feat: implement createNodeConnectedFromSource functionality for enhanced node creation

- Added a new mutation to create nodes connected to existing nodes, improving the canvas interaction model.
- Updated the CanvasPlacementContext to include createNodeConnectedFromSource, allowing for seamless node connections.
- Refactored the PromptNode component to utilize the new connection method, enhancing the workflow for AI image generation.
- Introduced optimistic updates for immediate UI feedback during node creation and connection processes.

components/canvas/canvas-placement-context.tsx

@@ -58,6 +58,29 @@ type CreateNodeWithEdgeSplitMutation = ReactMutation<
   >
 >;
 
+type CreateNodeWithEdgeFromSourceMutation = ReactMutation<
+  FunctionReference<
+    "mutation",
+    "public",
+    {
+      canvasId: Id<"canvases">;
+      type: string;
+      positionX: number;
+      positionY: number;
+      width: number;
+      height: number;
+      data: unknown;
+      parentId?: Id<"nodes">;
+      zIndex?: number;
+      clientRequestId?: string;
+      sourceNodeId: Id<"nodes">;
+      sourceHandle?: string;
+      targetHandle?: string;
+    },
+    Id<"nodes">
+  >
+>;
+
 type FlowPoint = { x: number; y: number };
 
 type CreateNodeWithIntersectionInput = {
@@ -72,10 +95,19 @@ type CreateNodeWithIntersectionInput = {
   clientRequestId?: string;
 };
 
+export type CreateNodeConnectedFromSourceInput = CreateNodeWithIntersectionInput & {
+  sourceNodeId: Id<"nodes">;
+  sourceHandle?: string;
+  targetHandle?: string;
+};
+
 type CanvasPlacementContextValue = {
   createNodeWithIntersection: (
     input: CreateNodeWithIntersectionInput,
   ) => Promise<Id<"nodes">>;
+  createNodeConnectedFromSource: (
+    input: CreateNodeConnectedFromSourceInput,
+  ) => Promise<Id<"nodes">>;
 };
 
 const CanvasPlacementContext = createContext<CanvasPlacementContextValue | null>(
@@ -135,6 +167,7 @@ interface CanvasPlacementProviderProps {
   canvasId: Id<"canvases">;
   createNode: CreateNodeMutation;
   createNodeWithEdgeSplit: CreateNodeWithEdgeSplitMutation;
+  createNodeWithEdgeFromSource: CreateNodeWithEdgeFromSourceMutation;
   onCreateNodeSettled?: (payload: {
     clientRequestId?: string;
     realId: Id<"nodes">;
@@ -146,6 +179,7 @@ export function CanvasPlacementProvider({
   canvasId,
   createNode,
   createNodeWithEdgeSplit,
+  createNodeWithEdgeFromSource,
   onCreateNodeSettled,
   children,
 }: CanvasPlacementProviderProps) {
@@ -250,9 +284,57 @@ export function CanvasPlacementProvider({
     ],
   );
 
+  const createNodeConnectedFromSource = useCallback(
+    async ({
+      type,
+      position,
+      width,
+      height,
+      data,
+      zIndex,
+      clientRequestId,
+      sourceNodeId,
+      sourceHandle,
+      targetHandle,
+    }: CreateNodeConnectedFromSourceInput) => {
+      const defaults = NODE_DEFAULTS[type] ?? {
+        width: 200,
+        height: 100,
+        data: {},
+      };
+
+      const effectiveWidth = width ?? defaults.width;
+      const effectiveHeight = height ?? defaults.height;
+
+      const payload = {
+        canvasId,
+        type,
+        positionX: position.x,
+        positionY: position.y,
+        width: effectiveWidth,
+        height: effectiveHeight,
+        data: {
+          ...defaults.data,
+          ...(data ?? {}),
+          canvasId,
+        },
+        ...(zIndex !== undefined ? { zIndex } : {}),
+        ...(clientRequestId !== undefined ? { clientRequestId } : {}),
+        sourceNodeId,
+        sourceHandle,
+        targetHandle,
+      };
+
+      const realId = await createNodeWithEdgeFromSource(payload);
+      onCreateNodeSettled?.({ clientRequestId, realId });
+      return realId;
+    },
+    [canvasId, createNodeWithEdgeFromSource, onCreateNodeSettled],
+  );
+
   const value = useMemo(
-    () => ({ createNodeWithIntersection }),
+    () => ({ createNodeWithIntersection, createNodeConnectedFromSource }),
-    [createNodeWithIntersection],
+    [createNodeConnectedFromSource, createNodeWithIntersection],
   );
 
   return (

components/canvas/canvas.tsx

@@ -38,6 +38,12 @@ import {
   NODE_HANDLE_MAP,
   resolveMediaAspectRatio,
 } from "@/lib/canvas-utils";
+import {
+  AI_IMAGE_NODE_FOOTER_PX,
+  AI_IMAGE_NODE_HEADER_PX,
+  DEFAULT_ASPECT_RATIO,
+  parseAspectRatioString,
+} from "@/lib/image-formats";
 import CanvasToolbar from "@/components/canvas/canvas-toolbar";
 import { CanvasCommandPalette } from "@/components/canvas/canvas-command-palette";
 import { CanvasPlacementProvider } from "@/components/canvas/canvas-placement-context";
@@ -47,6 +53,7 @@ interface CanvasInnerProps {
 }
 
 const OPTIMISTIC_NODE_PREFIX = "optimistic_";
+const OPTIMISTIC_EDGE_PREFIX = "optimistic_edge_";
 
 function isOptimisticNodeId(id: string): boolean {
   return id.startsWith(OPTIMISTIC_NODE_PREFIX);
@@ -250,7 +257,10 @@ function mergeNodesPreservingLocalState(
       typeof (previousNode as { resizing?: boolean }).resizing === "boolean"
         ? (previousNode as { resizing?: boolean }).resizing
         : false;
-    const isMediaNode = incomingNode.type === "asset" || incomingNode.type === "image";
+    const isMediaNode =
+      incomingNode.type === "asset" ||
+      incomingNode.type === "image" ||
+      incomingNode.type === "ai-image";
     const shouldPreserveInteractivePosition =
       isMediaNode && (Boolean(previousNode.selected) || Boolean(previousNode.dragging) || previousResizing);
     const shouldPreserveInteractiveSize =
@@ -441,6 +451,66 @@ function CanvasInner({ canvasId }: CanvasInnerProps) {
       );
     },
   );
+
+  const createNodeWithEdgeFromSource = useMutation(
+    api.nodes.createWithEdgeFromSource,
+  ).withOptimisticUpdate((localStore, args) => {
+    const nodeList = localStore.getQuery(api.nodes.list, {
+      canvasId: args.canvasId,
+    });
+    const edgeList = localStore.getQuery(api.edges.list, {
+      canvasId: args.canvasId,
+    });
+    if (nodeList === undefined || edgeList === undefined) return;
+
+    const tempNodeId = (
+      args.clientRequestId
+        ? `${OPTIMISTIC_NODE_PREFIX}${args.clientRequestId}`
+        : `${OPTIMISTIC_NODE_PREFIX}${Date.now()}_${Math.random().toString(36).slice(2, 11)}`
+    ) as Id<"nodes">;
+
+    const tempEdgeId = (
+      args.clientRequestId
+        ? `${OPTIMISTIC_EDGE_PREFIX}${args.clientRequestId}`
+        : `${OPTIMISTIC_EDGE_PREFIX}${Date.now()}_${Math.random().toString(36).slice(2, 11)}`
+    ) as Id<"edges">;
+
+    const syntheticNode: Doc<"nodes"> = {
+      _id: tempNodeId,
+      _creationTime: Date.now(),
+      canvasId: args.canvasId,
+      type: args.type as Doc<"nodes">["type"],
+      positionX: args.positionX,
+      positionY: args.positionY,
+      width: args.width,
+      height: args.height,
+      status: "idle",
+      retryCount: 0,
+      data: args.data,
+      parentId: args.parentId,
+      zIndex: args.zIndex,
+    };
+
+    const syntheticEdge: Doc<"edges"> = {
+      _id: tempEdgeId,
+      _creationTime: Date.now(),
+      canvasId: args.canvasId,
+      sourceNodeId: args.sourceNodeId,
+      targetNodeId: tempNodeId,
+      sourceHandle: args.sourceHandle,
+      targetHandle: args.targetHandle,
+    };
+
+    localStore.setQuery(api.nodes.list, { canvasId: args.canvasId }, [
+      ...nodeList,
+      syntheticNode,
+    ]);
+    localStore.setQuery(api.edges.list, { canvasId: args.canvasId }, [
+      ...edgeList,
+      syntheticEdge,
+    ]);
+  });
+
   const createNodeWithEdgeSplit = useMutation(api.nodes.createWithEdgeSplit);
   const batchRemoveNodes = useMutation(api.nodes.batchRemove);
   const createEdge = useMutation(api.edges.create);
@@ -580,12 +650,14 @@ function CanvasInner({ canvasId }: CanvasInnerProps) {
           }
 
           const node = nds.find((candidate) => candidate.id === change.id);
-          if (!node || node.type !== "asset") {
+          if (!node) {
             return change;
           }
 
           const isActiveResize =
             change.resizing === true || change.resizing === false;
+
+          if (node.type === "asset") {
             if (!isActiveResize) {
               return change;
             }
@@ -660,6 +732,87 @@ function CanvasInner({ canvasId }: CanvasInnerProps) {
                 height: enforcedHeight,
               },
             };
+          }
+
+          if (node.type === "ai-image") {
+            if (!isActiveResize) {
+              return change;
+            }
+
+            const nodeData = node.data as { aspectRatio?: string };
+            const arLabel =
+              typeof nodeData.aspectRatio === "string" && nodeData.aspectRatio.trim()
+                ? nodeData.aspectRatio.trim()
+                : DEFAULT_ASPECT_RATIO;
+
+            let arW: number;
+            let arH: number;
+            try {
+              const parsed = parseAspectRatioString(arLabel);
+              arW = parsed.w;
+              arH = parsed.h;
+            } catch {
+              return change;
+            }
+
+            const chrome = AI_IMAGE_NODE_HEADER_PX + AI_IMAGE_NODE_FOOTER_PX;
+            const hPerW = arH / arW;
+
+            const previousWidth =
+              typeof node.style?.width === "number"
+                ? node.style.width
+                : change.dimensions.width;
+            const previousHeight =
+              typeof node.style?.height === "number"
+                ? node.style.height
+                : change.dimensions.height;
+
+            const widthDelta = Math.abs(change.dimensions.width - previousWidth);
+            const heightDelta = Math.abs(change.dimensions.height - previousHeight);
+
+            let constrainedWidth = change.dimensions.width;
+            let constrainedHeight = change.dimensions.height;
+
+            if (heightDelta > widthDelta) {
+              const viewportH = Math.max(1, constrainedHeight - chrome);
+              constrainedWidth = viewportH * (arW / arH);
+              constrainedHeight = chrome + viewportH;
+            } else {
+              constrainedHeight = chrome + constrainedWidth * hPerW;
+            }
+
+            const aiMinViewport = 120;
+            const aiMinOuterHeight = chrome + aiMinViewport;
+            const aiMinOuterWidthBase = 200;
+            const minimumAllowedWidth = Math.max(
+              aiMinOuterWidthBase,
+              aiMinViewport * (arW / arH),
+            );
+            const minimumAllowedHeight = Math.max(
+              aiMinOuterHeight,
+              chrome + minimumAllowedWidth * hPerW,
+            );
+
+            let enforcedWidth = Math.max(constrainedWidth, minimumAllowedWidth);
+            let enforcedHeight = chrome + enforcedWidth * hPerW;
+            if (enforcedHeight < minimumAllowedHeight) {
+              enforcedHeight = minimumAllowedHeight;
+              enforcedWidth = (enforcedHeight - chrome) * (arW / arH);
+            }
+            enforcedWidth = Math.max(enforcedWidth, minimumAllowedWidth);
+            enforcedHeight = chrome + enforcedWidth * hPerW;
+
+            return {
+              ...change,
+              dimensions: {
+                ...change.dimensions,
+                width: enforcedWidth,
+                height: enforcedHeight,
+              },
+            };
+          }
+
+          return change;
           })
           .filter((change): change is NodeChange => change !== null);
 
@@ -1114,6 +1267,7 @@ function CanvasInner({ canvasId }: CanvasInnerProps) {
       canvasId={canvasId}
       createNode={createNode}
       createNodeWithEdgeSplit={createNodeWithEdgeSplit}
+      createNodeWithEdgeFromSource={createNodeWithEdgeFromSource}
       onCreateNodeSettled={({ clientRequestId, realId }) =>
         syncPendingMoveForClientRequest(clientRequestId, realId)
       }

components/canvas/nodes/base-node-wrapper.tsx

@@ -17,7 +17,8 @@ const RESIZE_CONFIGS: Record<string, ResizeConfig> = {
   group: { minWidth: 150, minHeight: 100 },
   image: { minWidth: 140, minHeight: 120, keepAspectRatio: true },
   asset: { minWidth: 140, minHeight: 208, keepAspectRatio: false },
-  "ai-image": { minWidth: 200, minHeight: 200 },
+  // Chrome 88 + min. Viewport 120 → äußere Mindesthöhe 208 (siehe canvas onNodesChange)
+  "ai-image": { minWidth: 200, minHeight: 208, keepAspectRatio: false },
   compare: { minWidth: 300, minHeight: 200 },
   prompt: { minWidth: 260, minHeight: 220 },
   text: { minWidth: 220, minHeight: 90 },

components/canvas/nodes/prompt-node.tsx

@@ -118,9 +118,8 @@ export default function PromptNode({
     availableCredits !== null && availableCredits >= creditCost;
 
   const updateData = useMutation(api.nodes.updateData);
-  const createEdge = useMutation(api.edges.create);
   const generateImage = useAction(api.ai.generateImage);
-  const { createNodeWithIntersection } = useCanvasPlacement();
+  const { createNodeConnectedFromSource } = useCanvasPlacement();
 
   const debouncedSave = useDebouncedCallback(() => {
     const raw = dataRef.current as Record<string, unknown>;
@@ -215,7 +214,9 @@ export default function PromptNode({
       const viewport = getImageViewportSize(aspectRatio);
       const outer = getAiImageNodeOuterSize(viewport);
 
-      const aiNodeId = await createNodeWithIntersection({
+      const clientRequestId = crypto.randomUUID();
+
+      const aiNodeId = await createNodeConnectedFromSource({
         type: "ai-image",
         position: { x: posX, y: posY },
         width: outer.width,
@@ -229,13 +230,8 @@ export default function PromptNode({
           outputWidth: viewport.width,
           outputHeight: viewport.height,
         },
-        clientRequestId: crypto.randomUUID(),
+        clientRequestId,
-      });
-
-      await createEdge({
-        canvasId,
         sourceNodeId: id as Id<"nodes">,
-        targetNodeId: aiNodeId,
         sourceHandle: "prompt-out",
         targetHandle: "prompt-in",
       });
@@ -274,8 +270,7 @@ export default function PromptNode({
     id,
     getEdges,
     getNode,
-    createNodeWithIntersection,
+    createNodeConnectedFromSource,
-    createEdge,
     generateImage,
     creditCost,
     availableCredits,

convex/nodes.ts

@@ -224,6 +224,64 @@ export const createWithEdgeSplit = mutation({
   },
 });
 
+/**
+ * Neuen Node erstellen und sofort mit einem bestehenden Node verbinden
+ * (ein Roundtrip — z. B. Prompt → neue AI-Image-Node).
+ */
+export const createWithEdgeFromSource = mutation({
+  args: {
+    canvasId: v.id("canvases"),
+    type: v.string(),
+    positionX: v.number(),
+    positionY: v.number(),
+    width: v.number(),
+    height: v.number(),
+    data: v.any(),
+    parentId: v.optional(v.id("nodes")),
+    zIndex: v.optional(v.number()),
+    clientRequestId: v.optional(v.string()),
+    sourceNodeId: v.id("nodes"),
+    sourceHandle: v.optional(v.string()),
+    targetHandle: v.optional(v.string()),
+  },
+  handler: async (ctx, args) => {
+    const user = await requireAuth(ctx);
+    await getCanvasOrThrow(ctx, args.canvasId, user.userId);
+    void args.clientRequestId;
+
+    const source = await ctx.db.get(args.sourceNodeId);
+    if (!source || source.canvasId !== args.canvasId) {
+      throw new Error("Source node not found");
+    }
+
+    const nodeId = await ctx.db.insert("nodes", {
+      canvasId: args.canvasId,
+      type: args.type as Doc<"nodes">["type"],
+      positionX: args.positionX,
+      positionY: args.positionY,
+      width: args.width,
+      height: args.height,
+      status: "idle",
+      retryCount: 0,
+      data: args.data,
+      parentId: args.parentId,
+      zIndex: args.zIndex,
+    });
+
+    await ctx.db.insert("edges", {
+      canvasId: args.canvasId,
+      sourceNodeId: args.sourceNodeId,
+      targetNodeId: nodeId,
+      sourceHandle: args.sourceHandle,
+      targetHandle: args.targetHandle,
+    });
+
+    await ctx.db.patch(args.canvasId, { updatedAt: Date.now() });
+
+    return nodeId;
+  },
+});
+
 /**
  * Node-Position auf dem Canvas verschieben.
  */