From 14f8c38a7052bad8b0f4b4967132841c62007fc5 Mon Sep 17 00:00:00 2001
From: Selim Eser <2211482@stud.hs-mannheim.de>
Date: Sun, 9 Jun 2024 16:39:05 +0200
Subject: [PATCH 1/4] distance method implemented

---
 .../java/de/hs_mannheim/domain/System.java    | 29 +++++++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)

diff --git a/src/main/java/de/hs_mannheim/domain/System.java b/src/main/java/de/hs_mannheim/domain/System.java
index 128203d..ae22776 100644
--- a/src/main/java/de/hs_mannheim/domain/System.java
+++ b/src/main/java/de/hs_mannheim/domain/System.java
@@ -65,7 +65,7 @@ public class System {
                     zip_set.add(line);
                 }
             }
-        } catch (IOException e) {}
+        } catch (Exception e) {}
         
         return new ArrayList<>(zip_set);
     }
@@ -208,7 +208,32 @@ public class System {
     }
 
     public String distance(String destination_zip){
-        return "";
+        
+        double lon1 = 1;
+        double lon2 = 1;
+        double lat1 = 1;
+        double lat2 = 1;
+
+        InputStream inputStream = Main.class.getResourceAsStream("/zip.csv");
+
+        try (BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream))) {
+            String line;
+            while ((line = reader.readLine()) != null) {
+                line = line.replace("\"", "");
+                
+                if(line.split(";")[0].equals(destination_zip)){
+                    lon2 = Double.parseDouble(line.split(";")[2]);
+                    lat2 = Double.parseDouble(line.split(";")[3]);
+                }
+
+                if(line.split(";")[0].equals(current_user.getZip())){
+                    lon1 = Double.parseDouble(line.split(";")[2]);
+                    lat1 = Double.parseDouble(line.split(";")[3]);
+                }
+            }
+        } catch (Exception e) {}
+        
+        return "" + 6378.388 * Math.acos(Math.sin(lat1) * Math.sin(lat2) + Math.cos(lat1) * Math.cos(lat2) * Math.cos(lon2 - lon1));
     }
 
     public String[] travel_time(String destination_zip){

From 39cfdc4d438d8e0b3ae522c9749a138d3eb5789e Mon Sep 17 00:00:00 2001
From: Selim Eser <2211482@stud.hs-mannheim.de>
Date: Sun, 9 Jun 2024 17:01:39 +0200
Subject: [PATCH 2/4] Fixed second if statement and corrected return formula

---
 src/main/java/de/hs_mannheim/domain/System.java | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/main/java/de/hs_mannheim/domain/System.java b/src/main/java/de/hs_mannheim/domain/System.java
index ae22776..5d8c180 100644
--- a/src/main/java/de/hs_mannheim/domain/System.java
+++ b/src/main/java/de/hs_mannheim/domain/System.java
@@ -226,14 +226,15 @@ public class System {
                     lat2 = Double.parseDouble(line.split(";")[3]);
                 }
 
-                if(line.split(";")[0].equals(current_user.getZip())){
+                if(line.split(";")[0].equals(""+current_user.getZip())){
                     lon1 = Double.parseDouble(line.split(";")[2]);
                     lat1 = Double.parseDouble(line.split(";")[3]);
                 }
             }
         } catch (Exception e) {}
-        
-        return "" + 6378.388 * Math.acos(Math.sin(lat1) * Math.sin(lat2) + Math.cos(lat1) * Math.cos(lat2) * Math.cos(lon2 - lon1));
+
+        return "" + (Math.acos(Math.sin(lat1) * Math.sin(lat2) + Math.cos(lat1) * Math.cos(lat2) * Math.cos(lon2 - lon1)) * 111.324) + " km";
+    
     }
 
     public String[] travel_time(String destination_zip){

From 523ff6a4a6f0040c2623a414ac9f61293615bf10 Mon Sep 17 00:00:00 2001
From: Selim Eser <2211482@stud.hs-mannheim.de>
Date: Sun, 9 Jun 2024 17:54:58 +0200
Subject: [PATCH 3/4] Changed destination formula to Haversine and multiplied
 return distance by 1.25 for distance using the streets

---
 src/main/java/de/hs_mannheim/domain/System.java | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/main/java/de/hs_mannheim/domain/System.java b/src/main/java/de/hs_mannheim/domain/System.java
index 5d8c180..897cf8e 100644
--- a/src/main/java/de/hs_mannheim/domain/System.java
+++ b/src/main/java/de/hs_mannheim/domain/System.java
@@ -233,7 +233,14 @@ public class System {
             }
         } catch (Exception e) {}
 
-        return "" + (Math.acos(Math.sin(lat1) * Math.sin(lat2) + Math.cos(lat1) * Math.cos(lat2) * Math.cos(lon2 - lon1)) * 111.324) + " km";
+        double dLat = lat2-lat1;
+        double dLon = lon2-lon1;
+
+        double a = Math.pow(Math.sin(Math.toRadians(dLat/2.0)), 2) + Math.pow(Math.sin(Math.toRadians(dLon/2.0)), 2) * Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2));
+
+        double distance = 6378.388 * 2.0 * Math.atan2(Math.sqrt(a), Math.sqrt(1.0-a));
+
+        return "" + (distance * 1.25) + " km";
     
     }
 

From 067617e8c0e8fc473c67ab3ce23b66e390e3286a Mon Sep 17 00:00:00 2001
From: Selim Eser <2211482@stud.hs-mannheim.de>
Date: Sun, 9 Jun 2024 18:00:26 +0200
Subject: [PATCH 4/4] test method implemented and build successful

---
 src/test/java/de/hs_mannheim/domain/SystemTest.java | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/test/java/de/hs_mannheim/domain/SystemTest.java b/src/test/java/de/hs_mannheim/domain/SystemTest.java
index bc8acac..4a546a0 100644
--- a/src/test/java/de/hs_mannheim/domain/SystemTest.java
+++ b/src/test/java/de/hs_mannheim/domain/SystemTest.java
@@ -39,4 +39,17 @@ public class SystemTest {
 
     }
 
+    @Test
+    public void distance(){
+
+        System current_system = new System("35a75437476f12302f72e55d368485db");
+
+        current_system.set_current_user_zip("68161");
+        
+        assertEquals("88.4596509227594 km", current_system.distance("60306")); // Frankfurt 
+        assertEquals("581.1091061333296 km", current_system.distance("20095")); // Hamburg
+        assertEquals("603.6077163174941 km", current_system.distance("10115")); // Berlin
+
+    }
+
 }