import { ok, err, type CommandContext } from "@tailor-platform/erp-kit/core";
import type { Transaction } from "../generated/kysely-tailordb";
import {
  PositionNotFoundError,
  PositionAlreadyAbolishedError,
  PositionHasOpenAssignmentError,
} from "../lib/errors.generated";

export interface AbolishPositionInput {
  id: string;
  effectiveEnd: Date;
}

/** Function: run
 Description: Closes the current generation of a Position (sets effectiveEnd) when the post is eliminated. */
export async function run(db: Transaction, input: AbolishPositionInput, _ctx: CommandContext) {
  const position = await db
    .selectFrom("Position")
    .selectAll()
    .where("id", "=", input.id)
    .forUpdate()
    .executeTakeFirst();

  if (!position) return err(new PositionNotFoundError(input.id));
  if (position.effectiveEnd !== null) return err(new PositionAlreadyAbolishedError(input.id));

  const openAssignment = await db
    .selectFrom("Assignment")
    .select("id")
    .where("positionId", "=", input.id)
    .where("effectiveEnd", "is", null)
    .executeTakeFirst();
  if (openAssignment) return err(new PositionHasOpenAssignmentError(input.id));

  const updated = await db
    .updateTable("Position")
    .set({ effectiveEnd: input.effectiveEnd })
    .where("id", "=", input.id)
    .returningAll()
    .executeTakeFirstOrThrow();

  return ok({ position: updated });
}