using Microsoft.AspNetCore.Http;
using System.Text;
using System.Web;

namespace HuanMeng.DotNetCore.Extensions
{
    /// <summary>
    /// HttpContext扩展方法
    /// </summary>
    public static class HttpContextExtensions
    {
        /// <summary>
        /// 动态消息的头部名称
        /// </summary>
        public const string DynamicMessageHeaderName = "X-Dynamic-Message";

        /// <summary>
        /// 设置动态消息
        /// </summary>
        /// <param name="httpContext">HTTP上下文</param>
        /// <param name="message">消息内容</param>
        public static void SetDynamicMessage(this HttpContext httpContext, string message)
        {
            if (string.IsNullOrEmpty(message))
                return;

            // URL编码消息内容，防止特殊字符导致问题
            string encodedMessage = HttpUtility.UrlEncode(message);
            httpContext.Response.Headers[DynamicMessageHeaderName] = encodedMessage;
        }

        /// <summary>
        /// 获取动态消息
        /// </summary>
        /// <param name="httpContext">HTTP上下文</param>
        /// <returns>消息内容，如果不存在则返回空字符串</returns>
        public static string GetDynamicMessage(this HttpContext httpContext)
        {
            if (httpContext.Response.Headers.TryGetValue(DynamicMessageHeaderName, out var value))
            {
                // URL解码消息内容
                return HttpUtility.UrlDecode(value);
            }

            return string.Empty;
        }
    }
}