using System.Text.RegularExpressions;
using System.Text;
using Mapster;
using Masuit.Tools;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Filters;
using YuanXuan.IM.Common.Response;
using YuanXuan.IM.Common.Exceptions;

namespace LearningOfficer.OA.Mobile.Api.Filters
{
    /// <summary>
    /// 全局异常捕获过滤器
    /// </summary>
    public class GlobalExceptionCatchFilter : IAsyncExceptionFilter
    {
        private readonly ILogger<GlobalExceptionCatchFilter> _logger;

        public GlobalExceptionCatchFilter(ILogger<GlobalExceptionCatchFilter> logger)
        {
            _logger = logger; //在构造函数中注入日志处理实例
        }

        public async Task OnExceptionAsync(ExceptionContext context)
        {
            // 如果异常没有被处理则进行处理
            if (context.ExceptionHandled == false)
            {
                // 定义返回类型
                BaseResponse<object> result;

                // 如果为业务逻辑抛出的内部异常
                if (context.Exception is BusinessException ex)
                {
                    if (ex.BussinessExceptionData != null)
                    {
                        result = new BaseResponse<object>((int)ex.ErrorCode, context.Exception.Message, ex.BussinessExceptionData);
                        //将result的data转换为Dictionary<string, object>
                        var data = result.data.ToDictionary();

                        ConvertKeysToCamelCase(data);
                        result.data = data;
                    }
                    else
                    {
                        result = new BaseResponse<object>((int)ex.ErrorCode, context.Exception.Message);
                    }
                }
                else
                {
                    // 程序异常,不对外暴露程序异常细节
                    result = new BaseResponse<object>((int)BusinessExceptionCode.AppError, "服务器好像出错了！"
                    //    ,new
                    //{
                    //    RequestId = context.HttpContext.TraceIdentifier
                    //}
                        );

                    //使用日志对象 _logger 的 LogError() 方法将异常信息写入日志文件
                    _logger.LogError(context.Exception, context.Exception.Message);
                }

                context.Result = new ContentResult
                {
                    // 返回状态码设置为200，表示成功
                    StatusCode = StatusCodes.Status200OK,
                    // 设置返回格式
                    ContentType = "application/json;charset=utf-8",
                    Content = result.ToJsonString()
                };


            }

            // 设置为true，表示异常已经被处理了
            context.ExceptionHandled = true;
        }

        public static void ConvertKeysToCamelCase(Dictionary<string, object> dictionary)
        {
            var keys = dictionary.Keys.ToList();
            foreach (var key in keys)
            {
                string ItemKey = key;
                if (ItemKey.Length >= 1 && char.IsUpper(ItemKey[0]))
                {
                    ItemKey = char.ToLower(ItemKey[0]) + ItemKey.Substring(1);
                }
                var camelCaseKey = ChangeName(ItemKey);
                if (dictionary.ContainsKey(camelCaseKey))
                {
                    dictionary[camelCaseKey] = dictionary[key];
                }
                else
                {
                    dictionary.Add(camelCaseKey, dictionary[key]);
                }
                dictionary.Remove(key);
            }
        }

        /// <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 static 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;
        }

    }
}