// Encoding: UTF-8
#include "calendar.h"
#include <cstdio>
#include <ctime>

/*以下为"calendar.h规定之量*/
double pi = 3.14159265358979323846;
double day = 86400;
double delta = 1e-11;
char jieqi[25][10] = {"冬至", "小寒", "大寒", "立春", "雨水", "惊蛰", "春分",
                      "清明", "谷雨", "立夏", "小满", "芒种", "夏至", "小暑",
                      "大暑", "立秋", "处暑", "白露", "秋分", "寒露", "霜降",
                      "立冬", "小雪", "大雪", "冬至"};

/*计算需要用的类的实例化*/
Julian julian;
parameter p;
List list;

Date *input(char *argv) {
    Date *date = new Date;

    // 输入年份，自当年元旦起算
    date->tm_year = atoi(argv) - 1900;
    date->tm_mon = 0;
    date->tm_mday = 1;
    date->tm_hour = 0;
    date->tm_min = 0;
    date->tm_sec = 0;

    return date;
}

/*计算当年二十四节气时刻，自去年冬至到本年冬至*/
void JieQi(Date *date) {
    //计算起始时间为去年12月19日0时，开始寻找去年冬至
    time_t time = mktime(date);
    time -= 13 * day;

    double t, t_end, t_middle; //采用二分法计算，t与t_end为间隔24h的两个时刻
    double target_angle; //目标角度
    Date *date_tmp;

    //计算每个节气对应太阳地心黄经
    for (int i = 0; i < 25; i++, time += 12 * day) {
        target_angle = 15 * i + 270;
        if (target_angle >= 360)
            target_angle -= 360;

        t = julian.getJulianKiloYear(time);
        t_end = julian.getJulianKiloYear(time + day);

        if (target_angle == 0) {
            while (p.sun_longitude(t_end) > 300) {
                time += day;
                t = t_end;
                t_end = julian.getJulianKiloYear(time + day);
            }
            if (!(p.sun_longitude(t) > 300 && p.sun_longitude(t_end) < 2)) {
                fprintf(stderr, "Error: Can't find the target angle\n");
                exit(1);
            }
            while (t_end - t > delta) {
                t_middle = (t + t_end) / 2;
                if (p.sun_longitude(t_middle) < 2) {
                    t_end = t_middle;
                } else {
                    t = t_middle;
                }
            }
        } else {
            while (p.sun_longitude(t_end) < target_angle) {
                time += day;
                t = t_end;
                t_end = julian.getJulianKiloYear(time + day);
            }
            while (t_end - t > delta) {
                t_middle = (t + t_end) / 2;
                if (p.sun_longitude(t_middle) < target_angle) {
                    t = t_middle;
                } else {
                    t_end = t_middle;
                }
            }
        }

        //链表记录节气信息
        time = julian.kiloYearToTime(t, i == 0 ? date->tm_year + 1899
                                               : date->tm_year + 1900);
        date_tmp = localtime(&time);
        list.append(date_tmp, false, true, i % 2 == 0, i, t);
    }
}

// 用以判断朔日的函数，返回true则太阳地心黄经大于月球地心黄经，即朔日在此后
bool date_forward(double sun_longitude, double moon_longitude) {
    /* 判断逻辑
     * 当moon_longitude<sun_longitude时，由于时刻已经在朔日附近
     * 因而可以判断朔日在该时刻之后
     * 反之，当moon_longitude>sun_longitude时，
     * 如果moon_longitude-sun_longitude<20，即度数相差不大，可知朔日在此前
     * 否则，大于20时候，度数相差过大，理论上只可能为moon_longitude已接近360，sun_longitude略微大于0
     * 此时实际上是月亮应当追赶太阳，因而朔日在此后
     */
    return moon_longitude < sun_longitude
               ? true
               : (moon_longitude - sun_longitude >= 20);
}

void ShuoRi(int year) {
    double t, t_end, end,
        t_middle; //采用二分法计算，t与t_end为间隔24h的两个时刻
    time_t time;
    Date *date_tmp = new Date;

    //根据zhongqi_vec的最后一项（今年冬至）计算冬至下一日的0时刻
    date_tmp->tm_year = list.zhongqi_vec[12]->year - 1900;
    date_tmp->tm_mon = list.zhongqi_vec[12]->mon - 1;
    date_tmp->tm_mday = list.zhongqi_vec[12]->day + 1;
    date_tmp->tm_hour = 0;
    date_tmp->tm_min = 0;
    date_tmp->tm_sec = 0;
    date_tmp->tm_isdst = -1;
    time = mktime(date_tmp);
    end = julian.getJulianKiloYear(time);

    // 计算去年冬至时刻的time
    date_tmp->tm_year = list.zhongqi_vec[0]->year - 1900;
    date_tmp->tm_mon = list.zhongqi_vec[0]->mon - 1;
    date_tmp->tm_mday = list.zhongqi_vec[0]->day;
    date_tmp->tm_hour = list.zhongqi_vec[0]->hour;
    date_tmp->tm_min = list.zhongqi_vec[0]->min;
    date_tmp->tm_sec = list.zhongqi_vec[0]->sec;
    date_tmp->tm_isdst = -1;
    time = mktime(date_tmp);

    delete date_tmp;

    // 定朔日
    for (t = julian.getJulianKiloYear(time); t <= end; time += 25 * day) {
        // 每月长度为28-30天，因而每次循环前进25天
        t = julian.getJulianKiloYear(time);
        t_end = julian.getJulianKiloYear(time + day);

        // 太阳在月亮之前，月亮追赶，故朔日在后，t和t_end前进24h
        while (date_forward(p.sun_longitude(t_end), p.moon_longitude(t_end))) {
            time += day;
            t = t_end;
            t_end = julian.getJulianKiloYear(time + day);
        }
        // 太阳在月亮之后，月亮落后，故朔日在前，t和t_end后退24h（用以保险）
        while (!date_forward(p.sun_longitude(t), p.moon_longitude(t))) {
            time -= day;
            t_end = t;
            t = julian.getJulianKiloYear(time);
        }

        while (t_end - t >= delta) {
            t_middle = (t + t_end) / 2;
            if (date_forward(p.sun_longitude(t_middle),
                             p.moon_longitude(t_middle))) {
                t = t_middle;
            } else {
                t_end = t_middle;
            }
        }
        // 输出朔日信息
        time = julian.kiloYearToTime(t, year - 1);
        date_tmp = localtime(&time);
        list.append(date_tmp, true, false, false, -1, t);
    }
}

int main(int argc, char *argv[]) {

    if (argc != 2) {
        printf("Usage: %s year\\n\n", argv[0]);
        return 0;
    }
    Date *date = input(argv[1]);
    int year = date->tm_year + 1900;
    double begin, end;

    JieQi(date);
    ShuoRi(year);

    list.lunar_sort();

    // 奉旨置闰
    list.Run();

    // 输出
    list.output();

    // 释放内存，使用List的析构函数

    delete date;

    return 0;
}