Admin.java

import java.util.regex.*;
import java.util.*;
import java.io.*;
public class Admin{

	static Scanner input = new Scanner(System.in); // Scanner object
	static int ids[];
	static String[] registeredCourses;
	static String[] courseDetails;
	static String[] availableCourse;

	public static void admin() {
		System.out.print("************************************************\n");
		System.out.print("\t\tAdmin Panel\n");
		System.out.print("************************************************\n\n");

		// Looping the menu
		while(true){
			System.out.print("\n1. Student Details \n");
			System.out.print("2. Course Details \n");
			System.out.print("3. Cafe Details \n");
			System.out.print("4. Library Details \n");
			System.out.print("5. Transport Details \n");
			System.out.print("6. Previous Menu \n");
			System.out.print("7. Exit \n\n");
			System.out.print("Enter your choice : ");

			try{
				int choice = input.nextInt();
				switch(choice){
					case 1: {
						studentDetails();
						break;
					}
					case 2: {
						courseDetails();
						break;
					}
					case 3: {
						cafeDetails();
						break;
					}
					case 4: {
						libraryDetails();
						break;
					}
					case 5: {
						transportDetails();
						break;
					}
					case 6: {
						Main.Choices();
						break;
					}
					case 7: {
						System.exit(0);
					}
					default: {
						System.out.print("Invalid Data! Try again...\n");
					input.nextLine();
					}
				}
			}
			catch(Exception e){
				System.out.print("Invalid Data! Try again...\n");
				input.nextLine();
			}

		}
	}

	// Course Details 
	public static void courseDetails(){
		System.out.print("*************************************************\n");
		System.out.print("\t\t Course Details \n");
		System.out.print("*************************************************\n\n");
		input.nextLine();


		while(true){
			System.out.print("Enter the Student ID(XXXX-XXX-XXX) : ");
			String regNumber = input.nextLine().toUpperCase();
			if(Pattern.matches("SP\\d{2}-\\w{3}-\\d{3}|FA\\d{2}-\\w{3}-\\d{3}",regNumber)){
				try{
					File myfile = new File("students_data/courses/"+ regNumber +".txt");
		            if(myfile.exists()){
		                manageCourse(regNumber);
		            }
		            else{
		            	File ff = new File("students_data/"+regNumber+".txt");
		            	if(ff.exists()){
		            		System.out.print("Student must have to register a course firstly!\n");
		            		break;
		            	}
		            	else{
		            		System.out.print("Student is not registered!\n");
		            		break;
		            	}

		            }
					
				}
				catch(Exception e){
					System.out.print(e);
					input.nextLine();
				}
			}
			else{
				System.out.print("Invalid ID! Try Again....\n");
			}
		}


	}


	// ManageCourse
	public static void manageCourse(String regNumber){
		boolean validInput = false;
		while(true){
			System.out.print("1. View Registered Courses\n");
			System.out.print("2. Add new Course\n");
			System.out.print("3. Delete course\n");
			System.out.print("4. Previous Menu\n");
			System.out.print("5. Exit\n");

			System.out.print("Enter choice : ");
			try{
				int choice = input.nextInt();

				switch(choice){
					case 1:{
						validInput = true;
						viewCourse(regNumber);
						break;
					}
					case 2:{
						validInput = true;
						addCourse(regNumber);
						break;
					}
					case 3:{
						validInput = true;
						deleteCourse(regNumber);
						break;
					}
					case 4:{
						validInput = true;
						admin();
						break;
					}
					case 5:{
						validInput = true;
						System.exit(0);
						break;
					}
					default:{
						System.out.print("Invalid input! Try again!!\n");
					}
				}
			}
			catch(Exception e){
				System.out.print("Invalid input! Try again!!\n");
				input.nextLine();
			}
		}

	}


	// View Course
	public static void viewCourse(String regNumber){

		int length = 0;
		try{
			File file = new File("students_data/courses/"+ regNumber +".txt");
         	Scanner sc = new Scanner(file);
         	while(sc.hasNextLine()){
         		String line = sc.nextLine();
         		length++;
         	}
         	sc.close();
		}
		catch(Exception e){
			System.out.print(e);
		}

		registeredCourses = new String[length];

		System.out.print(regNumber +" registered in following courses : \n");
        int[] space = {15,30,15,30};
        try{
         File file = new File("students_data/courses/"+ regNumber +".txt");
         Scanner sc = new Scanner(file);
         int i=0,j=0;
         System.out.print("\n\n");
         System.out.printf("%-5s%-15s%-30s%-15s%-30s%n","ID","Course_Code","Course_Title","Credit_Hours","Instructor");
         System.out.println("------------------------------------------------------------------------------------------");
         while(sc.hasNextLine()){
            System.out.printf("%-5d",i);
            String line = sc.nextLine();
            registeredCourses[i] = line;
            String[] data = line.split(",",4);
            for(String item:data){
                System.out.printf(("%-"+space[j]+"s"),item);
                j++;
            }
            i++;
            j=0;
            System.out.println();
         }
         sc.close();
        }
        catch(Exception e){
         System.out.print(e);
        }
        System.out.print("\n\n");
	}






	// Add new Course
	public static void addCourse(String regNumber){
		
		int semester = 0;
        String sub = "";
        try{
        	sub = regNumber.substring(0,4);

            // Eliminating the semester from the st. ID
            if(sub.compareTo("SP18")==0){
                semester = 8;
            }
            else if(sub.compareTo("FA18")==0){
                semester = 7;
            }
            else if(sub.compareTo("SP19")==0){
                semester = 6;
            }
            else if(sub.compareTo("FA19")==0){
                semester = 5;
            }
            else if(sub.compareTo("SP20")==0){
                semester = 4;
            }
            else if(sub.compareTo("SP20")==0){
                semester = 3;
            }
            else if(sub.compareTo("SP21")==0){
                semester = 2;
            }
            else if(sub.compareTo("FA21")==0){
                semester = 1;
            }



            // finding total_courses in file 
            int total_courses = 0;
            try{
             File file = new File("courses/"+ semester +".txt");
             Scanner sc = new Scanner(file);
             while(sc.hasNextLine()){
                String line = sc.nextLine();
                total_courses++;
             }
             sc.close();
            }
            catch(Exception e){
             System.out.print(e);
            }


            courseDetails = new String[total_courses];



            // Stroring data in a array.
            try{
             File file = new File("courses/"+ semester +".txt");
             Scanner sc = new Scanner(file);
             int i=0;
             while(sc.hasNextLine()){
                String line = sc.nextLine();
                courseDetails[i] = line;
                i++;
             }
             sc.close();
            }
            catch(Exception e){
             System.out.print(e);
            }


            // filtering data in a array.
            try{
             File file = new File("students_data/courses/"+ regNumber +".txt");
             Scanner sc = new Scanner(file);
             while(sc.hasNextLine()){
                String line = sc.nextLine();
                for(int i=0;i<courseDetails.length;i++){
                	if(courseDetails[i].compareTo(line)==0){
                		courseDetails[i] = "";
                	}
                }
             }
             sc.close();
            }
            catch(Exception e){
             System.out.print(e);
            }


            // Didplaying available courses
            int[] space = {15,30,15,30};
            int size=0;
            try{
             int i=0,j=0;
             System.out.print("\n\n");
             System.out.printf("%-5s%-15s%-30s%-15s%-30s%n","ID","Course_Code","Course_Title","Credit_Hours","Instructor");
             System.out.println("------------------------------------------------------------------------------------------");
             for(String line : courseDetails){
                if(line!=""){
                	System.out.printf("%-5d",i);
	                String[] data = line.split(",",4);
	              	size++;
	                for(String item:data){
	                    System.out.printf(("%-"+space[j]+"s"),item);
	                    j++;
	                }
	                i++;
	                j=0;
	                System.out.println();
                }
             }
            }
            catch(Exception e){
             System.out.print(e);
            }

            availableCourse = new String[size];
            int index=0;
            for(int y=0;y<courseDetails.length;y++){
            	if(courseDetails[y]!=""){
            		availableCourse[index] = courseDetails[y];
            		index++;
            	}
            }

         	


         	while(true){
                try{
                    System.out.print("\nHow many courses student wants to add more :");
                    int amount = input.nextInt();
                    if(amount>availableCourse.length || amount<0){
                        System.out.print("Invalid input\n");
                        continue;
                    }
                    else if(amount==0){
                    	break;
                    }


                    // Storing course ids in array..
                    int x=0;
                    String[] toRegister = new String[amount];
                    boolean alreadyAdded = false;
                    while(true){
                        try{
                            alreadyAdded = false;
                            System.out.print("\n*************course"+(x+1)+"*******************\n");
                            System.out.print("Enter choice :");
                            int choice = input.nextInt();
                            for(int z=0;z<x;z++){
                                if(toRegister[z].compareTo(availableCourse[choice])==0){
                                    alreadyAdded = true;
                                    break;
                                }
                            }
                            if(alreadyAdded){
                                System.out.print("Already Registered!\n");
                                continue;
                            }
                            else if(choice<availableCourse.length && choice>=0){
                                toRegister[x] = availableCourse[choice];
                                x++;
                                if(x==amount){
	                                break;
	                            }
                            }
                            else{
                                System.out.print("Invalid Id, Try again!\n");
                                continue;
                            }
                        }
                        catch(Exception e){
                            System.out.print(e);
                        }

                    }

                    
                    try{
                        FileWriter fileWriter = new FileWriter("students_data/courses/"+ regNumber +".txt",true);

                        int j=0;
                        for(String e:toRegister){
                            fileWriter.write(e+"\n");
                        }
                                
                        fileWriter.close();
                        System.out.println("Courses Added Successfully!");
                        break;
                    }
                    catch(Exception e){
                        System.out.print(e);
                    }
                }
                catch(Exception e){
                    System.out.print("Invalid input! Try again");
                    input.nextLine();
                }
            }




        }
        catch(Exception e){
        	System.out.print("error occurred!\n");
        }



	}







	// Delete Course
	
	public static void deleteCourse(String regNumber){
		viewCourse(regNumber);

		int remainingCourses = 0;
		int canDelete = registeredCourses.length-4;
        while(true){
        	System.out.print("You can drop only "+(canDelete)+" courses because student must have pick 4 courses!\n");
            try{
            	if(canDelete==0){
					System.out.print("You can't drop any course\n");
					break;
				}
                System.out.print("\nHow many courses student wants to drop :");
                int amount = input.nextInt();
                remainingCourses = registeredCourses.length-amount;
                if(amount>canDelete){
                    System.out.print("You can drop only "+(canDelete)+" courses because student must have pick 4 courses!\n");
                    continue;
                }
                else if(amount<0){
                    System.out.print("Invalid input! Try again!\n");
                    continue;
                }
                else if(amount==0 || canDelete==0){
                	System.out.print("No course can be dropped!\n");
                	break;
                }


                // Storing course ids in array..
                int x=0;
                while(true){
                    try{
                    	if(x==amount){
                        	break;
                        }
                        System.out.print("\n*************course"+(x+1)+"*******************\n");
                        System.out.print("Enter choice :");
                        int choice = input.nextInt();

                        if(choice<registeredCourses.length){
                        	if(registeredCourses[choice]==""){
	                            System.out.print("Same course can't be delete twice or more!\n");
                        		continue;
	                        }
	                        else{
	                        	registeredCourses[choice]="";
                        		x++;
	                        }
                        }
                        else{
                            System.out.print("Invalid Id, Try again!\n");
                            continue;
                        }

                    }
                    catch(Exception e){
                        System.out.print("Invalid input! Try again...");
                        input.nextLine();
                    }

                }




                try{
                    FileWriter fileWriter = new FileWriter("students_data/courses/"+ regNumber +".txt");
                    fileWriter.write("");
                    fileWriter.close();
                }
                catch(Exception e){
                    System.out.print(e);
                }

            }
            catch(Exception e){
                System.out.print("Invalid input! Try again\n");
                input.nextLine();
                continue;
            }


            try{
	            FileWriter ff = new FileWriter("students_data/courses/"+ regNumber +".txt",true);
	            for(int i=0;i<registeredCourses.length;i++){
	            	if(registeredCourses[i]!=""){
	            		ff.write(registeredCourses[i]+"\n");
	            	}
	            }
	            ff.close();
	        }
	        catch(Exception e){
	            System.out.print(e);
	        }

	        System.out.print("Courses deleted Successfully!\n");
	        break;


        }

	}






	// Student details
	public static void studentDetails(){
		System.out.print("*************************************************\n");
		System.out.print("\t\t Student Details \n");
		System.out.print("*************************************************\n\n");
		input.nextLine();


		while(true){
			System.out.print("Enter the Student ID(XXXX-XXX-XXX) : ");
			String regNumber = input.nextLine().toUpperCase();
			if(Pattern.matches("SP\\d{2}-\\w{3}-\\d{3}|FA\\d{2}-\\w{3}-\\d{3}",regNumber)){
				try{
					File file = new File("students_data/"+regNumber+".txt");
					if(file.exists()){
						Scanner sc = new Scanner(file);
						System.out.print("\n");
						while(sc.hasNextLine()){
							String line = sc.nextLine();
							String[] data = line.split(":");
							System.out.printf("%-20s%-10s%s%n",data[0].toUpperCase(),":",data[1]);
						}
						System.out.print("\n******************************************************************\n");
						sc.close();
						break;
					}
					else{
						System.out.print("No Record Found\n");
						break;
					}
				}
				catch(Exception e){
					System.out.print(e);
					input.nextLine();
				}
			}
			else{
				System.out.print("Invalid ID! Try Again....\n");
			}
		}


	}

	// Cafe Details
	public static void cafeDetails(){

		System.out.print("*************************************************\n");
		System.out.print("\t\t Cafe Details \n");
		System.out.print("*************************************************\n\n");
		input.nextLine();
		String regNumber="";

		while(true){
			System.out.print("Enter the Student ID(XXXX-XXX-XXX) : ");
			regNumber = input.nextLine().toUpperCase();
			if(Pattern.matches("SP\\d{2}-\\w{3}-\\d{3}|FA\\d{2}-\\w{3}-\\d{3}",regNumber)){
				try{
					File file = new File("cafe/CafeBills/FinalBills/"+regNumber+".txt");
					if(file.exists()){
						Scanner sc = new Scanner(file);
						System.out.print("\n");
						int i=1;
						while(sc.hasNextLine()){
							String line = sc.nextLine();
							System.out.print(line+"\n");
						}
						System.out.print("*****************************************************\n");
						sc.close();
						break;
					}
					else{
						System.out.print("No Record Found\n");
						break;
					}
				}
				catch(Exception e){
					System.out.print(e);
					input.nextLine();
				}
			}
			else{
				System.out.print("Invalid ID! Try Again....\n");
			}
		}



		// Displaying menu..
		while(true) {
			System.out.print("\n1. DesiFood Bill Details \n");
			System.out.print("2. FastFood Bill Details \n");
			System.out.print("3. Coffee Bill Details \n");
			System.out.print("4. SoftDrinks Bill Details \n");
			System.out.print("5. Juices Bill Drink \n");
			System.out.print("6. Exit \n\n");
			System.out.print("Enter your choice : ");

			boolean flag = false;
			try{
				int choice = input.nextInt();
				switch(choice){
					case 1: {
						System.out.print("**********  Desi Food Bill *********\n");
						try{
							File file = new File("cafe/CafeBills/DesiFood/"+regNumber+".txt");
							if(file.exists()){
								Scanner sc = new Scanner(file);
								System.out.print("\n");
								int i=1;
								while(sc.hasNextLine()){
									String line = sc.nextLine();
									System.out.print(line+"\n");
								}
								System.out.print("*****************************************************\n");
								sc.close();
								break;
							}
							else{
								System.out.print("No Record Found\n");
								break;
							}
						}
						catch(Exception e){
							System.out.print(e);
							input.nextLine();
						}
						break;
					}
					case 2: {
						System.out.print("**********  Fast Food Bill *********\n");
						try{
							File file = new File("cafe/CafeBills/FastFood/"+regNumber+".txt");
							if(file.exists()){
								Scanner sc = new Scanner(file);
								System.out.print("\n");
								int i=1;
								while(sc.hasNextLine()){
									String line = sc.nextLine();
									System.out.print(line+"\n");
								}
								System.out.print("*****************************************************\n");
								sc.close();
								break;
							}
							else{
								System.out.print("No Record Found\n");
								break;
							}
						}
						catch(Exception e){
							System.out.print(e);
							input.nextLine();
						}
						break;
					}
					case 3: {
						System.out.print("**********  Coffee Bill *********\n");
						try{
							File file = new File("cafe/CafeBills/MyCoffee/"+regNumber+".txt");
							if(file.exists()){
								Scanner sc = new Scanner(file);
								System.out.print("\n");
								int i=1;
								while(sc.hasNextLine()){
									String line = sc.nextLine();
									System.out.print(line+"\n");
								}
								System.out.print("*****************************************************\n");
								sc.close();
								break;
							}
							else{
								System.out.print("No Record Found\n");
								break;
							}
						}
						catch(Exception e){
							System.out.print(e);
							input.nextLine();
						}
						break;
					}
					case 4: {
						System.out.print("**********  SoftDrinks Bill *********\n");
						try{
							File file = new File("cafe/CafeBills/MySoftDrinks/"+regNumber+".txt");
							if(file.exists()){
								Scanner sc = new Scanner(file);
								System.out.print("\n");
								int i=1;
								while(sc.hasNextLine()){
									String line = sc.nextLine();
									System.out.print(line+"\n");
								}
								System.out.print("*****************************************************\n");
								sc.close();
								break;
							}
							else{
								System.out.print("No Record Found\n");
								break;
							}
						}
						catch(Exception e){
							System.out.print(e);
							input.nextLine();
						}
						break;
					}
					case 5: {
						System.out.print("**********   Juices Bill *********\n");
						try{
							File file = new File("cafe/CafeBills/MyJuiceOrPlantDrink/"+regNumber+".txt");
							if(file.exists()){
								Scanner sc = new Scanner(file);
								System.out.print("\n");
								int i=1;
								while(sc.hasNextLine()){
									String line = sc.nextLine();
									System.out.print(line+"\n");
								}
								System.out.print("*****************************************************\n");
								sc.close();
								break;
							}
							else{
								System.out.print("No Record Found\n");
								break;
							}
						}
						catch(Exception e){
							System.out.print(e);
							input.nextLine();
						}
						break;
					}
					case 6: {
						System.out.print("\n");
						flag = true;
						break;
					}
					default: {
						System.out.print("Invalid Data! Try again...\n");
						input.nextLine();
					}
				}

				if(flag){
					break;
				}
			}
			catch(Exception e){
				System.out.print("Invalid Data! Try again...\n");
				input.nextLine();
			}

		}


	}

	// Library Details
	public static void libraryDetails(){
		System.out.print("*************************************************\n");
		System.out.print("\t\t Library Details \n");
		System.out.print("*************************************************\n\n");
		input.nextLine();


		while(true){
			System.out.print("Enter the Student ID(XXXX-XXX-XXX) : ");
			String regNumber = input.nextLine().toUpperCase();
			if(Pattern.matches("SP\\d{2}-\\w{3}-\\d{3}|FA\\d{2}-\\w{3}-\\d{3}",regNumber)){
				try{
					File file = new File("library/BorrowedBooks/"+regNumber+".txt");
					if(file.exists()){
						Scanner sc = new Scanner(file);
						System.out.print("\n");
						System.out.print("Following books has been borrowed : \n");
						int i=1;
						while(sc.hasNextLine()){
							String line = sc.nextLine();
							System.out.print(i+". "+line+"\n");
						}
						System.out.print("*****************************************************\n");
						sc.close();
						break;
					}
					else{
						System.out.print("No Record Found\n");
						break;
					}
				}
				catch(Exception e){
					System.out.print(e);
				}
			}
			else{
				System.out.print("Invalid ID! Try Again....\n");
			}
		}

	}

	// Transport Details
	public static void transportDetails(){
		
		System.out.print("*************************************************\n");
		System.out.print("\t\t Transport Details \n");
		System.out.print("*************************************************\n\n");
		input.nextLine();


		while(true){
			System.out.print("Enter the Student ID(XXXX-XXX-XXX) : ");
			String regNumber = input.nextLine().toUpperCase();
			if(Pattern.matches("SP\\d{2}-\\w{3}-\\d{3}|FA\\d{2}-\\w{3}-\\d{3}",regNumber)){
				try{
					File file = new File("transport/TransportFiles/"+regNumber+".txt");
					if(file.exists()){
						Scanner sc = new Scanner(file);
						System.out.print("\n");
						int i=1;
						while(sc.hasNextLine()){
							String line = sc.nextLine();
							System.out.print(line+"\n");
						}
						System.out.print("*****************************************************\n");
						sc.close();
						break;
					}
					else{
						System.out.print("No Record Found\n");
						break;
					}
				}
				catch(Exception e){
					System.out.print(e);
					input.nextLine();
				}
			}
			else{
				System.out.print("Invalid ID! Try Again....\n");
			}
		}

	}


}