/**
 * TrackerMap
 * Copyright (C) 2021-2022  Iván Ávalos <avalos@disroot.org>, Henoch Ojeda <imhenoch@protonmail.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package mx.trackermap.TrackerMap.utils

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

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

    sealed class ReportPeriod {
        val timezone = TimeZone.currentSystemDefault()
        val clock = Clock.System
        val instant = clock.now()
        val dateTime = instant.toLocalDateTime(timezone)
        val date = dateTime.date

        abstract fun getObjectDates(): Pair<LocalDateTime, LocalDateTime>

        fun getStringDates(): Pair<String, String> {
            val (from, to) = getObjectDates()
            return formatDateTime(from) to formatDateTime(to)
        }

        fun formatDateTime(dateTime: LocalDateTime) =
            dateTime.toInstant(timezone).toString()

        class Today : ReportPeriod() {
            override fun getObjectDates(): Pair<LocalDateTime, LocalDateTime> {
                val from = date.atTime(0, 0)
                val to = dateTime
                return from to to
            }
        }

        class Last24 : ReportPeriod() {
            override fun getObjectDates(): Pair<LocalDateTime, LocalDateTime> {
                val from = instant
                    .minus(1, DateTimeUnit.DAY, timezone)
                    .toLocalDateTime(timezone)
                val to = dateTime
                return from to to
            }
        }

        class Yesterday : ReportPeriod() {
            override fun getObjectDates(): Pair<LocalDateTime, LocalDateTime> {
                val yesterday = instant
                    .minus(1, DateTimeUnit.DAY, timezone)
                    .toLocalDateTime(timezone).date
                val from = yesterday.atTime(0, 0)
                val to = yesterday.atTime(23, 59)
                return from to to
            }
        }

        class ThisWeek : ReportPeriod() {
            override fun getObjectDates(): Pair<LocalDateTime, LocalDateTime> {
                val from = instant
                    .minus(date.dayOfWeek.isoDayNumber - 1, DateTimeUnit.DAY, timezone)
                    .toLocalDateTime(timezone).date
                    .atTime(0, 0)
                val to = dateTime
                return from to to
            }
        }

        class Last7 : ReportPeriod() {
            override fun getObjectDates(): Pair<LocalDateTime, LocalDateTime> {
                val from = instant
                    .minus(1, DateTimeUnit.WEEK, timezone)
                    .toLocalDateTime(timezone).date
                    .atTime(0, 0)
                val to = dateTime
                return from to to
            }
        }

        class ThisMonth : ReportPeriod() {
            override fun getObjectDates(): Pair<LocalDateTime, LocalDateTime> {
                val from = instant
                    .minus(date.dayOfMonth - 1, DateTimeUnit.DAY, timezone)
                    .toLocalDateTime(timezone).date
                    .atTime(0, 0)
                val to = dateTime
                return from to to
            }
        }

        class Last30 : ReportPeriod() {
            override fun getObjectDates(): Pair<LocalDateTime, LocalDateTime> {
                val from = instant
                    .minus(1, DateTimeUnit.MONTH, timezone)
                    .toLocalDateTime(timezone).date
                    .atTime(0, 0)
                val to = dateTime
                return from to to
            }
        }

        class Custom (
            private val from: LocalDateTime? = null,
            private val to: LocalDateTime? = null
        ) : ReportPeriod() {
            override fun getObjectDates(): Pair<LocalDateTime, LocalDateTime> {
                return Pair(
                    from ?: date.atTime(0, 0),
                    to ?: dateTime
                )
            }

            fun withFrom (from: LocalDateTime): Custom = Custom (from, to)
            fun withTo (to: LocalDateTime): Custom = Custom (from, to)
        }
    }
}