feat: integrate credit cost tracking in AI image generation and prompt nodes

- Added credit cost tracking to AI image nodes, displaying the cost in Euro-Cent.
- Updated prompt node to create edges between prompt and AI image nodes during image generation.
- Enhanced Convex action to include credit cost in image generation data handling.
- Introduced utility function for formatting Euro-Cent values for better user display.

components/canvas/nodes/ai-image-node.tsx

@@ -7,6 +7,7 @@ import { api } from "@/convex/_generated/api";
 import type { Id } from "@/convex/_generated/dataModel";
 import BaseNodeWrapper from "./base-node-wrapper";
 import { DEFAULT_MODEL_ID, getModel } from "@/lib/ai-models";
+import { cn, formatEurFromCents } from "@/lib/utils";
 import {
   Loader2,
   AlertCircle,
@@ -21,6 +22,8 @@ type AiImageNodeData = {
   model?: string;
   modelTier?: string;
   generatedAt?: number;
+  /** Gebuchte Credits in Euro-Cent (PRD: nach Commit) */
+  creditCost?: number;
   canvasId?: string;
   _status?: string;
   _statusMessage?: string;
@@ -116,7 +119,7 @@ export default function AiImageNode({
         </div>
       </div>
 
-      <div className="relative h-[320px] overflow-hidden bg-muted">
+      <div className="group relative h-[320px] overflow-hidden bg-muted">
         {status === "idle" && !nodeData.url && (
           <div className="absolute inset-0 flex flex-col items-center justify-center gap-3 text-muted-foreground">
             <ImageIcon className="h-10 w-10 opacity-30" />
@@ -174,8 +177,25 @@ export default function AiImageNode({
           />
         )}
 
+        {nodeData.creditCost != null &&
+          nodeData.url &&
+          !isLoading &&
+          status !== "error" && (
+            <div
+              className="pointer-events-none absolute bottom-2 right-2 z-[15] rounded-md border border-border/80 bg-background/85 px-1.5 py-0.5 text-[10px] tabular-nums text-muted-foreground shadow-sm backdrop-blur-sm"
+              title="Gebuchte Credits (Cent) für diese Generierung"
+            >
+              {formatEurFromCents(nodeData.creditCost)}
+            </div>
+          )}
+
         {status === "done" && nodeData.url && !isLoading && (
-          <div className="absolute inset-0 z-20 flex items-end justify-end p-2 opacity-0 transition-opacity hover:opacity-100">
+          <div
+            className={cn(
+              "absolute right-2 z-20 opacity-0 transition-opacity group-hover:opacity-100",
+              nodeData.creditCost != null ? "bottom-12" : "bottom-2",
+            )}
+          >
             <button
               type="button"
               onClick={() => void handleRegenerate()}

components/canvas/nodes/prompt-node.tsx

@@ -41,6 +41,7 @@ export default function PromptNode({
 
   const updateData = useMutation(api.nodes.updateData);
   const createNode = useMutation(api.nodes.create);
+  const createEdge = useMutation(api.edges.create);
   const generateImage = useAction(api.ai.generateImage);
 
   const debouncedSave = useDebouncedCallback((value: string) => {
@@ -107,6 +108,14 @@ export default function PromptNode({
         },
       });
 
+      await createEdge({
+        canvasId,
+        sourceNodeId: id as Id<"nodes">,
+        targetNodeId: aiNodeId,
+        sourceHandle: "prompt-out",
+        targetHandle: "prompt-in",
+      });
+
       await generateImage({
         canvasId,
         nodeId: aiNodeId,
@@ -127,6 +136,7 @@ export default function PromptNode({
     getEdges,
     getNode,
     createNode,
+    createEdge,
     generateImage,
   ]);
 

convex/ai.ts

@@ -69,6 +69,7 @@ export const generateImage = action({
       const existing = await ctx.runQuery(api.nodes.get, { nodeId: args.nodeId });
       if (!existing) throw new Error("Node not found");
       const prev = (existing.data ?? {}) as Record<string, unknown>;
+      const creditCost = modelConfig.estimatedCostPerImage;
 
       await ctx.runMutation(api.nodes.updateData, {
         nodeId: args.nodeId,
@@ -79,6 +80,7 @@ export const generateImage = action({
           model: modelId,
           modelTier: modelConfig.tier,
           generatedAt: Date.now(),
+          creditCost,
         },
       });
 
@@ -89,7 +91,7 @@ export const generateImage = action({
 
       await ctx.runMutation(api.credits.commit, {
         transactionId: reservationId,
-        actualCost: modelConfig.estimatedCostPerImage,
+        actualCost: creditCost,
       });
     } catch (error) {
       await ctx.runMutation(api.credits.release, {

lib/utils.ts

@@ -4,3 +4,11 @@ import { twMerge } from "tailwind-merge"
 export function cn(...inputs: ClassValue[]) {
   return twMerge(clsx(inputs))
 }
+
+/** Credits / Preise: Werte sind Euro-Cent (siehe PRD, Manifest). */
+export function formatEurFromCents(cents: number) {
+  return new Intl.NumberFormat("de-DE", {
+    style: "currency",
+    currency: "EUR",
+  }).format(cents / 100)
+}