Combine.java

import java.util.*;
import java.io.*;
// import java.io.File;
// import java.io.BufferedReader;
// import java.io.BufferedWriter;
// import java.io.PrintWriter;
// import java.io.FileReader;
// import java.io.FileWriter;
// import java.io.IOException;

class Combine{
	public static void main(String[] args) throws IOException{
		Scanner read = new Scanner(System.in);
		System.out.println("Welcome to the Attendance Management System.");
		char c = '1';
		while (c!= '0')
		{
			System.out.println("\nEnter the choice of the operation you want to perform:");
			System.out.println("Press 1 for updating the attendance of a particular lab.");
			System.out.println("Press 2 to view the details of a particular lab.");
			System.out.println("Press 3 to get the student details of the batch.");
			System.out.println("Press 4 to check the attendance of a particular student.");
			System.out.println("Press 0 to quit.");
			c=read.next().charAt(0);
			switch(c){
				case '1':
					updateAttendace();
					break;
				case '2':
					LabDetails();
					break;
				case '3':
					BatchDetails();
					break;
				case '4':
					StudentDetails();
					break;
				case '0':
					System.out.println("Thanks! Have a great day ahead.");
					break;
				default:
					System.out.println("Invalid choice. Please enter again.");
			}
		}
	}

	//Updating attendance of each of the student who attended the lab, and incrementing the total labs attended.
	public static void updateAttendace() throws IOException{		
		Batch B= SupremeClass.getBatch();						
		for(Student stu:B.students){
			stu.totalLabs++;					//Incrementing the total labs held for each student, whenever a lab is held.
		}
		try {
			System.out.println("Enter Date(dd-mm-yy) for which the attendance has to be updated: ");
			BufferedReader kIP = new BufferedReader(new InputStreamReader(System.in));
			String dt;
			dt = kIP.readLine();
			File file = new File( "./srv/files", dt + ".csv");
			FileReader fr = new FileReader(file);
			BufferedReader br = new BufferedReader(fr);
			Student student1;
			String line = "";
			StudentInLab stud;
			String[] tempArr;
			
			line= br.readLine();
			tempArr=line.split("-");
			Lab thislab = new Lab(Integer.parseInt(tempArr[0]),Integer.parseInt(tempArr[1]),Integer.parseInt(tempArr[2]));
			line= br.readLine();
			tempArr=line.split(" ");
			thislab.addMinLabDuration(Integer.parseInt(tempArr[0]));
			while ((line = br.readLine()) != null) {
				tempArr = line.split(",");
				stud=thislab.addStudent(tempArr[0]);
				student1=B.getStudentById(tempArr[0]);
				stud.setReference(student1);
				student1.present();
			}
			br.close();

			//Saving the new attendance of each of the student in the file attendance.csv
			try{
				PrintWriter pw=new PrintWriter("attendence.csv","UTF-8");
				pw.println(String.valueOf(B.students[0].totalLabs));
				for(int i=0;i<B.classStrength;i++){
					pw.println(String.valueOf(B.students[i].getAttendence()));
				}
				System.out.println("Attendance of the lab has been updated successfully.");
				pw.close();
				System.out.println("Do you want to see the list of students who attended the lab today?");
				System.out.println("Enter y for Yes or else enter any other character.");
				char choice;
				choice = kIP.readLine().charAt(0);
				if (choice == 'y')
					thislab.studentsAttended();
			}
			catch(IOException e){
				e.printStackTrace();
			}
		}
		catch (IOException ex) {
			ex.printStackTrace();
		}
	}

	//Printing  the details of the students who attended the lab today. We will later create a function to do this, whenever it is called.
	public static void LabDetails() throws IOException{
		try{
			Batch B= SupremeClass.getBatch();						
			Student student1;
			String line = "";
			StudentInLab stud;	
			System.out.println("Enter Date(dd-mm-yy) for which you want the lab details: ");
			BufferedReader kIP = new BufferedReader(new InputStreamReader(System.in));
			String dt;
			dt = kIP.readLine();
			File file = new File( "./srv/files", dt + ".csv");
			FileReader fr = new FileReader(file);
			BufferedReader br = new BufferedReader(fr);
			String[] tempArr;
			line= br.readLine();
			tempArr=line.split("-");
			Lab currentlab = new Lab(Integer.parseInt(tempArr[0]),Integer.parseInt(tempArr[1]),Integer.parseInt(tempArr[2]));
			line= br.readLine();
			tempArr=line.split(" ");
			currentlab.addMinLabDuration(Integer.parseInt(tempArr[0]));
			while ((line = br.readLine()) != null) {
				tempArr = line.split(",");
				stud=currentlab.addStudent(tempArr[0]);
				student1=B.getStudentById(tempArr[0]);
				stud.setReference(student1);
			}
			br.close();
			System.out.println("The details of the lab conducted on: " + dt);
			System.out.println("Minimum Duration of the lab: " + currentlab.getminLabDuration() + " hrs");					
			System.out.println("The list of students who attended the lab is:");
			currentlab.studentsAttended();
		}
		catch(Exception e){
			e.printStackTrace();
		}
	}
	
	public static void BatchDetails() throws IOException {	
		Batch batch= SupremeClass.getBatch();
		System.out.println(batch);
	}

	public static void StudentDetails() throw IOException{
		Batch ba = SupremeClass.getBatch();
		System.out.println("Enter the roll number of the student to check his/her attendance: ")
		Scanner read = new Scanner(System.in);
		String IdNO;
		IdNO = read.nextLine();
		Student s = ba.getStudentById(IdNO);
		s.CheckAttendance();			
	}
}