release: v1.4.3

Add a Telegram channel or group storage backend, with proxied image URLs and an optional API proxy.
2026-10-09 15:39:24 +08:00
1 parent 4ed4692f5e
commit cc19dc6435
@@ -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 }
+  }
+}