diff --git a/src/main/java/ntnu/idatt2016/v233/SmartMat/controller/group/WasteController.java b/src/main/java/ntnu/idatt2016/v233/SmartMat/controller/group/WasteController.java
index efb3e0361b544a547bcb51eba8c0bb1632d464e6..a139cfcefc28198377bd89840206532a1cb7e004 100644
--- a/src/main/java/ntnu/idatt2016/v233/SmartMat/controller/group/WasteController.java
+++ b/src/main/java/ntnu/idatt2016/v233/SmartMat/controller/group/WasteController.java
@@ -79,4 +79,17 @@ public class WasteController {
return wasteService.getCakeDiagram(groupId).map(ResponseEntity::ok).orElseGet(()->ResponseEntity.notFound().build());
}
+
+ /**
+ * Get the information of the last months of a specific group.
+ *
+ * @param groupId the id of the group to get the information for
+ * @return a ResponseEntity object containing an array of doubles representing the waste for each category
+ * in the last four months, or a not found response if the group does not exist or has no waste data
+ */
+ @GetMapping("/statistic/lastMonths/{groupId}")
+ public ResponseEntity<double[]> getInformationOfLastMoths(@PathVariable("groupId") long groupId){
+ return wasteService.getLastMonth(groupId).map(ResponseEntity::ok).orElseGet(()->ResponseEntity.notFound().build());
+ }
+
}
diff --git a/src/main/java/ntnu/idatt2016/v233/SmartMat/service/group/WasteService.java b/src/main/java/ntnu/idatt2016/v233/SmartMat/service/group/WasteService.java
index 8f43267c5e6805f2d2924544274c110db0510b25..fab7d6071c995c666bacba4ad54cd04c4062d8d7 100644
--- a/src/main/java/ntnu/idatt2016/v233/SmartMat/service/group/WasteService.java
+++ b/src/main/java/ntnu/idatt2016/v233/SmartMat/service/group/WasteService.java
@@ -1,5 +1,6 @@
package ntnu.idatt2016.v233.SmartMat.service.group;
+import java.nio.channels.FileChannel;
import java.sql.Timestamp;
import java.util.List;
import lombok.AllArgsConstructor;
@@ -77,4 +78,15 @@ public class WasteService {
return group.map(value -> StatisticUtil.getNumberOfWasteByCategoryName(wasteRepository.findByGroupId(value).get()));
}
+ /**
+ * Retrieve an optional array of doubles representing the amount of waste produced in each of the last 4 months for a given group.
+ *
+ * @param groupId a long representing the id of the group whose waste production statistics are to be retrieved
+ * @return an optional array of doubles representing the amount of waste produced in each of the last 4 months for the given group,
+ * or an empty optional if the group could not be found or no waste was produced in the last 4 months
+ */
+ public Optional<double[]> getLastMonth(long groupId) {
+ Optional<Group> group = groupRepository.findByGroupId(groupId);
+ return group.map(value -> StatisticUtil.getNumberOfWasteByLastMonth(wasteRepository.findByGroupId(value).get()));
+ }
}
diff --git a/src/main/java/ntnu/idatt2016/v233/SmartMat/util/StatisticUtil.java b/src/main/java/ntnu/idatt2016/v233/SmartMat/util/StatisticUtil.java
index 4ec0de83f551862e720a27aa4185cf3d83a92d6d..47a389707c90e7980d6bd55554de6b05fb3e72a6 100644
--- a/src/main/java/ntnu/idatt2016/v233/SmartMat/util/StatisticUtil.java
+++ b/src/main/java/ntnu/idatt2016/v233/SmartMat/util/StatisticUtil.java
@@ -3,6 +3,9 @@ package ntnu.idatt2016.v233.SmartMat.util;
import ntnu.idatt2016.v233.SmartMat.entity.Waste;
import java.sql.Date;
+import java.time.LocalDate;
+import java.util.ArrayList;
+import java.util.HashMap;
import java.util.List;
@@ -47,4 +50,71 @@ public class StatisticUtil {
}
return numberOfWastes;
}
+
+ /**
+ * Calculates the sum of waste for each of the four previous months.
+ * The amount of waste is converted to kilograms if the unit is in liters, grams, milliliters, centiliters, or deciliters.
+ *
+ * @param wastes the list of wastes to calculate the sum from
+ * @return an array of four doubles representing the sum of waste for each of the last four months,
+ * in the same order as the months are counted backwards from the current month
+ */
+ public static double[] getNumberOfWasteByLastMonth(List<Waste> wastes){
+ double[] result = new double[4];
+ HashMap<Integer,List<Waste>> hashMap = new HashMap<>();
+
+ LocalDate localDate = LocalDate.now();
+ int currentMonth = localDate.getMonthValue();
+ int currentYear = localDate.getYear();
+ for(Waste waste : wastes){
+ LocalDate localDate1 = waste.getTimestamp().toLocalDateTime().toLocalDate();
+ if(currentMonth == localDate1.getMonthValue() && currentYear == localDate1.getYear()){
+ hashMap.computeIfAbsent(0, k -> new ArrayList<>());
+ hashMap.get(0).add(waste);
+ }
+ if(Math.abs((currentMonth-1) % 12) == localDate1.getMonthValue() && currentYear == localDate1.getYear()){
+ hashMap.computeIfAbsent(1, k -> new ArrayList<>());
+ hashMap.get(1).add(waste);
+ }
+ if(Math.abs((currentMonth-2) % 12) == localDate1.getMonthValue() && currentYear == localDate1.getYear()){
+ hashMap.computeIfAbsent(2, k -> new ArrayList<>());
+ hashMap.get(2).add(waste);
+ }
+ if(Math.abs((currentMonth-3) % 12) == localDate1.getMonthValue() && currentYear == localDate1.getYear()){
+ hashMap.computeIfAbsent(3, k -> new ArrayList<>());
+ hashMap.get(3).add(waste);
+ }
+ }
+ for(int i = 0; i < 4; i++){
+ result[i] = getSumOfWaste(hashMap.get(i));
+ }
+ return result;
+ }
+
+ /**
+ * Calculates the sum of waste for a list of wastes, and converts the amounts to kilograms if the unit is in liters,
+ * grams, milliliters, centiliters, or deciliters.
+ *
+ * @param wastes the list of wastes to calculate the sum from
+ * @return the sum of waste in kilograms
+ */
+ private static double getSumOfWaste(List<Waste> wastes){
+ double sum = 0.0;
+ if(wastes == null){
+ wastes = new ArrayList<>();
+ }
+ for(Waste waste: wastes){
+ switch (waste.getEan().getUnit()){
+ case "l" -> sum += waste.getAmount() * 0.998;
+ case "kg" -> sum += waste.getAmount();
+ case "g" -> sum += waste.getAmount() * 0.001;
+ case "ml" -> sum += waste.getAmount() * 0.000998;
+ case "cl" -> sum += waste.getAmount() * 0.00998;
+ case "dl" -> sum += waste.getAmount() * 0.0998;
+ default -> sum += 0.1;
+ }
+ }
+ return sum;
+ }
+
}
\ No newline at end of file