Update duration display

mirai-core/src/commonMain/kotlin/net.mamoe.mirai/BotImpl.kt

@@ -24,6 +24,7 @@ import net.mamoe.mirai.network.closeAndJoin
 import net.mamoe.mirai.utils.*
 import net.mamoe.mirai.utils.internal.retryCatching
 import kotlin.coroutines.CoroutineContext
+import kotlin.time.Duration
 import kotlin.time.ExperimentalTime
 import kotlin.time.measureTime
 
@@ -138,7 +139,7 @@ abstract class BotImpl<N : BotNetworkHandler> constructor(
                         reconnect()
                     }
 
-                    logger.info { "Reconnected successfully in ${time.inMilliseconds} ms" }
+                    logger.info { "Reconnected successfully in ${time.asHumanReadable}" }
                 }
                 is BotOfflineEvent.Active -> {
                     val msg = if (event.cause == null) {

mirai-core/src/commonMain/kotlin/net.mamoe.mirai/utils/TimeUtils.kt

@@ -15,6 +15,10 @@ package net.mamoe.mirai.utils
 import kotlin.jvm.JvmMultifileClass
 import kotlin.jvm.JvmName
 import kotlin.jvm.JvmSynthetic
+import kotlin.math.floor
+import kotlin.time.Duration
+import kotlin.time.DurationUnit
+import kotlin.time.ExperimentalTime
 
 /**
  * 时间戳
@@ -76,4 +80,21 @@ inline val Int.weeksToSeconds: Long
 
 @get:JvmSynthetic
 inline val Int.monthsToSeconds: Long
-    get() = this * 30.daysToSeconds
+    get() = this * 30.daysToSeconds
+
+@ExperimentalTime
+val Duration.asHumanReadable: String
+    get() {
+        val builder = StringBuilder()
+        val days = toInt(DurationUnit.DAYS)
+        val hours = toInt(DurationUnit.HOURS) % 24
+        val minutes = toInt(DurationUnit.MINUTES) % 60
+        val s = floor(toDouble(DurationUnit.SECONDS) % 60 * 1000) / 1000
+        with(builder) {
+            if (days != 0) append("${days}d ")
+            if (hours != 0) append("${hours}h ")
+            if (minutes != 0) append("${minutes}min ")
+            append("${s}s")
+        }
+        return builder.toString()
+    }

mirai-core/src/commonTest/kotlin/net/mamoe/mirai/utils/TimeTest.kt

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2020 Mamoe Technologies and contributors.
+ * 此源代码的使用受 GNU AFFERO GENERAL PUBLIC LICENSE version 3 许可证的约束, 可以在以下链接找到该许可证.
+ * Use of this source code is governed by the GNU AGPLv3 license that can be found through the following link.
+ *
+ * https://github.com/mamoe/mirai/blob/master/LICENSE
+ */
+
+package net.mamoe.mirai.utils
+
+import kotlin.test.Test
+import kotlin.test.assertTrue
+import kotlin.time.DurationUnit
+import kotlin.time.ExperimentalTime
+import kotlin.time.toDuration
+
+internal class TimeTest {
+    @ExperimentalTime
+    @Test
+    fun testTimeHumanReadable() {
+        val time0 = 1.toDuration(DurationUnit.DAYS) +
+                20.toDuration(DurationUnit.HOURS) +
+                15.toDuration(DurationUnit.MINUTES) +
+                2057.toDuration(DurationUnit.MILLISECONDS)
+        println(time0.asHumanReadable)
+        assertTrue { time0.asHumanReadable == "1d 20h 15min 2.057s" }
+        val time1 = 1.toDuration(DurationUnit.DAYS) + 59.toDuration(DurationUnit.MINUTES)
+        println(time1.asHumanReadable)
+        assertTrue { time1.asHumanReadable == "1d 59min 0.0s" }
+    }
+}