Add getLocalDateTime and formatLocalTime function.

Also rename formatDate function to formatLocalDate.

app/src/main/java/chat/rocket/android/app/DateTimeHelper.kt

 import android.content.Context
 import chat.rocket.android.R
-import org.threeten.bp.LocalDate
-import org.threeten.bp.LocalDateTime
-import org.threeten.bp.Period
+import org.threeten.bp.*
 import org.threeten.bp.format.DateTimeFormatter
 import org.threeten.bp.format.FormatStyle
 import org.threeten.bp.format.TextStyle
@@ -14,20 +12,20 @@ object DateTimeHelper {
     private val lastWeek = today.minusWeeks(1)
 
     /**
-     * Returns a date from a LocalDateTime or the textual representation if the LocalDateTime has a max period of a week from the current date.
+     * Returns a date from a [LocalDateTime] or the textual representation if the [LocalDateTime] has a max period of a week from the current date.
      *
-     * @param localDateTime The LocalDateTime.
+     * @param localDateTime The [LocalDateTime].
      * @param context The context.
-     * @return The date or the textual representation from a LocalDateTime.
+     * @return The date or the textual representation from a [LocalDateTime].
      */
     fun getDate(localDateTime: LocalDateTime, context: Context): String {
         val localDate = localDateTime.toLocalDate()
         return when (localDate) {
-            today -> localDateTime.toLocalTime().toString()
+            today -> formatLocalTime(localDateTime.toLocalTime())
             yesterday -> context.getString(R.string.msg_yesterday)
             else -> {
                 if (Period.between(lastWeek, localDate).days <= 0) {
-                    formatDate(localDate)
+                    formatLocalDate(localDate)
                 } else {
                     localDate.dayOfWeek.getDisplayName(TextStyle.FULL, Locale.getDefault())
                 }
@@ -36,18 +34,33 @@ object DateTimeHelper {
     }
 
     /**
-     * Returns a time from a LocalDateTime.
+     * Returns a time from a [LocalDateTime].
      *
-     * @param localDateTime The LocalDateTime.
-     * @return The time from a LocalDateTime.
+     * @param localDateTime The [LocalDateTime].
+     * @return The time from a [LocalDateTime].
      */
     fun getTime(localDateTime: LocalDateTime): String {
         val formatter = DateTimeFormatter.ofLocalizedTime(FormatStyle.SHORT)
         return localDateTime.toLocalTime().format(formatter).toString()
     }
 
-    private fun formatDate(localDate: LocalDate): String {
+    /**
+     * Returns a [LocalDateTime] from a [Long].
+     *
+     * @param long The [Long]
+     * @return The [LocalDateTime] from a [Long].
+     */
+    fun getLocalDateTime(long: Long): LocalDateTime {
+        return LocalDateTime.ofInstant(Instant.ofEpochMilli(long), ZoneId.systemDefault())
+    }
+
+    private fun formatLocalDate(localDate: LocalDate): String {
         val formatter = DateTimeFormatter.ofLocalizedDate(FormatStyle.SHORT)
         return localDate.format(formatter).toString()
     }
+
+    private fun formatLocalTime(localTime: LocalTime): String {
+        val formatter = DateTimeFormatter.ofLocalizedTime(FormatStyle.SHORT)
+        return localTime.format(formatter).toString()
+    }
 }
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