fix: scope HTTP image media handles to database and conversation

tests/integration/local-api-auth.test.ts

@@ -187,6 +187,32 @@ describe('Local API authentication', () => {
     expect(body.messages[0].contentData).not.toHaveProperty('aeskey')
   })
 
+  it('serves opaque media handles while preserving the chatlog message id', async () => {
+    const mediaId = `image:${'a'.repeat(64)}`
+    const previousUrl = fixture.chatlogMessages[0].media.url
+    fixture.chatlogMessages[0].media.url = `/api/v1/media/${encodeURIComponent(mediaId)}`
+    try {
+      const provider = vi.fn(async (id: string) => {
+        expect(id).toBe(mediaId)
+        return { buffer: Buffer.from([0xff, 0xd8, 0xff, 0xd9]), mimeType: 'image/jpeg' }
+      })
+      const handle = await startFixtureServer(() => VALID_TOKEN, provider)
+      const headers = { Authorization: `Bearer ${VALID_TOKEN}` }
+      const chatlog = await fetch(`${baseUrl(handle)}/api/v1/chatlog?talker=fixture`, { headers })
+      const body = await chatlog.json()
+      expect(body.messages[0].id).toBe('message:1')
+      expect(body.messages[0].media.url).not.toContain('message')
+      const response = await fetch(`${baseUrl(handle)}${body.messages[0].media.url}`, { headers })
+      expect(response.status).toBe(200)
+      expect(Buffer.from(await response.arrayBuffer())).toEqual(
+        Buffer.from([0xff, 0xd8, 0xff, 0xd9])
+      )
+      expect(provider).toHaveBeenCalledOnce()
+    } finally {
+      fixture.chatlogMessages[0].media.url = previousUrl
+    }
+  })
+
   it('maps media lookup failures to stable API statuses', async () => {
     const handle = await startFixtureServer(
       () => VALID_TOKEN,

tests/unit/chat-service-media.test.ts

@@ -0,0 +1,134 @@
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import type { WechatDb, WechatMessage } from '../../src/main/wechat-db'
+
+vi.mock('../../src/main/services/recall-archive-service', () => ({
+  recordRecallArchiveMessages: vi.fn(),
+  mergeRecallArchiveMessages: (_md5: string, messages: unknown[]) => messages
+}))
+
+import {
+  getImageMessageReference,
+  listMessages,
+  listMessagesAsync,
+  setChatDb,
+  type FormattedMessage
+} from '../../src/main/services/chat-service'
+
+const IMAGE_A = 'a'.repeat(32)
+const IMAGE_B = 'b'.repeat(32)
+
+function image(md5: string, overrides: Partial<WechatMessage> = {}): WechatMessage {
+  return {
+    mesLocalID: '56',
+    mesDes: 1,
+    messageType: '3',
+    msgCreateTime: '1756000000',
+    msgContent: `<msg><img md5="${md5}" /></msg>`,
+    serverId: '9007199254740993123',
+    ...overrides
+  }
+}
+
+function connect(messages: Record<string, WechatMessage[]>): void {
+  const client = { getUsernameByMd5: (md5: string) => `wxid_${md5}` }
+  setChatDb({
+    close: vi.fn(),
+    getWcdb4Client: () => client,
+    getUserMessages: (md5: string) => messages[md5] || [],
+    getUserMessagesAsync: async (md5: string) => messages[md5] || []
+  } as unknown as WechatDb)
+}
+
+function mediaId(message: FormattedMessage): string {
+  expect(message.media).toMatchObject({ type: 'image', available: true })
+  return decodeURIComponent(message.media!.url.slice('/api/v1/media/'.length))
+}
+
+describe('chat service image media handles', () => {
+  afterEach(() => setChatDb(null))
+
+  it('keeps colliding local ids readable across conversations and repeated reads', async () => {
+    connect({ first: [image(IMAGE_A)], second: [image(IMAGE_B)] })
+    const first = listMessages('first')[0]
+    const firstId = mediaId(first)
+    expect(first.id).toBe('56')
+    expect(firstId).toMatch(/^image:[a-f0-9]{64}$/)
+    expect(firstId).not.toContain('wxid_first')
+    expect(getImageMessageReference('56')?.imageMd5).toBe(IMAGE_A)
+
+    const second = (await listMessagesAsync('second'))[0]
+    const secondId = mediaId(second)
+    expect(second.id).toBe(first.id)
+    expect(secondId).not.toBe(firstId)
+    expect(getImageMessageReference(firstId)).toMatchObject({
+      sessionId: 'wxid_first',
+      imageMd5: IMAGE_A
+    })
+    expect(getImageMessageReference(secondId)).toMatchObject({
+      sessionId: 'wxid_second',
+      imageMd5: IMAGE_B
+    })
+    expect(getImageMessageReference('56')).toBeNull()
+
+    expect(mediaId(listMessages('first')[0])).toBe(firstId)
+    expect(mediaId((await listMessagesAsync('second'))[0])).toBe(secondId)
+    expect(getImageMessageReference(firstId)?.imageMd5).toBe(IMAGE_A)
+    expect(getImageMessageReference(secondId)?.imageMd5).toBe(IMAGE_B)
+    expect(getImageMessageReference('56')).toBeNull()
+  })
+
+  it('distinguishes images with the same local id within one conversation', () => {
+    connect({ first: [image(IMAGE_A), image(IMAGE_B, { serverId: '9007199254740993124' })] })
+    const [first, second] = listMessages('first').map(mediaId)
+    expect(first).not.toBe(second)
+    expect(getImageMessageReference(first)?.imageMd5).toBe(IMAGE_A)
+    expect(getImageMessageReference(second)?.imageMd5).toBe(IMAGE_B)
+    expect(getImageMessageReference('56')).toBeNull()
+  })
+
+  it('does not reuse media handles after reconnecting or switching accounts', () => {
+    const messages = { first: [image(IMAGE_A)] }
+    connect(messages)
+    const previousId = mediaId(listMessages('first')[0])
+    setChatDb(null)
+    expect(getImageMessageReference(previousId)).toBeNull()
+    connect(messages)
+    const currentId = mediaId(listMessages('first')[0])
+    expect(currentId).not.toBe(previousId)
+    expect(getImageMessageReference(previousId)).toBeNull()
+    expect(getImageMessageReference(currentId)?.imageMd5).toBe(IMAGE_A)
+  })
+
+  it('normalizes native server ids without losing integer precision', () => {
+    const message = image(IMAGE_A, { serverId: 9007199254740993123n })
+    connect({ first: [message] })
+    const firstId = mediaId(listMessages('first')[0])
+    message.serverId = '9007199254740993123'
+    expect(mediaId(listMessages('first')[0])).toBe(firstId)
+  })
+
+  it('scopes recovered images and supports images identified only by dat name', () => {
+    connect({
+      first: [image(IMAGE_A, { _wxe_recovered: true })],
+      second: [image(IMAGE_B, { _wxe_recovered: true })],
+      third: [image('', { msgContent: JSON.stringify({ imageDatName: IMAGE_A }) })]
+    })
+    const first = listMessages('first')[0]
+    const second = listMessages('second')[0]
+    expect(first.id).toBe('recovered:56')
+    expect(mediaId(second)).not.toBe(mediaId(first))
+    expect(getImageMessageReference(mediaId(first))?.imageMd5).toBe(IMAGE_A)
+    expect(getImageMessageReference(mediaId(second))?.imageMd5).toBe(IMAGE_B)
+    expect(getImageMessageReference('recovered:56')).toBeNull()
+    const third = listMessages('third')[0]
+    expect(getImageMessageReference(mediaId(third))?.imageDatName).toBe(IMAGE_A)
+  })
+
+  it('does not add media handles to text messages', () => {
+    connect({ first: [image(IMAGE_A, { messageType: '1', msgContent: 'text' })] })
+    const message = listMessages('first')[0]
+    expect(message.id).toBe('56')
+    expect(message.media).toBeUndefined()
+    expect(getImageMessageReference('56')).toBeNull()
+  })
+})