Admin client feature

desm-client/src/main/java/org/example/desm/client/ApiClient.java

@@ -0,0 +1,91 @@
+package org.example.desm.client;
+
+import com.google.gson.Gson;
+import com.google.gson.reflect.TypeToken;
+import org.example.desm.common.model.AverageEmission;
+import org.example.desm.common.model.ErrorResponse;
+import org.example.desm.common.model.PowerPlant;
+
+import java.io.IOException;
+import java.lang.reflect.Type;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.util.List;
+
+import static org.example.desm.common.Constant.API_BASE_URL;
+import static org.example.desm.common.Constant.ENDPOINT_PLANTS;
+import static org.example.desm.common.Constant.ENDPOINT_POLLUTION;
+
+/**
+ * ApiClient is a utility class for making HTTP requests to the Administration Server.
+ * It provides methods to fetch all power plants and to get average emissions
+ * within a specified time range.
+ */
+public class ApiClient {
+    private static final Gson gson = new Gson();
+    private static final HttpClient client = HttpClient.newHttpClient();
+
+    /**
+     * Fetches all power plants.
+     *
+     * @return a list of PowerPlant objects.
+     * @throws IOException if an I/O error occurs during the request.
+     * @throws InterruptedException if the request is interrupted.
+     * @throws ResponseErrorExceptions if the response indicates an error.
+     */
+    public static List<PowerPlant> getAllPlants()
+            throws IOException, InterruptedException, ResponseErrorExceptions {
+        String uri = API_BASE_URL + ENDPOINT_PLANTS;
+
+        HttpRequest req = HttpRequest.newBuilder()
+                .uri(URI.create(uri))
+                .GET()
+                .build();
+        HttpResponse<String> response = client.send(req, HttpResponse.BodyHandlers.ofString());
+        validateResponse(response);
+
+        Type listType = new TypeToken<List<PowerPlant>>() {}.getType();
+        return gson.fromJson(response.body(), listType);
+    }
+
+    /**
+     * Fetches the average emissions for a specified time range.
+     *
+     * @param t1 the start time in milliseconds since epoch.
+     * @param t2 the end time in milliseconds since epoch.
+     * @return an AverageEmission object containing the average emission's data.
+     * @throws IOException if an I/O error occurs during the request.
+     * @throws InterruptedException if the request is interrupted.
+     * @throws ResponseErrorExceptions if the response indicates an error.
+     */
+    public static AverageEmission getAverageEmission(long t1, long t2)
+            throws IOException, InterruptedException, ResponseErrorExceptions {
+        String uri = API_BASE_URL + ENDPOINT_POLLUTION + "?t1=" + t1 + "&t2=" + t2;
+
+        HttpRequest req = HttpRequest.newBuilder()
+                .uri(URI.create(uri))
+                .GET()
+                .build();
+
+        HttpResponse<String> resp = client.send(req, HttpResponse.BodyHandlers.ofString());
+        validateResponse(resp);
+
+        return gson.fromJson(resp.body(), AverageEmission.class);
+    }
+
+    /**
+     * Validates the HTTP response status code.
+     *
+     * @param response the HttpResponse to validate.
+     * @throws ResponseErrorExceptions if the response status code indicates an error.
+     */
+    private static void validateResponse(HttpResponse<String> response) throws ResponseErrorExceptions {
+        int status = response.statusCode();
+        if (status < 200 || status >= 300) {
+            ErrorResponse error = gson.fromJson(response.body(), ErrorResponse.class);
+            throw new ResponseErrorExceptions(error);
+        }
+    }
+}

desm-client/src/main/java/org/example/desm/client/Client.java

@@ -0,0 +1,87 @@
+package org.example.desm.client;
+
+import org.example.desm.client.command.AvailablePowerPlant;
+import org.example.desm.client.command.Command;
+import org.example.desm.client.command.QueryAverageEmission;
+
+import java.util.Map;
+import java.util.Scanner;
+import java.util.TreeMap;
+
+public class Client {
+    public final Scanner scanner;
+    private final Map<Integer, Command> commands;
+
+    /**
+     * Constructs a Client with default commands.
+     */
+    public Client() {
+        this.scanner = new Scanner(System.in);
+        this.commands = new TreeMap<>();
+        initDefaultCommands();
+    }
+
+    /**
+     * Initializes the default set of commands.
+     */
+    private void initDefaultCommands() {
+        int i = 0;
+        registerCommand(new AvailablePowerPlant(
+                ++i, "View all power plants", scanner));
+        registerCommand(new QueryAverageEmission(
+                ++i, "Query average emission of power plants", scanner));
+    }
+
+    /**
+     * Register a command in the command map.
+     *
+     * @param command Command to register
+     */
+    private void registerCommand(Command command) {
+        commands.put(command.getId(), command);
+    }
+
+    /**
+     * Starts the client, displaying the menu and processing user input.
+     */
+    public void start() {
+        while (true) {
+            printMenu();
+            System.out.print("Choose: ");
+            String input = scanner.nextLine().trim();
+
+            try {
+                int choice = Integer.parseInt(input);
+                if (choice == 0) {
+                    System.out.println("Exiting...");
+                    break;
+                }
+
+                Command command = commands.get(choice);
+                if (command != null) {
+                    command.execute();
+                } else {
+                    System.out.println("Invalid option.");
+                }
+            } catch (NumberFormatException e) {
+                System.out.println("Please enter a valid number.");
+            }
+        }
+        scanner.close();
+    }
+
+    /**
+     * Prints the menu with available commands.
+     */
+    private void printMenu() {
+        System.out.println("\n===== Administration Client =====");
+        for (Command command : commands.values()) {
+            System.out.println(command.getId() + ". " + command.getName());
+        }
+        System.out.println("0. Exit");
+    }
+
+    public static void main(String[] args) {
+        new Client().start();
+    }
+}

desm-client/src/main/java/org/example/desm/client/ResponseErrorExceptions.java

@@ -0,0 +1,12 @@
+package org.example.desm.client;
+
+import org.example.desm.common.model.ErrorResponse;
+
+/**
+ * Custom {@link Exception} which is thrown when there is an error response from the server.
+ */
+public class ResponseErrorExceptions extends Exception {
+    public ResponseErrorExceptions(ErrorResponse error) {
+        super(error.toString());
+    }
+}

desm-client/src/main/java/org/example/desm/client/command/AvailablePowerPlant.java

@@ -0,0 +1,36 @@
+package org.example.desm.client.command;
+
+import org.example.desm.client.ApiClient;
+import org.example.desm.client.ResponseErrorExceptions;
+import org.example.desm.common.model.PowerPlant;
+
+import java.util.List;
+import java.util.Scanner;
+
+/**
+ * Custom {@link Command} to retrieve and display all available power plants.
+ * This command fetches the list of power plants from the API and prints them.
+ */
+public class AvailablePowerPlant extends Command {
+    public AvailablePowerPlant(int id, String name, Scanner scanner) {
+        super(id, name, scanner);
+    }
+
+    @Override
+    public void execute() {
+        try {
+            List<PowerPlant> plants = ApiClient.getAllPlants();
+            if (plants.isEmpty()) {
+                System.out.println("No power plants registered.");
+            } else {
+                for (PowerPlant plant : plants) {
+                    System.out.println(plant);
+                }
+            }
+        } catch (ResponseErrorExceptions e) {
+            System.out.println(e.getMessage());
+        } catch (Exception e) {
+            System.out.println("Unable to retrieve plants!");
+        }
+    }
+}

desm-client/src/main/java/org/example/desm/client/command/Command.java

@@ -0,0 +1,27 @@
+package org.example.desm.client.command;
+
+import lombok.Getter;
+
+import java.util.Scanner;
+
+/**
+ * Abstract class that represents a command in the Administration Client.
+ * Each command has an ID, a name, and a scanner for input.
+ */
+@Getter
+public abstract class Command {
+    private final int id;
+    private final String name;
+    protected final Scanner scanner;
+
+    public Command(int id, String name, Scanner scanner) {
+        this.id = id;
+        this.name = name;
+        this.scanner = scanner;
+    }
+
+    /**
+     * Executes the command.
+     */
+    public abstract void execute();
+}

desm-client/src/main/java/org/example/desm/client/command/QueryAverageEmission.java

@@ -0,0 +1,38 @@
+package org.example.desm.client.command;
+
+import org.example.desm.client.ApiClient;
+import org.example.desm.client.ResponseErrorExceptions;
+import org.example.desm.common.model.AverageEmission;
+
+import java.util.Scanner;
+
+/**
+ * Custom {@link Command} to query the average emissions between two timestamps.
+ * This command prompts the user for start and end timestamps, retrieves the average emissions from the API,
+ * and prints the result.
+ */
+public class QueryAverageEmission extends Command {
+    public QueryAverageEmission(int id, String name, Scanner scanner) {
+        super(id, name, scanner);
+    }
+
+    @Override
+    public void execute() {
+        try {
+            System.out.print("Enter start timestamp: ");
+            long t1 = Long.parseLong(scanner.nextLine().trim());
+
+            System.out.print("Enter end timestamp: ");
+            long t2 = Long.parseLong(scanner.nextLine().trim());
+
+            AverageEmission result = ApiClient.getAverageEmission(t1, t2);
+            System.out.println(result.toString());
+        } catch (NumberFormatException e) {
+            System.out.println("Timestamps must be numeric.");
+        } catch (ResponseErrorExceptions e) {
+            System.out.println(e.getMessage());
+        } catch (Exception e) {
+            System.out.println("Failed to query emissions!");
+        }
+    }
+}

desm-client/src/test/java/org/example/desm/client/ClientTest.java

@@ -0,0 +1,65 @@
+package org.example.desm.client;
+
+import org.example.desm.common.model.AverageEmission;
+import org.example.desm.common.model.PowerPlant;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.MockedStatic;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import java.io.ByteArrayInputStream;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.mockito.Mockito.mockStatic;
+
+@ExtendWith(MockitoExtension.class)
+class ClientTest {
+    @Test
+    void testAvailablePowerPlantCommand() {
+        List<PowerPlant> mockPlants = List.of(
+                new PowerPlant( "plant-1", "localhost", 8080),
+                new PowerPlant( "plant-2", "localhost", 8081)
+        );
+
+        // Simulate command 1 and then 0 to exit
+        String commandInput = "1\n0\n";
+        System.setIn(new ByteArrayInputStream(commandInput.getBytes()));
+
+        try (MockedStatic<ApiClient> apiClientMockedStatic = mockStatic(ApiClient.class)) {
+            apiClientMockedStatic.when(ApiClient::getAllPlants)
+                    .thenReturn(mockPlants);
+
+            new Client().start();
+
+            apiClientMockedStatic.verify(ApiClient::getAllPlants);
+        }
+    }
+
+    @Test
+    void testQueryAverageEmissionCommand() {
+        long t1 = 1000L;
+        long t2 = 2000L;
+        AverageEmission mockEmission = new AverageEmission(t1, t2, 10.0);
+
+        // Simulate command 2 and then 0 to exit
+        String commandInput = String.format("2\n%d\n%d\n0\n", t1, t2);
+        System.setIn(new ByteArrayInputStream(commandInput.getBytes()));
+
+        try (MockedStatic<ApiClient> apiClientMockedStatic = mockStatic(ApiClient.class)) {
+            apiClientMockedStatic.when(() -> ApiClient.getAverageEmission(t1, t2))
+                    .thenReturn(mockEmission);
+
+            new Client().start();
+
+            apiClientMockedStatic.verify(() -> ApiClient.getAverageEmission(t1, t2));
+        }
+    }
+
+    @Test
+    void testInvalidCommandInput() {
+        String commandInput = "x\n0\n";
+        System.setIn(new ByteArrayInputStream(commandInput.getBytes()));
+        assertDoesNotThrow(() -> new Client().start());
+    }
+}

desm-core/src/main/java/org/example/desm/common/Constant.java

@@ -2,6 +2,7 @@
 
 public class Constant {
     public static final String MQTT_BROKER_ADDRESS = "tcp://localhost:1883";
+    public static final String API_BASE_URL = "http://localhost:8080";
 
     // MQTT topics
     public static final String TOPIC_ENERGY_REQUEST = "energy/request";

desm-core/src/main/java/org/example/desm/common/model/AverageEmission.java

@@ -11,4 +11,10 @@ public class AverageEmission {
     private long startTimestamp;
     private long endTimestamp;
     private double average_co2;
+
+    @Override
+    public String toString() {
+        return "[from: " + startTimestamp + ", to: " + endTimestamp + "] " +
+                "avg CO2: " + average_co2 + "g";
+    }
 }

desm-core/src/main/java/org/example/desm/common/model/ErrorResponse.java

@@ -11,4 +11,9 @@ public class ErrorResponse {
     private int status;
     private String error;
     private String message;
+
+    @Override
+    public String toString() {
+        return "[" + status + "] " + error + ": " + message;
+    }
 }