feat: support reverse gif using reply

src/main/kotlin/cn/rtast/fancybot/FancyBot.kt

@@ -85,6 +85,10 @@ class FancyBot : OneBotListener {
             val plainTextContent = getMsg.message
                 .filter { it.type == ArrayMessageType.text }
                 .joinToString { it.data.text!! }
+            if (command.contains("倒放") || command.contains("/df")) {
+                // 使用回复消息的方式对一个gif倒放
+                ReverseGIFCommand.reverse(message, getMsg)
+            }
             if (command.contains("/sl") || command.contains("/short")) {
                 // 使用回复消息的方式快速对一个url消息创建一个短链接
                 message.reply(plainTextContent.trim().makeShortLink())

src/main/kotlin/cn/rtast/fancybot/commands/parse/ReverseGIFCommand.kt

@@ -10,6 +10,7 @@ package cn.rtast.fancybot.commands.parse
 import cn.rtast.fancybot.annotations.CommandDescription
 import cn.rtast.fancybot.util.misc.makeGif
 import cn.rtast.fancybot.util.str.encodeToBase64
+import cn.rtast.rob.entity.GetMessage
 import cn.rtast.rob.entity.GroupMessage
 import cn.rtast.rob.enums.ArrayMessageType
 import cn.rtast.rob.util.BaseCommand
@@ -34,6 +35,20 @@ class ReverseGIFCommand : BaseCommand() {
             return gifBytes.encodeToBase64()
         }
 
+        suspend fun reverse(message: GroupMessage, getMsg: GetMessage.Data) {
+            val imageObject = getMsg.message.find { it.type == ArrayMessageType.image }
+            if (imageObject == null) {
+                message.reply("这个消息中没有图片呢")
+            } else {
+                val url = imageObject.data.file!!
+                val image = this.reverseGif(url)
+                val msg = MessageChain.Builder()
+                    .addImage(image, true)
+                    .build()
+                message.reply(msg)
+            }
+        }
+
         suspend fun callback(message: GroupMessage) {
             if (message.sender.userId !in waitingList) return
             waitingList.removeIf { it == message.sender.userId }