From f62a6a30ffc7779fc396995bc138744adcbd469e Mon Sep 17 00:00:00 2001
From: Paul Schaub <vanitasvitae@fsfe.org>
Date: Thu, 1 Dec 2022 15:21:00 +0100
Subject: [PATCH] Implement RegexSet to validate a single user-id against
 multiple wildcards

---
 .../org/pgpainless/algorithm/RegexSet.java    | 40 +++++++++++++++
 .../pgpainless/algorithm/RegexSetTest.java    | 51 +++++++++++++++++++
 2 files changed, 91 insertions(+)
 create mode 100644 pgpainless-core/src/main/java/org/pgpainless/algorithm/RegexSet.java
 create mode 100644 pgpainless-core/src/test/java/org/pgpainless/algorithm/RegexSetTest.java

diff --git a/pgpainless-core/src/main/java/org/pgpainless/algorithm/RegexSet.java b/pgpainless-core/src/main/java/org/pgpainless/algorithm/RegexSet.java
new file mode 100644
index 00000000..e4639e03
--- /dev/null
+++ b/pgpainless-core/src/main/java/org/pgpainless/algorithm/RegexSet.java
@@ -0,0 +1,40 @@
+// SPDX-FileCopyrightText: 2022 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.algorithm;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+
+public final class RegexSet {
+
+    private final Set<Regex> regexSet = new HashSet<>();
+
+    private RegexSet(Collection<Regex> regexes) {
+        this.regexSet.addAll(regexes);
+    }
+
+    public static RegexSet matchAnything() {
+        return new RegexSet(Collections.singleton(Regex.wildcard()));
+    }
+
+    public static RegexSet matchNothing() {
+        return new RegexSet(Collections.emptySet());
+    }
+
+    public static RegexSet matchSome(Collection<Regex> regexes) {
+        return new RegexSet(regexes);
+    }
+
+    public boolean matches(String userId) {
+        for (Regex regex : regexSet) {
+            if (regex.matches(userId)) {
+                return true;
+            }
+        }
+        return false;
+    }
+}
diff --git a/pgpainless-core/src/test/java/org/pgpainless/algorithm/RegexSetTest.java b/pgpainless-core/src/test/java/org/pgpainless/algorithm/RegexSetTest.java
new file mode 100644
index 00000000..ff8b12fe
--- /dev/null
+++ b/pgpainless-core/src/test/java/org/pgpainless/algorithm/RegexSetTest.java
@@ -0,0 +1,51 @@
+// SPDX-FileCopyrightText: 2022 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.algorithm;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.Arrays;
+
+import org.junit.jupiter.api.Test;
+
+public class RegexSetTest {
+
+    @Test
+    public void matchNothingTest() {
+        RegexSet set = RegexSet.matchNothing();
+        assertFalse(set.matches("<alice@pgpainless.org>"));
+        assertFalse(set.matches("Alice"));
+        assertFalse(set.matches("Alice <alice@pgpainless.org>"));
+        assertFalse(set.matches(""));
+    }
+
+    @Test
+    public void matchAnything() {
+        RegexSet set = RegexSet.matchAnything();
+        assertTrue(set.matches("Alice"));
+        assertTrue(set.matches("<alice@pgpainless.org>"));
+        assertTrue(set.matches("Alice <alice@pgpainless.org>"));
+        assertTrue(set.matches("Alice <alice@example.org>"));
+        assertTrue(set.matches(""));
+    }
+
+    @Test
+    public void matchSome() {
+        Regex pgpainless_org = RegexInterpreterFactory.createDefaultMailDomainRegex("pgpainless.org");
+        Regex example_org = RegexInterpreterFactory.createDefaultMailDomainRegex("example.org");
+
+        RegexSet set = RegexSet.matchSome(Arrays.asList(pgpainless_org, example_org));
+        assertTrue(set.matches("Alice <alice@pgpainless.org>"));
+        assertTrue(set.matches("<alice@pgpainless.org>"));
+        assertTrue(set.matches("Bob <bob@example.org>"));
+        assertTrue(set.matches("<bob@example.org>"));
+        assertFalse(set.matches("Bob <bob@example.com>"));
+        assertFalse(set.matches("Alice <alice@PGPainless.org>"));
+        assertFalse(set.matches("alice@pgpainless.org"));
+        assertFalse(set.matches("Alice"));
+        assertFalse(set.matches(""));
+    }
+}