import type { WorkspaceMergeResult } from "agent-relay-sdk";

// #638 — settle a `workspace.merge` command on whether it made progress, not on whether
// the merge function threw. Every no-progress outcome (origin moved ahead, an unpredicted
// replay conflict, a push race) returns merged:false with an `error` set; every genuine
// land / recycle / noop-resolve / PR-opened leaves `error` undefined. Reporting `succeeded`
// for an unlanded branch is what let the auto-merge job believe it was progressing and
// busy-loop the repo's merge lease. Mirrors the pr-merge / pr-arm settle contract.
export function mergeCommandStatus(result: WorkspaceMergeResult): "succeeded" | "failed" {
  return result.error ? "failed" : "succeeded";
}

// Command PATCH bodies are capped at 64 KiB by the relay. A failing full land gate
// may retain 256 KiB of output for artifact upload, so forwarding it verbatim can
// reject the *terminal* update and leave expiry to misreport a red gate as a timeout.
// Keep ordinary output intact; when it will not fit, retain the bounded tail that is
// already intended for the worker/coordinator notification.
const MAX_COMMAND_REPORT_CHARS = 60 * 1024;

export function prepareWorkspaceMergeResultForReport(result: WorkspaceMergeResult): WorkspaceMergeResult {
  const gateFailure = result.gateFailure;
  if (!gateFailure?.output) return result;
  const body = JSON.stringify({ status: mergeCommandStatus(result), result, error: result.error });
  if (body.length <= MAX_COMMAND_REPORT_CHARS) return result;
  return {
    ...result,
    gateFailure: {
      ...gateFailure,
      output: gateFailure.outputTail,
    },
  };
}