import { XllmError } from "../core/errors";
import type {
  XChatWithToolsOptions,
  XChatWithToolsResult,
  XClientOptions,
  XMessage,
  XRequest,
  XToolExecutorMap,
} from "../core/types";
import { generate } from "./generate";
import { runToolCall } from "./tool-loop-shared";

export const chatWithTools = async (
  options: XClientOptions,
  input: XChatWithToolsOptions,
  executors: XToolExecutorMap,
): Promise<XChatWithToolsResult> => {
  const maxRounds = input.maxRounds ?? 5;
  const strategy = input.toolErrorStrategy ?? "throw";
  if (maxRounds < 1) {
    throw new XllmError({
      code: "INVALID_REQUEST",
      message: "maxRounds must be >= 1",
      provider: input.provider ?? options.provider ?? "openai-compatible",
    });
  }

  let rounds = 0;
  let toolCallsExecuted = 0;
  let currentMessages = [...input.messages];
  const requestBase: Omit<XRequest, "messages"> = {
    tools: input.tools,
    toolChoice: input.toolChoice,
    stream: false,
    temperature: input.temperature,
    topP: input.topP,
    maxTokens: input.maxTokens,
    metadata: input.metadata,
    provider: input.provider,
    model: input.model,
    apiKey: input.apiKey,
    baseURL: input.baseURL,
  };

  while (rounds < maxRounds) {
    rounds += 1;
    const response = await generate(options, {
      ...requestBase,
      messages: currentMessages,
    });

    if (response.toolCalls.length === 0) {
      return { response, rounds, toolCallsExecuted };
    }

    const assistantMessage: XMessage = {
      role: "assistant",
      content: [{ type: "text", text: response.text }],
      toolCalls: response.toolCalls,
    };
    const toolMessages: XMessage[] = [];

    for (const toolCall of response.toolCalls) {
      const toolRunResult = await runToolCall(response.provider, toolCall, executors, strategy);
      if (!toolRunResult.handled || !toolRunResult.message) {
        continue;
      }
      toolMessages.push(toolRunResult.message);
      toolCallsExecuted += 1;
    }

    currentMessages = [...currentMessages, assistantMessage, ...toolMessages];
  }

  throw new XllmError({
    code: "PROVIDER_ERROR",
    message: `Tool loop exceeded maxRounds=${maxRounds}`,
    provider: input.provider ?? options.provider ?? "openai-compatible",
  });
};