added ability to configure paginators to be used

added paginator for warnings command

abstracto-application/core/core-impl/src/main/java/dev/sheldan/abstracto/core/model/PaginatorConfiguration.java

@@ -0,0 +1,18 @@
+package dev.sheldan.abstracto.core.model;
+
+import lombok.Builder;
+import lombok.Getter;
+import lombok.Setter;
+
+import java.util.List;
+
+@Getter
+@Setter
+@Builder
+public class PaginatorConfiguration {
+    private String headerText;
+    private List<String> items;
+    private Long timeoutSeconds;
+    private Boolean showPageNumbers;
+    private Boolean useNumberedItems;
+}

abstracto-application/core/core-impl/src/main/java/dev/sheldan/abstracto/core/service/PaginatorServiceBean.java

@@ -0,0 +1,70 @@
+package dev.sheldan.abstracto.core.service;
+
+import com.google.gson.Gson;
+import com.jagrosh.jdautilities.commons.waiter.EventWaiter;
+import com.jagrosh.jdautilities.menu.Paginator;
+import dev.sheldan.abstracto.core.model.PaginatorConfiguration;
+import dev.sheldan.abstracto.templating.service.TemplateService;
+import net.dv8tion.jda.api.entities.MessageEmbed;
+import org.apache.commons.lang3.ObjectUtils;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+
+@Component
+public class PaginatorServiceBean implements PaginatorService {
+
+    @Autowired
+    private BotService botService;
+
+    @Autowired
+    private TemplateService templateService;
+
+    @Autowired
+    private Gson gson;
+
+
+    @Override
+    public Paginator createPaginatorFromTemplate(String templateKey, Object model, EventWaiter waiter) {
+        String embedConfig = templateService.renderTemplate(templateKey + "_paginator", model);
+        PaginatorConfiguration configuration = gson.fromJson(embedConfig, PaginatorConfiguration.class);
+        botService.getInstance().addEventListener(waiter);
+        List<String> items = configuration.getItems();
+        int itemsPerPage = findAppropriateCountPerPage(items);
+
+        return new Paginator.Builder()
+                .setItemsPerPage(itemsPerPage)
+                .setText(configuration.getHeaderText())
+                .showPageNumbers(ObjectUtils.defaultIfNull(configuration.getShowPageNumbers(), false))
+                .setItems(configuration.getItems().toArray(new String[0]))
+                .useNumberedItems(ObjectUtils.defaultIfNull(configuration.getUseNumberedItems(), false))
+                .setEventWaiter(waiter)
+                .setTimeout(ObjectUtils.defaultIfNull(configuration.getTimeoutSeconds(), 120L), TimeUnit.SECONDS)
+                .setFinalAction(message -> {
+                    botService.getInstance().removeEventListener(waiter);
+                    message.delete().queue();
+                })
+                .build();
+    }
+
+    private int findAppropriateCountPerPage(List<String> items) {
+        int currentMin = Integer.MAX_VALUE;
+        // to be sure, because the paginator adds some characters here and there
+        int carefulMax = MessageEmbed.TEXT_MAX_LENGTH - 50;
+        for (int i = 0; i < items.size(); i++) {
+            int count = 0;
+            int length = 0;
+            for (String innerItem : items) {
+                length += innerItem.length();
+                if (length > carefulMax) {
+                    currentMin = Math.min(currentMin, count);
+                    break;
+                }
+                count++;
+            }
+        }
+        return currentMin;
+    }
+}