import {
  DEFAULT_MAX_BYTES,
  DEFAULT_MAX_LINES,
  formatSize,
  truncateHead,
} from "@mariozechner/pi-coding-agent";

export const wrapResult = (text: string) => {
  const truncation = truncateHead(text, {
    maxLines: DEFAULT_MAX_LINES,
    maxBytes: DEFAULT_MAX_BYTES,
  });

  let output = truncation.content;
  if (truncation.truncated) {
    output += `\n\n[Output truncated: ${truncation.outputLines} of ${truncation.totalLines} lines `;
    output += `(${formatSize(truncation.outputBytes)} of ${formatSize(truncation.totalBytes)}).]`;
  }

  return { content: [{ type: "text", text: output }] };
};

export const createWithCommonHandling = (deps: {
  callSerena: (toolName: string, args: Record<string, unknown>, timeoutMs: number) => Promise<string>;
  resetClient: () => Promise<void>;
  defaultTimeoutMs: number;
}) => {
  return async (
    signal: AbortSignal | undefined,
    timeoutSeconds: number | undefined,
    toolName: string,
    args: Record<string, unknown>,
  ) => {
    if (signal?.aborted) {
      return { content: [{ type: "text", text: "Request cancelled." }], isError: true };
    }

    const timeoutMs = timeoutSeconds ? timeoutSeconds * 1000 : deps.defaultTimeoutMs;

    try {
      const text = await deps.callSerena(toolName, args, timeoutMs);
      return wrapResult(text);
    } catch (err: any) {
      await deps.resetClient();
      const message = err?.message ? `Serena MCP error: ${err.message}` : "Serena MCP error.";
      return { content: [{ type: "text", text: message }], isError: true };
    }
  };
};