fix(common): UTC 상대시간 파싱을 보완한다

app/src/main/java/kr/co/vividnext/sodalive/common/RelativeTimeFormatter.kt

@@ -2,7 +2,7 @@ package kr.co.vividnext.sodalive.common
 
 import android.content.Context
 import kr.co.vividnext.sodalive.R
-import java.text.ParseException
+import java.text.ParsePosition
 import java.text.SimpleDateFormat
 import java.util.Calendar
 import java.util.Date
@@ -10,8 +10,9 @@ import java.util.Locale
 import java.util.TimeZone
 
 fun formatUtcRelativeTimeText(context: Context, utcText: String?): String {
-    val pastMillis = parseServerUtcToMillis(utcText)
+    val parsedTime = parseServerUtcToMillis(utcText)
         ?: return context.getString(R.string.character_comment_time_just_now)
+    val pastMillis = parsedTime.millis
 
     val nowMillis = System.currentTimeMillis()
     var diff = nowMillis - pastMillis
@@ -21,6 +22,10 @@ fun formatUtcRelativeTimeText(context: Context, utcText: String?): String {
     val hour = 60 * minute
     val day = 24 * hour
 
+    if (parsedTime.isIsoText && diff < RECENT_ISO_TIME_GRACE_MILLIS) {
+        return context.getString(R.string.character_comment_time_just_now)
+    }
+
     if (diff < minute) {
         return context.getString(R.string.character_comment_time_just_now)
     }
@@ -75,19 +80,25 @@ class AndroidUtcRelativeTimeTextFormatter(context: Context) : UtcRelativeTimeTex
     override fun format(utcText: String?): String = formatUtcRelativeTimeText(applicationContext, utcText)
 }
 
-private fun parseServerUtcToMillis(utcText: String?): Long? {
+private fun parseServerUtcToMillis(utcText: String?): ParsedServerTime? {
     if (utcText.isNullOrBlank()) return null
 
-    val value = utcText.trim()
+    val value = utcText.trim().normalizeIsoFraction()
     if (value.all { it.isDigit() }) {
         return try {
-            value.toLong()
+            val number = value.toLong()
+            ParsedServerTime(
+                millis = if (value.length <= EPOCH_SECONDS_MAX_LENGTH) number * 1000 else number,
+                isIsoText = false
+            )
         } catch (_: NumberFormatException) {
             null
         }
     }
 
     val patterns = listOf(
+        "yyyy-MM-dd'T'HH:mm:ss.SSSXXX",
+        "yyyy-MM-dd'T'HH:mm:ssXXX",
         "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'",
         "yyyy-MM-dd'T'HH:mm:ss'Z'",
         "yyyy-MM-dd'T'HH:mm:ss",
@@ -99,11 +110,26 @@ private fun parseServerUtcToMillis(utcText: String?): Long? {
         try {
             val dateFormat = SimpleDateFormat(pattern, Locale.US)
             dateFormat.timeZone = TimeZone.getTimeZone("UTC")
-            val parsed: Date? = dateFormat.parse(value)
+            val position = ParsePosition(0)
-            if (parsed != null) return parsed.time
+            val parsed: Date? = dateFormat.parse(value, position)
-        } catch (_: ParseException) {
+            if (parsed != null && position.index == value.length) {
+                return ParsedServerTime(millis = parsed.time, isIsoText = true)
+            }
+        } catch (_: RuntimeException) {
         }
     }
 
     return null
 }
+
+private fun String.normalizeIsoFraction(): String {
+    return replace(Regex("""\.(\d{3})\d+"""), ".$1")
+}
+
+private data class ParsedServerTime(
+    val millis: Long,
+    val isIsoText: Boolean
+)
+
+private const val EPOCH_SECONDS_MAX_LENGTH = 10
+private const val RECENT_ISO_TIME_GRACE_MILLIS = 10 * 60_000L

app/src/test/java/kr/co/vividnext/sodalive/common/RelativeTimeFormatterTest.kt

@@ -0,0 +1,70 @@
+package kr.co.vividnext.sodalive.common
+
+import android.app.Application
+import android.content.Context
+import androidx.test.core.app.ApplicationProvider
+import kr.co.vividnext.sodalive.R
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+import org.robolectric.annotation.Config
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
+import java.util.TimeZone
+
+@RunWith(RobolectricTestRunner::class)
+@Config(sdk = [28], application = Application::class)
+class RelativeTimeFormatterTest {
+
+    private val context: Context = ApplicationProvider.getApplicationContext()
+
+    @Test
+    fun `epoch millis는 기존처럼 실제 경과 분을 표시한다`() {
+        val twoMinutesAgoMillis = System.currentTimeMillis() - 2 * MINUTE
+
+        val text = formatUtcRelativeTimeText(context, twoMinutesAgoMillis.toString())
+
+        assertEquals(context.getString(R.string.character_comment_time_minutes, 2), text)
+    }
+
+    @Test
+    fun `epoch seconds는 초 단위로 파싱한다`() {
+        val twoHoursAgoSeconds = (System.currentTimeMillis() - 2 * HOUR) / 1000
+
+        val text = formatUtcRelativeTimeText(context, twoHoursAgoSeconds.toString())
+
+        assertEquals(context.getString(R.string.character_comment_time_hours, 2), text)
+    }
+
+    @Test
+    fun `ISO UTC 문자열은 작성 직후 서버 단말 시계 차이를 방금전으로 보정한다`() {
+        val sixMinutesAgoIso = utcIso(System.currentTimeMillis() - 6 * MINUTE)
+
+        val text = formatUtcRelativeTimeText(context, sixMinutesAgoIso)
+
+        assertEquals(context.getString(R.string.character_comment_time_just_now), text)
+    }
+
+    @Test
+    fun `ISO offset 문자열과 6자리 fraction을 UTC 기준으로 파싱한다`() {
+        val value = utcIso(System.currentTimeMillis())
+            .replace(".000Z", ".123456+00:00")
+
+        val text = formatUtcRelativeTimeText(context, value)
+
+        assertEquals(context.getString(R.string.character_comment_time_just_now), text)
+    }
+
+    private fun utcIso(millis: Long): String {
+        return SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", Locale.US).apply {
+            timeZone = TimeZone.getTimeZone("UTC")
+        }.format(Date(millis))
+    }
+
+    private companion object {
+        const val MINUTE = 60_000L
+        const val HOUR = 60 * MINUTE
+    }
+}