package org.terst.doot.widget.ui

import org.junit.Assert.assertEquals
import org.junit.Assert.assertFalse
import org.junit.Assert.assertTrue
import org.junit.Test
import org.terst.doot.widget.data.WidgetItem
import java.time.LocalDate
import java.time.ZoneId

class DootWidgetMultiDayTest {
    private val zone: ZoneId = ZoneId.of("UTC")

    private fun event(start: String, end: String, isAllDay: Boolean = false): WidgetItem = WidgetItem(
        id = "e1", title = "Event", source = "calendar", type = "event",
        start = start, end = end, isAllDay = isAllDay
    )

    @Test
    fun `isMultiDayEvent is false for a same-day timed event`() {
        assertFalse(isMultiDayEvent(event("2026-07-13T10:00:00Z", "2026-07-13T11:00:00Z"), zone))
    }

    @Test
    fun `isMultiDayEvent is true when start and end fall on different calendar days`() {
        assertTrue(isMultiDayEvent(event("2026-07-13T17:35:00Z", "2026-07-30T22:30:00Z"), zone))
    }

    @Test
    fun `isMultiDayEvent is true for a genuine all-day multi-day event`() {
        assertTrue(isMultiDayEvent(event("2026-07-13T00:00:00Z", "2026-07-15T00:00:00Z", isAllDay = true), zone))
    }

    @Test
    fun `isMultiDayEvent is false for non-event types`() {
        val task = WidgetItem(
            id = "t1", title = "Task", source = "doot", type = "task",
            start = "2026-07-13T10:00:00Z", end = "2026-07-30T22:30:00Z"
        )
        assertFalse(isMultiDayEvent(task, zone))
    }

    @Test
    fun `multiDayVariant returns STARTS on the event's start day`() {
        val item = event("2026-07-13T17:35:00Z", "2026-07-30T22:30:00Z")
        assertEquals(MultiDayVariant.STARTS, multiDayVariant(item, LocalDate.of(2026, 7, 13), zone))
    }

    @Test
    fun `multiDayVariant returns ENDS on the event's end day`() {
        val item = event("2026-07-13T17:35:00Z", "2026-07-30T22:30:00Z")
        assertEquals(MultiDayVariant.ENDS, multiDayVariant(item, LocalDate.of(2026, 7, 30), zone))
    }

    @Test
    fun `multiDayVariant returns SPANS on a day strictly between start and end`() {
        val item = event("2026-07-13T17:35:00Z", "2026-07-30T22:30:00Z")
        assertEquals(MultiDayVariant.SPANS, multiDayVariant(item, LocalDate.of(2026, 7, 20), zone))
    }

    @Test
    fun `multiDayVariant returns NONE for a day outside the event's span`() {
        val item = event("2026-07-13T17:35:00Z", "2026-07-30T22:30:00Z")
        assertEquals(MultiDayVariant.NONE, multiDayVariant(item, LocalDate.of(2026, 8, 1), zone))
    }

    @Test
    fun `isMultiDayEvent is false for a single-day all-day event (exclusive end-date)`() {
        // Google Calendar's all-day End is EXCLUSIVE: a single-day all-day event on
        // July 13 has start=Jul13 00:00, end=Jul14 00:00 (one day past its own day).
        assertFalse(isMultiDayEvent(event("2026-07-13T00:00:00Z", "2026-07-14T00:00:00Z", isAllDay = true), zone))
    }

    @Test
    fun `isMultiDayEvent is true for a 3-day all-day event`() {
        // 3-day all-day event (Jul 13-15 inclusive) has end=Jul16 00:00 (exclusive).
        assertTrue(isMultiDayEvent(event("2026-07-13T00:00:00Z", "2026-07-16T00:00:00Z", isAllDay = true), zone))
    }

    @Test
    fun `multiDayVariant reports ENDS on the real last day of a multi-day all-day event, not the exclusive end date`() {
        val item = event("2026-07-13T00:00:00Z", "2026-07-16T00:00:00Z", isAllDay = true)
        assertEquals(MultiDayVariant.ENDS, multiDayVariant(item, LocalDate.of(2026, 7, 15), zone))
        assertEquals(MultiDayVariant.NONE, multiDayVariant(item, LocalDate.of(2026, 7, 16), zone))
    }
}