import { ok, err, type CommandContext } from "@tailor-platform/erp-kit/core";
import { shiftScheduleLifecycle } from "../db/shiftSchedule.lifecycle.generated";
import type { Transaction } from "../generated/kysely-tailordb";
import {
  ShiftScheduleNotFoundError,
  ShiftScheduleAlreadyConfirmedError,
} from "../lib/errors.generated";

export interface ConfirmShiftScheduleInput {
  id: string;
}

/**
 * Function: confirmShiftSchedule
 * Description: Commits a whole shiftSchedule period to workers in one act (公開) — the operation that
 * used to require calling publishShift once per slot. Confirming freezes the period's shift
 * definitions; staffing (ShiftPlacement) stays changeable afterwards, because a same-day
 * substitution is a change of plan, not a re-publication of the table.
 */
export async function run(db: Transaction, input: ConfirmShiftScheduleInput, _ctx: CommandContext) {
  const shiftSchedule = await db
    .selectFrom("ShiftSchedule")
    .selectAll()
    .where("id", "=", input.id)
    .forUpdate()
    .executeTakeFirst();
  if (!shiftSchedule) {
    return err(new ShiftScheduleNotFoundError(input.id));
  }
  // The admissible transition comes from the generated lifecycle (docs/model/ShiftSchedule.md's
  // State Transitions table), so the state machine lives in one place instead of being restated
  // as a status comparison here. The module's own error is kept: "already confirmed" says more to
  // a caller than a generic invalid-transition code, and CONFIRMED is the only other state.
  const nextStatus = shiftScheduleLifecycle.tryTransition(shiftSchedule.status, "confirm");
  if (!nextStatus) {
    return err(new ShiftScheduleAlreadyConfirmedError(input.id));
  }

  const updated = await db
    .updateTable("ShiftSchedule")
    .set({ status: nextStatus, confirmedAt: new Date() })
    .where("id", "=", input.id)
    .returningAll()
    .executeTakeFirstOrThrow();

  return ok({ shiftSchedule: updated });
}