/* Java class that contains methods for converting calendar dates in 
** various formats into yyyymmdd format (e.g., "19650515").  The date 
** formats supported are the following (with examples):
**
**   Format           Examples
**   ---------------  ------------------------------------------
**   mm/dd/yyyy       "10/08/2019", "10/8/2019", "5/15/1965"
**   dd-mm-yyyy       "08-10-2019", "8-10-2019", "15-5-1965"
**   yyyy-mm-dd       "2019-10-08", "2019-10-8", "1965-5-15"
**   dd-Mon-yyyy      "08-Oct-2019", "8-Oct-2019", "15-May-1965"
**   Month day, year  "October 08, 2019", "October 8, 2019"
**   day Month year   "08 October 2019", "8 October 2019"
**
** As implied by the examples, day and month numerals can include leading
** zeros but they need not.  (Year numerals can also be less than four
** digits, but no such examples are shown.)
**
** Each method attempts to convert the date given to it (via a parameter)
** into the corresponding date in the yyyymmdd format (e.g., "20191008").
** Each method has as a pre-condition that the date given to it is in the
** format that it expects, and therefore it is not responsible for what 
** it does if the string passed to it is not of the expected form.  For
** example, in such a case it may return a nonsensical string or it may
** cause an exception to be thrown.
** 
** None of the methods attempts to determine whether the date given to it
** is "semantically" (as opposed to "syntactically") correct.  For example,
** the method that handles mm/dd/yyyy dates will happily produce "19852357"
** when given the string "23/57/1985", even though there is no 23rd month 
** and no month has a 57th day.
**
** Authors: P.M. Jackowitz & R. McCloskey & < YOUR NAME >
** Date: October 2019
** CMPS 134  Fall 2019  Prog. Assg. #4
** Collaborated with: ...
** Known Defects: ...
*/

public class DateConverters {

   // Global constants
   // ----------------
   private static final char QUOTES = '"';
   private static final char SLASH = '/';
   private static final char BLANK = ' ';
   
   
   /* Converts the given string, which is assumed to be a calendar date
   ** in mm/dd/yyyy form, to the corresponding date in yyyymmdd form.
   ** Example: Given "04/15/1985", returns "19850415".
   */
   public static String convertMMDDYYYY(String given) {
      String result = "";

      // Locate the two SLASHs
      int posOf1stSlash = given.indexOf(SLASH);
      int posOfLastSlash = given.lastIndexOf(SLASH);

      // Extract each of the three parts
      String month = given.substring(0,posOf1stSlash);
      String day   = given.substring(posOf1stSlash+1, posOfLastSlash);
      String year  = given.substring(posOfLastSlash+1);

      // Concatenate the three parts, adding leading zeros where needed to
      // make the year of length 4 and each of the month and day of length 2.
      result = Pad.padLeft(year,4,'0') + 
               Pad.padLeft(month,2,'0') + 
               Pad.padLeft(day,2,'0');
      return result;
   }
   
   /* Converts the given string, which is assumed to be a calendar date
   ** in dd-mm-yyyy form, to the corresponding date in yyyymmdd form.
   ** Example: Given "24-10-2019", returns "20191024".
   */
   public static String convertDDMMYYYY(String given) {
      String result = "";
      // S t u b b e d ! ! !
      return result;
   }

   /* Converts the given string, which is assumed to be a calendar date
   ** in yyyy-mm-dd form, to the corresponding date in yyyymmdd form.
   ** Example: Given "2019-07-21", returns "20190721".
   */
   public static String convertYYYYMMDD(String given) {
      String result = "";
      // S t u b b e d ! ! !
      return result;
   }

   /* Converts the given string, which is assumed to be a calendar date
   ** in dd-Mon-yyyy form, to the corresponding date in yyyymmdd form.
   ** Example: Given "24-Oct-2019", returns "20191024".
   */
   public static String convertDDMonYYYY(String given) {
      String result = "";
      // S t u b b e d ! ! !
      return result;
   }

   /* Converts the given string, which is assumed to be a calendar date in
   ** "Month day, year" form, to the corresponding date in yyyymmdd form.
   ** Example: Given "April 8, 2019", returns "20190408".
   */
   public static String convertMonthDayYear(String given) {
      String result = "";
      // S t u b b e d ! ! !
      return result;
   }

   /* Converts the given string, which is assumed to be a calendar date in
   ** "day Month year" form, to the corresponding date in yyyymmdd form.
   ** Example: Given "8 July 2014", returns "20140708".
   */
   public static String convertDayMonthYear(String given) {
      String result = "";
      // S t u b b e d ! ! !
      return result;
   }

}