/******************************* MAIN HEADER **********************************
    Title:       Oops4 Date Exception Handling
    File:        Oops4.java
    
    Author:      James D. Skrentny, skrentny@cs.wisc.edu
                 copyright 2000 all rights reserved
    Course:      CS 302: Lectures 1 & 2
    
    Compiler:    CodeWarrior IDE 4.0 (JDK 1.2)
    Platform:    Windows NT 4.0
 **************************** 80 columns wide *********************************/

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

/**
 * This program demonstrates how to catch an exception that we
 *  created - InvalidDateException.
 **/
 class Oops4 {

    // allows stdin to be shared
    private static BufferedReader stdin = new BufferedReader
                   (new InputStreamReader(System.in));

    // driver program
    public static void main (String[ ] args) {
        Date start = getDate("\n\nEnter start date.");
        System.out.println(start);
        Date stop  = getDate("\n\nEnter stop date.");
        System.out.println(stop);
    }
    
    /**         
    * A general input method to read a date.
    * @param prompt user prompt
    * @return the date inputted
    **/
    private static Date getDate (String prompt)  {
    
        System.out.println(prompt);
        int    day = 0, year = 0;
        String month = null;

        // require input until a valid date is entered      
        while (true) {
            try {
                day   = getInt ("Enter day of month [1-31]: ", 1, 31);
                month = getWord("Enter month [e.g. Jan]: ");
                year  = getInt ("Enter year [>0]: ", 1, Integer.MAX_VALUE);
            }
            catch (IOException oops) {
                System.err.println("Error #2: cute message");
                System.err.println(oops.getMessage());
                oops.printStackTrace();
                System.exit(1);
            }

            //could combine this with try statement above       
            try {
                return new Date(day, month, year);
            }
            //catch the exception we created
            catch (InvalidDateException oops) {
                System.out.print("INVALID date: ");
                switch (oops.getType()) {
                    case 1:  System.out.println("bad day value");   break;
                    case 2:  System.out.println("bad month value"); break;
                    case 3:  System.out.println("bad year value");  break;
                    default: System.out.println("unknown");         break;
                }
            }
        }
    }
    
    /**         
    * A general input method to read an integer within specified limits.
    * @param prompt user prompt
    * @param min specified lower limit
    * @param max specified upper limit
    * @return the integer inputted
    **/
    private static int getInt (String prompt, int min, int max)
                                        throws IOException {
        boolean repeat;
        int i = 0;
        
        do {
            repeat = false; // assume user correctly enters # > 0
            
            // get input
            System.out.println(prompt);
            String s = stdin.readLine();
            
            // try to parse to integer and verify within limits
            try {
                i = Integer.parseInt(s);
                if (i < min || i > max) {
                    System.out.println(i + " is INVALID! must be from "
                                       + min + " to " + max + "\n\n");
                    repeat = true;
                }
            }
            // handle invalid number format (i.e. catch locally)
            catch (NumberFormatException oops) {
                System.out.println(s + " is INVALID! must be an integer\n\n");
                repeat = true;
            }
                
        } while (repeat);
        
        return i;
    }
    
    /**         
    * A general input method a single word.
    * @param prompt user prompt
    * @return the one word inputted
    **/
    private static String getWord (String prompt) throws IOException { 
         
        boolean repeat;
        String s;
        
        do {
            repeat = false; // assume user correctly enters one word

            // get input
            System.out.println(prompt);
            s = stdin.readLine();
            
            // count tokens
            StringTokenizer t = new StringTokenizer(s, " \t");
            if (t.countTokens() > 1) {
                System.out.println(s + " is INVALID! must be 1 word");
                repeat = true;
            }
            
        } while (repeat);
        
        return s;
    }
}