using Newtonsoft.Json;
using System.Reflection;
using Newtonsoft.Json.Serialization;
using System.Text.RegularExpressions;
using System.Text;

namespace LearningOfficer.OA.Mobile.Api.Filters
{
    public class CustomContractResolver : DefaultContractResolver
    {
        protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
        {
            var property = base.CreateProperty(member, memberSerialization);

            if (!string.IsNullOrEmpty(member.Name))
            {
                if (member.Name.Length >= 1 && char.IsUpper(member.Name[0]))
                {
                    property.PropertyName = char.ToLower(member.Name[0]) + member.Name.Substring(1);
                }
                property.PropertyName = ChangeName(property.PropertyName);
            }
            return property;
        }
        /// <summary>
        /// 将下划线命名转换为小驼峰命名
        /// </summary>
        /// <param name="name">变量名</param>
        /// <returns></returns>
        private string ChangeName(string name)
        {
            Match mt = Regex.Match(name, @"_(\w*)*");
            if (mt.Success) {
                var sb = new StringBuilder();
                bool toUpper = false;
                for (int i = 0; i < name.Length; i++)
                {
                    char c = name[i];
                    if (c == '_')
                    {
                        toUpper = true;
                    }
                    else
                    {
                        sb.Append(toUpper ? char.ToUpperInvariant(c) : c);
                        toUpper = false;
                    }
                }
                if (sb.Length > 0)
                    sb[0] = char.ToLowerInvariant(sb[0]);
                return sb.ToString();
            }
            return name;
        }
    }
}