add

app/models/chat/ChatMessage.php

@@ -0,0 +1,69 @@
+<?php
+
+namespace app\models\chat;
+
+use think\Model;
+
+/**
+ * 聊天消息模型
+ * Class ChatMessage
+ * @package app\models\chat
+ */
+class ChatMessage extends Model
+{
+    protected $table = 'cg_chat_message';
+    protected $pk = 'id';
+    protected $autoWriteTimestamp = false;
+
+    // 发送者类型
+    const SENDER_USER = 1;   // 用户
+    const SENDER_ADMIN = 2;  // 客服
+
+    // 消息类型
+    const MSG_TYPE_TEXT = 1;   // 文字
+    const MSG_TYPE_IMAGE = 2;  // 图片
+
+    // 消息状态
+    const STATUS_PENDING = 0;    // 待发送
+    const STATUS_SENT = 1;       // 已发送
+    const STATUS_DELIVERED = 2;  // 已送达
+    const STATUS_READ = 3;       // 已读
+    const STATUS_FAILED = 4;     // 发送失败
+
+    /**
+     * 获取会话消息列表
+     */
+    public static function getBySessionId(int $sessionId, int $limit = 50, int $lastId = 0): array
+    {
+        $query = self::where('session_id', $sessionId);
+        if ($lastId > 0) {
+            $query->where('id', '<', $lastId);
+        }
+        return $query->order('id', 'desc')
+            ->limit($limit)
+            ->select()
+            ->toArray();
+    }
+
+    /**
+     * 获取会话未读消息
+     */
+    public static function getUnreadBySessionId(int $sessionId, int $senderType, int $limit = 50): array
+    {
+        return self::where('session_id', $sessionId)
+            ->where('sender_type', '<>', $senderType)
+            ->where('status', '<', self::STATUS_READ)
+            ->order('id', 'asc')
+            ->limit($limit)
+            ->select()
+            ->toArray();
+    }
+
+    /**
+     * 检查消息ID是否存在(幂等性)
+     */
+    public static function existsByMsgId(int $msgId): bool
+    {
+        return self::where('msg_id', $msgId)->count() > 0;
+    }
+}