Provide mock-like DB manager for integration testing

src/main/java/hhn/temp/project/provider/SimpleDatabaseManager.java

@@ -8,87 +8,186 @@ import java.util.*;
 
 public class SimpleDatabaseManager implements DatabaseManager {
 
+  private boolean connected = false;
+  private Map<Integer, Task> temporaryTaskList = new HashMap();
+  private Map<Integer, Worker> temporaryWorkerList = new HashMap<>();
+
   @Override
   public void saveTask(Task task) throws SQLException {
-    throw new SQLException();
+    if (!connected) {
+      throw new SQLException("[CONNECTION FAILED] Instance is not connected to database.");
+    }
+
+    if (!temporaryTaskList.containsKey(task.getTaskId())) {
+      temporaryTaskList.put(task.getTaskId(), task);
+    } else {
+      throw new SQLException("[INSERTION FAILED] Task with the same Task ID already exists.");
+    }
   }
 
   @Override
   public void saveTasks(Collection<Task> tasks) throws SQLException {
-    throw new SQLException();
+    for (Task task : tasks) {
+      saveTask(task);
+    }
   }
 
   @Override
   public void saveWorker(Worker worker) throws SQLException {
-    throw new SQLException();
+    if (!connected) {
+      throw new SQLException("[CONNECTION FAILED] Instance is not connected to database.");
+    }
+
+    if (!temporaryWorkerList.containsKey(worker.getId())) {
+      temporaryWorkerList.put(worker.getId(), worker);
+    } else {
+      throw new SQLException("[INSERTION FAILED] Task with the same Task ID already exists.");
+    }
   }
 
   @Override
   public void saveWorkers(Collection<Worker> workers) throws SQLException {
-    throw new SQLException();
+    for (Worker worker : workers) {
+      saveWorker(worker);
+    }
   }
 
   @Override
   public void updateTask(int taskId, Task newTaskObject) throws SQLException {
-    throw new SQLException();
+    if (!connected) {
+      throw new SQLException("[CONNECTION FAILED] Instance is not connected to database.");
+    }
+
+    if (temporaryTaskList.containsKey(taskId) && newTaskObject.getTaskId() == taskId) {
+      temporaryTaskList.remove(taskId);
+      temporaryTaskList.put(taskId, newTaskObject);
+      return;
+    }
+
+    throw new SQLException("[UPDATE FAILED] Task ID not found OR Task ID does not equal New Task ID.");
   }
 
   @Override
   public void updateWorker(int workerId, Worker newWorkerObject) throws SQLException {
-    throw new SQLException();
+    if (!connected) {
+      throw new SQLException("[CONNECTION FAILED] Instance is not connected to database.");
+    }
+
+    if (temporaryWorkerList.containsKey(workerId) && newWorkerObject.getId() == workerId) {
+      temporaryWorkerList.remove(workerId);
+      temporaryWorkerList.put(workerId, newWorkerObject);
+      return;
+    }
+
+    throw new SQLException("[UPDATE FAILED] Worker ID not found OR Worker ID does not equal New Worker ID.");
   }
 
   @Override
   public void deleteTask(int taskId) throws SQLException {
-    throw new SQLException();
+    if (!connected) {
+      throw new SQLException("[CONNECTION FAILED] Instance is not connected to database.");
+    }
+
+    if (temporaryTaskList.containsKey(taskId)) {
+      temporaryTaskList.remove(taskId);
+      return;
+    }
+
+    throw new SQLException("[DELETION FAILED] Could not find Task ID. Nothing to delete.");
   }
 
   @Override
   public void deleteWorker(int workerId) throws SQLException {
-    throw new SQLException();
+    if (!connected) {
+      throw new SQLException("[CONNECTION FAILED] Instance is not connected to database.");
+    }
+
+    if (temporaryWorkerList.containsKey(workerId)) {
+      temporaryWorkerList.remove(workerId);
+      return;
+    }
+
+    throw new SQLException("[DELETION FAILED] Could not find Worker ID. Nothing to delete.");
   }
 
   @Override
   public Collection<Task> getTasks() throws SQLException {
-    throw new SQLException();
+    if (!connected) {
+      throw new SQLException("[CONNECTION FAILED] Instance is not connected to database.");
+    }
+
+    return temporaryTaskList.values();
   }
 
   @Override
   public Collection<Worker> getWorkers() throws SQLException {
-    throw new SQLException();
+    if (!connected) {
+      throw new SQLException("[CONNECTION FAILED] Instance is not connected to database.");
+    }
+
+    return temporaryWorkerList.values();
   }
 
   @Override
   public Task getTaskByTaskId(int taskId) throws SQLException {
-    return new Task(0, 0, null, null);
+    if (!connected) {
+      throw new SQLException("[CONNECTION FAILED] Instance is not connected to database.");
+    }
+
+    if (temporaryTaskList.containsKey(taskId)) {
+      return temporaryTaskList.get(taskId);
+    }
+
+    throw new SQLException("[SELECTION FAILED] Could not find Task ID. Nothing to get.");
   }
 
   @Override
   public Worker getWorkerByWorkerId(int workerId) throws SQLException {
-    return new Worker(null, 0);
+    if (!connected) {
+      throw new SQLException("[CONNECTION FAILED] Instance is not connected to database.");
+    }
+
+    if (temporaryWorkerList.containsKey(workerId)) {
+      return temporaryWorkerList.get(workerId);
+    }
+
+    throw new SQLException("[SELECTION FAILED] Could not find Worker ID. Nothing to get.");
   }
 
   @Override
   public int getTotalNumberOfTasks() throws SQLException {
-    return -1;
+    if (!connected) {
+      throw new SQLException("[CONNECTION FAILED] Instance is not connected to database.");
+    }
+
+    return temporaryTaskList.size();
   }
 
   @Override
   public int getTotalNumberOfWorkers() throws SQLException {
-    return -1;
+    if (!connected) {
+      throw new SQLException("[CONNECTION FAILED] Instance is not connected to database.");
+    }
+
+    return temporaryWorkerList.size();
   }
 
   public void clearDatabase() throws SQLException {
-    throw new SQLException();
+    if (!connected) {
+      throw new SQLException("[CONNECTION FAILED] Instance is not connected to database.");
+    }
+
+    temporaryTaskList.clear();
+    temporaryWorkerList.clear();
   }
 
   @Override
   public void connect() throws SQLException {
-    throw new SQLException();
+    connected = true;
   }
 
   @Override
   public void close() throws SQLException {
-    throw new SQLException();
+    connected = false;
   }
 }