Create freeai_proxy.ts

freeai_proxy.ts

@@ -0,0 +1,437 @@
+// freeai_proxy.ts
+import { serve } from "https://deno.land/std@0.190.0/http/server.ts";
+
+const FREEAI_API_BASE = "https://freeaichatplayground.com/api/v1";
+const DEFAULT_MODEL = "Deepseek R1";
+
+// 获取可用模型列表
+async function fetchModels() {
+  try {
+    const response = await fetch(`${FREEAI_API_BASE}/models`, {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json",
+        "User-Agent": "Mozilla/5.0 (X11; Linux x86_64; rv:137.0) Gecko/20100101 Firefox/137.0",
+        "Origin": "https://freeaichatplayground.com",
+        "Referer": "https://freeaichatplayground.com/chat",
+      },
+      body: JSON.stringify({ type: "text" }),
+    });
+
+    if (!response.ok) {
+      throw new Error(`Failed to fetch models: ${response.status}`);
+    }
+
+    const models = await response.json();
+    return models;
+  } catch (error) {
+    console.error("Error fetching models:", error);
+    return [];
+  }
+}
+
+// 转换为 OpenAI 格式的模型列表
+function transformModelsToOpenAIFormat(models) {
+  return {
+    object: "list",
+    data: models.map(model => ({
+      id: model.name,
+      object: "model",
+      created: new Date(model.createdAt).getTime() / 1000,
+      owned_by: model.provider,
+      permission: [],
+      root: model.name,
+      parent: null,
+    })),
+  };
+}
+
+// 解析 SSE 格式的响应
+async function parseSSEResponse(response) {
+  const reader = response.body.getReader();
+  let content = "";
+  let id = `chatcmpl-${Date.now()}`;
+  let finishReason = "stop";
+  
+  try {
+    while (true) {
+      const { done, value } = await reader.read();
+      if (done) break;
+      
+      const chunk = new TextDecoder().decode(value);
+      content += chunk;
+    }
+    
+    // 解析所有 SSE 消息
+    const messages = content.split('\n\n')
+      .filter(msg => msg.trim().startsWith('data:'))
+      .map(msg => {
+        const jsonStr = msg.replace('data:', '').trim();
+        try {
+          return JSON.parse(jsonStr);
+        } catch (e) {
+          console.warn("Failed to parse SSE message:", jsonStr);
+          return null;
+        }
+      })
+      .filter(Boolean);
+    
+    // 找到最后一条完整消息
+    const lastCompleteMessage = messages.findLast(msg => 
+      msg.choices && msg.choices[0] && msg.choices[0].message && msg.choices[0].message.content
+    );
+    
+    if (lastCompleteMessage) {
+      id = lastCompleteMessage.id || id;
+      if (lastCompleteMessage.choices && 
+          lastCompleteMessage.choices[0] && 
+          lastCompleteMessage.choices[0].finish_reason) {
+        finishReason = lastCompleteMessage.choices[0].finish_reason;
+      }
+      
+      return {
+        id,
+        content: lastCompleteMessage.choices[0].message.content,
+        finish_reason: finishReason,
+        usage: lastCompleteMessage.usage || null
+      };
+    }
+    
+    // 如果没有找到完整消息，尝试从所有消息中提取内容
+    let combinedContent = "";
+    for (const msg of messages) {
+      if (msg.choices && msg.choices[0] && msg.choices[0].delta && msg.choices[0].delta.content) {
+        combinedContent += msg.choices[0].delta.content;
+      } else if (msg.choices && msg.choices[0] && msg.choices[0].message && msg.choices[0].message.content) {
+        combinedContent += msg.choices[0].message.content;
+      }
+    }
+    
+    return {
+      id,
+      content: combinedContent || "No content found in response",
+      finish_reason: finishReason,
+      usage: null
+    };
+    
+  } catch (error) {
+    console.error("Error parsing SSE response:", error);
+    return {
+      id,
+      content: "Error parsing response: " + error.message,
+      finish_reason: "error",
+      usage: null
+    };
+  }
+}
+
+// 发送聊天请求到 freeaichatplayground
+async function sendChatRequest(modelName, messages) {
+  try {
+    const formattedMessages = messages.map((msg, index) => ({
+      id: `${Date.now() + index}`,
+      role: msg.role,
+      content: msg.content,
+      model: {
+        id: "", // 这个ID会在下面被填充
+        name: modelName,
+        icon: "",
+        provider: "",
+        contextWindow: 63920
+      }
+    }));
+
+    // 获取模型列表以找到正确的ID
+    const models = await fetchModels();
+    const selectedModel = models.find(m => m.name === modelName);
+    
+    if (!selectedModel) {
+      throw new Error(`Model "${modelName}" not found`);
+    }
+    
+    // 填充模型信息
+    formattedMessages.forEach(msg => {
+      if (msg.model) {
+        msg.model.id = selectedModel.id;
+        msg.model.icon = selectedModel.icon;
+        msg.model.provider = selectedModel.provider;
+      }
+    });
+
+    const response = await fetch(`${FREEAI_API_BASE}/chat/completions`, {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json",
+        "User-Agent": "Mozilla/5.0 (X11; Linux x86_64; rv:137.0) Gecko/20100101 Firefox/137.0",
+        "Origin": "https://freeaichatplayground.com",
+        "Referer": "https://freeaichatplayground.com/chat",
+      },
+      body: JSON.stringify({
+        model: modelName,
+        messages: formattedMessages,
+      }),
+    });
+
+    if (!response.ok) {
+      const errorText = await response.text();
+      throw new Error(`Chat completion failed: ${response.status} - ${errorText}`);
+    }
+
+    // 处理 SSE 流式响应
+    const parsedResponse = await parseSSEResponse(response);
+    return parsedResponse;
+  } catch (error) {
+    console.error("Error in chat completion:", error);
+    throw error;
+  }
+}
+
+// 转换为 OpenAI 格式的聊天响应
+function transformChatResponseToOpenAIFormat(response, modelName) {
+  return {
+    id: response.id || `chatcmpl-${Date.now()}`,
+    object: "chat.completion",
+    created: Math.floor(Date.now() / 1000),
+    model: modelName,
+    choices: [
+      {
+        index: 0,
+        message: {
+          role: "assistant",
+          content: response.content,
+        },
+        finish_reason: response.finish_reason || "stop",
+      },
+    ],
+    usage: response.usage || {
+      prompt_tokens: 0,
+      completion_tokens: 0,
+      total_tokens: 0,
+    },
+  };
+}
+
+// 处理流式响应请求
+async function handleStreamRequest(request, modelName, messages) {
+  const encoder = new TextEncoder();
+  const formattedMessages = messages.map((msg, index) => ({
+    id: `${Date.now() + index}`,
+    role: msg.role,
+    content: msg.content,
+    model: {
+      id: "", // 这个ID会在下面被填充
+      name: modelName,
+      icon: "",
+      provider: "",
+      contextWindow: 63920
+    }
+  }));
+
+  // 获取模型列表以找到正确的ID
+  const models = await fetchModels();
+  const selectedModel = models.find(m => m.name === modelName);
+  
+  if (!selectedModel) {
+    throw new Error(`Model "${modelName}" not found`);
+  }
+  
+  // 填充模型信息
+  formattedMessages.forEach(msg => {
+    if (msg.model) {
+      msg.model.id = selectedModel.id;
+      msg.model.icon = selectedModel.icon;
+      msg.model.provider = selectedModel.provider;
+    }
+  });
+
+  const response = await fetch(`${FREEAI_API_BASE}/chat/completions`, {
+    method: "POST",
+    headers: {
+      "Content-Type": "application/json",
+      "User-Agent": "Mozilla/5.0 (X11; Linux x86_64; rv:137.0) Gecko/20100101 Firefox/137.0",
+      "Origin": "https://freeaichatplayground.com",
+      "Referer": "https://freeaichatplayground.com/chat",
+    },
+    body: JSON.stringify({
+      model: modelName,
+      messages: formattedMessages,
+      stream: true,
+    }),
+  });
+
+  if (!response.ok) {
+    const errorText = await response.text();
+    throw new Error(`Chat completion failed: ${response.status} - ${errorText}`);
+  }
+
+  const stream = new ReadableStream({
+    async start(controller) {
+      const reader = response.body.getReader();
+      const chatId = `chatcmpl-${Date.now()}`;
+      
+      // 发送初始消息
+      const initialChunk = {
+        id: chatId,
+        object: "chat.completion.chunk",
+        created: Math.floor(Date.now() / 1000),
+        model: modelName,
+        choices: [{
+          index: 0,
+          delta: { role: "assistant" },
+          finish_reason: null
+        }]
+      };
+      controller.enqueue(encoder.encode(`data: ${JSON.stringify(initialChunk)}\n\n`));
+      
+      try {
+        let buffer = "";
+        
+        while (true) {
+          const { done, value } = await reader.read();
+          if (done) break;
+          
+          const chunk = new TextDecoder().decode(value);
+          buffer += chunk;
+          
+          // 处理缓冲区中的所有完整 SSE 消息
+          const messages = buffer.split('\n\n');
+          buffer = messages.pop() || ""; // 保留最后一个可能不完整的消息
+          
+          for (const msg of messages) {
+            if (!msg.trim().startsWith('data:')) continue;
+            
+            try {
+              const jsonStr = msg.replace('data:', '').trim();
+              const data = JSON.parse(jsonStr);
+              
+              if (data.choices && data.choices[0]) {
+                // 转换为 OpenAI 流式格式
+                const openAIChunk = {
+                  id: chatId,
+                  object: "chat.completion.chunk",
+                  created: Math.floor(Date.now() / 1000),
+                  model: modelName,
+                  choices: [{
+                    index: 0,
+                    delta: {},
+                    finish_reason: data.choices[0].finish_reason || null
+                  }]
+                };
+                
+                // 提取内容
+                if (data.choices[0].delta && data.choices[0].delta.content) {
+                  openAIChunk.choices[0].delta.content = data.choices[0].delta.content;
+                } else if (data.choices[0].message && data.choices[0].message.content) {
+                  openAIChunk.choices[0].delta.content = data.choices[0].message.content;
+                }
+                
+                controller.enqueue(encoder.encode(`data: ${JSON.stringify(openAIChunk)}\n\n`));
+                
+                // 如果是最后一条消息，发送 [DONE]
+                if (data.choices[0].finish_reason) {
+                  controller.enqueue(encoder.encode("data: [DONE]\n\n"));
+                }
+              }
+            } catch (e) {
+              console.warn("Failed to parse SSE message:", msg);
+              continue;
+            }
+          }
+        }
+        
+        // 确保发送最终的 [DONE] 消息
+        controller.enqueue(encoder.encode("data: [DONE]\n\n"));
+        controller.close();
+      } catch (error) {
+        console.error("Stream processing error:", error);
+        controller.error(error);
+      }
+    }
+  });
+
+  return new Response(stream, {
+    headers: {
+      "Content-Type": "text/event-stream",
+      "Cache-Control": "no-cache",
+      "Connection": "keep-alive",
+      "Access-Control-Allow-Origin": "*",
+    }
+  });
+}
+
+// 处理请求
+async function handleRequest(request) {
+  const url = new URL(request.url);
+  const path = url.pathname;
+
+  // CORS 预检请求处理
+  if (request.method === "OPTIONS") {
+    return new Response(null, {
+      status: 200,
+      headers: {
+        "Access-Control-Allow-Origin": "*",
+        "Access-Control-Allow-Methods": "GET, POST, OPTIONS",
+        "Access-Control-Allow-Headers": "Content-Type, Authorization",
+      },
+    });
+  }
+
+  // 设置通用响应头
+  const headers = {
+    "Content-Type": "application/json",
+    "Access-Control-Allow-Origin": "*",
+  };
+
+  try {
+    // 模型列表接口
+    if (path === "/v1/models" && request.method === "GET") {
+      const models = await fetchModels();
+      const openAIModels = transformModelsToOpenAIFormat(models);
+      return new Response(JSON.stringify(openAIModels), { headers });
+    }
+    
+    // 聊天完成接口
+    else if (path === "/v1/chat/completions" && request.method === "POST") {
+      const requestData = await request.json();
+      const modelName = requestData.model || DEFAULT_MODEL;
+      const messages = requestData.messages || [];
+      const stream = requestData.stream || false;
+      
+      // 处理流式响应
+      if (stream) {
+        return handleStreamRequest(request, modelName, messages);
+      }
+      
+      // 处理普通响应
+      const chatResponse = await sendChatRequest(modelName, messages);
+      const openAIResponse = transformChatResponseToOpenAIFormat(chatResponse, modelName);
+      
+      return new Response(JSON.stringify(openAIResponse), { headers });
+    }
+    
+    // 未知路径
+    else {
+      return new Response(JSON.stringify({
+        error: {
+          message: "Not found",
+          type: "invalid_request_error",
+          code: "path_not_found",
+        }
+      }), { status: 404, headers });
+    }
+  } catch (error) {
+    console.error("Error handling request:", error);
+    return new Response(JSON.stringify({
+      error: {
+        message: error.message,
+        type: "server_error",
+        code: "internal_server_error",
+      }
+    }), { status: 500, headers });
+  }
+}
+
+// 启动服务器
+const port = parseInt(Deno.env.get("PORT") || "8000");
+console.log(`Starting server on port ${port}...`);
+serve(handleRequest, { port });