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

/* Java application for purpose of testing the methods of the CalendarDate
** class.
**
** Author: R. McCloskey, November 2022
*/
public class CalendarDateTester {

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

   public static void main(String[] args) throws FileNotFoundException {
      System.out.println("Welcome to the CalendarDateTester 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" calendar date
      current = makeDate();
   
      // Establish the "previous" calendar date to be the default date. 
      prev = new CalendarDate();
   
      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(":> ");  // 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")) { testEquals(); }
         else if (command.equals("C")) { testCompareTo(); }
         else if (command.equals("S")) { testSetDate(comLineScanner); }
         else if (command.equals("RD")) { testRetreatDay(comLineScanner); }
         else if (command.equals("AD")) { testAdvanceDay(comLineScanner); }
         else if (command.equals("RW")) { testRetreatWeek(comLineScanner); }
         else if (command.equals("AW")) { testAdvanceWeek(comLineScanner); }
         else if (command.equals("RM")) { testRetreatMonth(comLineScanner); }
         else if (command.equals("AM")) { testAdvanceMonth(comLineScanner); }
         else if (command.equals("RY")) { testRetreatYear(comLineScanner); }
         else if (command.equals("AY")) { testAdvanceYear(comLineScanner); }
         else { System.out.println("Unknown command; ignoring."); }
      }
   }

   private static void printHelp() {
      System.out.println("Available commands ([n] means optional natural number):");
      System.out.println("-------------------------------------------------------");
      System.out.println("  Q        (Quit)");
      System.out.println("  H        (Help)");
      System.out.println("  E        (test Equals())");
      System.out.println("  C        (test compareTo())");
      System.out.println("  S date   (test setDate(date))");
      System.out.println("  RD [n]   (test retreatDay())");
      System.out.println("  AD [n]   (test advanceDay())");
      System.out.println("  RW [n]   (test retreatWeek())");
      System.out.println("  AW [n]   (test advanceWeek())");
      System.out.println("  RM [n]   (test retreatMonth())");
      System.out.println("  AM [n]   (test advanceMonth())");
      System.out.println("  RY [n]   (test retreatYear())");
      System.out.println("  AY [n]   (test advanceYear())");
   }

   /* Compares 'current' and 'prev' using the equals() method, and reports the
   ** result.
   */
   private static void testEquals() {
      System.out.printf("equals() says that %s and %s are ", current, prev);
      if (!current.equals(prev)) {
         System.out.print("NOT ");
      }
      System.out.println("equal.");
   }


   /* 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("comes before %s", prev); }
      else if (compareResult > 0)
      { System.out.printf("comes after %s", prev); }
      else { 
         System.out.printf("is equal to %s", prev);
      }
      System.out.println();
   }

   /* Calls the setDate() method and reports the result.
   */
   private static void testSetDate(Scanner comLineScanner) {
      prev.setDate(current);
      String arg = "";;
      if (comLineScanner.hasNext()) {
         arg = comLineScanner.next();
         current.setDate(arg);
      }
      System.out.printf("After calling setDate(%s), current is %s and prev is %s\n",
                        arg, current, prev);
   }

   private static void testRetreatDay(Scanner comLineScanner) {
      prev.setDate(current);
      String arg;
      if (comLineScanner.hasNextInt()) {
         int days = comLineScanner.nextInt();
         current.retreatDay(days);
         arg = days + "";
      }
      else {
         current.retreatDay();
         arg = "";
      }
      System.out.printf("After calling retreatDay(%s), current is %s and prev is %s\n",
                        arg, current, prev);
   }

   private static void testAdvanceDay(Scanner comLineScanner) {
      prev.setDate(current);
      String arg;
      if (comLineScanner.hasNextInt()) {
         int days = comLineScanner.nextInt();
         current.advanceDay(days);
         arg = days + "";
      }
      else {
         current.advanceDay();
         arg = "";
      }
      System.out.printf("After calling advanceDay(%s), current is %s and prev is %s\n",
                        arg, current, prev);
   }

   private static void testRetreatWeek(Scanner comLineScanner) {
      prev.setDate(current);
      String arg;
      if (comLineScanner.hasNextInt()) {
         int weeks = comLineScanner.nextInt();
         current.retreatWeek(weeks);
         arg = weeks + "";
      }
      else {
         current.retreatWeek();
         arg = "";
      }
      System.out.printf("After calling retreatWeek(%s), current is %s and prev is %s\n",
                        arg, current, prev);
   }

   private static void testAdvanceWeek(Scanner comLineScanner) {
      prev.setDate(current);
      String arg;
      if (comLineScanner.hasNextInt()) {
         int weeks = comLineScanner.nextInt();
         current.advanceWeek(weeks);
         arg = weeks + "";
      }
      else {
         current.advanceWeek();
         arg = "";
      }
      System.out.printf("After calling advanceWeek(%s), current is %s and prev is %s\n",
                        arg, current, prev);
   }


   private static void testRetreatMonth(Scanner comLineScanner) {
      prev.setDate(current);
      String arg;
      if (comLineScanner.hasNextInt()) {
         int months = comLineScanner.nextInt();
         current.retreatMonth(months);
         arg = months + "";
      }
      else {
         current.retreatMonth();
         arg = "";
      }
      System.out.printf("After calling retreatMonth(%s), current is %s and prev is %s\n",
                        arg, current, prev);
   }

   private static void testAdvanceMonth(Scanner comLineScanner) {
      prev.setDate(current);
      String arg;
      if (comLineScanner.hasNextInt()) {
         int months = comLineScanner.nextInt();
         current.advanceMonth(months);
         arg = months + "";
      }
      else {
         current.advanceMonth();
         arg = "";
      }
      System.out.printf("After calling advanceMonth(%s), current is %s and prev is %s\n",
                        arg, current, prev);
   }

   private static void testRetreatYear(Scanner comLineScanner) {
      prev.setDate(current);
      String arg;
      if (comLineScanner.hasNextInt()) {
         int years = comLineScanner.nextInt();
         current.retreatYear(years);
         arg = years + "";
      }
      else {
         current.retreatYear();
         arg = "";
      }
      System.out.printf("After calling retreatYear(%s), current is %s and prev is %s\n",
                        arg, current, prev);
   }

   private static void testAdvanceYear(Scanner comLineScanner) {
      prev.setDate(current);
      String arg;
      if (comLineScanner.hasNextInt()) {
         int years = comLineScanner.nextInt();
         current.advanceYear(years);
         arg = years + "";
      }
      else {
         current.advanceYear();
         arg = "";
      }
      System.out.printf("After calling advanceYear(%s), current is %s and prev is %s\n",
                        arg, current, prev);
   }



   /* Returns a new CalendarDate object set to the date specified by
   ** an input string.
   */
   private static CalendarDate makeDate() {
      CalendarDate result = null;
      String dateStr = getInput("Enter date in mm/dd/yyyy format:>");
      try {
         result = new CalendarDate(dateStr);
      }
      catch (Exception e) {
         e.printStackTrace(System.out);
         System.out.println("\nProgram 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;
      }
   }
}