using System.Text;
using Microsoft.AspNetCore.Mvc.ModelBinding;

namespace Microsoft.AspNetCore.Mvc
{
    public static class ModelStateExtensions
    {
        /// <summary>
        /// 获取模型验证内的所有错误信息
        /// </summary>
        /// <param name="modelState">模型验证对象</param>
        /// <returns></returns>
        public static string GetErrorMessage(this ModelStateDictionary modelState)
        {
            ArgumentException.ThrowIfNullOrEmpty(nameof(modelState));

            StringBuilder sb = new();
            foreach (var key in modelState.Keys)
            {
                var entry = modelState[key];
                if (entry.ValidationState == ModelValidationState.Invalid)
                {
                    sb.Append(string.Join("; ", entry.Errors));
                }
            }

            return sb.ToString();
        }
    }
}