Upload index.js

index.js

@@ -0,0 +1,327 @@
+import { createServerAdapter } from '@whatwg-node/server'
+import { AutoRouter, json, error, cors } from 'itty-router'
+import { createServer } from 'http'
+import dotenv from 'dotenv'
+
+dotenv.config()
+
+class Config {
+  constructor() {
+    this.API_PREFIX = process.env.API_PREFIX || '/'
+    this.API_KEY = process.env.API_KEY || ''
+    this.MAX_RETRY_COUNT = process.env.MAX_RETRY_COUNT || 3
+    this.RETRY_DELAY = process.env.RETRY_DELAY || 5000
+    this.FAKE_HEADERS = process.env.FAKE_HEADERS || {
+      Accept: '*/*',
+      'Accept-Encoding': 'gzip, deflate, br, zstd',
+      'Accept-Language': 'zh-CN,zh;q=0.9',
+      Origin: 'https://duckduckgo.com/',
+      Cookie: 'l=wt-wt; ah=wt-wt; dcm=6',
+      Dnt: '1',
+      Priority: 'u=1, i',
+      Referer: 'https://duckduckgo.com/',
+      'Sec-Ch-Ua': '"Microsoft Edge";v="129", "Not(A:Brand";v="8", "Chromium";v="129"',
+      'Sec-Ch-Ua-Mobile': '?0',
+      'Sec-Ch-Ua-Platform': '"Windows"',
+      'Sec-Fetch-Dest': 'empty',
+      'Sec-Fetch-Mode': 'cors',
+      'Sec-Fetch-Site': 'same-origin',
+      'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.0.0 Safari/537.36',
+    }
+  }
+}
+
+const config = new Config()
+
+const { preflight, corsify } = cors({
+  origin: '*',
+  allowMethods: '*',
+  exposeHeaders: '*',
+})
+
+const withBenchmarking = (request) => {
+  request.start = Date.now()
+}
+
+const withAuth = (request) => {
+  if (config.API_KEY) {
+    const authHeader = request.headers.get('Authorization')
+    if (!authHeader || !authHeader.startsWith('Bearer ')) {
+      return error(401, 'Unauthorized: Missing or invalid Authorization header')
+    }
+    const token = authHeader.substring(7)
+    if (token !== config.API_KEY) {
+      return error(403, 'Forbidden: Invalid API key')
+    }
+  }
+}
+
+const logger = (res, req) => {
+  console.log(req.method, res.status, req.url, Date.now() - req.start, 'ms')
+}
+
+const router = AutoRouter({
+  before: [withBenchmarking, preflight, withAuth],
+  missing: () => error(404, '404 not found.'),
+  finally: [corsify, logger],
+})
+
+router.get('/', () => json({ message: 'API 服务运行中~' }))
+router.get('/ping', () => json({ message: 'pong' }))
+router.get(config.API_PREFIX + '/v1/models', () =>
+  json({
+    object: 'list',
+    data: [
+      { id: 'gpt-4o-mini', object: 'model', owned_by: 'ddg' },
+      { id: 'claude-3-haiku', object: 'model', owned_by: 'ddg' },
+      { id: 'llama-3.1-70b', object: 'model', owned_by: 'ddg' },
+      { id: 'mixtral-8x7b', object: 'model', owned_by: 'ddg' },
+    ],
+  })
+)
+
+router.post(config.API_PREFIX + '/v1/chat/completions', (req) => handleCompletion(req))
+
+async function handleCompletion(request) {
+  try {
+    const { model: inputModel, messages, stream: returnStream } = await request.json()
+    const model = convertModel(inputModel)
+    const content = messagesPrepare(messages)
+    return createCompletion(model, content, returnStream)
+  } catch (err) {
+    error(500, err.message)
+  }
+}
+
+async function createCompletion(model, content, returnStream, retryCount = 0) {
+  const token = await requestToken()
+  try {
+    const response = await fetch(`https://duckduckgo.com/duckchat/v1/chat`, {
+      method: 'POST',
+      headers: {
+        ...config.FAKE_HEADERS,
+        Accept: 'text/event-stream',
+        'Content-Type': 'application/json',
+        'x-vqd-4': token,
+      },
+      body: JSON.stringify({
+        model: model,
+        messages: [
+          {
+            role: 'user',
+            content: content,
+          },
+        ],
+      }),
+    })
+
+    if (!response.ok) {
+      throw new Error(`HTTP error! status: ${response.status}`)
+    }
+    return handlerStream(model, response.body, returnStream)
+  } catch (err) {
+    console.log(err)
+    if (retryCount < config.MAX_RETRY_COUNT) {
+      console.log('Retrying... count', ++retryCount)
+      await new Promise((resolve) => setTimeout(resolve, config.RETRY_DELAY))
+      return await createCompletion(model, content, returnStream, retryCount)
+    }
+    throw err
+  }
+}
+
+async function handlerStream(model, rb, returnStream) {
+  let bwzChunk = ''
+  let previousText = ''
+  const handChunkData = (chunk) => {
+    chunk = chunk.trim()
+    if (bwzChunk != '') {
+      chunk = bwzChunk + chunk
+      bwzChunk = ''
+    }
+
+    if (chunk.includes('[DONE]')) {
+      return chunk
+    }
+
+    if (chunk.slice(-2) !== '"}') {
+      bwzChunk = chunk
+    }
+    return chunk
+  }
+  const reader = rb.getReader()
+  const decoder = new TextDecoder()
+  const encoder = new TextEncoder()
+  const stream = new ReadableStream({
+    async start(controller) {
+      while (true) {
+        const { done, value } = await reader.read()
+        if (done) {
+          return controller.close()
+        }
+        const chunkStr = handChunkData(decoder.decode(value))
+        if (bwzChunk !== '') {
+          continue
+        }
+
+        chunkStr.split('\n').forEach((line) => {
+          if (line.length < 6) {
+            return
+          }
+          line = line.slice(6)
+          if (line !== '[DONE]') {
+            const originReq = JSON.parse(line)
+
+            if (originReq.action !== 'success') {
+              return controller.error(new Error('Error: originReq stream chunk is not success'))
+            }
+
+            if (originReq.message) {
+              previousText += originReq.message
+              if (returnStream) {
+                controller.enqueue(
+                  encoder.encode(`data: ${JSON.stringify(newChatCompletionChunkWithModel(originReq.message, originReq.model))}\n\n`)
+                )
+              }
+            }
+          } else {
+            if (returnStream) {
+              controller.enqueue(encoder.encode(`data: ${JSON.stringify(newStopChunkWithModel('stop', model))}\n\n`))
+            } else {
+              controller.enqueue(encoder.encode(JSON.stringify(newChatCompletionWithModel(previousText, model))))
+            }
+            return controller.close()
+          }
+        })
+        continue
+      }
+    },
+  })
+
+  return new Response(stream, {
+    headers: {
+      'Content-Type': returnStream ? 'text/event-stream' : 'application/json',
+    },
+  })
+}
+
+function messagesPrepare(messages) {
+  let content = ''
+  for (const message of messages) {
+    let role = message.role === 'system' ? 'user' : message.role
+
+    if (['user', 'assistant'].includes(role)) {
+      const contentStr = Array.isArray(message.content)
+        ? message.content
+            .filter((item) => item.text)
+            .map((item) => item.text)
+            .join('') || ''
+        : message.content
+      content += `${role}:${contentStr};\r\n`
+    }
+  }
+  return content
+}
+
+async function requestToken() {
+  const response = await fetch(`https://duckduckgo.com/duckchat/v1/status`, {
+    method: 'GET',
+    headers: {
+      ...config.FAKE_HEADERS,
+      'x-vqd-accept': '1',
+    },
+  })
+
+  if (!response.ok) {
+    throw new Error(`HTTP error! status: ${response.status}`)
+  }
+
+  const token = response.headers.get('x-vqd-4')
+  return token
+}
+
+function convertModel(inputModel) {
+  let model
+  switch (inputModel.toLowerCase()) {
+    case 'claude-3-haiku':
+      model = 'claude-3-haiku-20240307'
+      break
+    case 'llama-3.1-70b':
+      model = 'meta-llama/Meta-Llama-3.1-70B-Instruct-Turbo'
+      break
+    case 'mixtral-8x7b':
+      model = 'mistralai/Mixtral-8x7B-Instruct-v0.1'
+      break
+  }
+  return model || 'gpt-4o-mini'
+}
+
+function newChatCompletionChunkWithModel(text, model) {
+  return {
+    id: 'chatcmpl-QXlha2FBbmROaXhpZUFyZUF3ZXNvbWUK',
+    object: 'chat.completion.chunk',
+    created: 0,
+    model,
+    choices: [
+      {
+        index: 0,
+        delta: {
+          content: text,
+        },
+        finish_reason: null,
+      },
+    ],
+  }
+}
+
+function newStopChunkWithModel(reason, model) {
+  return {
+    id: 'chatcmpl-QXlha2FBbmROaXhpZUFyZUF3ZXNvbWUK',
+    object: 'chat.completion.chunk',
+    created: 0,
+    model,
+    choices: [
+      {
+        index: 0,
+        finish_reason: reason,
+      },
+    ],
+  }
+}
+
+function newChatCompletionWithModel(text, model) {
+  return {
+    id: 'chatcmpl-QXlha2FBbmROaXhpZUFyZUF3ZXNvbWUK',
+    object: 'chat.completion',
+    created: 0,
+    model,
+    usage: {
+      prompt_tokens: 0,
+      completion_tokens: 0,
+      total_tokens: 0,
+    },
+    choices: [
+      {
+        message: {
+          content: text,
+          role: 'assistant',
+        },
+        index: 0,
+      },
+    ],
+  }
+}
+
+// Serverless Service
+
+;(async () => {
+  //For Cloudflare Workers
+  if (typeof addEventListener === 'function') return
+  // For Nodejs
+  const ittyServer = createServerAdapter(router.fetch)
+  console.log(`Listening on http://localhost:${process.env.PORT || 8787}`)
+  const httpServer = createServer(ittyServer)
+  httpServer.listen(8787)
+})()
+
+// export default router