package com.qxueyou.scc.base.util;



public class UserCodeUtils {
	
	public static final String allChars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
	
	// 0 - 9     对应ascii值为  48 --> 57
	// A - Z  对应ascii值为  65 --> 90
	// a - z  对应ascii值为  97 --> 122

	public static void main(String[] args) {
		
		long index = 56800235585L ;
		
		generateCode(6,index);
		
	}
	
	/**
	 * 生成code
	 * @param length
	 * @param index
	 * @return
	 */
	public static String generateCode(int length,long index){
		
		String code = "";
		
		int[] allIndex = generateCodeIndex(length,index);
		
		for(int i = 0 ; i < length; i++) {
			
			code = code + allChars.charAt(allIndex[5-i]);
			
		}
		
		return code ;
		
	}
	
	/**
	 * 生成每个位置上的序号
	 * @param length
	 * @param index
	 * @return
	 */
	private static int[] generateCodeIndex(int length,long index){
		
		int[] result = new int[]{0,0,0,0,0,0};
		
		for(int loopTime = 0 ; loopTime < length ; loopTime ++ ){
			
			result[loopTime] = (int)(index % 62)  ;
			
			index = index / 62 ;
			
		}
		
		return result ;
	}
	
}