package control;

import java.util.*;
import java.io.*;
import model.Student;

public class Business 
{
	public static void switchMenu(int n,Vector stuVector) throws IOException
	{
		switch(n)
		{
			case 1:
			//輸入學(xué)生成績(jī)
			    enterStuResult(stuVector);
			    break;
			case 2:
			//查詢學(xué)生成績(jī)
			    searchStuInfo(stuVector);
			    break;
			case 3:
			//統(tǒng)計(jì)學(xué)生成績(jī)
			    statisticAll(stuVector);
			    break;
			case 4:
			//統(tǒng)計(jì)學(xué)生平均成績(jī)
			    statisticAvg(stuVector);
			    break;
			case 5:
			//退出系統(tǒng)
			    System.out.println("謝謝您的使用，再見(jiàn)");
			    System.exit(0);
			    break;
			default:
			    System.out.println("您輸入有誤，請(qǐng)重新輸入");    
		}
	}
	
	public static void enterStuResult(Vector stuVector) throws IOException
	{
		printLine();
		InputStreamReader in=new InputStreamReader(System.in);
		BufferedReader reader=new BufferedReader(in);
		String yesOrNo;
		do
		{
			System.out.println("請(qǐng)輸入學(xué)生的基本信息");
			Student student=new Student();
			student.setStuNu(inputStuNu("學(xué)號(hào)：",reader,stuVector));
			//這里為什么要加上vector這樣的一個(gè)參數(shù)呢？
			//主要是因?yàn)槲覀儽仨汄?yàn)證我們?cè)谳斎霑r(shí)是否有相同的學(xué)號(hào)，我們必須到我們的動(dòng)態(tài)數(shù)據(jù)庫(kù)中驗(yàn)證
			student.setName(inputStuName("姓名：",reader));
			student.setAge(inputInt("年齡：",reader));
			student.setResult(inputDouble("成績(jī)：",reader));
			stuVector.addElement(student);
			System.out.println();
			System.out.println("輸入成功,按q鍵終止！");
			yesOrNo=reader.readLine();
			
		}while(!yesOrNo.toLowerCase().equals("q"));
	}
	public static void searchStuInfo(Vector stuVector) throws IOException
	{
		printLine();
		System.out.println("請(qǐng)輸入這個(gè)學(xué)生的學(xué)號(hào)：");
		InputStreamReader in=new InputStreamReader(System.in);
		BufferedReader reader=new BufferedReader(in);
		String stuNu=reader.readLine();
		System.out.println("正在查詢這個(gè)學(xué)生的成績(jī).......");
		for(int i=0;i<stuVector.size();i++)
		{
			Student student=(Student)stuVector.elementAt(i);
			if(student.hasSuchStudent(stuNu))
			{
				student.printStuInfo();
			}
		}
		
	}
	public static void statisticAll(Vector stuVector)throws IOException
	{
		System.out.println();
		printLine();
		System.out.println("正在統(tǒng)計(jì)學(xué)生的總成績(jī)......");
		System.out.println("您輸入了"+stuVector.size()+"個(gè)學(xué)生成績(jī)信息");
		System.out.print("總成績(jī)：");
		double totalResult=0;
		for(int i=0;i<stuVector.size();i++)
		{
			Student student=(Student)stuVector.elementAt(i);
			totalResult+=student.getResult();
		}
		System.out.print(totalResult);
	}
	public static void statisticAvg(Vector stuVector)
	{
		System.out.println();
		printLine();
		System.out.println("正在統(tǒng)計(jì)學(xué)生的平均成績(jī)......");
		System.out.println("您輸入了"+stuVector.size()+"個(gè)學(xué)生成績(jī)信息");
		System.out.print("平均成績(jī)：");
		double totalResult=0;
		double averageResult=0;
		for(int i=0;i<stuVector.size();i++)
		{
			Student student=(Student)stuVector.elementAt(i);
			totalResult+=student.getResult();
			
		}
		averageResult=totalResult/stuVector.size();
		System.out.print(averageResult);
	}
	
	public static String inputStuNu(String prompt,BufferedReader reader,Vector stuVector)
	{
		String ret="";
		do
		{
			try
			{
				ret=inputString(prompt,reader);
				if(!stuNuUnique(stuVector,ret))
				   throw new Exception();
				return ret;	
			}
			catch(Exception e)
			{
				System.out.println("對(duì)不起，您輸入的學(xué)號(hào)已經(jīng)存在，請(qǐng)重試");
				continue;
			}
			
		}
		while(true);
	}
	
	
	public static String inputStuName(String prompt,BufferedReader reader)
	{
		String temp="";
		do
		{
			temp=inputString(prompt,reader);
			return temp;
		}while(true);
	}
	
	
	public static String inputString(String prompt,BufferedReader reader)
	{
		String ret="";
		do
		{
			try
			{
				System.out.print(prompt);
				ret=reader.readLine();
				if(ret.trim().length()==0)
				   throw new Exception();	
				return ret;
			}
			catch(Exception e)
			{
				System.out.println("您還沒(méi)有輸入字符，請(qǐng)重試！");
				continue;
			}
		}while(true);
	}
	public static int inputInt(String prompt,BufferedReader reader)
	{
		int ret=0;
		do
		{
			try
			{
			   	System.out.print(prompt);
	            ret=Integer.parseInt(reader.readLine());
	            return ret;
			}
			catch(Exception e)
            {
            	System.out.println("您輸入的不是數(shù)字，請(qǐng)重新輸入");
            	continue;
            }
		}while(true);
	    
	}
	
	public static double inputDouble(String prompt,BufferedReader reader)
	{
		double ret=0;
		do
		{
			try
			{
			   	System.out.print(prompt);
	            ret=Double.parseDouble(reader.readLine());
	            return ret;
			}
			catch(Exception e)
            {
            	System.out.println("您輸入的不是數(shù)字，請(qǐng)重新輸入");
            	continue;
            }
		}while(true);
	    
	}
	public static boolean stuNuUnique(Vector stuVector,String stuNu)throws IOException
	{
		boolean flag=true;
		for(int i=0;i<stuVector.size();i++)
		{
			Student student=(Student)stuVector.elementAt(i);
			if(student.hasSuchStudent(stuNu))
			{
				 flag=false;
			}
		}
		return flag;
	}
	//打印出菜單，由于我們實(shí)在命令行的窗口中，所以這就是我們的所謂的用戶界面窗口
	public static void printMenu()
	{
		printLine();
		System.out.println("\t=====菜單=====");
		System.out.println("\t1：輸入學(xué)生成績(jī)");
		System.out.println("\t2：查詢學(xué)生成績(jī)");
		System.out.println("\t3：統(tǒng)計(jì)學(xué)生成績(jī)");
		System.out.println("\t4：統(tǒng)計(jì)學(xué)生平均成績(jī)");
		System.out.println("\t5：退出系統(tǒng)");
		System.out.print("\n請(qǐng)輸入您的選擇");
		
		
	}
	
	//打印出我們的項(xiàng)目主題，由于我們實(shí)在命令行的窗口中，所以這就是我們的所謂的用戶界面窗口
	public static void printLine()
	{
		System.out.println("===========學(xué)生成績(jī)管理系統(tǒng)==========");
	}
}