Improve time format of posts when using absolute time (#2413)

* Improve time format of posts when using absolute time

* fix AbsoluteTimeFormatter, add tests

* fix tests

Co-authored-by: Conny Duck <k.pozniak@gmx.at>

app/src/test/java/com/keylesspalace/tusky/util/AbsoluteTimeFormatterTest.kt

@@ -0,0 +1,46 @@
+package com.keylesspalace.tusky.util
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import java.time.Instant
+import java.util.Date
+import java.util.TimeZone
+
+class AbsoluteTimeFormatterTest {
+
+    private val formatter = AbsoluteTimeFormatter(TimeZone.getTimeZone("UTC"))
+    private val now = Date.from(Instant.parse("2022-04-11T00:00:00.00Z"))
+
+    @Test
+    fun `null handling`() {
+        assertEquals("??", formatter.format(null, true, now))
+        assertEquals("??", formatter.format(null, false, now))
+    }
+
+    @Test
+    fun `same day formatting`() {
+        val tenTen = Date.from(Instant.parse("2022-04-11T10:10:00.00Z"))
+        assertEquals("10:10", formatter.format(tenTen, true, now))
+        assertEquals("10:10", formatter.format(tenTen, false, now))
+    }
+
+    @Test
+    fun `same year formatting`() {
+        val nextDay = Date.from(Instant.parse("2022-04-12T00:10:00.00Z"))
+        assertEquals("04-12 00:10", formatter.format(nextDay, true, now))
+        assertEquals("04-12 00:10", formatter.format(nextDay, false, now))
+        val endOfYear = Date.from(Instant.parse("2022-12-31T23:59:00.00Z"))
+        assertEquals("12-31 23:59", formatter.format(endOfYear, true, now))
+        assertEquals("12-31 23:59", formatter.format(endOfYear, false, now))
+    }
+
+    @Test
+    fun `other year formatting`() {
+        val firstDayNextYear = Date.from(Instant.parse("2023-01-01T00:00:00.00Z"))
+        assertEquals("2023-01-01", formatter.format(firstDayNextYear, true, now))
+        assertEquals("2023-01-01 00:00", formatter.format(firstDayNextYear, false, now))
+        val inTenYears = Date.from(Instant.parse("2032-04-11T10:10:00.00Z"))
+        assertEquals("2032-04-11", formatter.format(inTenYears, true, now))
+        assertEquals("2032-04-11 10:10", formatter.format(inTenYears, false, now))
+    }
+}