Remove unused services and refactor SDK structure

Deleted outdated SDKs and services, including DocumentService and markdown-sdk. Consolidated and relocated SDKs into a unified "providers" structure to improve maintainability. Updated imports and adjusted utils naming for consistency.

workers/site/providers/openai.ts

@@ -0,0 +1,95 @@
+import { OpenAI } from "openai";
+import ChatSdk from "../sdk/chat-sdk";
+
+export class OpenAiChatSdk {
+  static async handleOpenAiStream(
+    ctx: {
+      openai: OpenAI;
+      systemPrompt: any;
+      preprocessedContext: any;
+      maxTokens: unknown | number | undefined;
+      messages: any;
+      model: any;
+    },
+    dataCallback: (data: any) => any,
+  ) {
+    const {
+      openai,
+      systemPrompt,
+      maxTokens,
+      messages,
+      model,
+      preprocessedContext,
+    } = ctx;
+
+    if (!messages?.length) {
+      return new Response("No messages provided", { status: 400 });
+    }
+
+    const assistantPrompt = ChatSdk.buildAssistantPrompt({
+      maxTokens: maxTokens,
+    });
+    const safeMessages = ChatSdk.buildMessageChain(messages, {
+      systemPrompt: systemPrompt,
+      model,
+      assistantPrompt,
+      toolResults: preprocessedContext,
+    });
+
+    return OpenAiChatSdk.streamOpenAiResponse(
+      safeMessages,
+      {
+        model,
+        maxTokens: maxTokens as number,
+        openai: openai,
+      },
+      dataCallback,
+    );
+  }
+
+  private static async streamOpenAiResponse(
+    messages: any[],
+    opts: {
+      model: string;
+      maxTokens: number | undefined;
+      openai: OpenAI;
+    },
+    dataCallback: (data: any) => any,
+  ) {
+    const isO1 = () => {
+      if (opts.model === "o1-preview" || opts.model === "o1-mini") {
+        return true;
+      }
+    };
+
+    const tuningParams: Record<string, any> = {};
+
+    const gpt4oTuningParams = {
+      temperature: 0.86,
+      top_p: 0.98,
+      presence_penalty: 0.1,
+      frequency_penalty: 0.3,
+      max_tokens: opts.maxTokens,
+    };
+
+    const getTuningParams = () => {
+      if (isO1()) {
+        tuningParams["temperature"] = 1;
+        tuningParams["max_completion_tokens"] = opts.maxTokens + 10000;
+        return tuningParams;
+      }
+      return gpt4oTuningParams;
+    };
+
+    const openAIStream = await opts.openai.chat.completions.create({
+      model: opts.model,
+      messages: messages,
+      stream: true,
+      ...getTuningParams(),
+    });
+
+    for await (const chunk of openAIStream) {
+      dataCallback({ type: "chat", data: chunk });
+    }
+  }
+}