import message from './LLM'

const streamToComponent = async (
    chatContent: message[],
    setTargetText: React.Dispatch<React.SetStateAction<message[]>>
  ) => {
    const url = "https://api.openai.com/v1/chat/completions";
  
    // set initial value for the chat
    setTargetText([...chatContent, { role: "", content: "" }]);
  
    const body = JSON.stringify({
      messages: chatContent,
      stream: true,
      model: "gpt-3.5-turbo",
      max_tokens: 2000,
    });
  
    try {
      const response = await fetch(url, {
        method: "POST",
        mode: "cors",
        headers: {
          "Content-Type": "application/json",
          Accept: "text/event-stream",
          Authorization:
          "Access-Control-Allow-Origin": "*",
        },
        body,
      });
  
      const reader = response.body!.getReader();
      const decoder = new TextDecoder();
      while (true) {
        // Read a chunk from the stream
        const { value, done } = await reader.read();
  
        // If the stream is done, break the loop
        if (done) {
          break;
        }
        const string_payload: string = decoder.decode(value, { stream: true });
        const list_payload: string[] = string_payload
          .split("\n")
          .filter((line) => line.trim() !== "");
  
        for (const line of list_payload) {
          const message = line.replace(/^data: /, "");
          if (message.startsWith("[DONE]")) {
            return; // Stream finished
          }
          try {
            const parsed = JSON.parse(message);
            const result: any = parsed.choices[0].delta;
            //console.log(result);
            if ("role" in result) {
              setTargetText((targetText: message[]) => [
                ...targetText.slice(0, -1),
                {
                  ...targetText[targetText.length - 1],
                  role: result.role.toString(),
                },
              ]);
            }
            if ("content" in result) {
              setTargetText((targetText: message[]) => [
                ...targetText.slice(0, -1),
                {
                  ...targetText[targetText.length - 1],
                  content:
                    targetText[targetText.length - 1].content +
                    result.content.toString(),
                },
              ]);
            }
          } catch (error) {
            console.error("Could not JSON parse stream message", message, error);
          }
        }
      }
    } catch (error) {
      console.error(error);
    }
  };

  export default streamToComponent;