package mx.trackermap.TrackerMap.utils

import kotlinx.coroutines.DelicateCoroutinesApi
import kotlinx.datetime.*

@DelicateCoroutinesApi
class ReportDates {
    enum class ReportPeriod {
        TODAY, LAST_24, YESTERDAY, THIS_WEEK, LAST_7, THIS_MONTH, LAST_30
    }

    companion object {
        private fun formatDateTime(dateTime: LocalDateTime, timezone: TimeZone) =
            dateTime.toInstant(timezone).toString()

        fun getDates(period: ReportPeriod): Pair<String, String> {
            val timezone = TimeZone.currentSystemDefault()
            val clock = Clock.System
            val instant = clock.now()
            val dateTime = instant.toLocalDateTime(timezone)
            val date = dateTime.date

            var currentDate: LocalDateTime? = null
            var previousDate: LocalDateTime? = null
            when (period) {
                ReportPeriod.TODAY -> {
                    previousDate = date.atTime(0, 0)
                    currentDate = dateTime
                }
                ReportPeriod.LAST_24 -> {
                    previousDate = instant
                        .minus(1, DateTimeUnit.DAY, timezone)
                        .toLocalDateTime(timezone)
                    currentDate = dateTime
                }
                ReportPeriod.YESTERDAY -> {
                    val yesterday = instant
                        .minus(1, DateTimeUnit.DAY, timezone)
                        .toLocalDateTime(timezone).date
                    previousDate = yesterday.atTime(0, 0)
                    currentDate = yesterday.atTime(23, 59)
                }
                ReportPeriod.THIS_WEEK -> {
                    previousDate = instant
                        .minus(date.dayOfWeek.isoDayNumber - 1, DateTimeUnit.DAY, timezone)
                        .toLocalDateTime(timezone).date
                        .atTime(0, 0)
                    currentDate = dateTime
                }
                ReportPeriod.LAST_7 -> {
                    previousDate = instant
                        .minus(1, DateTimeUnit.WEEK, timezone)
                        .toLocalDateTime(timezone).date
                        .atTime(0, 0)
                    currentDate = dateTime
                }
                ReportPeriod.THIS_MONTH -> {
                    previousDate = instant
                        .minus(date.dayOfMonth - 1, DateTimeUnit.DAY, timezone)
                        .toLocalDateTime(timezone).date
                        .atTime(0, 0)
                    currentDate = dateTime
                }
                ReportPeriod.LAST_30 -> {
                    previousDate = instant
                        .minus(1, DateTimeUnit.MONTH, timezone)
                        .toLocalDateTime(timezone).date
                        .atTime(0, 0)
                    currentDate = dateTime
                }
            }

            return Pair(
                formatDateTime(currentDate, timezone),
                formatDateTime(previousDate, timezone)
            )
        }
    }
}