feat: отслеживание дубликатов изображений

src/main/kotlin/com/github/djaler/evilbot/entity/ImageHash.kt

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+package com.github.djaler.evilbot.entity
+
+import javax.persistence.*
+
+@Entity
+@Table(name = "image_hashes")
+data class ImageHash(
+    @Column
+    val hash: String,
+
+    @Column
+    val chatId: Short,
+
+    @Column
+    val messageId: Long,
+
+    @Column
+    val fileId: String,
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    val id: Int = 0
+)

src/main/kotlin/com/github/djaler/evilbot/handlers/SeenMemeHandler.kt

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+package com.github.djaler.evilbot.handlers
+
+import com.github.djaler.evilbot.handlers.base.MessageHandler
+import com.github.djaler.evilbot.service.ChatService
+import com.github.djaler.evilbot.service.DuplicateImageChecker
+import dev.inmo.tgbotapi.bot.RequestsExecutor
+import dev.inmo.tgbotapi.extensions.api.files.downloadFile
+import dev.inmo.tgbotapi.extensions.api.send.reply
+import dev.inmo.tgbotapi.extensions.utils.asContentMessage
+import dev.inmo.tgbotapi.extensions.utils.asPhotoContent
+import dev.inmo.tgbotapi.extensions.utils.asPublicChat
+import dev.inmo.tgbotapi.extensions.utils.formatting.makeLinkToMessage
+import dev.inmo.tgbotapi.types.message.abstracts.Message
+import dev.inmo.tgbotapi.utils.buildEntities
+import dev.inmo.tgbotapi.utils.link
+import org.springframework.stereotype.Component
+import java.io.ByteArrayInputStream
+import javax.imageio.ImageIO
+
+@Component
+class SeenMemeHandler(
+    private val requestExecutor: RequestsExecutor,
+    private val duplicateImageChecker: DuplicateImageChecker,
+    private val chatService: ChatService,
+) : MessageHandler() {
+    override suspend fun handleMessage(message: Message): Boolean {
+        val chat = message.chat.asPublicChat() ?: return false
+        val imageFile = message.asContentMessage()?.content?.asPhotoContent()?.media ?: return false
+
+        val photoBytes = requestExecutor.downloadFile(imageFile)
+        val image = ByteArrayInputStream(photoBytes).use {
+            ImageIO.read(it)
+        }
+
+        val (chatEntity, _) = chatService.getOrCreateChatFrom(chat)
+        val originalMessageId: Long? = duplicateImageChecker.findDuplicate(image, chatEntity)
+
+        if (originalMessageId == null) {
+            duplicateImageChecker.saveHash(image, chatEntity, message.messageId, imageFile.fileId)
+            return false
+        } else {
+            val messageLink = makeLinkToMessage(message.chat, originalMessageId) ?: return false
+
+            requestExecutor.reply(
+                message,
+                buildEntities {
+                    +"Уже было - " + link(messageLink)
+                }
+            )
+            return true
+        }
+    }
+}

src/main/kotlin/com/github/djaler/evilbot/repository/ImageHashRepository.kt

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+package com.github.djaler.evilbot.repository
+
+import com.github.djaler.evilbot.entity.ImageHash
+import org.springframework.data.jpa.repository.JpaRepository
+
+interface ImageHashRepository : JpaRepository<ImageHash, Int> {
+    fun findByChatIdAndHash(chatId: Short, hash: String): ImageHash?
+}

src/main/kotlin/com/github/djaler/evilbot/service/DuplicateImageChecker.kt

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+package com.github.djaler.evilbot.service
+
+import com.github.djaler.evilbot.entity.Chat
+import com.github.djaler.evilbot.entity.ImageHash
+import com.github.djaler.evilbot.repository.ImageHashRepository
+import dev.inmo.tgbotapi.requests.abstracts.FileId
+import dev.inmo.tgbotapi.types.MessageIdentifier
+import korlibs.crypto.encoding.hex
+import org.springframework.stereotype.Component
+import java.awt.image.BufferedImage
+import java.io.ByteArrayOutputStream
+import java.security.DigestOutputStream
+import java.security.MessageDigest
+import javax.imageio.ImageIO
+
+@Component
+class DuplicateImageChecker(
+    private val imageHashRepository: ImageHashRepository,
+) {
+    fun findDuplicate(image: BufferedImage, chat: Chat): MessageIdentifier? {
+        val hash = resizeAndGetHash(image)
+
+        val duplicate = imageHashRepository.findByChatIdAndHash(chat.id, hash)
+
+        return duplicate?.messageId
+    }
+
+    fun saveHash(image: BufferedImage, chat: Chat, messageId: MessageIdentifier, fileId: FileId) {
+        val hash = resizeAndGetHash(image)
+
+        imageHashRepository.save(ImageHash(
+            hash,
+            chat.id,
+            messageId,
+            fileId.fileId
+        ))
+    }
+
+    // TODO cache
+    private fun resizeAndGetHash(image: BufferedImage): String {
+        val resizedImage = resizeImage(image, width = 64, height = 64)
+
+        return getImageHash(resizedImage)
+    }
+
+    private fun resizeImage(image: BufferedImage, width: Int, height: Int): BufferedImage {
+        return BufferedImage(width, height, image.type).apply {
+            graphics.drawImage(image, 0, 0, 64, 64, null)
+        }
+    }
+
+    private fun getImageHash(image: BufferedImage): String {
+        val messageDigest = MessageDigest.getInstance("MD5")
+        ByteArrayOutputStream().use { baos ->
+            DigestOutputStream(baos, messageDigest).use { dos ->
+                ImageIO.write(image, "png", dos)
+                dos.flush()
+            }
+        }
+
+        return messageDigest.digest().hex
+    }
+}

src/main/resources/db/migration/V9__add_image_hashes_table.sql

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+CREATE TABLE image_hashes
+(
+    id         SERIAL PRIMARY KEY,
+    hash       VARCHAR  NOT NULL,
+    chat_id    SMALLINT NOT NULL,
+    message_id BIGINT   NOT NULL,
+    file_id    VARCHAR  NOT NULL,
+
+    UNIQUE (chat_id, hash)
+);