fix(design): connect video preparation and playable history

src/pages/ImageCanvas/video-first-frame.ts

@@ -0,0 +1,104 @@
+import type {
+  DesignAsset,
+  DesignSpecificationValues,
+  DesignUserFieldOperation,
+  DesignWorkspace,
+} from '../../../shared/image-workspace';
+import {
+  insertReferenceToken,
+  promptReferencesImage,
+} from './reference-tokens';
+
+type ReferenceValue = DesignSpecificationValues['references'][number];
+
+function createReferenceId(): string {
+  const random = globalThis.crypto?.randomUUID?.()
+    ?? `${Date.now()}-${Math.random().toString(16).slice(2)}`;
+  return `reference-${random}`.slice(0, 64);
+}
+
+export function creatorPromptForWorkspace(workspace: DesignWorkspace): string {
+  const values = workspace.form.specification.values;
+  return values.content.concept?.trim()
+    || values.content.narrative?.trim()
+    || [
+      ...values.content.subjects.map((subject) => subject.description.trim()),
+      values.content.action?.trim(),
+      values.content.environment?.trim(),
+      values.content.emotional_tone?.trim(),
+    ].filter((value): value is string => Boolean(value)).join('，');
+}
+
+/**
+ * Build the explicit field changes for using an existing image as a video's
+ * first frame. The asset is only bound to the design; it is never copied or
+ * deleted, and existing reference rows stay in place so @图片 numbers remain
+ * stable.
+ */
+export function createVideoFirstFrameOperations(
+  workspace: DesignWorkspace,
+  asset: DesignAsset,
+  promptOverride?: string,
+): { operations: DesignUserFieldOperation[]; nextPrompt: string; referenceIndex: number } {
+  if (asset.mediaType !== 'image') {
+    throw new Error('视频开始画面必须使用图片');
+  }
+
+  const values = workspace.form.specification.values;
+  const references = values.references;
+  const currentFirstFrameIndex = references.findIndex((reference) => (
+    reference.role === 'first_frame'
+    || reference.asset_id === values.video.first_frame_asset_id
+  ));
+  const selectedReferenceIndex = references.findIndex((reference) => (
+    reference.asset_id === asset.assetId
+  ));
+
+  let nextReferences: ReferenceValue[];
+  let referenceIndex: number;
+  if (selectedReferenceIndex >= 0) {
+    referenceIndex = selectedReferenceIndex;
+    nextReferences = references.map((reference, index) => {
+      if (index === referenceIndex) return { ...reference, role: 'first_frame' };
+      if (index === currentFirstFrameIndex && index !== referenceIndex) {
+        return { ...reference, role: 'inspiration' };
+      }
+      return reference;
+    });
+  } else if (currentFirstFrameIndex >= 0) {
+    referenceIndex = currentFirstFrameIndex;
+    nextReferences = references.map((reference, index) => (
+      index === referenceIndex
+        ? { ...reference, asset_id: asset.assetId, asset_revision: null, role: 'first_frame' }
+        : reference
+    ));
+  } else {
+    referenceIndex = references.length;
+    nextReferences = [
+      ...references,
+      {
+        id: createReferenceId(),
+        asset_id: asset.assetId,
+        asset_revision: null,
+        role: 'first_frame',
+        preserve: [],
+        adapt: [],
+        do_not_copy: [],
+        reviewed_observations: [],
+      },
+    ];
+  }
+
+  const prompt = promptOverride ?? creatorPromptForWorkspace(workspace);
+  const inserted = promptReferencesImage(prompt, referenceIndex)
+    ? { value: prompt }
+    : insertReferenceToken(prompt, referenceIndex, null);
+  const operations: DesignUserFieldOperation[] = [
+    { kind: 'set', path: 'references', value: nextReferences },
+    { kind: 'set', path: 'video.first_frame_asset_id', value: asset.assetId },
+  ];
+  if (inserted.value.trim() !== prompt.trim()) {
+    operations.push({ kind: 'set', path: 'content.concept', value: inserted.value.trim() });
+  }
+  return { operations, nextPrompt: inserted.value.trim(), referenceIndex };
+}