import java.util.Scanner;
import java.io.File;
import java.io.FileNotFoundException;

/* Java application for purpose of testing the behavior of objects from the
** TimeOfDay class.
**
** Author: R. McCloskey, January 2025
*/
public class TimeOfDayTester {

   private static Scanner input;
   private static boolean echo;
   private static boolean keepGoing;
   private static TimeOfDay current, prev;

   public static void main(String[] args) throws FileNotFoundException {
      System.out.println("Welcome to the TimeOfDayTester program.\n");
   
      // Establish the source of input to which the Scanner is attached.
      // If a command line argument is provided, it is taken to be the
      // name of a file from which to read input.  Otherwise input is
      // read from the keyboard.
      establishInputSource(args);
   
      // Establish the initial "current" time of day
      current = makeTimeOfDay();
   
      // Establish the "previous" time of day to be midnight. 
      prev = new TimeOfDay(0,0);

      System.out.printf("After initialization, current is %s and prev is %s\n\n",
                        current, prev);
   
      printHelp();

      keepGoing = true;
      while (keepGoing) {
         try {
            performCommand();
         }
         catch (Exception e) {
            e.printStackTrace(System.out);
         }
      }
      System.out.println("Goodbye.");
   }

   private static void performCommand() {
      String spacesPattern = " +";
      System.out.print("\n> ");  // prompt for input
      String commandLine = input.nextLine().toUpperCase();  // read line of input
      if (echo) { System.out.println(commandLine); }
      Scanner comLineScanner = new Scanner(commandLine);
      if (!comLineScanner.hasNext())
         { }   // empty command
      else {
         String command = comLineScanner.next();
         if (command.equals("Q")) { keepGoing = false; }
         else if (command.equals("H")) { printHelp(); }
         else if (command.equals("E")) { testIsEarlierThan(); }
         else if (command.equals("L")) { testIsLaterThan(); }
         else if (command.equals("C")) { testCompareTo(); }
         else if (command.equals("A1")) { testAdvanceByOneMinute(); }
         else if (command.equals("A")) { testAdvanceBy(comLineScanner); }
         else if (command.equals("D1")) { testDecreaseByOneMinute(); }
         else if (command.equals("D")) { testDecreaseBy(comLineScanner); }
         else if (command.equals("12")) { testSetTo12HourMode(); }
         else if (command.equals("24")) { testSetTo24HourMode(); }
         // else if (command.equals("S")) { testSetTo(comLineScanner); }
         else { System.out.println("Unknown command; ignoring."); }
      }
   }

   private static void printHelp() {
      System.out.println("Available commands (h, and r stand for natural numbers):");
      System.out.println("-----------------------------------------------------------");
      System.out.println("  Q        (Quit)");
      System.out.println("  H        (Help)");
      System.out.println("  C        (test compareTo(prev))");
      System.out.println("  E        (test isEarlierThan(prev))");
      System.out.println("  L        (test isLaterThan(prev))");
      System.out.println("  A1       (test advanceByOneMinute())");
      System.out.println("  A        (test advanceBy(h,r))");
      System.out.println("  D1       (test decreaseByOneMinute())");
      System.out.println("  D        (test decreaseBy(h,r))");
      System.out.println("  12       (test setTo12HourMode())");
      System.out.println("  24       (test setTo24HourMode())");
      //System.out.println("  S h r    (test setTo(h,r))");
   }

   /* Compares 'current' and 'prev' using the compareTo() method, and reports the
   ** result.
   */
   private static void testCompareTo() {
      int compareResult = current.compareTo(prev);
      System.out.printf("compareTo() says that %s ", current); 
      if (compareResult < 0)
         { System.out.printf("is less than %s", prev); }
      else if (compareResult > 0)
         { System.out.printf("is greater than %s", prev); }
      else { 
         System.out.printf("is equal to %s", prev);
      }
      System.out.println();
   }

   /* Compares 'current' and 'prev' using the isEarlierThan() method, and 
   ** reports the result.
   */
   private static void testIsEarlierThan() {
      boolean compareResult = current.isEarlierThan(prev);
      String emptyOrNOT = compareResult ? "" : " NOT";
      System.out.printf("isEarlierThan() says that %s is%s earlier than %s", 
                        current, emptyOrNOT, prev); 
      System.out.println();
   }

   /* Compares 'current' and 'prev' using the isLaterThan() method, and 
   ** reports the result.
   */
   private static void testIsLaterThan() {
      boolean compareResult = current.isLaterThan(prev);
      String emptyOrNOT = compareResult ? "" : " NOT";
      System.out.printf("isLaterThan() says that %s is%s later than %s", 
                        current, emptyOrNOT, prev); 
      System.out.println();
   }


   /* Calls the setTo() method and reports the result.
   */
/*  Not applicable in Spring 2025 

   private static void testSetTo(Scanner comLineScanner) {
      try {
         // Read the hour and minute arguments 
         int hourArg = comLineScanner.nextInt();
         int minuteArg = comLineScanner.nextInt();

         // Modify 'prev' to make it identical to 'current'
         prev.setTo(current.hourOf(), current.minuteOf());
         current.setTo(hourArg, minuteArg);
         System.out.printf("After calling setTo(%d,%d), current is %s and prev is %s\n",
                           hourArg, minuteArg, current, prev);
      }
      catch (Exception e) {
         e.printStackTrace(System.out);
      }
   }
*/

   private static void testAdvanceByOneMinute() {
      prev.setTo(current);
      current.advanceByOneMinute();
      System.out.printf("After calling advanceByOneMinute(), current is %s and prev is %s\n",
                        current, prev);
   }

   private static void testAdvanceBy(Scanner comLineScanner) {
      try {
         int h = comLineScanner.nextInt();
         int m = comLineScanner.nextInt();
         if (h < 0 || m < 0) { throw new Exception(); }
         prev.setTo(current);
         current.advanceBy(h,m);
         System.out.printf("After calling advanceBy(%d,%d), current is %s and prev is %s\n",
                           h, m, current, prev);
      }
      catch (Exception e) {
         System.out.println("Command aborted; two nonnegative integers were expected");
      }
   }

   private static void testDecreaseByOneMinute() {
      prev.setTo(current);
      current.decreaseByOneMinute();
      System.out.printf("After calling decreaseByOneMinute(), current is %s and prev is %s\n",
                        current, prev);
   }

   private static void testDecreaseBy(Scanner comLineScanner) {
      try {
         int h = comLineScanner.nextInt();
         int m = comLineScanner.nextInt();
         if (h < 0 || m < 0) { throw new Exception(); }
         prev.setTo(current);
         current.decreaseBy(h,m);
         System.out.printf("After calling decreaseBy(%d,%d), current is %s and prev is %s\n",
                           h, m, current, prev);
      }
      catch (Exception e) {
         System.out.println("Command aborted; two nonnegative integers were expected");
      }
   }

   private static void testSetTo12HourMode() {
      current.setTo12HourMode(); 
      System.out.printf("After calling setTo12HourMode(), current is %s and prev is %s\n",
                        current, prev);
   }

   private static void testSetTo24HourMode() {
      current.setTo24HourMode(); 
      System.out.printf("After calling setTo24HourMode(), current is %s and prev is %s\n",
                        current, prev);
   }


   /* Returns a new TimeOfDay object set to the time of day specified by
   ** two integer inputs obtained via the 'input' Scanner.
   */
   private static TimeOfDay makeTimeOfDay() {
      TimeOfDay result = null;
      
      String hourMinuteStr = getInput("Enter initial hour and minute values: ");
      try {
         Scanner scanner = new Scanner(hourMinuteStr);
         int h = scanner.nextInt();
         int m = scanner.nextInt();
         result = new TimeOfDay(h,m);
      }
      catch (Exception e) {
         e.printStackTrace(System.out);
         System.out.println("\nInvalid input: Program aborting.");
         System.exit(0);
      }
      return result;
   }

   private static String getInput(String prompt) {
      System.out.print(prompt);
      String result = input.nextLine();
      if (echo) { System.out.println(result); }
      return result;
   }

   /* Establishes the source of input from which the Scanner ('input') 
   ** will read.  If args[] is not empty, the file whose name is args[0]
   ** will be the input source.  Otherwise it will be the keyboard.
   */
   private static void establishInputSource(String[] args) throws FileNotFoundException {
      if (args.length != 0) {
         input = new Scanner(new File(args[0]));
         echo = true;
      }
      else {
         input = new Scanner(System.in);
         echo = false;
      }
   }
}