Add missing file

src/MTProtoTools/DialogId.php

@@ -0,0 +1,87 @@
+<?php declare(strict_types=1);
+
+namespace danog\MadelineProto\MTProtoTools;
+
+use AssertionError;
+use danog\MadelineProto\Magic;
+use Webmozart\Assert\Assert;
+
+/**
+ * Represents the type of a bot API dialog ID.
+ */
+enum DialogId
+{
+    case USER;
+    case CHAT;
+    case CHANNEL_OR_SUPERGROUP;
+    case SECRET_CHAT;
+
+    /**
+     * Get the type of a dialog using just its bot API dialog ID.
+     *
+     * For more detailed types, use API::getType, instead.
+     *
+     * @param integer $id Bot API ID.
+     */
+    public static function getType(int $id): self
+    {
+        if ($id < 0) {
+            if (-Magic::MAX_CHAT_ID <= $id) {
+                return DialogId::CHAT;
+            }
+            if (Magic::ZERO_CHANNEL_ID - Magic::MAX_CHANNEL_ID <= $id && $id !== Magic::ZERO_CHANNEL_ID) {
+                return DialogId::CHANNEL_OR_SUPERGROUP;
+            }
+            if (Magic::ZERO_SECRET_CHAT_ID + Magic::MIN_INT32 <= $id && $id !== Magic::ZERO_SECRET_CHAT_ID) {
+                return DialogId::SECRET_CHAT;
+            }
+        } elseif (0 < $id && $id <= Magic::MAX_USER_ID) {
+            return DialogId::USER;
+        }
+        throw new AssertionError("Invalid ID $id provided!");
+    }
+
+    /**
+     * Convert MTProto secret chat ID to bot API secret chat ID.
+     *
+     * @param int $id MTProto secret chat ID
+     *
+     * @return int Bot API secret chat ID
+     */
+    public static function fromSecretChatId(int $id): int
+    {
+        return Magic::ZERO_SECRET_CHAT_ID + $id;
+    }
+    /**
+     * Convert bot API secret chat ID to MTProto secret chat ID.
+     *
+     * @param int $id Bot API secret chat ID
+     *
+     * @return int MTProto secret chat ID
+     */
+    public static function toSecretChatId(int $id): int
+    {
+        Assert::eq(self::getType($id), self::SECRET_CHAT);
+        return $id - Magic::ZERO_SECRET_CHAT_ID;
+    }
+
+    /**
+     * Convert MTProto channel ID to bot API channel ID.
+     *
+     * @param int $id MTProto channel ID
+     */
+    public static function toSupergroupOrChannel(int $id): int
+    {
+        return Magic::ZERO_CHANNEL_ID - $id;
+    }
+    /**
+     * Convert bot API channel ID to MTProto channel ID.
+     *
+     * @param int $id Bot API channel ID
+     */
+    public static function fromSupergroupOrChannel(int $id): int
+    {
+        Assert::eq(self::getType($id), self::SECRET_CHAT);
+        return (-$id) + Magic::ZERO_CHANNEL_ID;
+    }
+}