add Reaction type

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/types/Common.kt

@@ -229,6 +229,7 @@ const val textEntitiesField = "text_entities"
 const val entitiesField = "entities"
 const val stickerSetNameField = "set_name"
 const val customEmojiIdField = "custom_emoji_id"
+const val customEmojiField = "custom_emoji"
 const val customEmojiIdsField = "custom_emoji_ids"
 const val premiumAnimationField = "premium_animation"
 const val stickerSetNameFullField = "sticker_set_name"

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/types/reactions/Reaction.kt

@@ -0,0 +1,93 @@
+package dev.inmo.tgbotapi.types.reactions
+
+import dev.inmo.tgbotapi.types.CustomEmojiId
+import dev.inmo.tgbotapi.types.customEmojiField
+import dev.inmo.tgbotapi.types.emojiField
+import dev.inmo.tgbotapi.utils.internal.ClassCastsIncluded
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.json.JsonDecoder
+import kotlinx.serialization.json.JsonElement
+
+@Serializable
+@ClassCastsIncluded
+sealed interface Reaction {
+    val type: String
+
+    @Serializable(Reaction.Companion::class)
+    data class Emoji(
+        val emoji: String
+    ) : Reaction {
+        override val type: String
+            get() = Companion.type
+        companion object {
+            const val type: String = "emoji"
+        }
+    }
+
+    @Serializable(Reaction.Companion::class)
+    data class CustomEmoji(
+        val customEmoji: CustomEmojiId
+    ) : Reaction {
+        override val type: String
+            get() = Companion.type
+        companion object {
+            const val type: String = "custom_emoji"
+        }
+    }
+
+    @Serializable(Reaction.Companion::class)
+    data class Unknown(
+        override val type: String,
+        val sourceJson: JsonElement?
+    ) : Reaction
+
+    @Serializable
+    private data class Surrogate(
+        val type: String,
+        @SerialName(emojiField)
+        val emoji: String? = null,
+        @SerialName(customEmojiField)
+        val customEmoji: CustomEmojiId? = null
+    )
+
+    companion object : KSerializer<Reaction> {
+        override val descriptor: SerialDescriptor
+            get() = Surrogate.serializer().descriptor
+
+        override fun deserialize(decoder: Decoder): Reaction {
+            val (surrogate, json) = if (decoder is JsonDecoder) {
+                val json = decoder.decodeJsonElement()
+                decoder.json.decodeFromJsonElement(Surrogate.serializer(), json) to json
+            } else {
+                Surrogate.serializer().deserialize(decoder) to null
+            }
+
+            return when {
+                surrogate.emoji != null -> Emoji(surrogate.emoji)
+                surrogate.customEmoji != null -> CustomEmoji(surrogate.customEmoji)
+                else -> Unknown(surrogate.type, json)
+            }
+        }
+
+        override fun serialize(encoder: Encoder, value: Reaction) {
+            if (value is Unknown && value.sourceJson != null) {
+                JsonElement.serializer().serialize(encoder, value.sourceJson)
+            } else {
+                Surrogate.serializer().serialize(
+                    encoder,
+                    Surrogate(
+                        type = value.type,
+                        emoji = (value as? Emoji) ?.emoji,
+                        customEmoji = (value as? CustomEmoji) ?.customEmoji,
+                    )
+                )
+            }
+        }
+
+    }
+}