[backend] Added action for viewing diagnosis trends

iTrust/src/edu/ncsu/csc/itrust/action/ViewDiagnosisStatisticsAction.java

@@ -93,6 +93,43 @@ public class ViewDiagnosisStatisticsAction {
         
         return dsBean;
     }
+
+    public List<DiagnosisStatisticsBean> getDiagnosisTrends(String dateString, String icdCode, String zip) throws FormValidationException, ITrustException {
+        ArrayList<DiagnosisStatisticsBean> dsBean = null;
+        if (dateString == null || icdCode == null)
+            return null;
+        
+        try {
+            if (!zip.matches("([0-9]{5})|([0-9]{5}-[0-9]{4})"))
+                throw new FormValidationException("Zip Code must be 5 digits!");
+
+            Date next = new SimpleDateFormat("MM/dd/yyyy").parse(dateString);
+
+            dsBean = new ArrayList<>();
+            
+            boolean validCode = false;
+            for(DiagnosisBean diag : getDiagnosisCodes()) {
+                if (diag.getICDCode().equals(icdCode)) {
+                    validCode = true;
+                }
+            }
+            if (validCode == false) {
+                throw new FormValidationException("ICDCode must be valid diagnosis!");
+            }
+            
+            Calendar cal = Calendar.getInstance();
+            cal.setTime(next);
+            for (int i = 0; i < 8; i++) {
+                Date weekDate = cal.getTime();
+                dsBean.add(diagnosesDAO.getCountForWeekBefore(icdCode, zip, weekDate));
+                cal.add(Calendar.HOUR, -24*7);
+            }
+        } catch (ParseException e) {
+            throw new FormValidationException("Enter dates in MM/dd/yyyy");
+        }
+        
+        return dsBean;
+    }
     
     /**
      * Gets the local and regional counts for the specified week and calculates the prior average.