From 88c479077025332714ec5d9524df3b4be219b91a Mon Sep 17 00:00:00 2001
From: Ryanba <92616678+Gujiassh@users.noreply.github.com>
Date: Fri, 17 Jul 2026 17:53:38 +0800
Subject: [PATCH] fix(stage-ui): recover stale stage model selection (#2033)

---
 .../src/stores/settings/stage-model.test.ts   | 63 +++++++++++++++++++
 .../src/stores/settings/stage-model.ts        |  9 ++-
 2 files changed, 71 insertions(+), 1 deletion(-)
 create mode 100644 packages/stage-ui/src/stores/settings/stage-model.test.ts

diff --git a/packages/stage-ui/src/stores/settings/stage-model.test.ts b/packages/stage-ui/src/stores/settings/stage-model.test.ts
new file mode 100644
index 000000000..f35d3be36
--- /dev/null
+++ b/packages/stage-ui/src/stores/settings/stage-model.test.ts
@@ -0,0 +1,63 @@
+import type { DisplayModelURL } from '../display-models'
+
+import { createPinia, setActivePinia } from 'pinia'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import { DisplayModelFormat, useDisplayModelsStore } from '../display-models'
+import { useSettingsStageModel } from './stage-model'
+
+vi.mock('@proj-airi/stage-shared/composables', async () => {
+  const { refManualReset } = await import('@vueuse/core')
+
+  return {
+    useLocalStorageManualReset: (_key: string, value: string) => refManualReset(value),
+  }
+})
+
+vi.mock('@vueuse/core', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('@vueuse/core')>()
+
+  return {
+    ...actual,
+    useEventListener: vi.fn(),
+  }
+})
+
+describe('settings stage model store', () => {
+  beforeEach(() => {
+    setActivePinia(createPinia())
+  })
+
+  // https://github.com/moeru-ai/airi/issues/1984
+  it('issue #1984: falls back to the default preset when a custom stage model is missing', async () => {
+    const fallbackModel: DisplayModelURL = {
+      id: 'preset-live2d-1',
+      format: DisplayModelFormat.Live2dZip,
+      type: 'url',
+      url: 'https://example.com/preset-live2d.zip',
+      name: 'Preset Live2D',
+      importedAt: 1,
+    }
+
+    const displayModelsStore = useDisplayModelsStore()
+    const getDisplayModelSpy = vi.spyOn(displayModelsStore, 'getDisplayModel').mockImplementation(async (id) => {
+      if (id === 'display-model-missing')
+        return undefined
+      if (id === fallbackModel.id)
+        return fallbackModel
+      return undefined
+    })
+
+    const store = useSettingsStageModel()
+    store.stageModelSelected = 'display-model-missing'
+
+    await store.initializeStageModel()
+
+    expect(store.stageModelSelected).toBe(fallbackModel.id)
+    expect(store.stageModelSelectedDisplayModel).toEqual(fallbackModel)
+    expect(store.stageModelSelectedUrl).toBe(fallbackModel.url)
+    expect(store.stageModelRenderer).toBe('live2d')
+    expect(getDisplayModelSpy).toHaveBeenCalledWith('display-model-missing')
+    expect(getDisplayModelSpy).toHaveBeenCalledWith(fallbackModel.id)
+  })
+})
diff --git a/packages/stage-ui/src/stores/settings/stage-model.ts b/packages/stage-ui/src/stores/settings/stage-model.ts
index 45e0bc0b3..300d7147a 100644
--- a/packages/stage-ui/src/stores/settings/stage-model.ts
+++ b/packages/stage-ui/src/stores/settings/stage-model.ts
@@ -14,8 +14,9 @@ export const useSettingsStageModel = defineStore('settings-stage-model', () => {
   const displayModelsStore = useDisplayModelsStore()
   let stageModelUpdateSequence = 0
   const stageModelStorageKey = 'settings/stage/model'
+  const defaultStageModelId = 'preset-live2d-1'
 
-  const stageModelSelectedState = useLocalStorageManualReset<string>(stageModelStorageKey, 'preset-live2d-1')
+  const stageModelSelectedState = useLocalStorageManualReset<string>(stageModelStorageKey, defaultStageModelId)
   const stageModelSelected = computed<string>({
     get: () => stageModelSelectedState.value,
     set: (value) => {
@@ -77,6 +78,12 @@ export const useSettingsStageModel = defineStore('settings-stage-model', () => {
       return
 
     if (!model) {
+      if (selectedModelId !== defaultStageModelId) {
+        stageModelSelectedState.value = defaultStageModelId
+        await updateStageModel()
+        return
+      }
+
       replaceStageModelUrl(undefined)
       stageModelSelectedDisplayModel.value = undefined
       stageModelBuiltInRenderer.value = 'disabled'