package com.ycl.utils;

import java.math.BigDecimal;
import java.text.DecimalFormat;

public class StringUtils {

    /**
     * 不处理大小写
     * helloWorld=>hello_World
     * HelloWorld=>Hello_World
     *
     * @param content
     * @return
     */
    private static String camelToUnderlineIgnoreCase(String content) {
        return new StringBuilder(16)
                .append(content.substring(0, 1))
                .append(content.substring(1).replaceAll("([A-Z])", "_$1"))
                .toString();
    }


    /**
     * 驼峰转全小下划线
     * helloWorld=>hello_world
     * HelloWorld=>hello_world
     *
     * @return
     */
    public static String camelToUnderlineLowerCase(String content) {
        return camelToUnderlineIgnoreCase(content).toLowerCase();
    }


    /**
     * 驼峰转全大写下划线
     * helloWorld=>HELLO_WORLD
     * HelloWorld=>HELLO_WORLD
     *
     * @return
     */
    public static String camelToUnderlineUpperCase(String content) {
        return camelToUnderlineIgnoreCase(content)
                .toLowerCase();
    }


    /**
     * 下划线转小驼峰
     * hello_world=>helloWorld
     * HELLO_WORLD=>helloWorld
     * Hello_World=>helloWorld
     *
     * @param content
     * @return
     */
    public static String underlineToLowerCamelCase(String content) {
        return new StringBuilder(16)
                .append(content.substring(0, 1).toLowerCase())
                .append(content.substring(1).replaceAll("_([a-zA-Z])", "$1".toUpperCase()))
                .toString();
    }


    /**
     * 下划线转大驼峰
     * hello_world=>HelloWorld
     * HELLO_WORLD=>HelloWorld
     * Hello_World=>HelloWorld
     *
     * @param content
     * @return
     */
    public static String underlineToCamelUpperCase(String content) {
        return new StringBuilder(16)
                .append(content.substring(0, 1).toUpperCase())
                .append(content.substring(1).replaceAll("_([a-zA-Z])", "$1".toUpperCase()))
                .toString();
    }

    public static String doubleTwo(Double value) {
        return String.format("%.2f", value);
    }
}