Remove At.display and defer it to message elems conversions

mirai-core-api/src/commonMain/kotlin/message/data/At.kt

@@ -10,14 +10,14 @@
 @file:JvmMultifileClass
 @file:JvmName("MessageUtils")
 
-@file:Suppress("EXPERIMENTAL_API_USAGE")
+@file:Suppress("EXPERIMENTAL_API_USAGE", "NOTHING_TO_INLINE")
 
 package net.mamoe.mirai.message.data
 
 import kotlinx.serialization.Serializable
 import net.mamoe.mirai.LowLevelApi
 import net.mamoe.mirai.contact.Member
-import net.mamoe.mirai.contact.nameCardOrNick
+import net.mamoe.mirai.contact.UserOrBot
 import net.mamoe.mirai.message.code.CodableMessage
 import net.mamoe.mirai.utils.PlannedRemoval
 
@@ -26,30 +26,16 @@ import net.mamoe.mirai.utils.PlannedRemoval
  * At 一个群成员. 只能发送给一个群.
  *
  * ## mirai 码支持
- * 格式: [mirai:at:*[target]*,*[display]*]
+ * 格式: [mirai:at:*[target]*]
  *
  * @see AtAll 全体成员
  */
 @Serializable
-public data class At @LowLevelApi constructor(
+public data class At(
     public val target: Long,
-    /**
-     * "@群员名片"
-     */
-    public val display: String
 ) : MessageContent, CodableMessage {
-
-    /**
-     * 构造一个 [At] 实例. 这是唯一的公开的构造方式.
-     */
-    public constructor(member: Member) : this(member.id, "@${member.nameCardOrNick}")
-
-    public override fun equals(other: Any?): Boolean {
-        return other is At && other.target == this.target && other.display == this.display
-    }
-
-    public override fun toString(): String = "[mirai:at:$target,$display]"
-    public override fun contentToString(): String = this.display
+    public override fun toString(): String = "[mirai:at:$target]"
+    public override fun contentToString(): String = "@$target"
 
     public companion object {
         /**
@@ -58,9 +44,9 @@ public data class At @LowLevelApi constructor(
         @Suppress("FunctionName")
         @JvmStatic
         @LowLevelApi
-        @Deprecated("Use constructor instead", ReplaceWith("At(target, display)", "net.mamoe.mirai.message.data.At"))
+        @Deprecated("Use constructor instead", ReplaceWith("At(target)", "net.mamoe.mirai.message.data.At"))
         @PlannedRemoval("2.0-M2")
-        public fun _lowLevelConstructAtInstance(target: Long, display: String): At = At(target, display)
+        public fun _lowLevelConstructAtInstance(target: Long, display: String): At = At(target)
     }
 
     // 自动为消息补充 " "
@@ -70,18 +56,19 @@ public data class At @LowLevelApi constructor(
         }
         return super<MessageContent>.followedBy(PlainText(" ")) + tail
     }
-
-    public override fun hashCode(): Int {
-        var result = target.hashCode()
-        result = 31 * result + display.hashCode()
-        return result
-    }
-
 }
 
+/**
+ * 构造 [At]
+ *
+ * @see At
+ * @see Member.at
+ */
+@JvmSynthetic
+public inline fun At(user: UserOrBot): At = At(user.id)
+
 /**
  * At 这个成员
  */
 @JvmSynthetic
-@Suppress("NOTHING_TO_INLINE")
 public inline fun Member.at(): At = At(this)

mirai-core/src/commonMain/kotlin/message/atImpl.kt

@@ -11,13 +11,15 @@ package net.mamoe.mirai.internal.message
 
 import kotlinx.io.core.buildPacket
 import kotlinx.io.core.readBytes
+import net.mamoe.mirai.contact.Group
+import net.mamoe.mirai.contact.nameCardOrNick
 import net.mamoe.mirai.internal.network.protocol.data.proto.ImMsgBody
 import net.mamoe.mirai.message.data.At
 import net.mamoe.mirai.message.data.AtAll
 
 
-internal fun At.toJceData(): ImMsgBody.Text {
-    val text = this.display
+internal fun At.toJceData(group: Group?): ImMsgBody.Text {
+    val text = group?.members?.get(this.target)?.nameCardOrNick ?: "@$target"
     return ImMsgBody.Text(
         str = text,
         attr6Buf = buildPacket {

mirai-core/src/commonMain/kotlin/message/conversions.kt

@@ -365,7 +365,7 @@ internal fun List<ImMsgBody.Elem>.joinToMessageChain(groupIdOrZero: Long, botId:
                     if (id == 0L) {
                         list.add(AtAll)
                     } else {
-                        list.add(At._lowLevelConstructAtInstance(id, element.text.str))
+                        list.add(At(id)) // element.text.str
                     }
                 }
             }