Merge pull request #6 from euchangxian/branch-C-NaturalDates

Add more special date inputs

src/main/java/duke/util/TimeUtil.java

@@ -1,5 +1,6 @@
 package duke.util;
 
+import java.time.DayOfWeek;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.format.DateTimeFormatter;
@@ -84,15 +85,18 @@ public static String formatLocalDateTime(LocalDateTime localDate) {
      */
     public static String getHelpMessage() {
         return "Invalid date format! Please use one of the following formats:"
-                + "\n- yyyy-MM-dd HHmm (e.g. 2023-05-28 1800)"
-                + "\n- yyyyMMdd HHmm (e.g. 2023-05-28 1800)"
-                + "\n- yyyy-MM-dd (e.g. 2023-05-28)"
-                + "\n- yyyymmdd (e.g. 20230528)"
-                + "\n- d MMM yyyy (e.g. 1 Jan 2023)"
-                + "\n- d MMMM yyyy (e.g. 1 January 2023)"
-                + "\nOr use special terms like:"
-                + "\n- today"
-                + "\n- tomorrow";
+            + "\n- yyyy-MM-dd HHmm (e.g. 2023-05-28 1800)"
+            + "\n- yyyyMMdd HHmm (e.g. 2023-05-28 1800)"
+            + "\n- yyyy-MM-dd (e.g. 2023-05-28)"
+            + "\n- yyyymmdd (e.g. 20230528)"
+            + "\n- d MMM yyyy (e.g. 1 Jan 2023)"
+            + "\n- d MMMM yyyy (e.g. 1 January 2023)"
+            + "\nOr use special terms like:"
+            + "\n- today"
+            + "\n- tomorrow"
+            + "\n- monday (for the next Monday)"
+            + "\n- tuesday (for the next Tuesday)"
+            + "\n- ... (similarly for other days of the week)";
     }
 
     /**
@@ -110,8 +114,36 @@ private static LocalDateTime handleSpecialStrings(String input) {
             return LocalDateTime.now().withHour(23).withMinute(59);
         case "tomorrow":
             return LocalDateTime.now().plusDays(1).withHour(23).withMinute(59);
+        case "monday":
+        case "tuesday":
+        case "wednesday":
+        case "thursday":
+        case "friday":
+        case "saturday":
+        case "sunday":
+            return getNextDayOfWeek(DayOfWeek.valueOf(input.toUpperCase()));
         default:
             return null;
         }
     }
+
+    /**
+     * Returns the LocalDateTime of the next occurrence of the specified day of the week.
+     * <p>
+     * This method calculates the number of days between the current day and the desired day of the week.
+     * If the desired day is the same as the current day, it returns the date of the next week's occurrence.
+     * </p>
+     *
+     * @param desiredDay The desired day of the week as a DayOfWeek enum value.
+     * @return A LocalDateTime representing the next occurrence of the desired day, with the time set to 23:59.
+     */
+    private static LocalDateTime getNextDayOfWeek(DayOfWeek desiredDay) {
+        LocalDateTime now = LocalDateTime.now();
+        int daysUntilDesired = desiredDay.getValue() - now.getDayOfWeek().getValue();
+        if (daysUntilDesired <= 0) { // if today is the desired day or a later day in the week
+            daysUntilDesired += 7; // get the next occurrence of the desired day
+        }
+        return now.plusDays(daysUntilDesired).withHour(23).withMinute(59);
+    }
+
 }

src/test/java/duke/util/TimeUtilTest.java

@@ -5,6 +5,7 @@
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.junit.jupiter.api.Assertions.fail;
 
+import java.time.DayOfWeek;
 import java.time.LocalDateTime;
 import java.util.List;
 
@@ -67,6 +68,22 @@ public void testParseDateTimeString_withSpecialInputs() {
         }
     }
 
+    @Test
+    public void testParseDateTimeString_withDaysOfWeekInputs() {
+        List<String> daysOfWeekInputs = List.of("monday", "tuesday", "wednesday", "thursday", "friday",
+            "saturday", "sunday");
+        for (String input : daysOfWeekInputs) {
+            try {
+                LocalDateTime actual = TimeUtil.parseDateTimeString(input);
+                DayOfWeek expectedDay = DayOfWeek.valueOf(input.toUpperCase());
+                assertEquals(expectedDay, actual.getDayOfWeek());
+            } catch (TimeUtilException e) {
+                fail();
+            }
+        }
+    }
+
+
     @Test
     public void testParseDateTimeString_withInvalidInputs() {
         List<String> invalidInputs = List.of(