// CSE 143, Winter 2011, Marty Stepp
// This program hires and fires teaching assistants based on their experience.
// It demonstrates the use of the PriorityQueue data structure.

import java.io.*;
import java.util.*;

public class FiringSquad {
    public static void main(String[] args) throws IOException {
    	// read all current TAs from a file into a priority queue
    	Queue<TA> queue = readTAs("tas.txt");
    	System.out.println(queue);
        System.out.println();
        int oldSize = queue.size();
        
        // FIRE all TAs with <= 2 quarters of experience
        while (!queue.isEmpty() && queue.peek().getExperience() <= 2) {
        	queue.remove();  // Donald Trump: "You're fired."
        }
        int toHire = oldSize - queue.size();
        System.out.println("fired "  + toHire + " TAs.");
        System.out.println(queue);
        
        // hire an equivalent number of new replacement TAs
        Queue<TA> newTAs = readTAs("replacements.txt");
        for (int i = 0; i < toHire; i++) {
        	queue.add(newTAs.remove());
        }
        
        // print all TAs in increasing order of experience
        while (!queue.isEmpty()) {
        	TA ta = queue.remove();
        	System.out.println(ta);
        }
        
    }
    
    
    // Reads all TAs from the file with the given name and returns them
    // as a priority queue of TA objects.
    // Each line contains a name and quarters of experience, such as:  Lisa 12
    // Precondition: filename != null and refers to a file that exists, 
    // can be read, and is in the proper format 
    public static Queue<TA> readTAs(String filename) throws FileNotFoundException {
        Queue<TA> queue = new PriorityQueue<TA>();
        Scanner in = new Scanner(new File(filename));
        while (in.hasNext()) {
            String name = in.next();
            int exp = in.nextInt();
            TA ta = new TA(name, exp);
            queue.add(ta);
        }
		return queue;

    }
}