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

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

/** Function: run
 Description: Closes the current open generation of an Assignment (sets effectiveEnd) without creating a replacement generation. */
export async function run(db: Transaction, input: EndAssignmentInput, _ctx: CommandContext) {
  const assignment = await db
    .selectFrom("Assignment")
    .selectAll()
    .where("id", "=", input.id)
    .forUpdate()
    .executeTakeFirst();

  if (!assignment) return err(new AssignmentNotFoundError(input.id));
  if (assignment.effectiveEnd !== null) return err(new AssignmentAlreadyClosedError(input.id));

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

  return ok({ assignment: updated });
}