From c614dc0e7b6d702e6d81fc1fae942690e75eef6f Mon Sep 17 00:00:00 2001
From: Paul Schaub <vanitasvitae@fsfe.org>
Date: Fri, 4 Aug 2023 17:02:37 +0200
Subject: [PATCH] Kotlin conversion: CompressionAlgorithm

---
 .../algorithm/CompressionAlgorithm.java       | 79 -------------------
 .../algorithm/CompressionAlgorithm.kt         | 50 ++++++++++++
 2 files changed, 50 insertions(+), 79 deletions(-)
 delete mode 100644 pgpainless-core/src/main/java/org/pgpainless/algorithm/CompressionAlgorithm.java
 create mode 100644 pgpainless-core/src/main/java/org/pgpainless/algorithm/CompressionAlgorithm.kt

diff --git a/pgpainless-core/src/main/java/org/pgpainless/algorithm/CompressionAlgorithm.java b/pgpainless-core/src/main/java/org/pgpainless/algorithm/CompressionAlgorithm.java
deleted file mode 100644
index a2e78c5f..00000000
--- a/pgpainless-core/src/main/java/org/pgpainless/algorithm/CompressionAlgorithm.java
+++ /dev/null
@@ -1,79 +0,0 @@
-// SPDX-FileCopyrightText: 2018 Paul Schaub <vanitasvitae@fsfe.org>
-//
-// SPDX-License-Identifier: Apache-2.0
-
-package org.pgpainless.algorithm;
-
-import java.util.Map;
-import java.util.NoSuchElementException;
-import java.util.concurrent.ConcurrentHashMap;
-
-import org.bouncycastle.bcpg.CompressionAlgorithmTags;
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-
-/**
- * Enumeration of possible compression algorithms.
- *
- * @see <a href="https://tools.ietf.org/html/rfc4880#section-9.3">RFC4880: Compression Algorithm Tags</a>
- */
-public enum CompressionAlgorithm {
-
-    UNCOMPRESSED   (CompressionAlgorithmTags.UNCOMPRESSED),
-    ZIP            (CompressionAlgorithmTags.ZIP),
-    ZLIB           (CompressionAlgorithmTags.ZLIB),
-    BZIP2          (CompressionAlgorithmTags.BZIP2),
-    ;
-
-    private static final Map<Integer, CompressionAlgorithm> MAP = new ConcurrentHashMap<>();
-
-    static {
-        for (CompressionAlgorithm c : CompressionAlgorithm.values()) {
-            MAP.put(c.algorithmId, c);
-        }
-    }
-
-    /**
-     * Return the {@link CompressionAlgorithm} value that corresponds to the provided numerical id.
-     * If an invalid id is provided, null is returned.
-     *
-     * @param id id
-     * @return compression algorithm
-     */
-    @Nullable
-    public static CompressionAlgorithm fromId(int id) {
-        return MAP.get(id);
-    }
-
-    /**
-     * Return the {@link CompressionAlgorithm} value that corresponds to the provided numerical id.
-     * If an invalid id is provided, thrown an {@link NoSuchElementException}.
-     *
-     * @param id id
-     * @return compression algorithm
-     * @throws NoSuchElementException in case of an unmapped id
-     */
-    @Nonnull
-    public static CompressionAlgorithm requireFromId(int id) {
-        CompressionAlgorithm algorithm = fromId(id);
-        if (algorithm == null) {
-            throw new NoSuchElementException("No CompressionAlgorithm found for id " + id);
-        }
-        return algorithm;
-    }
-
-    private final int algorithmId;
-
-    CompressionAlgorithm(int id) {
-        this.algorithmId = id;
-    }
-
-    /**
-     * Return the numerical algorithm tag corresponding to this compression algorithm.
-     * @return id
-     */
-    public int getAlgorithmId() {
-        return algorithmId;
-    }
-}
diff --git a/pgpainless-core/src/main/java/org/pgpainless/algorithm/CompressionAlgorithm.kt b/pgpainless-core/src/main/java/org/pgpainless/algorithm/CompressionAlgorithm.kt
new file mode 100644
index 00000000..73179722
--- /dev/null
+++ b/pgpainless-core/src/main/java/org/pgpainless/algorithm/CompressionAlgorithm.kt
@@ -0,0 +1,50 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.algorithm
+
+/**
+ * Enumeration of possible compression algorithms.
+ *
+ * See also [RFC4880 - Compression Algorithm Tags](https://tools.ietf.org/html/rfc4880#section-9.3)
+ */
+enum class CompressionAlgorithm(val algorithmId: Int) {
+
+    UNCOMPRESSED(0),
+    ZIP(1),
+    ZLIB(2),
+    BZIP2(3),
+    ;
+
+    companion object {
+
+        /**
+         * Return the [CompressionAlgorithm] value that corresponds to the provided numerical id.
+         * If an invalid id is provided, null is returned.
+         *
+         * @param id id
+         * @return compression algorithm
+         */
+        @JvmStatic
+        fun fromId(id: Int): CompressionAlgorithm? {
+            return values().firstOrNull {
+                c -> c.algorithmId == id
+            }
+        }
+
+        /**
+         * Return the [CompressionAlgorithm] value that corresponds to the provided numerical id.
+         * If an invalid id is provided, throw an [NoSuchElementException].
+         *
+         * @param id id
+         * @return compression algorithm
+         * @throws NoSuchElementException in case of an unmapped id
+         */
+        @JvmStatic
+        fun requireFromId(id: Int): CompressionAlgorithm {
+            return fromId(id) ?:
+            throw NoSuchElementException("No CompressionAlgorithm found for id $id")
+        }
+    }
+}
\ No newline at end of file