Fix build

mirai-core/src/commonMain/kotlin/net.mamoe.mirai/utils/ExternalImage.kt

@@ -11,12 +11,15 @@
 
 package net.mamoe.mirai.utils
 
+import kotlinx.io.core.readBytes
+import kotlinx.io.core.use
 import net.mamoe.mirai.contact.Contact
 import net.mamoe.mirai.contact.Group
 import net.mamoe.mirai.contact.User
 import net.mamoe.mirai.message.MessageReceipt
 import net.mamoe.mirai.message.data.Image
 import net.mamoe.mirai.message.data.sendTo
+import net.mamoe.mirai.message.data.toUHexString
 import net.mamoe.mirai.utils.internal.DeferredReusableInput
 import net.mamoe.mirai.utils.internal.ReusableInput
 import kotlin.jvm.JvmSynthetic
@@ -30,16 +33,14 @@ import kotlin.jvm.JvmSynthetic
  * @See ExternalImage.upload 上传图片并得到 [Image] 消息
  */
 public class ExternalImage internal constructor(
-    override val input: ReusableInput
-) : ExternalFile {
-    public override val formatName: String by lazy {
-        TODO()
-        /*
+    internal val input: ReusableInput
+) {
+    internal val md5: ByteArray get() = input.md5
+    public val formatName: String by lazy {
         val hex = input.asInput().use {
-            //it.asInput().readBytes(8).toUHexString("")
-            TODO()
+            it.readBytes(8).toUHexString("")
         }
-        return@lazy hex.detectFormatName() as String*/
+        return@lazy hex.detectFormatName()
     }
 
     init {

mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/utils/internal/DeferredReusableInput.jvm.kt

@@ -45,7 +45,7 @@ internal actual class DeferredReusableInput actual constructor(
         return delegate?.writeTo(out) ?: error("DeferredReusableInput not yet initialized")
     }
 
-    override fun asInput(): InputStream {
+    override fun asInput(): Input {
         return delegate?.asInput() ?: error("DeferredReusableInput not yet initialized")
     }
 

mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/utils/internal/asReusableInput.jvm.kt

@@ -37,8 +37,8 @@ internal actual fun ByteArray.asReusableInput(): ReusableInput {
             return this@asReusableInput.size.toLongUnsigned()
         }
 
-        override fun asInput(): InputStream {
-            return ByteArrayInputStream(this@asReusableInput)
+        override fun asInput(): Input {
+            return ByteArrayInputStream(this@asReusableInput).asInput()
         }
     }
 }
@@ -63,8 +63,8 @@ internal fun File.asReusableInput(deleteOnClose: Boolean): ReusableInput {
             return inputStream().use { it.copyTo(out) }
         }
 
-        override fun asInput(): InputStream {
-            return inputStream()
+        override fun asInput(): Input {
+            return inputStream().asInput()
         }
     }
 }
@@ -89,8 +89,8 @@ internal fun File.asReusableInput(deleteOnClose: Boolean, md5: ByteArray): Reusa
             return inputStream().use { it.copyTo(out) }
         }
 
-        override fun asInput(): InputStream {
-            return inputStream()
+        override fun asInput(): Input {
+            return inputStream().asInput()
         }
     }
 }