import { err, ok, type CommandContext } from "@tailor-platform/erp-kit/core";
import type { Transaction } from "../generated/kysely-tailordb";
import {
  validateNightWindow,
  validateRoundingDirections,
  validateTimeEntryCodeReferences,
  type WorkRulePremiumRatePercentInput,
} from "../lib/_workRuleValidation";

export interface CreateWorkRuleInput {
  displayName: string;
  /** Optional HolidayCalendar this rule uses for holiday classification; null = no calendar. */
  holidayCalendarId?: string | null;
  clockInRoundingUnitMinutes: number;
  clockInRoundingDirection: string;
  clockOutRoundingUnitMinutes: number;
  clockOutRoundingDirection: string;
  breakRoundingUnitMinutes: number;
  breakRoundingDirection: string;
  breakDeductionMinutes: number;
  dailyOvertimeThresholdMinutes: number;
  nightWindowStart: number;
  nightWindowEnd: number;
  premiumRatePercent: WorkRulePremiumRatePercentInput[];
  effectiveStart: Date;
}

/**
 * Function: createWorkRule
 * Description: Defines the initial effective-dated generation of a WorkRule —
 * the complete time-calculation rule: rounding, break deduction, daily
 * overtime threshold, night window, and premium-category TimeEntryCode
 * category/key pins.
 */
export async function run(db: Transaction, input: CreateWorkRuleInput, _ctx: CommandContext) {
  const roundingDirectionError = validateRoundingDirections(input);
  if (roundingDirectionError) {
    return err(roundingDirectionError);
  }

  const nightWindowError = validateNightWindow(input);
  if (nightWindowError) {
    return err(nightWindowError);
  }

  const timeEntryCodeReferenceError = await validateTimeEntryCodeReferences(
    db,
    input.premiumRatePercent,
  );
  if (timeEntryCodeReferenceError) {
    return err(timeEntryCodeReferenceError);
  }

  const id = crypto.randomUUID();
  const workRule = await db
    .insertInto("WorkRule")
    .values({
      id,
      displayName: input.displayName,
      holidayCalendarId: input.holidayCalendarId ?? null,
      clockInRoundingUnitMinutes: input.clockInRoundingUnitMinutes,
      clockInRoundingDirection: input.clockInRoundingDirection as "UP" | "DOWN" | "NEAREST",
      clockOutRoundingUnitMinutes: input.clockOutRoundingUnitMinutes,
      clockOutRoundingDirection: input.clockOutRoundingDirection as "UP" | "DOWN" | "NEAREST",
      breakRoundingUnitMinutes: input.breakRoundingUnitMinutes,
      breakRoundingDirection: input.breakRoundingDirection as "UP" | "DOWN" | "NEAREST",
      breakDeductionMinutes: input.breakDeductionMinutes,
      dailyOvertimeThresholdMinutes: input.dailyOvertimeThresholdMinutes,
      nightWindowStart: input.nightWindowStart,
      nightWindowEnd: input.nightWindowEnd,
      premiumRatePercent: input.premiumRatePercent,
      effectiveStart: input.effectiveStart,
      effectiveEnd: null,
      versionOf: id,
    })
    .returningAll()
    .executeTakeFirstOrThrow();

  return ok({ workRule });
}