release: v1.4.3

Add a Telegram channel or group storage backend, with proxied image URLs and an optional API proxy.

server/api/admin/storage/[id].patch.ts

@@ -9,6 +9,11 @@ import {
   type StorageBackendPatch
 } from '../../../utils/storage-backends'
 import { parseS3Config, validateS3Config } from '../../../utils/storage/s3'
+import {
+  parseTelegramConfig,
+  validateTelegramConfig,
+  validateApiProxyUrl
+} from '../../../utils/storage/telegram'
 import { parseQuotaBytes } from '../../../utils/storage-capacity'
 import type { ServingMode } from '../../../utils/storage/types'
 
@@ -20,10 +25,13 @@ interface StoragePatchBody {
     bucket?: string
     prefix?: string
     forcePathStyle?: boolean
+    chatId?: string
+    apiProxyUrl?: string
   }
   secrets?: {
     accessKeyId?: string
     secretAccessKey?: string
+    botToken?: string
   }
   servingMode?: ServingMode
   publicUrl?: string
@@ -63,6 +71,26 @@ export default defineEventHandler(async (event) => {
     patch.name = body.name.trim() || row.name
   }
 
+  if (body.config !== undefined && row.type === 'telegram') {
+    const current = parseTelegramConfig(row.config_json) ?? { chatId: '' }
+    const apiProxyUrl = body.config.apiProxyUrl?.trim() ?? current.apiProxyUrl ?? ''
+    const next = {
+      chatId: body.config.chatId?.trim() ?? current.chatId,
+      apiProxyUrl: apiProxyUrl || undefined
+    }
+    const error = validateTelegramConfig(next)
+    if (error) {
+      createApiError(event, 'INVALID_REQUEST', error, 400)
+    }
+    if (apiProxyUrl) {
+      const proxyError = validateApiProxyUrl(apiProxyUrl)
+      if (proxyError) {
+        createApiError(event, 'INVALID_REQUEST', proxyError, 400)
+      }
+    }
+    patch.config = next
+  }
+
   if (body.config !== undefined && row.type === 's3') {
     const current = parseS3Config(row.config_json) ?? {
       endpoint: '',
@@ -87,7 +115,11 @@ export default defineEventHandler(async (event) => {
     patch.secrets = body.secrets
   }
 
-  if (body.servingMode !== undefined) {
+  if (body.secrets !== undefined && row.type === 'telegram') {
+    patch.secrets = body.secrets
+  }
+
+  if (body.servingMode !== undefined && row.type !== 'telegram') {
     if (body.servingMode !== 'proxy' && body.servingMode !== 'public') {
       createApiError(event, 'INVALID_REQUEST', '访问方式无效', 400)
     }
@@ -99,7 +131,7 @@ export default defineEventHandler(async (event) => {
   }
 
   if (body.quotaBytes !== undefined) {
-    if (row.type === 's3') {
+    if (row.type === 's3' || row.type === 'telegram') {
       const quotaBytes = parseQuotaBytes(body.quotaBytes)
       if (!quotaBytes) {
         createApiError(event, 'INVALID_REQUEST', '请填写有效的存储套餐总量', 400)

server/api/admin/storage/index.post.ts

@@ -2,13 +2,19 @@ import { requireAdminAuth } from '../../../utils/access'
 import { createApiError } from '../../../utils/api-error'
 import {
   insertStorageBackend,
+  insertTelegramBackend,
   isStorageEnvConfigured
 } from '../../../utils/storage-backends'
 import { validateS3Config } from '../../../utils/storage/s3'
+import {
+  validateTelegramConfig,
+  validateApiProxyUrl
+} from '../../../utils/storage/telegram'
 import { parseQuotaBytes } from '../../../utils/storage-capacity'
 import type { ServingMode } from '../../../utils/storage/types'
 
 interface StorageCreateBody {
+  type?: 's3' | 'telegram'
   name?: string
   provider?: string
   config?: {
@@ -17,10 +23,13 @@ interface StorageCreateBody {
     bucket?: string
     prefix?: string
     forcePathStyle?: boolean
+    chatId?: string
+    apiProxyUrl?: string
   }
   secrets?: {
     accessKeyId?: string
     secretAccessKey?: string
+    botToken?: string
   }
   servingMode?: ServingMode
   publicUrl?: string
@@ -40,6 +49,50 @@ export default defineEventHandler(async (event) => {
     (): StorageCreateBody => ({})
   )
 
+  const backendType = body.type === 'telegram' ? 'telegram' : 's3'
+
+  if (backendType === 'telegram') {
+    const name = body.name?.trim() || 'Telegram 频道'
+    const chatId = body.config?.chatId?.trim() ?? ''
+    const apiProxyUrl = body.config?.apiProxyUrl?.trim() ?? ''
+    const botToken = body.secrets?.botToken?.trim() ?? ''
+
+    if (!chatId || !botToken) {
+      createApiError(event, 'INVALID_REQUEST', 'Bot Token 与 Chat ID 不能为空', 400)
+    }
+
+    const config = {
+      chatId,
+      apiProxyUrl: apiProxyUrl || undefined
+    }
+    const configError = validateTelegramConfig(config)
+    if (configError) {
+      createApiError(event, 'INVALID_REQUEST', configError, 400)
+    }
+    if (apiProxyUrl) {
+      const proxyError = validateApiProxyUrl(apiProxyUrl)
+      if (proxyError) {
+        createApiError(event, 'INVALID_REQUEST', proxyError, 400)
+      }
+    }
+
+    const quotaBytes = parseQuotaBytes(body.quotaBytes)
+    if (!quotaBytes) {
+      createApiError(event, 'INVALID_REQUEST', '请填写有效的存储套餐总量', 400)
+    }
+
+    const id = insertTelegramBackend({
+      name,
+      config,
+      secrets: { botToken },
+      quotaBytes,
+      enabled: body.enabled,
+      isDefault: body.isDefault
+    })
+
+    return { success: true, id }
+  }
+
   const name = body.name?.trim() || 'S3 兼容存储'
   const config = {
     endpoint: body.config?.endpoint?.trim() ?? '',

server/api/logs/index.get.ts

@@ -106,7 +106,11 @@ export default defineEventHandler(async (event) => {
           ? {
               id: row.backend_id,
               name: row.backend_name ?? row.backend_id,
-              type: (row.backend_type === 'local' ? 'local' : 's3') as 'local' | 's3'
+              type: (row.backend_type === 'local'
+                ? 'local'
+                : row.backend_type === 'telegram'
+                  ? 'telegram'
+                  : 's3') as 'local' | 's3' | 'telegram'
             }
           : null,
         ipAddress: row.ip_address,

server/utils/backup/full-export.ts

@@ -7,6 +7,7 @@ import {
   listStorageBackendRows
 } from '../storage-backends'
 import { parseS3Config } from '../storage/s3'
+import { parseTelegramConfig } from '../storage/telegram'
 import { createImageStream } from '../storage'
 import { copyDatabaseSnapshot } from './db-snapshot'
 import { markJobDone, markJobFailed, updateBackupJob } from './jobs'
@@ -27,7 +28,11 @@ function buildStorageBackendsMeta(): StorageBackendMetaExport[] {
     id: row.id,
     name: row.name,
     type: row.type,
-    config: row.type === 's3' ? (parseS3Config(row.config_json) ?? {}) : {},
+    config: row.type === 's3'
+      ? (parseS3Config(row.config_json) ?? {})
+      : row.type === 'telegram'
+        ? (parseTelegramConfig(row.config_json) ?? {})
+        : {},
     servingMode: row.serving_mode,
     publicUrl: row.public_url,
     quotaBytes: row.quota_bytes,

server/utils/process-image-upload.ts

@@ -12,8 +12,8 @@ import { generateImageKey } from './image-key'
 import { buildImageItem, sanitizeOriginalName } from './image-response'
 import { getStorageLayout, getWebpQuality } from './env'
 import {
-  formatMaxFileSizeMessage,
-  getMaxFileSizeBytes,
+  formatEffectiveMaxFileSizeMessage,
+  getEffectiveMaxFileSizeBytes,
   isMimeTypeAllowed,
   isPreserveOriginalUpload
 } from './upload-policy'
@@ -73,13 +73,13 @@ export async function processSingleImageUpload(
   const originalName = sanitizeOriginalName(input.filename ?? 'image')
   const bytes = input.bytes
 
-  if (bytes.byteLength > getMaxFileSizeBytes()) {
+  if (bytes.byteLength > getEffectiveMaxFileSizeBytes()) {
     return {
       error: {
         name: originalName,
         error: {
           code: 'FILE_TOO_LARGE',
-          message: formatMaxFileSizeMessage()
+          message: formatEffectiveMaxFileSizeMessage()
         }
       }
     }
@@ -144,12 +144,16 @@ export async function processSingleImageUpload(
       name: originalName,
       source: input.source ?? 'web'
     })
+    const detail = error instanceof Error ? error.message.trim() : ''
+    const message = detail.startsWith('Telegram') || detail.includes('群组')
+      ? detail
+      : '上传失败，请稍后重试'
     return {
       error: {
         name: originalName,
         error: {
           code: 'UPLOAD_FAILED',
-          message: '上传失败，请稍后重试'
+          message
         }
       }
     }

server/utils/storage-backends.ts

@@ -1,28 +1,99 @@
 import type { DatabaseSync } from 'node:sqlite'
 import { getDb } from './db'
 import { LocalStorageBackend } from './storage/local'
+import { deleteStorageObjectRefsForBackend } from './storage/storage-object-refs'
 import {
   parseS3Config,
   parseS3Secrets,
   S3StorageBackend
 } from './storage/s3'
+import {
+  parseTelegramConfig,
+  parseTelegramSecrets,
+  TelegramStorageBackend
+} from './storage/telegram'
 import type {
   S3BackendConfig,
   ServingMode,
   StorageBackendInfo,
   StorageBackendRow,
-  StorageBackendType
+  StorageBackendType,
+  TelegramBackendConfig,
+  TelegramBackendSecrets
 } from './storage/types'
 
 export const LOCAL_BACKEND_ID = 'local'
 export const S3_BACKEND_ID = 's3-primary'
 
+const STORAGE_SCHEMA_TELEGRAM_KEY = 'storage_schema_telegram_v1'
+
+function migrateStorageBackendTelegramType(database: DatabaseSync): void {
+  const flag = database.prepare(`
+    SELECT value FROM settings WHERE key = ?
+  `).get(STORAGE_SCHEMA_TELEGRAM_KEY) as { value?: string } | undefined
+  if (flag?.value === '1') {
+    return
+  }
+
+  const tableRow = database.prepare(`
+    SELECT sql FROM sqlite_master WHERE type = 'table' AND name = 'storage_backends'
+  `).get() as { sql?: string } | undefined
+
+  const needsRebuild = Boolean(
+    tableRow?.sql && !tableRow.sql.includes('telegram')
+  )
+
+  if (!needsRebuild) {
+    database.prepare(`
+      INSERT OR REPLACE INTO settings (key, value, updated_at)
+      VALUES (?, '1', ?)
+    `).run(STORAGE_SCHEMA_TELEGRAM_KEY, new Date().toISOString())
+    return
+  }
+
+  database.exec('PRAGMA foreign_keys = OFF')
+  database.exec('BEGIN')
+  try {
+    database.exec(`
+      CREATE TABLE storage_backends_new (
+        id TEXT PRIMARY KEY,
+        name TEXT NOT NULL,
+        type TEXT NOT NULL CHECK(type IN ('local', 's3', 'telegram')),
+        config_json TEXT NOT NULL DEFAULT '{}',
+        secret_json TEXT NOT NULL DEFAULT '{}',
+        serving_mode TEXT NOT NULL DEFAULT 'proxy' CHECK(serving_mode IN ('proxy', 'public')),
+        public_url TEXT NOT NULL DEFAULT '',
+        quota_bytes INTEGER,
+        enabled INTEGER NOT NULL DEFAULT 1,
+        is_default INTEGER NOT NULL DEFAULT 0,
+        sort_order INTEGER NOT NULL DEFAULT 0
+      )
+    `)
+    database.exec(`
+      INSERT INTO storage_backends_new
+      SELECT * FROM storage_backends
+    `)
+    database.exec('DROP TABLE storage_backends')
+    database.exec('ALTER TABLE storage_backends_new RENAME TO storage_backends')
+    database.prepare(`
+      INSERT OR REPLACE INTO settings (key, value, updated_at)
+      VALUES (?, '1', ?)
+    `).run(STORAGE_SCHEMA_TELEGRAM_KEY, new Date().toISOString())
+    database.exec('COMMIT')
+  } catch (error) {
+    database.exec('ROLLBACK')
+    throw error
+  } finally {
+    database.exec('PRAGMA foreign_keys = ON')
+  }
+}
+
 function migrateStorageTables(database: DatabaseSync): void {
   database.exec(`
     CREATE TABLE IF NOT EXISTS storage_backends (
       id TEXT PRIMARY KEY,
       name TEXT NOT NULL,
-      type TEXT NOT NULL CHECK(type IN ('local', 's3')),
+      type TEXT NOT NULL CHECK(type IN ('local', 's3', 'telegram')),
       config_json TEXT NOT NULL DEFAULT '{}',
       secret_json TEXT NOT NULL DEFAULT '{}',
       serving_mode TEXT NOT NULL DEFAULT 'proxy' CHECK(serving_mode IN ('proxy', 'public')),
@@ -47,7 +118,15 @@ function migrateStorageTables(database: DatabaseSync): void {
     CREATE INDEX IF NOT EXISTS idx_images_backend_id ON images(backend_id);
     CREATE INDEX IF NOT EXISTS idx_images_user_id ON images(user_id);
     CREATE INDEX IF NOT EXISTS idx_images_folder ON images(folder);
+    CREATE TABLE IF NOT EXISTS storage_object_refs (
+      backend_id TEXT NOT NULL,
+      key TEXT NOT NULL,
+      ref_json TEXT NOT NULL,
+      PRIMARY KEY (backend_id, key),
+      FOREIGN KEY (backend_id) REFERENCES storage_backends(id)
+    );
   `)
+  migrateStorageBackendTelegramType(database)
 }
 
 export function ensureStorageSchema(): void {
@@ -109,7 +188,9 @@ function rowToInfo(row: StorageBackendRow, _maskSecrets = true): StorageBackendI
 } {
   const config = row.type === 's3'
     ? (parseS3Config(row.config_json) ?? {})
-    : {}
+    : row.type === 'telegram'
+      ? (parseTelegramConfig(row.config_json) ?? {})
+      : {}
   let secretsMasked: Record<string, string> = {}
   if (row.type === 's3') {
     const secrets = parseS3Secrets(row.secret_json)
@@ -121,6 +202,11 @@ function rowToInfo(row: StorageBackendRow, _maskSecrets = true): StorageBackendI
         ? maskSecret(secrets.secretAccessKey)
         : ''
     }
+  } else if (row.type === 'telegram') {
+    const secrets = parseTelegramSecrets(row.secret_json)
+    secretsMasked = {
+      botToken: secrets?.botToken ? maskSecret(secrets.botToken) : ''
+    }
   }
 
   return {
@@ -213,7 +299,11 @@ export function setDefaultBackend(id: string): void {
 export interface StorageBackendPatch {
   name?: string
   config?: Record<string, unknown>
-  secrets?: { accessKeyId?: string, secretAccessKey?: string }
+  secrets?: {
+    accessKeyId?: string
+    secretAccessKey?: string
+    botToken?: string
+  }
   servingMode?: ServingMode
   publicUrl?: string
   quotaBytes?: number | null
@@ -234,7 +324,9 @@ export function updateStorageBackend(id: string, patch: StorageBackendPatch): vo
   if (patch.config !== undefined) {
     const current = row.type === 's3'
       ? (parseS3Config(row.config_json) ?? {})
-      : {}
+      : row.type === 'telegram'
+        ? (parseTelegramConfig(row.config_json) ?? { chatId: '' })
+        : {}
     configJson = JSON.stringify({ ...current, ...patch.config })
   }
 
@@ -254,7 +346,20 @@ export function updateStorageBackend(id: string, patch: StorageBackendPatch): vo
     secretJson = JSON.stringify(next)
   }
 
-  const servingMode = patch.servingMode ?? row.serving_mode
+  if (patch.secrets !== undefined && row.type === 'telegram') {
+    const current = parseTelegramSecrets(row.secret_json) ?? { botToken: '' }
+    const next = {
+      botToken: patch.secrets.botToken?.trim()
+        ? patch.secrets.botToken.trim()
+        : current.botToken
+    }
+    secretJson = JSON.stringify(next)
+  }
+
+  let servingMode = patch.servingMode ?? row.serving_mode
+  if (row.type === 'telegram') {
+    servingMode = 'proxy'
+  }
   const publicUrl = patch.publicUrl ?? row.public_url
   const quotaBytes = patch.quotaBytes !== undefined
     ? patch.quotaBytes
@@ -323,6 +428,15 @@ export function createBackendInstance(row: StorageBackendRow) {
     )
   }
 
+  if (row.type === 'telegram') {
+    const config = parseTelegramConfig(row.config_json)
+    const secrets = parseTelegramSecrets(row.secret_json)
+    if (!config || !secrets) {
+      throw new Error(`Invalid Telegram configuration for backend ${row.id}`)
+    }
+    return new TelegramStorageBackend(row.id, config, secrets)
+  }
+
   const config = parseS3Config(row.config_json)
   const secrets = parseS3Secrets(row.secret_json)
   if (!config || !secrets) {
@@ -368,7 +482,7 @@ function getNextSortOrder(): number {
   return row.max_order + 1
 }
 
-export type ObjectStorageIdPrefix = 'r2' | 'cos' | 'oss' | 's3'
+export type ObjectStorageIdPrefix = 'r2' | 'cos' | 'oss' | 's3' | 'tg'
 
 /** 根据表单预设或 endpoint 推断新建后端的 id 前缀 */
 export function resolveObjectStorageIdPrefix(
@@ -438,6 +552,41 @@ export function insertStorageBackend(input: {
   return id
 }
 
+export function insertTelegramBackend(input: {
+  id?: string
+  name: string
+  config: TelegramBackendConfig
+  secrets: TelegramBackendSecrets
+  quotaBytes?: number | null
+  enabled?: boolean
+  isDefault?: boolean
+}): string {
+  ensureDefaultBackends()
+  const id = input.id ?? generateStorageBackendId('tg')
+  const sortOrder = getNextSortOrder()
+
+  getDb().prepare(`
+    INSERT INTO storage_backends
+      (id, name, type, config_json, secret_json, serving_mode, public_url,
+       quota_bytes, enabled, is_default, sort_order)
+    VALUES (?, ?, 'telegram', ?, ?, 'proxy', '', ?, ?, 0, ?)
+  `).run(
+    id,
+    input.name,
+    JSON.stringify(input.config),
+    JSON.stringify(input.secrets),
+    input.quotaBytes ?? null,
+    input.enabled === false ? 0 : 1,
+    sortOrder
+  )
+
+  if (input.isDefault) {
+    setDefaultBackend(id)
+  }
+
+  return id
+}
+
 export function deleteStorageBackend(id: string): void {
   if (id === LOCAL_BACKEND_ID) {
     throw new Error('Cannot delete local backend')
@@ -457,5 +606,6 @@ export function deleteStorageBackend(id: string): void {
     throw new Error('Cannot delete the default backend')
   }
 
+  deleteStorageObjectRefsForBackend(id)
   getDb().prepare('DELETE FROM storage_backends WHERE id = ?').run(id)
 }

server/utils/storage-capacity.ts

@@ -51,11 +51,11 @@ function buildQuotaCapacity(quotaBytes: number, indexBytes: number): StorageCapa
 
 export async function buildBackendCapacity(
   backendId: string,
-  backendType: 'local' | 's3',
+  backendType: 'local' | 's3' | 'telegram',
   indexBytes: number,
   quotaBytes: number | null
 ): Promise<StorageCapacity> {
-  if (backendType === 's3') {
+  if (backendType === 's3' || backendType === 'telegram') {
     if (quotaBytes && quotaBytes > 0) {
       return buildQuotaCapacity(quotaBytes, indexBytes)
     }

server/utils/storage/index.ts

@@ -1,3 +1,10 @@
 export { getActiveBackend, getBackendForKey, getActiveBackendRow, getBackendRowForKey } from './resolver'
 export { LocalStorageBackend } from './local'
 export { S3StorageBackend, buildObjectKey, parseS3Config, validateS3Config } from './s3'
+export {
+  TelegramStorageBackend,
+  parseTelegramConfig,
+  parseTelegramSecrets,
+  validateTelegramConfig,
+  TELEGRAM_MAX_FILE_BYTES
+} from './telegram'

server/utils/storage/storage-object-refs.ts

@@ -0,0 +1,44 @@
+import { getDb } from '../db'
+import type { TelegramObjectRef } from './types'
+
+export function getStorageObjectRef(
+  backendId: string,
+  key: string
+): TelegramObjectRef | null {
+  const row = getDb().prepare(`
+    SELECT ref_json FROM storage_object_refs
+    WHERE backend_id = ? AND key = ?
+  `).get(backendId, key) as { ref_json: string } | undefined
+
+  if (!row) return null
+
+  try {
+    return JSON.parse(row.ref_json) as TelegramObjectRef
+  } catch {
+    return null
+  }
+}
+
+export function setStorageObjectRef(
+  backendId: string,
+  key: string,
+  ref: TelegramObjectRef
+): void {
+  getDb().prepare(`
+    INSERT INTO storage_object_refs (backend_id, key, ref_json)
+    VALUES (?, ?, ?)
+    ON CONFLICT(backend_id, key) DO UPDATE SET ref_json = excluded.ref_json
+  `).run(backendId, key, JSON.stringify(ref))
+}
+
+export function deleteStorageObjectRef(backendId: string, key: string): void {
+  getDb().prepare(`
+    DELETE FROM storage_object_refs WHERE backend_id = ? AND key = ?
+  `).run(backendId, key)
+}
+
+export function deleteStorageObjectRefsForBackend(backendId: string): void {
+  getDb().prepare(`
+    DELETE FROM storage_object_refs WHERE backend_id = ?
+  `).run(backendId)
+}

server/utils/storage/telegram.test.ts

@@ -0,0 +1,297 @@
+import { describe, expect, it, vi, beforeEach, afterEach } from 'vitest'
+import {
+  parseTelegramConfig,
+  parseTelegramSecrets,
+  validateApiProxyUrl,
+  validateTelegramConfig,
+  TelegramStorageBackend,
+  TELEGRAM_MAX_FILE_BYTES
+} from './telegram'
+import {
+  deleteStorageObjectRef,
+  getStorageObjectRef
+} from './storage-object-refs'
+import {
+  ensureDefaultBackends,
+  ensureStorageSchema,
+  getStorageBackendRow,
+  insertTelegramBackend
+} from '../storage-backends'
+
+describe('telegram config', () => {
+  it('parses chat id and optional proxy', () => {
+    const config = parseTelegramConfig(JSON.stringify({
+      chatId: '-1001',
+      apiProxyUrl: 'http://127.0.0.1:7890'
+    }))
+    expect(config).toEqual({
+      chatId: '-1001',
+      apiProxyUrl: 'http://127.0.0.1:7890'
+    })
+  })
+
+  it('rejects invalid proxy protocol', () => {
+    expect(validateApiProxyUrl('socks5://127.0.0.1:1080')).toMatch(/http/)
+  })
+
+  it('accepts http proxy', () => {
+    expect(validateApiProxyUrl('http://127.0.0.1:7890')).toBeNull()
+  })
+
+  it('validates required chat id', () => {
+    expect(validateTelegramConfig({ chatId: '' })).toBeTruthy()
+    expect(validateTelegramConfig({ chatId: '-100' })).toBeNull()
+  })
+
+  it('parses bot token secret', () => {
+    expect(parseTelegramSecrets(JSON.stringify({ botToken: '123:abc' }))).toEqual({
+      botToken: '123:abc'
+    })
+  })
+
+  it('exposes 20MB limit constant', () => {
+    expect(TELEGRAM_MAX_FILE_BYTES).toBe(20 * 1024 * 1024)
+  })
+})
+
+describe('TelegramStorageBackend', () => {
+  const backendId = 'tg-test'
+  const key = 'images/2026/01/test.webp'
+
+  beforeEach(() => {
+    ensureStorageSchema()
+    ensureDefaultBackends()
+    if (!getStorageBackendRow(backendId)) {
+      insertTelegramBackend({
+        id: backendId,
+        name: 'TG test',
+        config: { chatId: '-100' },
+        secrets: { botToken: 'token' },
+        quotaBytes: 1024 * 1024 * 1024,
+        enabled: false
+      })
+    }
+    vi.stubGlobal('fetch', vi.fn())
+  })
+
+  afterEach(() => {
+    deleteStorageObjectRef(backendId, key)
+    vi.unstubAllGlobals()
+  })
+
+  it('retries sendDocument after supergroup chat id migration', async () => {
+    const fetchMock = vi.mocked(fetch)
+    fetchMock
+      .mockResolvedValueOnce({
+        ok: true,
+        status: 200,
+        json: async () => ({
+          ok: false,
+          description: 'Bad Request: group chat was upgraded to a supergroup chat',
+          parameters: { migrate_to_chat_id: -100999 }
+        })
+      } as Response)
+      .mockResolvedValueOnce({
+        ok: true,
+        status: 200,
+        json: async () => ({
+          ok: true,
+          result: {
+            message_id: 99,
+            document: { file_id: 'MIG', file_unique_id: 'UQ2' }
+          }
+        })
+      } as Response)
+
+    const backend = new TelegramStorageBackend(
+      backendId,
+      { chatId: '-123' },
+      { botToken: 'token' }
+    )
+
+    await backend.put(key, new Uint8Array([4, 5]), {
+      originalName: 'test.webp',
+      uploadedAt: new Date().toISOString(),
+      contentType: 'image/webp',
+      size: 2
+    })
+
+    expect(fetchMock).toHaveBeenCalledTimes(2)
+    const ref = getStorageObjectRef(backendId, key)
+    expect(ref?.fileId).toBe('MIG')
+  })
+
+  it('put accepts a single photo object and sticker file id', async () => {
+    const fetchMock = vi.mocked(fetch)
+    fetchMock.mockResolvedValueOnce({
+      ok: true,
+      status: 200,
+      json: async () => ({
+        ok: true,
+        result: {
+          message_id: 8,
+          sticker: { file_id: 'stk', file_unique_id: 'us' }
+        }
+      })
+    } as Response)
+
+    const backend = new TelegramStorageBackend(
+      backendId,
+      { chatId: '-100' },
+      { botToken: 'token' }
+    )
+
+    await backend.put(key, new Uint8Array([1]), {
+      originalName: 'test.webp',
+      uploadedAt: new Date().toISOString(),
+      contentType: 'image/webp',
+      size: 1
+    })
+
+    expect(getStorageObjectRef(backendId, key)?.fileId).toBe('stk')
+  })
+
+  it('put accepts photo array when document is absent', async () => {
+    const fetchMock = vi.mocked(fetch)
+    fetchMock.mockResolvedValueOnce({
+      ok: true,
+      status: 200,
+      json: async () => ({
+        ok: true,
+        result: {
+          message_id: 7,
+          photo: [
+            { file_id: 'small', file_unique_id: 'u1', width: 90, height: 90 },
+            { file_id: 'large', file_unique_id: 'u2', width: 800, height: 600 }
+          ]
+        }
+      })
+    } as Response)
+
+    const backend = new TelegramStorageBackend(
+      backendId,
+      { chatId: '-100' },
+      { botToken: 'token' }
+    )
+
+    await backend.put(key, new Uint8Array([1]), {
+      originalName: 'test.png',
+      uploadedAt: new Date().toISOString(),
+      contentType: 'image/png',
+      size: 1
+    })
+
+    const ref = getStorageObjectRef(backendId, key)
+    expect(ref?.fileId).toBe('large')
+  })
+
+  it('put stores file ref after sendDocument', async () => {
+    const fetchMock = vi.mocked(fetch)
+    fetchMock.mockResolvedValueOnce({
+      ok: true,
+      status: 200,
+      json: async () => ({
+        ok: true,
+        result: {
+          message_id: 42,
+          document: {
+            file_id: 'AAA',
+            file_unique_id: 'UQ'
+          }
+        }
+      })
+    } as Response)
+
+    const backend = new TelegramStorageBackend(
+      backendId,
+      { chatId: '-100' },
+      { botToken: 'token' }
+    )
+
+    await backend.put(key, new Uint8Array([1, 2, 3]), {
+      originalName: 'test.webp',
+      uploadedAt: new Date().toISOString(),
+      contentType: 'image/webp',
+      size: 3
+    })
+
+    const ref = getStorageObjectRef(backendId, key)
+    expect(ref?.fileId).toBe('AAA')
+    expect(ref?.messageId).toBe(42)
+  })
+
+  it('testConnection reports telegram errors', async () => {
+    const fetchMock = vi.mocked(fetch)
+    fetchMock.mockResolvedValueOnce({
+      ok: true,
+      status: 200,
+      json: async () => ({ ok: false, description: 'Unauthorized' })
+    } as Response)
+
+    const backend = new TelegramStorageBackend(
+      backendId,
+      { chatId: '-100' },
+      { botToken: 'bad' }
+    )
+
+    const result = await backend.testConnection()
+    expect(result.ok).toBe(false)
+    expect(result.message).toContain('Unauthorized')
+  })
+
+  it('createStream downloads file bytes', async () => {
+    const fetchMock = vi.mocked(fetch)
+    fetchMock.mockResolvedValueOnce({
+      ok: true,
+      status: 200,
+      json: async () => ({
+        ok: true,
+        result: {
+          message_id: 1,
+          document: { file_id: 'FILE1', file_unique_id: 'U1' }
+        }
+      })
+    } as Response)
+
+    const putBackend = new TelegramStorageBackend(
+      backendId,
+      { chatId: '-100' },
+      { botToken: 'token' }
+    )
+    await putBackend.put(key, new Uint8Array([1]), {
+      originalName: 'test.webp',
+      uploadedAt: new Date().toISOString(),
+      contentType: 'image/webp',
+      size: 1
+    })
+
+    fetchMock.mockReset()
+    fetchMock
+      .mockResolvedValueOnce({
+        ok: true,
+        status: 200,
+        json: async () => ({
+          ok: true,
+          result: { file_id: 'FILE1', file_path: 'photos/file.jpg' }
+        })
+      } as Response)
+      .mockResolvedValueOnce({
+        ok: true,
+        status: 200,
+        arrayBuffer: async () => new Uint8Array([9, 8, 7]).buffer
+      } as Response)
+
+    const backend = new TelegramStorageBackend(
+      backendId,
+      { chatId: '-100' },
+      { botToken: 'token' }
+    )
+
+    const stream = await backend.createStream(key)
+    const chunks: Buffer[] = []
+    for await (const chunk of stream) {
+      chunks.push(Buffer.isBuffer(chunk) ? chunk : Buffer.from(chunk))
+    }
+    expect(Buffer.concat(chunks)).toEqual(Buffer.from([9, 8, 7]))
+  })
+})

server/utils/storage/telegram.ts

@@ -0,0 +1,510 @@
+import { Readable } from 'node:stream'
+import { getImageIndexAsStored } from '../image-index'
+import { validateImageKey } from '../image-key'
+import { logException } from '../logger'
+import {
+  deleteStorageObjectRef,
+  getStorageObjectRef,
+  setStorageObjectRef
+} from './storage-object-refs'
+import type {
+  ServingMode,
+  StoredImage,
+  StoredImageMeta,
+  StorageBackend,
+  TelegramBackendConfig,
+  TelegramBackendSecrets,
+  TelegramObjectRef
+} from './types'
+
+export const TELEGRAM_MAX_FILE_BYTES = 20 * 1024 * 1024
+const TELEGRAM_API_BASE = 'https://api.telegram.org'
+
+export function parseTelegramConfig(raw: string): TelegramBackendConfig | null {
+  try {
+    const parsed = JSON.parse(raw) as Partial<TelegramBackendConfig>
+    if (!parsed.chatId?.trim()) return null
+    const apiProxyUrl = parsed.apiProxyUrl?.trim()
+    return {
+      chatId: parsed.chatId.trim(),
+      apiProxyUrl: apiProxyUrl || undefined
+    }
+  } catch {
+    return null
+  }
+}
+
+export function parseTelegramSecrets(raw: string): TelegramBackendSecrets | null {
+  try {
+    const parsed = JSON.parse(raw) as Partial<TelegramBackendSecrets>
+    if (!parsed.botToken?.trim()) return null
+    return { botToken: parsed.botToken.trim() }
+  } catch {
+    return null
+  }
+}
+
+export function validateTelegramConfig(config: TelegramBackendConfig): string | null {
+  if (!config.chatId.trim()) {
+    return 'Chat ID 不能为空'
+  }
+  if (config.apiProxyUrl) {
+    const error = validateApiProxyUrl(config.apiProxyUrl)
+    if (error) return error
+  }
+  return null
+}
+
+export function validateApiProxyUrl(url: string): string | null {
+  const trimmed = url.trim()
+  if (!trimmed) return null
+  try {
+    const parsed = new URL(trimmed)
+    if (parsed.protocol === 'http:' || parsed.protocol === 'https:') {
+      return null
+    }
+    return 'API 代理仅支持 http:// 或 https:// 地址'
+  } catch {
+    return 'API 代理地址格式无效'
+  }
+}
+
+interface TelegramApiResponse<T> {
+  ok: boolean
+  result?: T
+  description?: string
+  parameters?: {
+    retry_after?: number
+    migrate_to_chat_id?: number
+  }
+}
+
+export class TelegramApiCallError extends Error {
+  readonly migrateToChatId?: number
+
+  constructor(description: string, migrateToChatId?: number) {
+    super(formatTelegramApiErrorMessage(description, migrateToChatId))
+    this.name = 'TelegramApiCallError'
+    this.migrateToChatId = migrateToChatId
+  }
+}
+
+function formatTelegramApiErrorMessage(
+  description: string,
+  migrateToChatId?: number
+): string {
+  if (migrateToChatId != null) {
+    return `Telegram 群组已升级，请使用 Chat ID：${migrateToChatId}`
+  }
+  const lower = description.toLowerCase()
+  if (lower.includes('upgraded to a supergroup')) {
+    return '群组已升级为超级群组，请在存储设置中更新 Chat ID（新 ID 一般为 -100 开头，可向 @GetTheirIDBot 查询）'
+  }
+  return description
+}
+
+interface TelegramFileIdentity {
+  file_id: string
+  file_unique_id: string
+}
+
+interface TelegramSentMessage {
+  message_id: number
+  document?: TelegramFileIdentity & { file_name?: string, thumbnail?: TelegramFileIdentity }
+  photo?: TelegramFileIdentity[] | TelegramFileIdentity
+  animation?: TelegramFileIdentity & { thumbnail?: TelegramFileIdentity }
+  video?: TelegramFileIdentity & { thumbnail?: TelegramFileIdentity }
+  sticker?: TelegramFileIdentity & { thumbnail?: TelegramFileIdentity }
+  audio?: TelegramFileIdentity
+  voice?: TelegramFileIdentity
+  video_note?: TelegramFileIdentity
+}
+
+function asFileIdentity(value: unknown): TelegramFileIdentity | null {
+  if (!value || typeof value !== 'object') return null
+  const rec = value as Partial<TelegramFileIdentity>
+  if (typeof rec.file_id !== 'string' || !rec.file_id) return null
+  return {
+    file_id: rec.file_id,
+    file_unique_id: typeof rec.file_unique_id === 'string' ? rec.file_unique_id : ''
+  }
+}
+
+function photoList(photo: TelegramSentMessage['photo']): TelegramFileIdentity[] {
+  if (!photo) return []
+  if (Array.isArray(photo)) {
+    return photo.map(asFileIdentity).filter((item): item is TelegramFileIdentity => item != null)
+  }
+  const single = asFileIdentity(photo)
+  return single ? [single] : []
+}
+
+function fileRefFromSentMessage(
+  message: TelegramSentMessage
+): TelegramObjectRef | null {
+  const messageId = message.message_id
+  const document = asFileIdentity(message.document)
+  if (document) {
+    return {
+      fileId: document.file_id,
+      fileUniqueId: document.file_unique_id,
+      messageId
+    }
+  }
+
+  const photos = photoList(message.photo)
+  const largest = photos.at(-1)
+  if (largest) {
+    return {
+      fileId: largest.file_id,
+      fileUniqueId: largest.file_unique_id,
+      messageId
+    }
+  }
+
+  for (const media of [
+    message.sticker,
+    message.animation,
+    message.video,
+    message.audio,
+    message.voice,
+    message.video_note
+  ]) {
+    const file = asFileIdentity(media)
+    if (file) {
+      return {
+        fileId: file.file_id,
+        fileUniqueId: file.file_unique_id,
+        messageId
+      }
+    }
+  }
+
+  return null
+}
+
+interface TelegramFile {
+  file_id: string
+  file_unique_id: string
+  file_path?: string
+  file_size?: number
+}
+
+function apiUrl(botToken: string, method: string): string {
+  return `${TELEGRAM_API_BASE}/bot${botToken}/${method}`
+}
+
+function fileDownloadUrl(botToken: string, filePath: string): string {
+  return `${TELEGRAM_API_BASE}/file/bot${botToken}/${filePath}`
+}
+
+async function telegramFetch(
+  url: string,
+  init: RequestInit,
+  apiProxyUrl?: string
+): Promise<Response> {
+  const proxy = apiProxyUrl?.trim()
+  if (!proxy) {
+    return fetch(url, init)
+  }
+
+  const undici = await import('undici')
+  const dispatcher = new undici.ProxyAgent(proxy)
+  const response = await undici.fetch(url, {
+    ...init,
+    dispatcher
+  } as Parameters<typeof undici.fetch>[1])
+  return response as unknown as Response
+}
+
+async function callTelegramApi<T>(
+  botToken: string,
+  method: string,
+  init: RequestInit,
+  apiProxyUrl?: string,
+  attempt = 0
+): Promise<T> {
+  const response = await telegramFetch(apiUrl(botToken, method), init, apiProxyUrl)
+  const body = await response.json() as TelegramApiResponse<T>
+
+  if (!body.ok) {
+    const retryAfter = body.parameters?.retry_after
+    if (response.status === 429 && retryAfter && attempt < 2) {
+      await new Promise(resolve => setTimeout(resolve, retryAfter * 1000))
+      return callTelegramApi(botToken, method, init, apiProxyUrl, attempt + 1)
+    }
+    const description = body.description ?? `HTTP ${response.status}`
+    if (response.status === 429 || description.toLowerCase().includes('too many')) {
+      throw new Error('Telegram 请求过于频繁，请稍后重试')
+    }
+    const migrateToChatId = body.parameters?.migrate_to_chat_id
+    throw new TelegramApiCallError(description, migrateToChatId)
+  }
+
+  if (body.result === undefined) {
+    throw new Error('Telegram API 返回为空')
+  }
+
+  return body.result
+}
+
+function filenameFromKey(key: string): string {
+  const base = key.split('/').pop() ?? 'image'
+  return base.replace(/[^\w.-]+/g, '_').slice(0, 200) || 'image'
+}
+
+/** Node fetch + FormData/Blob 发往 Telegram 时经常丢文件，改用手写 multipart。 */
+function buildSendDocumentMultipart(input: {
+  chatId: string
+  caption: string
+  filename: string
+  bytes: Uint8Array
+}): { body: Uint8Array, contentType: string } {
+  const boundary = `----PicHost${crypto.randomUUID().replace(/-/g, '')}`
+  const crlf = '\r\n'
+  const safeFilename = input.filename.replace(/"/g, '\\"')
+  const preamble = [
+    `--${boundary}${crlf}`,
+    `Content-Disposition: form-data; name="chat_id"${crlf}${crlf}`,
+    `${input.chatId}${crlf}`,
+    `--${boundary}${crlf}`,
+    `Content-Disposition: form-data; name="disable_content_type_detection"${crlf}${crlf}`,
+    `true${crlf}`,
+    `--${boundary}${crlf}`,
+    `Content-Disposition: form-data; name="caption"${crlf}${crlf}`,
+    `${input.caption}${crlf}`,
+    `--${boundary}${crlf}`,
+    `Content-Disposition: form-data; name="document"; filename="${safeFilename}"${crlf}`,
+    // 固定 octet-stream，避免 Telegram 把图片转成 photo 后响应里不带 file_id
+    `Content-Type: application/octet-stream${crlf}${crlf}`
+  ].join('')
+
+  const suffix = `${crlf}--${boundary}--${crlf}`
+  const body = Buffer.concat([
+    Buffer.from(preamble, 'utf8'),
+    Buffer.from(input.bytes),
+    Buffer.from(suffix, 'utf8')
+  ])
+
+  return {
+    body: new Uint8Array(body),
+    contentType: `multipart/form-data; boundary=${boundary}`
+  }
+}
+
+export class TelegramStorageBackend implements StorageBackend {
+  readonly id: string
+  readonly type = 'telegram' as const
+  readonly servingMode: ServingMode = 'proxy'
+  readonly publicUrl = ''
+  private chatId: string
+  private readonly botToken: string
+  private readonly apiProxyUrl?: string
+
+  constructor(
+    id: string,
+    config: TelegramBackendConfig,
+    secrets: TelegramBackendSecrets
+  ) {
+    this.id = id
+    this.chatId = config.chatId
+    this.botToken = secrets.botToken
+    this.apiProxyUrl = config.apiProxyUrl
+  }
+
+  private async persistChatIdMigration(newChatId: string): Promise<void> {
+    if (newChatId === this.chatId) return
+    this.chatId = newChatId
+    const { updateStorageBackend } = await import('../storage-backends')
+    updateStorageBackend(this.id, { config: { chatId: newChatId } })
+  }
+
+  private async withChatIdMigrationRetry<T>(
+    fn: (chatId: string) => Promise<T>
+  ): Promise<T> {
+    try {
+      return await fn(this.chatId)
+    } catch (error) {
+      if (
+        error instanceof TelegramApiCallError
+        && error.migrateToChatId != null
+      ) {
+        const newId = String(error.migrateToChatId)
+        await this.persistChatIdMigration(newId)
+        return await fn(newId)
+      }
+      throw error
+    }
+  }
+
+  async put(key: string, bytes: Uint8Array, _meta: StoredImageMeta): Promise<void> {
+    if (!validateImageKey(key)) {
+      throw new Error('Invalid image key')
+    }
+    if (bytes.byteLength > TELEGRAM_MAX_FILE_BYTES) {
+      throw new Error('文件超过 Telegram 存储上限（20MB）')
+    }
+
+    const filename = filenameFromKey(key)
+    const caption = key.length <= 1024 ? key : key.slice(0, 1021) + '...'
+
+    const message = await this.withChatIdMigrationRetry(async (chatId) => {
+      const { body, contentType: multipartType } = buildSendDocumentMultipart({
+        chatId,
+        caption,
+        filename,
+        bytes
+      })
+      return callTelegramApi<TelegramSentMessage>(
+        this.botToken,
+        'sendDocument',
+        {
+          method: 'POST',
+          headers: { 'Content-Type': multipartType },
+          body: body.buffer.slice(
+            body.byteOffset,
+            body.byteOffset + body.byteLength
+          ) as ArrayBuffer
+        },
+        this.apiProxyUrl
+      )
+    })
+
+    const ref = fileRefFromSentMessage(message)
+    if (!ref) {
+      if (message.message_id != null) {
+        await this.deleteChatMessage(this.chatId, message.message_id).catch((error) => {
+          logException('telegram rollback message failed', error, {
+            messageId: message.message_id
+          })
+        })
+      }
+      logException(
+        'telegram sendDocument: message has no file id',
+        new Error('Telegram 未返回文件信息'),
+        {
+          messageId: message.message_id,
+          keys: Object.keys(message)
+        }
+      )
+      throw new Error('Telegram 未返回文件信息')
+    }
+    setStorageObjectRef(this.id, key, ref)
+  }
+
+  async head(key: string): Promise<StoredImage | null> {
+    if (!validateImageKey(key)) return null
+
+    const indexed = getImageIndexAsStored(key)
+    if (!indexed || indexed.backendId !== this.id) {
+      return null
+    }
+
+    const ref = getStorageObjectRef(this.id, key)
+    if (!ref) return null
+
+    return { ...indexed, backendId: this.id }
+  }
+
+  private async deleteChatMessage(chatId: string, messageId: number): Promise<void> {
+    await callTelegramApi<boolean>(
+      this.botToken,
+      'deleteMessage',
+      {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({
+          chat_id: chatId,
+          message_id: messageId
+        })
+      },
+      this.apiProxyUrl
+    )
+  }
+
+  async delete(key: string): Promise<void> {
+    const ref = getStorageObjectRef(this.id, key)
+    deleteStorageObjectRef(this.id, key)
+
+    if (ref?.messageId == null) return
+
+    try {
+      await this.withChatIdMigrationRetry(chatId =>
+        this.deleteChatMessage(chatId, ref.messageId as number)
+      )
+    } catch (error) {
+      logException('telegram deleteMessage failed', error, { key, messageId: ref.messageId })
+    }
+  }
+
+  async createStream(
+    key: string,
+    range?: { start: number, end: number }
+  ): Promise<Readable> {
+    const ref = getStorageObjectRef(this.id, key)
+    if (!ref?.fileId) {
+      throw new Error('Telegram 文件引用不存在')
+    }
+
+    const file = await callTelegramApi<TelegramFile>(
+      this.botToken,
+      'getFile',
+      {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ file_id: ref.fileId })
+      },
+      this.apiProxyUrl
+    )
+
+    if (!file.file_path) {
+      throw new Error('Telegram 文件路径不可用')
+    }
+
+    const downloadUrl = fileDownloadUrl(this.botToken, file.file_path)
+    const response = await telegramFetch(downloadUrl, { method: 'GET' }, this.apiProxyUrl)
+    if (!response.ok) {
+      throw new Error(`Telegram 文件下载失败（${response.status}）`)
+    }
+
+    const buffer = Buffer.from(await response.arrayBuffer())
+
+    if (range) {
+      const slice = buffer.subarray(range.start, range.end + 1)
+      return Readable.from(slice)
+    }
+
+    return Readable.from(buffer)
+  }
+
+  async testConnection(): Promise<{ ok: boolean, message: string }> {
+    try {
+      await callTelegramApi<{ id: number, username?: string }>(
+        this.botToken,
+        'getMe',
+        { method: 'GET' },
+        this.apiProxyUrl
+      )
+      await this.withChatIdMigrationRetry(chatId =>
+        callTelegramApi<{ id: number, title?: string }>(
+          this.botToken,
+          'getChat',
+          {
+            method: 'POST',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify({ chat_id: chatId })
+          },
+          this.apiProxyUrl
+        )
+      )
+      return { ok: true, message: '连接成功' }
+    } catch (error) {
+      const message = error instanceof Error ? error.message : '连接失败'
+      return { ok: false, message }
+    }
+  }
+
+  async getUsageStats(): Promise<{ count: number, bytes: number }> {
+    return { count: 0, bytes: 0 }
+  }
+}

server/utils/storage/types.ts

@@ -28,7 +28,7 @@ export interface FolderStorageStat {
   bytes: number
 }
 
-export type StorageBackendType = 'local' | 's3'
+export type StorageBackendType = 'local' | 's3' | 'telegram'
 export type ServingMode = 'proxy' | 'public'
 
 export interface S3BackendConfig {
@@ -44,6 +44,21 @@ export interface S3BackendSecrets {
   secretAccessKey: string
 }
 
+export interface TelegramBackendConfig {
+  chatId: string
+  apiProxyUrl?: string
+}
+
+export interface TelegramBackendSecrets {
+  botToken: string
+}
+
+export interface TelegramObjectRef {
+  fileId: string
+  fileUniqueId?: string
+  messageId?: number
+}
+
 export interface StorageBackendRow {
   id: string
   name: string
@@ -62,7 +77,7 @@ export interface StorageBackendInfo {
   id: string
   name: string
   type: StorageBackendType
-  config: S3BackendConfig | Record<string, never>
+  config: S3BackendConfig | TelegramBackendConfig | Record<string, never>
   servingMode: ServingMode
   publicUrl: string
   quotaBytes: number | null

server/utils/upload-policy.ts

@@ -3,6 +3,8 @@ import {
   type AllowedMimeType
 } from './constants'
 import { getSetting, setSetting } from './db'
+import { getActiveBackendRow } from './storage/resolver'
+import { TELEGRAM_MAX_FILE_BYTES } from './storage/telegram'
 
 export const SETTINGS_UPLOAD_MAX_FILE_SIZE_MB = 'upload_max_file_size_mb'
 export const SETTINGS_ALLOWED_MIME_TYPES = 'allowed_mime_types'
@@ -180,6 +182,15 @@ export function getMaxFileSizeBytes(): number {
   return getUploadMaxFileSizeMb() * 1024 * 1024
 }
 
+export function getEffectiveMaxFileSizeBytes(): number {
+  const configured = getMaxFileSizeBytes()
+  const row = getActiveBackendRow()
+  if (row?.type === 'telegram') {
+    return Math.min(configured, TELEGRAM_MAX_FILE_BYTES)
+  }
+  return configured
+}
+
 export function getAllowedMimeTypesList(): AllowedMimeType[] {
   const dbRaw = getSetting(SETTINGS_ALLOWED_MIME_TYPES)
   if (dbRaw !== null) {
@@ -279,6 +290,19 @@ export function formatMaxFileSizeMessage(): string {
   return `图片大小不能超过 ${getUploadMaxFileSizeMb()} MB`
 }
 
+export function formatEffectiveMaxFileSizeMessage(): string {
+  const row = getActiveBackendRow()
+  if (row?.type === 'telegram') {
+    const mb = TELEGRAM_MAX_FILE_BYTES / (1024 * 1024)
+    const siteMb = getUploadMaxFileSizeMb()
+    if (siteMb * 1024 * 1024 <= TELEGRAM_MAX_FILE_BYTES) {
+      return formatMaxFileSizeMessage()
+    }
+    return `图片大小不能超过 ${mb} MB（Telegram 存储上限）`
+  }
+  return formatMaxFileSizeMessage()
+}
+
 export function getUploadPolicySettingsPayload() {
   return {
     uploadMaxFileSizeMb: getUploadMaxFileSizeMb(),