/**
 * CopilotKit Adapter for the OpenAI Assistant API.
 *
 * Use this adapter to get responses from the OpenAI Assistant API.
 *
 * <RequestExample>
 * ```typescript
 * const copilotKit = new CopilotRuntime();
 * return copilotKit.response(
 *   req,
 *   new OpenAIAssistantAdapter({
 *    assistantId: "your-assistant-id"
 *   })
 * );
 * ```
 * </RequestExample>
 */
import OpenAI from "openai";
import {
  CopilotServiceAdapter,
  CopilotRuntimeChatCompletionRequest,
  CopilotRuntimeChatCompletionResponse,
} from "../service-adapter";
import { Message, ResultMessage, TextMessage } from "../../graphql/types/converted";
import {
  convertActionInputToOpenAITool,
  convertMessageToOpenAIMessage,
  convertSystemMessageToAssistantAPI,
} from "./utils";
import { RunSubmitToolOutputsStreamParams } from "openai/resources/beta/threads/runs/runs";
import { AssistantStream } from "openai/lib/AssistantStream";
import { RuntimeEventSource } from "../events";
import { ActionInput } from "../../graphql/inputs/action.input";
import { AssistantStreamEvent, AssistantTool } from "openai/resources/beta/assistants";

export interface OpenAIAssistantAdapterParams {
  /**
   * The ID of the assistant to use.
   */
  assistantId: string;

  /**
   * An instance of `OpenAI` to use for the request. If not provided, a new instance will be created.
   */
  openai?: OpenAI;

  /**
   * Whether to enable the code interpreter. Defaults to `true`.
   */
  codeInterpreterEnabled?: boolean;

  /**
   * Whether to enable retrieval. Defaults to `true`.
   */
  fileSearchEnabled?: boolean;
}

export class OpenAIAssistantAdapter implements CopilotServiceAdapter {
  private openai: OpenAI;
  private codeInterpreterEnabled: boolean;
  private assistantId: string;
  private fileSearchEnabled: boolean;

  constructor(params: OpenAIAssistantAdapterParams) {
    this.openai = params.openai || new OpenAI({});
    this.codeInterpreterEnabled = params.codeInterpreterEnabled === false || true;
    this.fileSearchEnabled = params.fileSearchEnabled === false || true;
    this.assistantId = params.assistantId;
  }

  async process(
    request: CopilotRuntimeChatCompletionRequest,
  ): Promise<CopilotRuntimeChatCompletionResponse> {
    const { messages, actions, eventSource, runId } = request;
    // if we don't have a threadId, create a new thread
    let threadId = request.threadId || (await this.openai.beta.threads.create()).id;

    const lastMessage = messages.at(-1);

    let nextRunId: string | undefined = undefined;

    // submit function outputs
    if (lastMessage instanceof ResultMessage && runId) {
      nextRunId = await this.submitToolOutputs(threadId, runId, messages, eventSource);
    }
    // submit user message
    else if (lastMessage instanceof TextMessage) {
      nextRunId = await this.submitUserMessage(threadId, messages, actions, eventSource);
    }
    // unsupported message
    else {
      throw new Error("No actionable message found in the messages");
    }

    return {
      threadId,
      runId: nextRunId,
    };
  }

  private async submitToolOutputs(
    threadId: string,
    runId: string,
    messages: Message[],
    eventSource: RuntimeEventSource,
  ) {
    let run = await this.openai.beta.threads.runs.retrieve(threadId, runId);
    if (!run.required_action) {
      throw new Error("No tool outputs required");
    }

    // get the required tool call ids
    const toolCallsIds = run.required_action.submit_tool_outputs.tool_calls.map(
      (toolCall) => toolCall.id,
    );

    // search for these tool calls
    const resultMessages = messages.filter(
      (message) =>
        message instanceof ResultMessage && toolCallsIds.includes(message.actionExecutionId),
    ) as ResultMessage[];

    if (toolCallsIds.length != resultMessages.length) {
      throw new Error("Number of function results does not match the number of tool calls");
    }

    // submit the tool outputs
    const toolOutputs: RunSubmitToolOutputsStreamParams.ToolOutput[] = resultMessages.map(
      (message) => {
        return {
          tool_call_id: message.actionExecutionId,
          output: message.result,
        };
      },
    );

    const stream = this.openai.beta.threads.runs.submitToolOutputsStream(threadId, runId, {
      tool_outputs: toolOutputs,
    });

    await this.streamResponse(stream, eventSource);
    return runId;
  }

  private async submitUserMessage(
    threadId: string,
    messages: Message[],
    actions: ActionInput[],
    eventSource: RuntimeEventSource,
  ) {
    messages = [...messages];

    // get the instruction message
    const instructionsMessage = messages.shift();
    const instructions =
      instructionsMessage instanceof TextMessage ? instructionsMessage.content : "";

    // get the latest user message
    const userMessage = messages
      .map(convertMessageToOpenAIMessage)
      .map(convertSystemMessageToAssistantAPI)
      .at(-1);

    if (userMessage.role !== "user") {
      throw new Error("No user message found");
    }

    // create a new message on the thread
    await this.openai.beta.threads.messages.create(threadId, {
      role: "user",
      content: userMessage.content,
    });

    const openaiTools = actions.map(convertActionInputToOpenAITool);

    const tools = [
      ...openaiTools,
      ...(this.codeInterpreterEnabled ? [{ type: "code_interpreter" } as AssistantTool] : []),
      ...(this.fileSearchEnabled ? [{ type: "file_search" } as AssistantTool] : []),
    ];

    // run the thread
    let stream = this.openai.beta.threads.runs.stream(threadId, {
      assistant_id: this.assistantId,
      instructions,
      tools: tools,
    });

    await this.streamResponse(stream, eventSource);

    return getRunIdFromStream(stream);
  }

  private async streamResponse(stream: AssistantStream, eventSource: RuntimeEventSource) {
    eventSource.stream(async (eventStream$) => {
      let inFunctionCall = false;

      for await (const chunk of stream) {
        switch (chunk.event) {
          case "thread.message.created":
            if (inFunctionCall) {
              eventStream$.sendActionExecutionEnd();
            }
            eventStream$.sendTextMessageStart(chunk.data.id);
            break;
          case "thread.message.delta":
            if (chunk.data.delta.content?.[0].type === "text") {
              eventStream$.sendTextMessageContent(chunk.data.delta.content?.[0].text.value);
            }
            break;
          case "thread.message.completed":
            eventStream$.sendTextMessageEnd();
            break;
          case "thread.run.step.delta":
            let toolCallId: string | undefined;
            let toolCallName: string | undefined;
            let toolCallArgs: string | undefined;
            if (
              chunk.data.delta.step_details.type === "tool_calls" &&
              chunk.data.delta.step_details.tool_calls?.[0].type === "function"
            ) {
              toolCallId = chunk.data.delta.step_details.tool_calls?.[0].id;
              toolCallName = chunk.data.delta.step_details.tool_calls?.[0].function.name;
              toolCallArgs = chunk.data.delta.step_details.tool_calls?.[0].function.arguments;
            }

            if (toolCallName && toolCallId) {
              if (inFunctionCall) {
                eventStream$.sendActionExecutionEnd();
              }
              inFunctionCall = true;
              eventStream$.sendActionExecutionStart(toolCallId, toolCallName);
            } else if (toolCallArgs) {
              eventStream$.sendActionExecutionArgs(toolCallArgs);
            }
            break;
        }
      }
      if (inFunctionCall) {
        eventStream$.sendActionExecutionEnd();
      }
      eventStream$.complete();
    });
  }
}

function getRunIdFromStream(stream: AssistantStream): Promise<string> {
  return new Promise<string>((resolve, reject) => {
    let runIdGetter = (event: AssistantStreamEvent) => {
      if (event.event === "thread.run.created") {
        const runId = event.data.id;
        stream.off("event", runIdGetter);
        resolve(runId);
      }
    };
    stream.on("event", runIdGetter);
  });
}