package com.nuvole.util;

import java.math.RoundingMode;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;

/**
 * 计算工具类
 *
 * @Author: lc
 * @Date: 2019/5/23 19:10
 */
public class ComputeUtil {

    /**
     * 计算百分比
     *
     * @param num   占比值
     * @param total 总数
     * @param scale 小数
     * @Author: lc
     * @Date: 2019/8/22 10:32
     */
    public static String percentum(double num, double total, int scale) {
        if (num == 0 || total == 0) {
            return "0";
        }
        DecimalFormat df = (DecimalFormat) NumberFormat.getInstance();
        //可以设置精确几位小数
        df.setMaximumFractionDigits(scale);
        //模式 例如四舍五入
        df.setRoundingMode(RoundingMode.HALF_UP);
        double accuracy_num = num / total * 100;
        return df.format(accuracy_num);
    }


    /**
     * 获取两个日期之间所有日期（年月日）
     *
     * @Author: lc
     * @Date: 2019/8/23 13:41
     */
    public static List<String> getBetweenDates(String begin, String end, String formatString) {
        SimpleDateFormat format = new SimpleDateFormat(formatString);
        List<String> result = new ArrayList<String>();
        try {
            Calendar tempStart = Calendar.getInstance();
            tempStart.setTime(format.parse(begin));
            tempStart.add(Calendar.DAY_OF_YEAR, 1);

            Calendar tempEnd = Calendar.getInstance();
            tempEnd.setTime(format.parse(end));
            result.add(format.format(format.parse(begin)));
            while (tempStart.before(tempEnd)) {
                result.add(format.format(tempStart.getTime()));
                tempStart.add(Calendar.DAY_OF_YEAR, 1);
            }
            result.add(format.format(format.parse(end)));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }

    /**
     * 获取俩个日期间的所有日期（年月）
     *
     * @Author: lc
     * @Date: 2019/8/24 16:31
     */
    public static List<String> getBetweenMonths(String minDate, String maxDate, String formatString) {
        ArrayList<String> result = new ArrayList<String>();
        try {
            SimpleDateFormat sdf = new SimpleDateFormat(formatString);//格式化为年月

            Calendar min = Calendar.getInstance();
            Calendar max = Calendar.getInstance();
            min.setTime(sdf.parse(minDate));
            min.set(min.get(Calendar.YEAR), min.get(Calendar.MONTH), 1);

            max.setTime(sdf.parse(maxDate));
            max.set(max.get(Calendar.YEAR), max.get(Calendar.MONTH), 2);

            Calendar curr = min;
            while (curr.before(max)) {
                result.add(sdf.format(curr.getTime()));
                curr.add(Calendar.MONTH, 1);
            }
        } catch (ParseException e) {
            e.printStackTrace();
        }

        return result;
    }

}