Get date list between start - end date

CalculateLeave.kt

import java.time.DayOfWeek
import java.time.LocalDate

data class Holiday(
    val date: LocalDate,
    val userId: Int,
) {
    companion object {
        val all = listOf(
            Holiday(date = LocalDate.of(2023, 2, 6), userId = 1),
        )
    }
}

data class LeavePlan(
    val date: LocalDate,
    val userId: Int,
) {
    companion object {
        val all = listOf(
            LeavePlan(date = LocalDate.of(2023, 2, 1), userId = 1),
            LeavePlan(date = LocalDate.of(2023, 2, 2), userId = 1),
        )
    }
}

fun calculateDateList(start: LocalDate, end: LocalDate): List<LocalDate> {
    var date = start
    val dateList = mutableListOf<LocalDate>()
    while (!date.isAfter(end)) {
        dateList.add(date)
        date = date.plusDays(1)
    }
    return dateList
}

fun isWeekday(date: LocalDate): Boolean {
    val dayOfWeek = date.dayOfWeek
    return dayOfWeek != DayOfWeek.SATURDAY && dayOfWeek != DayOfWeek.SUNDAY
}


fun main(args: Array<String>) {

    val userId = 1
    val isSale = false
    val start = LocalDate.of(2023, 1, 31)
    val end = LocalDate.of(2023, 2, 7)

    val dateList = calculateDateList(start, end)
    dateList.forEach { local ->

        val isHoliday = Holiday.all.indexOfFirst { it.date.compareTo(local) == 0 && it.userId == userId } > -1

        val isLeavePlan = LeavePlan.all.indexOfFirst { it.date.compareTo(local) == 0 && it.userId == userId } > -1

        // Check sale
        var weekday = true
        if (isSale.not()) {
            weekday = isWeekday(local)
        }

        if (isHoliday.not() && isLeavePlan.not() && weekday) {
            println(local)
        }

        // Result:
        // 2023-01-31
        // 2023-02-03
        // 2023-02-07
    }

}