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

const HOLIDAY_KINDS = ["STATUTORY", "PRESCRIBED"] as const;

export type UpdateCompanyHolidayInput = {
  id: string;
} & {
  holidayDate?: Date;
  holidayKind?: string;
  name?: string;
};

/**
 * Function: updateCompanyHoliday
 * Description: Corrects a previously registered holiday's name or
 * holidayKind (or holidayDate) in place. Because CompanyHoliday is a plain
 * dated fact rather than an effective-dated series, the correction edits
 * the existing record directly instead of closing a generation.
 */
export async function run(db: Transaction, input: UpdateCompanyHolidayInput, _ctx: CommandContext) {
  const companyHoliday = await db
    .selectFrom("CompanyHoliday")
    .selectAll()
    .where("id", "=", input.id)
    .forUpdate()
    .executeTakeFirst();
  if (!companyHoliday) {
    return err(new HolidayNotFoundError(input.id));
  }

  if (
    input.holidayKind !== undefined &&
    !(HOLIDAY_KINDS as readonly string[]).includes(input.holidayKind)
  ) {
    return err(new InvalidHolidayKindError(input.holidayKind));
  }

  if (
    input.holidayDate !== undefined &&
    input.holidayDate.getTime() !== companyHoliday.holidayDate.getTime()
  ) {
    const duplicate = await db
      .selectFrom("CompanyHoliday")
      .selectAll()
      .where("calendarId", "=", companyHoliday.calendarId)
      .where("holidayDate", "=", input.holidayDate)
      .where("id", "!=", input.id)
      .forUpdate()
      .executeTakeFirst();
    if (duplicate) {
      return err(
        new DuplicateHolidayDateError(
          `${companyHoliday.calendarId}:${input.holidayDate.toISOString()}`,
        ),
      );
    }
  }

  const updates: {
    holidayDate?: Date;
    holidayKind?: (typeof HOLIDAY_KINDS)[number];
    name?: string;
  } = {};
  if (input.holidayDate !== undefined) updates.holidayDate = input.holidayDate;
  if (input.holidayKind !== undefined)
    updates.holidayKind = input.holidayKind as (typeof HOLIDAY_KINDS)[number];
  if (input.name !== undefined) updates.name = input.name;

  const updated = await db
    .updateTable("CompanyHoliday")
    .set(updates)
    .where("id", "=", input.id)
    .returningAll()
    .executeTakeFirstOrThrow();

  return ok({ companyHoliday: updated });
}