feat: support gif reverse and fix get image bug

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

@@ -10,6 +10,7 @@ package cn.rtast.fancybot
 import cn.rtast.fancybot.commands.*
 import cn.rtast.fancybot.commands.misc.BVParseCommand
 import cn.rtast.fancybot.commands.misc.ImageURLCommand
+import cn.rtast.fancybot.commands.misc.ReverseGIFCommand
 import cn.rtast.fancybot.entity.enums.WSType
 import cn.rtast.fancybot.items.BaisiItem
 import cn.rtast.fancybot.items.HeisiItem
@@ -42,8 +43,13 @@ class FancyBot : OBMessage {
             val command = message.message.reversed().find { it.type == ArrayMessageType.text }!!.data.text!!
             val replyId = message.message.find { it.type == ArrayMessageType.reply }!!.data.id!!
             if (command.contains("图来") || command.contains("图链")) {
+                // get image url
                 this.getMessage(replyId.toString().toLong(), "imageUrl", message.groupId)
             }
+            if (command.contains("倒放") || command.contains("df")) {
+                // reverse gif
+                this.getMessage(replyId.toString().toLong(), "reverseGif", message.groupId)
+            }
         }
     }
 
@@ -61,6 +67,7 @@ class FancyBot : OBMessage {
         when (message.data.id) {
             "revoke" -> AntiRevokeCommand.getMessageCallback(this, message)
             "imageUrl" -> ImageURLCommand.callback(this, message)
+            "reverseGif" -> ReverseGIFCommand.callback(this, message)
         }
     }
 

src/main/kotlin/cn/rtast/fancybot/commands/misc/ImageURLCommand.kt

@@ -15,13 +15,18 @@ import cn.rtast.rob.util.ob.OBMessage
 object ImageURLCommand {
 
     suspend fun callback(listener: OBMessage, message: GetMessage) {
-        val image = message.data.message.find { it.type == ArrayMessageType.image }!!
         val msg = MessageChain.Builder()
             .addReply(message.data.messageId)
             .addText("哈哈哈哈图片来咯~")
             .addNewLine()
-            .addText(image.data.file!!)
-            .build()
-        listener.sendGroupMessage(message.data.groupId!!, msg)
+        val image = message.data.message.find { it.type == ArrayMessageType.image }
+        if (image == null) {
+            val gif = message.data.message.find { it.type == ArrayMessageType.mface }!!
+            msg.addText(gif.data.url!!)
+        } else {
+            msg.addText(image.data.file!!)
+
+        }
+        listener.sendGroupMessage(message.data.groupId!!, msg.build())
     }
 }

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

@@ -0,0 +1,49 @@
+/*
+ * Copyright © 2024 RTAkland
+ * Author: RTAkland
+ * Date: 2024/9/8
+ */
+
+
+package cn.rtast.fancybot.commands.misc
+
+import cn.rtast.fancybot.util.str.encodeToBase64
+import cn.rtast.rob.entity.GetMessage
+import cn.rtast.rob.enums.ArrayMessageType
+import cn.rtast.rob.util.ob.MessageChain
+import cn.rtast.rob.util.ob.OBMessage
+import com.madgag.gif.fmsware.AnimatedGifEncoder
+import com.madgag.gif.fmsware.GifDecoder
+import java.io.ByteArrayOutputStream
+import java.net.URI
+
+object ReverseGIFCommand {
+
+    private fun reverseGif(gifUrl: String): String {
+        val gifStream = URI(gifUrl).toURL().openStream()
+        val decoder = GifDecoder()
+        decoder.read(gifStream)
+        val frames = (0 until decoder.frameCount).map { decoder.getFrame(it) }.reversed()
+        val byteArrayOutputStream = ByteArrayOutputStream()
+        val encoder = AnimatedGifEncoder()
+        encoder.start(byteArrayOutputStream)
+        encoder.setRepeat(0)
+        for (i in frames.indices) {
+            encoder.setDelay(decoder.getDelay(decoder.frameCount - i - 1))
+            encoder.addFrame(frames[i])
+        }
+        encoder.finish()
+        val gifBytes = byteArrayOutputStream.toByteArray()
+        return gifBytes.encodeToBase64()
+    }
+
+    suspend fun callback(listener: OBMessage, message: GetMessage) {
+        val gifUrl = message.data.message.find { it.type == ArrayMessageType.mface }!!.data.url!!
+        val base64String = this.reverseGif(gifUrl)
+        val msg = MessageChain.Builder()
+            .addReply(message.data.messageId)
+            .addImage(base64String, true)
+            .build()
+        listener.sendGroupMessage(message.data.groupId!!, msg)
+    }
+}

src/main/kotlin/cn/rtast/fancybot/util/str/Base64.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright © 2024 RTAkland
+ * Author: RTAkland
+ * Date: 2024/9/8
+ */
+
+
+package cn.rtast.fancybot.util.str
+
+import java.util.*
+
+fun String.encodeToBase64(): String {
+    return Base64.getEncoder().encodeToString(this.toByteArray())
+}
+
+fun ByteArray.encodeToBase64(): String {
+    return Base64.getEncoder().encodeToString(this)
+}
+
+fun String.decodeToString(): String {
+    return String(Base64.getDecoder().decode(this))
+}