TunnelComparator: naturally sort tunnel list

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

ui/src/main/java/com/wireguard/android/model/TunnelComparator.kt

@@ -0,0 +1,60 @@
+/*
+ * Copyright © 2020 WireGuard LLC. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.wireguard.android.model
+
+import java.util.Locale
+
+object TunnelComparator : Comparator<String> {
+    private class NaturalSortString(originalString: String) {
+        class NaturalSortToken(val maybeString: String?, val maybeNumber: Int?) : Comparable<NaturalSortToken> {
+            override fun compareTo(other: NaturalSortToken): Int {
+                if (maybeString == null) {
+                    if (other.maybeString != null || maybeNumber!! < other.maybeNumber!!) {
+                        return -1
+                    } else if (maybeNumber > other.maybeNumber) {
+                        return 1
+                    }
+                } else if (other.maybeString == null || maybeString > other.maybeString) {
+                    return 1
+                } else if (maybeString < other.maybeString) {
+                    return -1
+                }
+                return 0
+            }
+        }
+        val tokens: MutableList<NaturalSortToken> = ArrayList()
+        init {
+            for (s in NATURAL_SORT_DIGIT_FINDER.findAll(originalString.split(WHITESPACE_FINDER).joinToString(" ").toLowerCase(Locale.ENGLISH))) {
+                try {
+                    val n = s.value.toInt()
+                    tokens.add(NaturalSortToken(null, n))
+                } catch (_: NumberFormatException) {
+                    tokens.add(NaturalSortToken(s.value, null))
+                }
+            }
+        }
+        private companion object {
+            private val NATURAL_SORT_DIGIT_FINDER = Regex("""\d+|\D+""")
+            private val WHITESPACE_FINDER = Regex("""\s""")
+        }
+    }
+
+    override fun compare(a: String, b: String): Int {
+        if (a == b)
+            return 0
+        val na = NaturalSortString(a)
+        val nb = NaturalSortString(b)
+        for (i in 0 until nb.tokens.size) {
+            if (i == na.tokens.size) {
+                return -1
+            }
+            val c = na.tokens[i].compareTo(nb.tokens[i])
+            if (c != 0)
+                return c
+        }
+        return 1
+    }
+}

ui/src/main/java/com/wireguard/android/model/TunnelManager.kt

@@ -24,7 +24,6 @@ import com.wireguard.android.configStore.ConfigStore
 import com.wireguard.android.util.ExceptionLoggers
 import com.wireguard.android.databinding.ObservableSortedKeyedArrayList
 import com.wireguard.config.Config
-import java9.util.Comparators
 import java9.util.concurrent.CompletableFuture
 import java9.util.concurrent.CompletionStage
 import java.util.ArrayList
@@ -36,7 +35,7 @@ class TunnelManager(private val configStore: ConfigStore) : BaseObservable() {
     val tunnels = CompletableFuture<ObservableSortedKeyedArrayList<String, ObservableTunnel>>()
     private val context: Context = get()
     private val delayedLoadRestoreTunnels = ArrayList<CompletableFuture<Void>>()
-    private val tunnelMap: ObservableSortedKeyedArrayList<String, ObservableTunnel> = ObservableSortedKeyedArrayList(COMPARATOR)
+    private val tunnelMap: ObservableSortedKeyedArrayList<String, ObservableTunnel> = ObservableSortedKeyedArrayList(TunnelComparator)
     private var haveLoaded = false
 
     private fun addToList(name: String, config: Config?, state: Tunnel.State): ObservableTunnel? {
@@ -230,7 +229,6 @@ class TunnelManager(private val configStore: ConfigStore) : BaseObservable() {
             .supplyAsync { getBackend().getStatistics(tunnel) }.thenApply(tunnel::onStatisticsChanged)
 
     companion object {
-        private val COMPARATOR = Comparators.thenComparing(java.lang.String.CASE_INSENSITIVE_ORDER, Comparators.naturalOrder())
         private const val KEY_LAST_USED_TUNNEL = "last_used_tunnel"
         private const val KEY_RESTORE_ON_BOOT = "restore_on_boot"
         private const val KEY_RUNNING_TUNNELS = "enabled_configs"