Now when user unsubscribe, their timers are also cancelled

Signed-off-by: Louis Vallat <louis@louis-vallat.xyz>

app/build.gradle

@@ -35,7 +35,6 @@ jar {
 }
 
 dependencies {
-    testImplementation 'junit:junit:4.13'
     implementation 'com.discord4j:discord4j-core:3.1.1'
     implementation 'ch.qos.logback:logback-classic:1.2.3'
     implementation 'org.postgresql:postgresql:42.2.18.jre7'

app/src/main/java/xyz/vallat/louis/App.java

@@ -4,26 +4,22 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import xyz.vallat.louis.managers.database.DBManager;
 import xyz.vallat.louis.managers.discord.DiscordManager;
-import xyz.vallat.louis.timertasks.AutoReimport;
+import xyz.vallat.louis.timer.TimerManager;
-
-import java.util.Calendar;
-import java.util.Timer;
-import java.util.concurrent.TimeUnit;
 
 public class App {
 
-    private static final Logger logger = LoggerFactory.getLogger(App.class.getCanonicalName());
     public static final String PREFIX = "+";
     public static final String NAME = "PrésencEirb";
     public static final String DESCRIPTION = "Tu as pensé à pointer ?";
     public static final String VERSION = "0.1-SNAPSHOT";
+    private static final Logger logger = LoggerFactory.getLogger(App.class.getCanonicalName());
 
     public static void main(String[] args) {
         logger.info("Starting {} ver. {}.", NAME, VERSION);
         DBManager.testConnection();
         DBManager.initializeDatabase();
         DiscordManager.login();
-        setTimers();
+        TimerManager.startAutoReimportTimer();
 
         Runtime.getRuntime().addShutdownHook(new Thread(() -> {
             logger.info("Received shut down signal. Bye!");
@@ -32,15 +28,4 @@ public class App {
 
         DiscordManager.onDisconnect();
     }
-
-    private static void setTimers() {
-        Calendar midday = Calendar.getInstance();
-        midday.set(Calendar.HOUR_OF_DAY, 12);
-        midday.set(Calendar.MINUTE, 30);
-        midday.set(Calendar.SECOND, 0);
-
-        Timer reimportCron = new Timer();
-        reimportCron.schedule(new AutoReimport(), midday.getTime(),
-                TimeUnit.MILLISECONDS.convert(12, TimeUnit.HOURS));
-    }
 }

app/src/main/java/xyz/vallat/louis/commands/Desinscription.java

@@ -3,6 +3,7 @@ package xyz.vallat.louis.commands;
 import discord4j.core.event.domain.message.MessageCreateEvent;
 import reactor.core.publisher.Mono;
 import xyz.vallat.louis.managers.database.StudentManager;
+import xyz.vallat.louis.timer.TimerManager;
 
 public class Desinscription extends Command {
 
@@ -16,6 +17,7 @@ public class Desinscription extends Command {
             if (event.getMessage().getAuthor().isEmpty() ||
                     !StudentManager.deleteFromSnowflake(event.getMessage().getAuthor().get().getId().asString()))
                 return channel.createMessage("On dirait que je ne t'ai pas dans ma base de données !");
+            TimerManager.cancelStudentTimer(event.getMessage().getAuthor().get().getId().asString());
             return channel.createMessage("C'est bon, tu n'es plus dans ma base de données ! :thumbs_up:");
         }).then().onErrorResume(t -> fatalError(event, t));
     }

app/src/main/java/xyz/vallat/louis/managers/calendar/CalendarManager.java

@@ -20,6 +20,7 @@ public final class CalendarManager {
 
     private static final Logger logger = LoggerFactory.getLogger(CalendarManager.class.getCanonicalName());
     public static final Calendar TZ_UTC = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
+    public static final Calendar TZ = Calendar.getInstance(TimeZone.getTimeZone("Europe/Paris"));
 
     private CalendarManager() {
     }

app/src/main/java/xyz/vallat/louis/managers/discord/DiscordManager.java

@@ -1,5 +1,6 @@
 package xyz.vallat.louis.managers.discord;
 
+import discord4j.common.util.Snowflake;
 import discord4j.core.DiscordClientBuilder;
 import discord4j.core.GatewayDiscordClient;
 import discord4j.core.event.domain.lifecycle.ReadyEvent;
@@ -26,7 +27,7 @@ public final class DiscordManager {
 
     static {
         commands.add(new Inscription(PREFIX + "inscription"));
-        commands.add(new Desinscription(PREFIX + "désincription"));
+        commands.add(new Desinscription(PREFIX + "désinscription"));
         commands.add(new Lien(PREFIX + "lien"));
         commands.add(new Version(PREFIX + "version"));
         commands.add(new Aide(PREFIX + "aide"));
@@ -66,6 +67,14 @@ public final class DiscordManager {
         registerDiscordCommands();
     }
 
+    public static Mono<Void> sendPrivateMessageToUser(String snowflake, String message) {
+        if (discordClient != null) {
+            Snowflake u = Snowflake.of(snowflake);
+            return discordClient.getUserById(u)
+                    .flatMap(user -> user.getPrivateChannel().flatMap(privateChannel -> privateChannel.createMessage(message))).then();
+        } else return Mono.empty();
+    }
+
     public static Mono<String> getClientImage() {
         if (discordClient == null) return Mono.empty();
         return discordClient.getSelf().map(User::getAvatarUrl);

app/src/main/java/xyz/vallat/louis/timer/TimerManager.java

@@ -0,0 +1,39 @@
+package xyz.vallat.louis.timer;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import xyz.vallat.louis.timer.tasks.AutoReimport;
+
+import java.util.*;
+import java.util.concurrent.TimeUnit;
+
+public final class TimerManager {
+
+    private static final Logger logger = LoggerFactory.getLogger(TimerManager.class.getCanonicalName());
+    private static final Map<String, List<Timer>> studentsTimers = new HashMap<>();
+
+    private TimerManager() {
+    }
+
+    public static void cancelStudentTimer(String snowflake) {
+        List<Timer> timers = studentsTimers.remove(snowflake);
+        for (Timer t : timers) {
+            try {
+                t.cancel();
+            } catch (Exception e) {
+                logger.warn("Got exception while cancelling student's timer:", e);
+            }
+        }
+    }
+
+    public static void startAutoReimportTimer() {
+        Calendar midday = Calendar.getInstance();
+        midday.set(Calendar.HOUR, 12);
+        midday.set(Calendar.MINUTE, 30);
+        midday.set(Calendar.SECOND, 0);
+
+        Timer reimportCron = new Timer();
+        reimportCron.schedule(new AutoReimport(), midday.getTime(),
+                TimeUnit.MILLISECONDS.convert(12, TimeUnit.HOURS));
+    }
+}

app/src/main/java/xyz/vallat/louis/timer/tasks/AutoReimport.java

@@ -1,4 +1,4 @@
-package xyz.vallat.louis.timertasks;
+package xyz.vallat.louis.timer.tasks;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

app/src/main/java/xyz/vallat/louis/timer/tasks/MessagePresence.java

@@ -0,0 +1,30 @@
+package xyz.vallat.louis.timer.tasks;
+
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import xyz.vallat.louis.environment.EnvironmentVariables;
+import xyz.vallat.louis.managers.discord.DiscordManager;
+
+import java.util.TimerTask;
+
+public class MessagePresence extends TimerTask {
+
+    private static final Logger logger = LoggerFactory.getLogger(MessagePresence.class.getCanonicalName());
+
+    private final String summary;
+    private final String snowflake;
+
+    public MessagePresence(String summary, String snowflake) {
+        this.summary = summary;
+        this.snowflake = snowflake;
+    }
+
+    @Override
+    public void run() {
+        logger.debug("Warning user {} for course '{}'.", snowflake, summary);
+        DiscordManager.sendPrivateMessageToUser(snowflake,
+                "Salut ! Tu as pensé à émarger pour ton cours de " + summary + " ? Le lien vers moodle est ici : " +
+                        System.getenv(EnvironmentVariables.MOODLE_PRESENCE_LINK.getValue())).subscribe();
+    }
+}