package de.marha.planer

import de.marha.planer.data.Dates
import org.junit.Assert.assertEquals
import org.junit.Assert.assertTrue
import org.junit.Test

class DatesTest {
    @Test fun monthGridStartsMondayBefore() {
        val grid = Dates.monthGrid(2026, 9)
        assertEquals(42, grid.size)
        assertEquals("2026-08-31", grid[0])
        assertEquals("2026-06-01", Dates.monthGrid(2026, 6)[0])
    }

    @Test fun weekStartsMonday() {
        assertEquals("2026-09-14", Dates.startOfWeek("2026-09-17"))
        assertEquals("2026-09-14", Dates.startOfWeek("2026-09-20"))
        assertEquals("2026-09-14", Dates.startOfWeek("2026-09-14"))
        assertEquals(7, Dates.weekDays("2026-09-17").size)
    }

    @Test fun isoWeek() {
        assertEquals(38, Dates.isoWeek("2026-09-17"))
        assertEquals(53, Dates.isoWeek("2027-01-01"))
    }

    @Test fun formats() {
        assertEquals("Do, 17.09.2026", Dates.formatDate("2026-09-17"))
        assertEquals("17.09.", Dates.formatDayMonth("2026-09-17"))
        assertEquals("September 2026", Dates.formatMonth(2026, 9))
        assertEquals(90, Dates.timeToMinutes("01:30"))
        assertEquals("01:30", Dates.minutesToTime(90))
    }

    // Gleiches Format wie die Extension, damit sich Zeitstempel als Strings vergleichen lassen
    @Test fun nowIsoHasMillisAndZ() {
        assertTrue(Regex("^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}\\.\\d{3}Z$").matches(Dates.nowIso()))
    }
}