import java.util.ArrayList;
import java.util.Scanner;
import java.io.File;
import java.io.FileReader;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.URL;
import java.net.MalformedURLException;
import java.io.InputStream;

class Student
{
    private void checkValidity( )
    {
        if( pantherID.length( ) != 7 )
            throw new IllegalArgumentException( "PantherID is 7 digits!" );

        for( int i = 0; i < pantherID.length( ); i++ )
            if( Character.isDigit( pantherID.charAt( i ) ) == false )
                throw new IllegalArgumentException( "ID not a number" );

        if( usedIDs.contains( pantherID ) )
            throw new IllegalArgumentException( "ID already used" );

        if( gpa < 0 )
            throw new IllegalArgumentException( "GPA out of bounds" );

        gpa = Math.min( gpa, 4.0 );

        checkMajor( major );

        // This Student is successfully constructed
        usedIDs.add( pantherID );  // add this pantherID to the used list
    }

    public static ArrayList<String> getAllIDs( )
    {
        return usedIDs;
    }

    public Student( String p, String ln, String fn, String m, double g )
    {
        pantherID = p;
        lastName = ln;
        firstName = fn;
        major = m;
        gpa = g;

        checkValidity( );
    }

    /**
     * 
     * @param studentInfo: in format
     *     ID LN FN MAJOR GPA
     */
    public Student( String studentInfo )
    {
        Scanner sc = new Scanner( studentInfo );
        pantherID = sc.next( );
        lastName = sc.next( );
        firstName = sc.next( );
        major = sc.next( );
        gpa = sc.nextDouble( );

        checkValidity( );
    }

    public String getName( )
    {
        return firstName  + " " + lastName;
    }

    public String getPantherID( )
    {
        return pantherID;
    }

    public double getGPA( )
    {
        return gpa;
    }

    public String getMajor( )
    {
        return major;
    }

    public void changeMajor( String newMajor )
    {
        checkMajor( newMajor );
        major = newMajor;
    }

    public boolean equals( Object other )
    {
        if( other instanceof Student == false )
            return false;

        Student rhs = (Student) other;

        return pantherID.equals( rhs.pantherID );
    }

    public String toString( )
    {
        return getName( ) + " " + "(" + pantherID + ")"
                  + " majoring in " + major + " with " + gpa + " gpa";
    }

    private String pantherID;
    private String lastName;
    private String firstName;
    private String major;
    private double gpa;
    private static ArrayList<String> usedIDs = new ArrayList<String>( );

    private void checkMajor( String proposedMajor )
    {
        for( String m : validMajors )
            if( m.equals( proposedMajor ) )
                return;   // found a major

        throw new IllegalArgumentException( "Invalid major " + proposedMajor );
    }

    public static final String [ ] validMajors = { "CS", "IT", "MIS" };
}

class Day05
{
    public static void processData( Scanner sc, String fileName )
    {
        ArrayList<Student> arr = new ArrayList<Student>( );

        System.out.println( "ALL VALID PANTHER IDS: " );
        System.out.println( Student.getAllIDs( ) );
        
        System.out.println( "Reading from " + fileName );
        while( sc.hasNextLine( ) )
            arr.add( new Student( sc.nextLine( ) ) );

        System.out.println( "Read " + arr.size( ) + " students" );
        for( Student s : arr )
            System.out.println( s );

        System.out.println( "DEAN'S LIST" );
        for( Student s : arr )
            if( s.getGPA( ) >= 3.75 )
                System.out.println( s );

        System.out.println( "ALL VALID PANTHER IDS: " );
        System.out.println( Student.getAllIDs( ) );
    }

    public static void main( String [ ] args )
    {
        final String resourceName =
                //  "http://users.cis.fiu.edu/~weiss/cop3804/Day04.txt";
                    "Day04.txt";
        try
        {
            //URL url = new URL( resourceName );
            //Scanner sc = new Scanner( url.openStream( ) );
            Scanner sc = new Scanner( new File( resourceName ) ) ;
            processData( sc, resourceName );
        }
        catch( IOException e )
        {
            System.out.println( "Error processing " + resourceName );
        }
    }
}