInfoResponse{
+		Object:                  "sub2api.key_billing",
+		SchemaVersion:           keyBillingInfoSchemaVersion,
+		BillingScope:            "token",
+		GroupRateMultiplier:     groupRate,
+		UserRateMultiplier:      userRate,
+		ResolvedRateMultiplier:  resolvedRate,
+		PeakRateEnabled:         apiKey.Group.PeakRateEnabled,
+		EffectiveRateMultiplier: resolvedRate * appliedPeak,
+		ObservedAt:              now.UTC(),
+	}
+	if apiKey.Group.PeakRateEnabled {
+		response.PeakStart = &apiKey.Group.PeakStart
+		response.PeakEnd = &apiKey.Group.PeakEnd
+		response.PeakRateMultiplier = &apiKey.Group.PeakRateMultiplier
+		response.AppliedPeakMultiplier = &appliedPeak
+		tz := timezone.Location().String()
+		response.Timezone = &tz
+	}
+	return response
+}