Fix issues with long placeholders in hosts. (#335)

* Hosts can be very long if they have placeholders (in templates) and this might not process correctlty. So we replace the placeholders with short ones and rereplace them after processing.

This is safe as this is only done for templates and placeholder format is well understood.

Added tests

* Fix formatting

* Added comment.

* Updated comment.

Co-authored-by: Andreas Rossbacher <andreas.rossbacher@airbnb.com>

Author: rossbacher

deeplinkdispatch-base/src/main/java/com/airbnb/deeplinkdispatch/DeepLinkUri.java

@@ -32,10 +32,12 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Locale;
+import java.util.Map;
 import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -321,7 +323,7 @@ Set<String> getSchemeHostPathPlaceholders() {
   }
 
   @NotNull
-  private Set<String> getPlaceHolders(String input) {
+  private static Set<String> getPlaceHolders(String input) {
     final Matcher matcher = PLACEHOLDER_REGEX.matcher(input);
     Set<String> placeholders = new HashSet<>(matcher.groupCount());
     while (matcher.find()) {
@@ -1215,7 +1217,22 @@ private static boolean decodeIpv4Suffix(
      */
     private static String domainToAscii(String input) {
       try {
-        String result = IDN.toASCII(input).toLowerCase(Locale.US);
+        // When this is a template URI it might get to long (> 256 chars) with all the placeholder
+        // definitions to pass verification.
+        // This will replace the placeholders with other shorter placeholders for URI validation.
+        Set<String> placeholders = getPlaceHolders(input);
+        String mappedInput = input;
+        Map<String, String> placeholderMap = new HashMap(placeholders.size());
+        int i = 0;
+        for (String placeholder : placeholders) {
+          String replacedValue = "" + (i++);
+          mappedInput = mappedInput.replace(placeholder, replacedValue);
+          placeholderMap.put(placeholder, replacedValue);
+        }
+        String result = IDN.toASCII(mappedInput).toLowerCase(Locale.US);
+        for (Map.Entry<String, String> entry : placeholderMap.entrySet()) {
+          result = result.replace(entry.getValue(), entry.getKey());
+        }
         if (result.isEmpty()) return null;
 
         if (result == null) return null;

deeplinkdispatch-base/src/test/java/com/airbnb/deeplinkdispatch/DeeplinkUriTest.kt

@@ -31,6 +31,17 @@ class DeeplinkUriTest {
         assertEquals(listOf("path1", "path2"), deeplinkUriTemplate.pathSegments())
     }
 
+    @Test
+    fun testParseDeepLinkUriTemplateWithVeryLongHost() {
+        val host =
+            "www.example.{url_domain_suffix(just|a|lot|of|values|in|here|that|make|the|url|very|long|longer|than|264|characters|to|be|creating|some|problems|with|ID|decode)}"
+        val deeplinkUriTemplate = DeepLinkUri.parseTemplate("http{scheme_suffix}://$host/path1/path2")
+        assertNotNull(deeplinkUriTemplate)
+        assertEquals("http{scheme_suffix}", deeplinkUriTemplate.scheme())
+        assertEquals(host, deeplinkUriTemplate.host())
+        assertEquals(listOf("path1", "path2"), deeplinkUriTemplate.pathSegments())
+    }
+
     @Test
     fun testParseDeepLinkUriTemplateWithOnlyPlaceholderAsHostAndScheme() {
         val deeplinkUriTemplate = DeepLinkUri.parseTemplate("{scheme}://{host}/path1/path2")