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

export interface CreateShiftScheduleInput {
  startDate: Date;
  endDate: Date;
}

/**
 * Function: createShiftSchedule
 * Description: Opens a shiftSchedule period in DRAFT. The period is exactly the from/to a planner
 * enters when generating shifts, so a generation run creates one ShiftSchedule and hangs its Shifts
 * off it. Overlapping periods are deliberately allowed: membership is the explicit Shift.shiftScheduleId
 * FK, so two shiftSchedules covering the same dates (a second site, a supplementary 応援 shiftSchedule, a
 * partial revision) are unambiguous rather than a conflict to reject.
 */
export async function run<CF extends Record<string, unknown>>(
  db: Transaction,
  input: CreateShiftScheduleInput & CF,
  _ctx: CommandContext,
) {
  const { startDate, endDate, ...customFields } = input;

  if (!startDate || !endDate) {
    return err(new MissingRequiredFieldError("startDate/endDate"));
  }
  if (endDate < startDate) {
    return err(new InvalidDateRangeError(`${startDate.toISOString()}..${endDate.toISOString()}`));
  }

  const shiftSchedule = await db
    .insertInto("ShiftSchedule")
    .values({
      ...(customFields as Record<string, unknown>),
      startDate,
      endDate,
      status: "DRAFT",
      confirmedAt: null,
    })
    .returningAll()
    .executeTakeFirstOrThrow();

  return ok({ shiftSchedule });
}