using LearningOfficer.OA.Common.Enums;
using LearningOfficer.OA.Common.Exceptions;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using UserCenter.Model.Common;
using UserCenter.Model.Enum;

namespace LearningOfficer.OA.Common.Helpers
{
    /// <summary>
    /// 解决方案工具年级转换帮助类
    /// </summary>
    public class SolutionToolGradeHelper
    {
        public static SolutionSemesterEnum ConvertToSolutionToolGradeEnum(string gradeLevel, int graduationYear)
        {
            var grade = GradeHelper.GetGradeByStudentGradeBase(gradeLevel, graduationYear);
            if (string.IsNullOrWhiteSpace(grade) || grade.Contains("届") || gradeLevel == GradeLevelEnum.小.ToString())
            {
                return SolutionSemesterEnum.None;
            }

            var gradeValue = GetGradeValue(gradeLevel, graduationYear);
            if (gradeValue == 0)
            {
                return SolutionSemesterEnum.None;
            }

            var semesterValue = GetSemesterValue();


            return (SolutionSemesterEnum)(gradeValue + semesterValue);
        }


        /// <summary>
        /// 获取年级的基础值
        /// </summary>
        /// <param name="gradeLevel"></param>
        /// <param name="graduationYear"></param>
        /// <returns></returns>
        /// <exception cref="BusinessException"></exception>
        private static int GetGradeValue(string gradeLevel, int graduationYear)
        {
            var now = DateTime.Now;

            // 获取当前年份与毕业年份的差值
            var diffYear = graduationYear - now.Year;
            if (diffYear < 0 || (diffYear == 0 && now.Date > new DateTime(now.Year, 8, 1)))
            {
                // 如果毕业年份小于当前年份，或者毕业年份为当前年份但当前日期在8月1日之后，代表已毕业，则返回0
                return 0;
            }
            // 取绝对值 
            diffYear = Math.Abs(diffYear);
            if (now.Date > new DateTime(now.Year, 8, 1))
            {
                // 如果当前日期在8月31日之后，说明已经进入新学年 
                diffYear--;
            }
            diffYear = diffYear * 10;

            var baseYearValue = 0;
            switch (gradeLevel)
            {
                case "初":
                    baseYearValue = 90;
                    break;
                case "高":
                    baseYearValue = 120;
                    break;
                default:
                    throw new BusinessException("未知年级值，年级转换值失败");
            }
            // 获取年级值
            return baseYearValue - diffYear;
        }

        /// <summary>
        /// 获取学期阶段基础值
        /// </summary>
        /// <returns></returns>
        private static int GetSemesterValue()
        {
            DateTime now = DateTime.Today;
            int month = now.Month;
            int day = now.Day;

            // 1月直接返回4
            if (month == 1)
            {
                return 2;
            }
            // 2月、3月 或 4月1-25日 返回1
            else if ((month == 2 || month == 3) || (month == 4 && day <= 25))
            {
                return 3;
            }
            // 4月26日-7月31日 返回2
            else if ((month == 4 && day >= 26) || (month >= 5 && month <= 7))
            {
                return 4;
            }
            // 8月、 9月、10月 或 11月1-8日 返回3
            else if ((month == 8 || month == 9 || month == 10) || (month == 11 && day <= 8))
            {
                return 1;
            }
            // 剩余情况（11月9日-12月31日）返回4
            else
            {
                return 2;
            }
        }
    }
}