Add RevocationState implementation from wot branch

pgpainless-core/src/main/java/org/pgpainless/algorithm/RevocationState.java

@@ -4,20 +4,128 @@
 
 package org.pgpainless.algorithm;
 
-public enum RevocationState {
+import org.pgpainless.util.DateUtil;
 
-    /**
-     * Certificate is not revoked.
-     */
-    notRevoked,
+import javax.annotation.Nonnull;
+import java.util.Date;
+import java.util.NoSuchElementException;
 
-    /**
-     * Certificate is revoked with a soft revocation.
-     */
-    softRevoked,
+public class RevocationState implements Comparable<RevocationState> {
 
-    /**
-     * Certificate is revoked with a hard revocation.
-     */
-    hardRevoked
+    private final RevocationStateType type;
+    private final Date date;
+
+    private RevocationState(RevocationStateType type) {
+        this(type, null);
+    }
+
+    private RevocationState(RevocationStateType type, Date date) {
+        this.type = type;
+        if (type == RevocationStateType.softRevoked && date == null) {
+            throw new NullPointerException("If type is 'softRevoked' then date cannot be null.");
+        }
+        this.date = date;
+    }
+
+    public static RevocationState notRevoked() {
+        return new RevocationState(RevocationStateType.notRevoked);
+    }
+
+    public static RevocationState softRevoked(@Nonnull Date date) {
+        return new RevocationState(RevocationStateType.softRevoked, date);
+    }
+
+    public static RevocationState hardRevoked() {
+        return new RevocationState(RevocationStateType.hardRevoked);
+    }
+
+    public RevocationStateType getType() {
+        return type;
+    }
+
+    public @Nonnull Date getDate() {
+        if (!isSoftRevocation()) {
+            throw new NoSuchElementException("RevocationStateType is not equal to 'softRevoked'. Cannot extract date.");
+        }
+        return date;
+    }
+
+    public boolean isHardRevocation() {
+        return getType() == RevocationStateType.hardRevoked;
+    }
+
+    public boolean isSoftRevocation() {
+        return getType() == RevocationStateType.softRevoked;
+    }
+
+    public boolean isNotRevoked() {
+        return getType() == RevocationStateType.notRevoked;
+    }
+
+    @Override
+    public String toString() {
+        String out = getType().toString();
+        if (isSoftRevocation()) {
+            out = out + " (" + DateUtil.formatUTCDate(date) + ")";
+        }
+        return out;
+    }
+
+    @Override
+    public int compareTo(@Nonnull RevocationState o) {
+        switch (getType()) {
+            case notRevoked:
+                if (o.isNotRevoked()) {
+                    return 0;
+                } else {
+                    return -1;
+                }
+
+            case softRevoked:
+                if (o.isNotRevoked()) {
+                    return 1;
+                } else if (o.isSoftRevocation()) {
+                    // Compare soft dates in reverse
+                    return o.getDate().compareTo(getDate());
+                } else {
+                    return -1;
+                }
+
+            case hardRevoked:
+                if (o.isHardRevocation()) {
+                    return 0;
+                } else {
+                    return 1;
+                }
+
+            default:
+                throw new AssertionError("Unknown type: " + type);
+        }
+    }
+
+    @Override
+    public int hashCode() {
+        return type.hashCode() * 31 + (isSoftRevocation() ? getDate().hashCode() : 0);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == null) {
+            return false;
+        }
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof RevocationState)) {
+            return false;
+        }
+        RevocationState other = (RevocationState) obj;
+        if (getType() != other.getType()) {
+            return false;
+        }
+        if (isSoftRevocation()) {
+            return DateUtil.toSecondsPrecision(getDate()).getTime() == DateUtil.toSecondsPrecision(other.getDate()).getTime();
+        }
+        return true;
+    }
 }

pgpainless-core/src/main/java/org/pgpainless/algorithm/RevocationStateType.java

@@ -0,0 +1,23 @@
+// SPDX-FileCopyrightText: 2022 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.algorithm;
+
+public enum RevocationStateType {
+
+    /**
+     * Certificate is not revoked.
+     */
+    notRevoked,
+
+    /**
+     * Certificate is revoked with a soft revocation.
+     */
+    softRevoked,
+
+    /**
+     * Certificate is revoked with a hard revocation.
+     */
+    hardRevoked
+}