feat: add image to ascii image command

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

@@ -0,0 +1,102 @@
+/*
+ * Copyright © 2024 RTAkland
+ * Author: RTAkland
+ * Date: 2024/9/20
+ */
+
+
+package cn.rtast.fancybot.commands.parse
+
+import cn.rtast.fancybot.util.str.encodeToBase64
+import cn.rtast.fancybot.util.toByteArray
+import cn.rtast.rob.entity.GroupMessage
+import cn.rtast.rob.enums.ArrayMessageType
+import cn.rtast.rob.util.BaseCommand
+import cn.rtast.rob.util.ob.MessageChain
+import cn.rtast.rob.util.ob.OneBotListener
+import java.awt.Color
+import java.awt.Font
+import java.awt.image.BufferedImage
+import java.net.URI
+import javax.imageio.ImageIO
+import kotlin.math.roundToInt
+
+class AsciiArtCommand : BaseCommand() {
+    override val commandNames = listOf("/ascii")
+
+    private val fontSize = 12
+    private val font = Font("Monospaced", Font.PLAIN, fontSize)
+
+    private fun BufferedImage.convertToAscii(): String {
+        val width = this.width
+        val height = this.height
+        val asciiArt = StringBuilder()
+
+        for (y in 0 until height step 2) {
+            for (x in 0 until width) {
+                val pixel = Color(this.getRGB(x, y))
+                val luminance = (0.2126 * pixel.red + 0.7152 * pixel.green + 0.0722 * pixel.blue).roundToInt()
+                val asciiChar = when (luminance) {
+                    in 0..15 -> ' '
+                    in 16..31 -> '.'
+                    in 32..47 -> ':'
+                    in 48..63 -> '-'
+                    in 64..79 -> '='
+                    in 80..95 -> '+'
+                    in 96..111 -> '*'
+                    in 112..127 -> '#'
+                    in 128..143 -> '%'
+                    in 144..159 -> '@'
+                    in 160..175 -> 'a'
+                    in 176..191 -> 'o'
+                    in 192..207 -> 'e'
+                    in 208..223 -> 'h'
+                    in 224..239 -> 'u'
+                    else -> '$'
+                }
+                asciiArt.append(asciiChar)
+            }
+            asciiArt.append("\n")
+        }
+
+        return asciiArt.toString()
+    }
+
+    private fun String.saveAsciiArtToImage(width: Int, height: Int): String {
+        val imgWidth = width * fontSize / 2
+        val imgHeight = height * fontSize / 2
+        val img = BufferedImage(imgWidth, imgHeight, BufferedImage.TYPE_INT_RGB)
+        val g2d = img.createGraphics()
+        g2d.color = Color.BLACK
+        g2d.fillRect(0, 0, imgWidth, imgHeight)
+        g2d.color = Color.WHITE
+        g2d.font = font
+        val lines = this.split("\n")
+        for ((index, line) in lines.withIndex()) {
+            g2d.drawString(line, 0, (index + 1) * fontSize)
+        }
+        g2d.dispose()
+        return img.toByteArray().encodeToBase64()
+    }
+
+    override suspend fun executeGroup(listener: OneBotListener, message: GroupMessage, args: List<String>) {
+        if (args.isEmpty()) {
+            val msg = MessageChain.Builder().addText("发送`/ascii <图片>`可以将图片转成ascii字符").build()
+            message.reply(msg)
+            return
+        }
+        val image = message.message.find { it.type == ArrayMessageType.image }
+        if (image == null) {
+            val msg = MessageChain.Builder().addText("输入一个图片来继续操作").build()
+            message.reply(msg)
+            return
+        } else {
+            val url = image.data.file!!
+            val bufferedImage = ImageIO.read(URI(url).toURL())
+            val ascii = bufferedImage.convertToAscii()
+            val image = ascii.saveAsciiArtToImage(bufferedImage.width, bufferedImage.height)
+            val msg = MessageChain.Builder().addImage(image, true).build()
+            message.reply(msg)
+        }
+    }
+}