import type { ExtensionAPI, ExtensionContext } from "@earendil-works/pi-coding-agent";
import { hasExecutionCwdOwner } from "../runs/shared/child-execution-cwd.ts";
import type { ReadonlyInput } from "./types/inputs.ts";

function validateDirectoryReply(
  result: { readonly cwd?: string; readonly error?: string } | undefined,
): void {
  if (result?.error !== undefined && result.error !== "") {
    throw new Error(result.error);
  }
  if (result && (result.cwd === undefined || result.cwd === "")) {
    throw new Error("Working-directory owner did not return an execution directory.");
  }
}
/** Capture the active directory owner once per invocation, before asynchronous preparation. */
export function resolveExecutionCwd(
  pi: ReadonlyInput<
    Pick<ExtensionAPI, "events"> & Partial<Pick<ExtensionAPI, "getAllTools" | "getCommands">>
  >,
  ctx: ExtensionContext,
): string {
  const request: {
    sessionManager: ExtensionContext["sessionManager"];
    result?: { cwd?: string; error?: string };
  } = { sessionManager: ctx.sessionManager };
  pi.events.emit("pi-change-working-dir:resolve-execution-cwd", request);
  validateDirectoryReply(request.result);
  if (
    !request.result &&
    pi.getAllTools &&
    pi.getCommands &&
    hasExecutionCwdOwner({ getAllTools: pi.getAllTools, getCommands: pi.getCommands })
  ) {
    throw new Error(
      "The loaded directory extension did not resolve the execution directory. Update pi-change-working-dir before delegating work.",
    );
  }
  return request.result?.cwd ?? ctx.cwd;
}