Added some statistics on the maps list GUI.

* NEW: Added a book displaying statistics on the maps list GUI, with images rendered, Minecraft maps used, and Minecraft-maps-limits-related statistics if these limits exists.

src/main/java/fr/moribus/imageonmap/gui/list/MapListGui.java

@@ -18,6 +18,7 @@
 
 package fr.moribus.imageonmap.gui.list;
 
+import fr.moribus.imageonmap.*;
 import fr.moribus.imageonmap.gui.core.*;
 import fr.moribus.imageonmap.map.*;
 import fr.moribus.imageonmap.ui.MapItemManager;
@@ -27,6 +28,7 @@ import org.bukkit.event.inventory.*;
 import org.bukkit.inventory.*;
 import org.bukkit.inventory.meta.*;
 
+import java.text.*;
 import java.util.*;
 
 
@@ -34,6 +36,8 @@ public class MapListGui extends AbstractGui
 {
 	private final Integer MAPS_PER_PAGE = 7 * 3;
 
+	private final NumberFormat bigNumbersFormatter = new DecimalFormat("###,###,###,###", DecimalFormatSymbols.getInstance(Locale.ENGLISH));
+
 
 	private List<ImageMap> maps = new ArrayList<>();
 
@@ -56,6 +60,68 @@ public class MapListGui extends AbstractGui
 
 		player.openInventory(getInventory());
 
+
+		/* ** Statistics ** */
+
+		int imagesCount = MapManager.getMapList(player.getUniqueId()).size();
+		int mapPartCount = MapManager.getMapPartCount(player.getUniqueId());
+
+		int mapGlobalLimit = PluginConfiguration.MAP_GLOBAL_LIMIT.getInteger();
+		int mapPersonalLimit = PluginConfiguration.MAP_PLAYER_LIMIT.getInteger();
+
+		int mapPartGloballyLeft = mapGlobalLimit - MapManager.getMapCount();
+		int mapPartPersonallyLeft = mapPersonalLimit - mapPartCount;
+
+		int mapPartLeft;
+		if(mapGlobalLimit <= 0 && mapPersonalLimit <= 0)
+			mapPartLeft = -1;
+		else if(mapGlobalLimit <= 0)
+			mapPartLeft = mapPartPersonallyLeft;
+		else if(mapPersonalLimit <= 0)
+			mapPartLeft = mapPartGloballyLeft;
+		else
+			mapPartLeft = Math.min(mapPartGloballyLeft, mapPartPersonallyLeft);
+
+		double percentageUsed = mapPartLeft < 0 ? 0 : ((double) mapPartCount) / ((double) (mapPartCount + mapPartLeft)) * 100;
+
+
+		ItemStack statistics = new ItemStack(Material.ENCHANTED_BOOK);
+		ItemMeta meta = statistics.getItemMeta();
+
+		meta.setDisplayName(ChatColor.BLUE + "Usage statistics");
+		meta.setLore(Arrays.asList(
+				"",
+				getStatisticText("Images rendered", imagesCount),
+				getStatisticText("Minecraft maps used", mapPartCount)
+		));
+
+		if(mapPartLeft >= 0)
+		{
+			List<String> lore = meta.getLore();
+
+			lore.add("");
+			lore.add(ChatColor.BLUE + "Minecraft maps limits");
+
+			lore.add("");
+			lore.add(getStatisticText("Server-wide limit", mapGlobalLimit, true));
+			lore.add(getStatisticText("Per-player limit", mapPersonalLimit, true));
+
+			lore.add("");
+			lore.add(getStatisticText("Current consumption", ((int) Math.rint(percentageUsed)) + " %"));
+			lore.add(getStatisticText("Maps left", mapPartLeft));
+			lore.add("");
+
+			meta.setLore(lore);
+		}
+
+		GuiUtils.removeVanillaInfos(meta);
+
+		statistics.setItemMeta(meta);
+		setSlotData(statistics, inventory.getSize() - 5, "");
+
+
+		/* ** Maps ** */
+
 		update(player);
 	}
 
@@ -270,4 +336,19 @@ public class MapListGui extends AbstractGui
 
 		return icon;
 	}
+
+	private String getStatisticText(String title, Integer value)
+	{
+		return getStatisticText(title, value, false);
+	}
+
+	private String getStatisticText(String title, Integer value, boolean zeroIsUnlimited)
+	{
+		return getStatisticText(title, zeroIsUnlimited && value <= 0 ? "unlimited" : bigNumbersFormatter.format(value));
+	}
+
+	private String getStatisticText(String title, String value)
+	{
+		return ChatColor.GRAY + title + ": " + ChatColor.WHITE + value;
+	}
 }

src/main/java/fr/moribus/imageonmap/map/MapManager.java

@@ -138,6 +138,18 @@ abstract public class MapManager
     {
         return getPlayerMapStore(playerUUID).getMapList();
     }
+
+    /**
+     * Returns the number of minecraft maps used by the images rendered by the given player.
+     *
+     * @param playerUUID The player's UUID.
+     *
+     * @return The count.
+     */
+    static public int getMapPartCount(UUID playerUUID)
+    {
+        return getPlayerMapStore(playerUUID).getMapCount();
+    }
     
     static public ImageMap getMap(UUID playerUUID, String mapId)
     {
@@ -231,7 +243,12 @@ abstract public class MapManager
         }
         getPlayerMapStore(userUUID).checkMapLimit(newMapsCount);
     }
-    
+
+    /**
+     * Returns the total number of minecraft maps used by ImageOnMap images.
+     *
+     * @return The count.
+     */
     static public int getMapCount()
     {
         int mapCount = 0;