using System;
using System.Collections.Generic;
// ReSharper disable InconsistentNaming
// ReSharper disable IdentifierTypo

namespace Lunar.Util
{
    /// <summary>
    /// 阳历工具
    /// </summary>
    public static class SolarUtil
    {
        /// <summary>
        /// 星期
        /// </summary>
        public static readonly string[] WEEK = { "日", "一", "二", "三", "四", "五", "六" };

        /// <summary>
        /// 每月天数
        /// </summary>
        public static readonly int[] DAYS_OF_MONTH = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

        /// <summary>
        /// 星座
        /// </summary>
        public static readonly string[] XING_ZUO = { "白羊", "金牛", "双子", "巨蟹", "狮子", "处女", "天秤", "天蝎", "射手", "摩羯", "水瓶", "双鱼" };

        /// <summary>
        /// 节日
        /// </summary>
        public static readonly Dictionary<string, string> FESTIVAL = new Dictionary<string, string>
        {
            { "1-1", "元旦节" },
            { "2-14", "情人节" },
            { "3-8", "妇女节" },
            { "3-12", "植树节" },
            { "3-15", "消费者权益日" },
            { "4-1", "愚人节" },
            { "5-1", "劳动节" },
            { "5-4", "青年节" },
            { "6-1", "儿童节" },
            { "7-1", "建党节" },
            { "8-1", "建军节" },
            { "9-10", "教师节" },
            { "10-1", "国庆节" },
            { "10-31", "万圣节前夜" },
            { "11-1", "万圣节" },
            { "12-24", "平安夜" },
            { "12-25", "圣诞节" }
        };

        /// <summary>
        /// 按星期的节日
        /// </summary>
        public static readonly Dictionary<string, string> WEEK_FESTIVAL = new Dictionary<string, string>
        {
            { "3-0-1", "全国中小学生安全教育日" },
            { "5-2-0", "母亲节" },
            { "5-3-0", "全国助残日" },
            { "6-3-0", "父亲节" },
            { "9-3-6", "全民国防教育日" },
            { "10-1-1", "世界住房日" },
            { "11-4-4", "感恩节" }
        };

        /// <summary>
        /// 非正式节日
        /// </summary>
        public static readonly Dictionary<string, List<string>> OTHER_FESTIVAL = new Dictionary<string, List<string>>
        {
            {"1-8", new List<string>(new[] {"周恩来逝世纪念日"})},
            {"1-10", new List<string>(new[] {"中国人民警察节"})},
            {"1-14", new List<string>(new[] {"日记情人节"})},
            {"1-21", new List<string>(new[] {"列宁逝世纪念日"})},
            {"1-26", new List<string>(new[] {"国际海关日"})},
            {"1-27", new List<string>(new[] {"国际大屠杀纪念日"})},
            {"2-2", new List<string>(new[] {"世界湿地日"})},
            {"2-4", new List<string>(new[] {"世界抗癌日"})},
            {"2-7", new List<string>(new[] {"京汉铁路罢工纪念日"})},
            {"2-10", new List<string>(new[] {"国际气象节"})},
            {"2-19", new List<string>(new[] {"邓小平逝世纪念日"})},
            {"2-20", new List<string>(new[] {"世界社会公正日"})},
            {"2-21", new List<string>(new[] {"国际母语日"})},
            {"2-24", new List<string>(new[] {"第三世界青年日"})},
            {"3-1", new List<string>(new[] {"国际海豹日"})},
            {"3-3", new List<string>(new[] {"世界野生动植物日", "全国爱耳日"})},
            {"3-5", new List<string>(new[] {"周恩来诞辰纪念日", "中国青年志愿者服务日"})},
            {"3-6", new List<string>(new[] {"世界青光眼日"})},
            {"3-7", new List<string>(new[] {"女生节"})},
            {"3-12", new List<string>(new[] {"孙中山逝世纪念日"})},
            {"3-14", new List<string>(new[] {"马克思逝世纪念日", "白色情人节"})},
            {"3-17", new List<string>(new[] {"国际航海日"})},
            {"3-18", new List<string>(new[] {"全国科技人才活动日", "全国爱肝日"})},
            {"3-20", new List<string>(new[] {"国际幸福日"})},
            {"3-21", new List<string>(new[] {"世界森林日", "世界睡眠日", "国际消除种族歧视日"})},
            {"3-22", new List<string>(new[] {"世界水日"})},
            {"3-23", new List<string>(new[] {"世界气象日"})},
            {"3-24", new List<string>(new[] {"世界防治结核病日"})},
            {"3-29", new List<string>(new[] {"中国黄花岗七十二烈士殉难纪念日"})},
            {"4-2", new List<string>(new[] {"国际儿童图书日", "世界自闭症日"})},
            {"4-4", new List<string>(new[] {"国际地雷行动日"})},
            {"4-7", new List<string>(new[] {"世界卫生日"})},
            {"4-8", new List<string>(new[] {"国际珍稀动物保护日"})},
            {"4-12", new List<string>(new[] {"世界航天日"})},
            {"4-14", new List<string>(new[] {"黑色情人节"})},
            {"4-15", new List<string>(new[] {"全民国家安全教育日"})},
            {"4-22", new List<string>(new[] {"世界地球日", "列宁诞辰纪念日"})},
            {"4-23", new List<string>(new[] {"世界读书日"})},
            {"4-24", new List<string>(new[] {"中国航天日"})},
            {"4-25", new List<string>(new[] {"儿童预防接种宣传日"})},
            {"4-26", new List<string>(new[] {"世界知识产权日", "全国疟疾日"})},
            {"4-28", new List<string>(new[] {"世界安全生产与健康日"})},
            {"4-30", new List<string>(new[] {"全国交通安全反思日"})},
            {"5-2", new List<string>(new[] {"世界金枪鱼日"})},
            {"5-3", new List<string>(new[] {"世界新闻自由日"})},
            {"5-5", new List<string>(new[] {"马克思诞辰纪念日"})},
            {"5-8", new List<string>(new[] {"世界红十字日"})},
            {"5-11", new List<string>(new[] {"世界肥胖日"})},
            {"5-12", new List<string>(new[] {"全国防灾减灾日", "护士节"})},
            {"5-14", new List<string>(new[] {"玫瑰情人节"})},
            {"5-15", new List<string>(new[] {"国际家庭日"})},
            {"5-19", new List<string>(new[] {"中国旅游日"})},
            {"5-20", new List<string>(new[] {"网络情人节"})},
            {"5-22", new List<string>(new[] {"国际生物多样性日"})},
            {"5-25", new List<string>(new[] {"525心理健康节"})},
            {"5-27", new List<string>(new[] {"上海解放日"})},
            {"5-29", new List<string>(new[] {"国际维和人员日"})},
            {"5-30", new List<string>(new[] {"中国五卅运动纪念日"})},
            {"5-31", new List<string>(new[] {"世界无烟日"})},
            {"6-3", new List<string>(new[] {"世界自行车日"})},
            {"6-5", new List<string>(new[] {"世界环境日"})},
            {"6-6", new List<string>(new[] {"全国爱眼日"})},
            {"6-8", new List<string>(new[] {"世界海洋日"})},
            {"6-11", new List<string>(new[] {"中国人口日"})},
            {"6-14", new List<string>(new[] {"世界献血日", "亲亲情人节"})},
            {"6-17", new List<string>(new[] {"世界防治荒漠化与干旱日"})},
            {"6-20", new List<string>(new[] {"世界难民日"})},
            {"6-21", new List<string>(new[] {"国际瑜伽日"})},
            {"6-25", new List<string>(new[] {"全国土地日"})},
            {"6-26", new List<string>(new[] {"国际禁毒日", "联合国宪章日"})},
            {"7-1", new List<string>(new[] {"香港回归纪念日"})},
            {"7-6", new List<string>(new[] {"国际接吻日", "朱德逝世纪念日"})},
            {"7-7", new List<string>(new[] {"七七事变纪念日"})},
            {"7-11", new List<string>(new[] {"世界人口日", "中国航海日"})},
            {"7-14", new List<string>(new[] {"银色情人节"})},
            {"7-18", new List<string>(new[] {"曼德拉国际日"})},
            {"7-30", new List<string>(new[] {"国际友谊日"})},
            {"8-3", new List<string>(new[] {"男人节"})},
            {"8-5", new List<string>(new[] {"恩格斯逝世纪念日"})},
            {"8-6", new List<string>(new[] {"国际电影节"})},
            {"8-8", new List<string>(new[] {"全民健身日"})},
            {"8-9", new List<string>(new[] {"国际土著人日"})},
            {"8-12", new List<string>(new[] {"国际青年节"})},
            {"8-14", new List<string>(new[] {"绿色情人节"})},
            {"8-19", new List<string>(new[] {"世界人道主义日", "中国医师节"})},
            {"8-22", new List<string>(new[] {"邓小平诞辰纪念日"})},
            {"8-29", new List<string>(new[] {"全国测绘法宣传日"})},
            {"9-3", new List<string>(new[] {"中国抗日战争胜利纪念日"})},
            {"9-5", new List<string>(new[] {"中华慈善日"})},
            {"9-8", new List<string>(new[] {"世界扫盲日"})},
            {"9-9", new List<string>(new[] {"毛泽东逝世纪念日", "全国拒绝酒驾日"})},
            {"9-14", new List<string>(new[] {"世界清洁地球日", "相片情人节"})},
            {"9-15", new List<string>(new[] {"国际民主日"})},
            {"9-16", new List<string>(new[] {"国际臭氧层保护日"})},
            {"9-17", new List<string>(new[] {"世界骑行日"})},
            {"9-18", new List<string>(new[] {"九一八事变纪念日"})},
            {"9-20", new List<string>(new[] {"全国爱牙日"})},
            {"9-21", new List<string>(new[] {"国际和平日"})},
            {"9-27", new List<string>(new[] {"世界旅游日"})},
            {"9-30", new List<string>(new[] {"中国烈士纪念日"})},
            {"10-1", new List<string>(new[] {"国际老年人日"})},
            {"10-2", new List<string>(new[] {"国际非暴力日"})},
            {"10-4", new List<string>(new[] {"世界动物日"})},
            {"10-11", new List<string>(new[] {"国际女童日"})},
            {"10-10", new List<string>(new[] {"辛亥革命纪念日"})},
            {"10-13", new List<string>(new[] {"国际减轻自然灾害日", "中国少年先锋队诞辰日"})},
            {"10-14", new List<string>(new[] {"葡萄酒情人节"})},
            {"10-16", new List<string>(new[] {"世界粮食日"})},
            {"10-17", new List<string>(new[] {"全国扶贫日"})},
            {"10-20", new List<string>(new[] {"世界统计日"})},
            {"10-24", new List<string>(new[] {"世界发展信息日", "程序员节"})},
            {"10-25", new List<string>(new[] {"抗美援朝纪念日"})},
            {"11-5", new List<string>(new[] {"世界海啸日"})},
            {"11-8", new List<string>(new[] {"记者节"})},
            {"11-9", new List<string>(new[] {"全国消防日"})},
            {"11-11", new List<string>(new[] {"光棍节"})},
            {"11-12", new List<string>(new[] {"孙中山诞辰纪念日"})},
            {"11-14", new List<string>(new[] {"电影情人节"})},
            {"11-16", new List<string>(new[] {"国际宽容日"})},
            {"11-17", new List<string>(new[] {"国际大学生节"})},
            {"11-19", new List<string>(new[] {"世界厕所日"})},
            {"11-28", new List<string>(new[] {"恩格斯诞辰纪念日"})},
            {"11-29", new List<string>(new[] {"国际声援巴勒斯坦人民日"})},
            {"12-1", new List<string>(new[] {"世界艾滋病日"})},
            {"12-2", new List<string>(new[] {"全国交通安全日"})},
            {"12-3", new List<string>(new[] {"世界残疾人日"})},
            {"12-4", new List<string>(new[] {"全国法制宣传日"})},
            {"12-5", new List<string>(new[] {"世界弱能人士日", "国际志愿人员日"})},
            {"12-7", new List<string>(new[] {"国际民航日"})},
            {"12-9", new List<string>(new[] {"世界足球日", "国际反腐败日"})},
            {"12-10", new List<string>(new[] {"世界人权日"})},
            {"12-11", new List<string>(new[] {"国际山岳日"})},
            {"12-12", new List<string>(new[] {"西安事变纪念日"})},
            {"12-13", new List<string>(new[] {"国家公祭日"})},
            {"12-14", new List<string>(new[] {"拥抱情人节"})},
            {"12-18", new List<string>(new[] {"国际移徙者日"})},
            {"12-26", new List<string>(new[] {"毛泽东诞辰纪念日"})}
        };

        /// <summary>
        /// 是否闰年
        /// </summary>
        /// <param name="year">年</param>
        /// <returns>true/false 闰年/非闰年</returns>
        public static bool IsLeapYear(int year)
        {
            if (year < 1600) 
            {
                return year % 4 == 0;
            }
            return (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0);
        }

        /// <summary>
        /// 获取某年有多少天（平年365天，闰年366天）
        /// </summary>
        /// <param name="year">年</param>
        /// <returns>天数</returns>
        public static int GetDaysOfYear(int year)
        {
            if (1582 == year) {
                return 355;
            }
            return IsLeapYear(year) ? 366 : 365;
        }

        /// <summary>
        /// 获取某年某月有多少天
        /// </summary>
        /// <param name="year">年</param>
        /// <param name="month">月</param>
        /// <returns>天数</returns>
        public static int GetDaysOfMonth(int year, int month)
        {
            if (1582 == year && 10 == month)
            {
                return 21;
            }
            int m = month - 1;
            int d = DAYS_OF_MONTH[m];
            //公历闰年2月多一天
            if (m == 1 && IsLeapYear(year)) {
                d++;
            }
            return d;
        }

        /// <summary>
        /// 获取某天为当年的第几天
        /// </summary>
        /// <param name="year">年</param>
        /// <param name="month">月</param>
        /// <param name="day">日</param>
        /// <returns>第几天</returns>
        public static int GetDaysInYear(int year, int month, int day)
        {
            var days = 0;
            for (var i = 1; i < month; i++)
            {
                days += GetDaysOfMonth(year, i);
            }
            var d = day;
            if (1582 == year && 10 == month) {
                if (day >= 15) {
                    d -= 10;
                } else if (day > 4)
                {
                    throw new ArgumentException($"wrong solar year {year} month {month} day {day}");
                }
            }
            days += d;
            return days;
        }

        /// <summary>
        /// 获取某年某月有多少周
        /// </summary>
        /// <param name="year">年</param>
        /// <param name="month">月</param>
        /// <param name="start">星期几作为一周的开始，1234560分别代表星期一至星期天</param>
        /// <returns>周数</returns>
        public static int GetWeeksOfMonth(int year, int month, int start)
        {
            return (int) Math.Ceiling((GetDaysOfMonth(year, month) + Solar.FromYmdHms(year, month, 1).Week - start) * 1D / WEEK.Length);
        }
        
        /// <summary>
        /// 获取两个日期之间相差的天数（如果日期a比日期b小，天数为正，如果日期a比日期b大，天数为负）
        /// </summary>
        /// <param name="ay">年a</param>
        /// <param name="am">月a</param>
        /// <param name="ad">日a</param>
        /// <param name="by">年b</param>
        /// <param name="bm">月b</param>
        /// <param name="bd">日b</param>
        /// <returns>天数</returns>
        public static int GetDaysBetween(int ay, int am, int ad, int by, int bm, int bd)
        {
            int n;
            int days;
            int i;
            if (ay == by)
            {
                n = GetDaysInYear(by, bm, bd) - GetDaysInYear(ay, am, ad);
            }
            else if (ay > by)
            {
                days = GetDaysOfYear(by) - GetDaysInYear(by, bm, bd);
                for (i = by + 1; i < ay; i++)
                {
                    days += GetDaysOfYear(i);
                }
                days += GetDaysInYear(ay, am, ad);
                n = -days;
            }
            else
            {
                days = GetDaysOfYear(ay) - GetDaysInYear(ay, am, ad);
                for (i = ay + 1; i < by; i++)
                {
                    days += GetDaysOfYear(i);
                }
                days += GetDaysInYear(by, bm, bd);
                n = days;
            }
            return n;
        }
    }
}