Implement reference solution for swift-scheduling practice exercise

Author: zamora-carlos

exercises/practice/swift-scheduling/.meta/src/reference/java/SwiftScheduling.java

@@ -1,7 +1,97 @@
+import java.time.DayOfWeek;
 import java.time.LocalDateTime;
 
+import static java.time.DayOfWeek.*;
+
 public class SwiftScheduling {
     public static LocalDateTime convertToDeliveryDate(LocalDateTime meetingStart, String description) {
-        throw new UnsupportedOperationException("Delete this statement and write your own implementation.");
+        if ("NOW".equals(description)) {
+            return meetingStart.plusHours(2);
+        }
+
+        if ("ASAP".equals(description)) {
+            LocalDateTime sameDayAt1pm = toStartOfDay(meetingStart).withHour(13);
+
+            if (meetingStart.isBefore(sameDayAt1pm)) {
+                return toStartOfDay(meetingStart).withHour(17);
+            } else {
+                return toStartOfDay(meetingStart).plusDays(1).withHour(13);
+            }
+        }
+
+        if ("EOW".equals(description)) {
+            DayOfWeek day = meetingStart.getDayOfWeek();
+            LocalDateTime deliveryDate = toStartOfDay(meetingStart);
+
+            if (day == MONDAY || day == TUESDAY || day == WEDNESDAY) {
+                deliveryDate = deliveryDate.withHour(17);
+                while (deliveryDate.getDayOfWeek() != FRIDAY) {
+                    deliveryDate = deliveryDate.plusDays(1);
+                }
+            } else if (day == THURSDAY || day == FRIDAY) {
+                deliveryDate = deliveryDate.withHour(20);
+                while (deliveryDate.getDayOfWeek() != SUNDAY) {
+                    deliveryDate = deliveryDate.plusDays(1);
+                }
+            } else {
+                throw new IllegalArgumentException("Invalid day of week");
+            }
+
+            return deliveryDate;
+        }
+
+        if (description.matches("\\d+M")) {
+            int month = Integer.parseInt(description.substring(0, description.length() - 1));
+            LocalDateTime targetMonth = toStartOfDay(meetingStart)
+                    .withMonth(month)
+                    .withDayOfMonth(1);
+
+            if (!meetingStart.isBefore(targetMonth)) {
+                targetMonth = targetMonth.plusYears(1);
+            }
+
+            LocalDateTime deliveryDate = targetMonth.withHour(8);
+            while (isWeekend(deliveryDate)) {
+                deliveryDate = deliveryDate.plusDays(1);
+            }
+
+            return deliveryDate;
+        }
+
+        if (description.matches("Q\\d")) {
+            int quarter = Integer.parseInt(description.substring(1));
+            LocalDateTime lastDayOfQuarter = getLastDayOfQuarter(meetingStart, quarter);
+
+            if (!meetingStart.isBefore(lastDayOfQuarter.plusDays(1))) {
+                lastDayOfQuarter = lastDayOfQuarter.plusYears(1);
+            }
+
+            LocalDateTime deliveryDate = lastDayOfQuarter.withHour(8);
+            while (isWeekend(deliveryDate)) {
+                deliveryDate = deliveryDate.minusDays(1);
+            }
+
+            return deliveryDate;
+        }
+
+        throw new IllegalArgumentException("Invalid description");
+    }
+
+    private static LocalDateTime toStartOfDay(LocalDateTime dateTime) {
+        return dateTime.toLocalDate().atStartOfDay();
+    }
+
+    private static LocalDateTime getLastDayOfQuarter(LocalDateTime dateTime, int quarter) {
+        int lastMonthOfQuarter = quarter * 3;
+        return toStartOfDay(dateTime)
+                .withMonth(lastMonthOfQuarter)
+                .withDayOfMonth(1)
+                .plusMonths(1)
+                .minusDays(1);
+    }
+
+    private static boolean isWeekend(LocalDateTime date) {
+        DayOfWeek dayOfWeek = date.getDayOfWeek();
+        return dayOfWeek == SATURDAY || dayOfWeek == SUNDAY;
     }
 }