Added support for depend in addon.yml

This enables add-ons that must load after another addon to mark it in
the depend line of addon.yml

src/main/java/world/bentobox/bentobox/api/addons/AddonClassLoader.java

@@ -4,6 +4,7 @@ import java.io.File;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLClassLoader;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -81,9 +82,13 @@ public class AddonClassLoader extends URLClassLoader {
     }
 
     private AddonDescription asDescription(YamlConfiguration data) {
-        return new AddonDescriptionBuilder(data.getString("name"))
+        AddonDescriptionBuilder adb = new AddonDescriptionBuilder(data.getString("name"))
                 .withVersion(data.getString("version"))
-                .withAuthor(data.getString("authors")).build();
+                .withAuthor(data.getString("authors"));
+        if (data.getString("depend") != null) {
+            adb.withDepend(Arrays.asList(data.getString("depend").split("\\s*,\\s*")));
+        }
+        return adb.build();
     }
 
 

src/main/java/world/bentobox/bentobox/api/addons/AddonDescription.java

@@ -1,5 +1,6 @@
 package world.bentobox.bentobox.api.addons;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
@@ -12,16 +13,18 @@ public final class AddonDescription {
     private String name;
     private String version;
     private String description;
-    private List<String> authors;
+    private List<String> authors = new ArrayList<>();
+    private List<String> depend = new ArrayList<>();
 
     public AddonDescription() {}
 
-    public AddonDescription(String main, String name, String version, String description, List<String> authors) {
+    public AddonDescription(String main, String name, String version, String description, List<String> authors, List<String> depend) {
         this.main = main;
         this.name = name;
         this.version = version;
         this.description = description;
         this.authors = authors;
+        this.depend = depend;
     }
 
     /**
@@ -59,6 +62,20 @@ public final class AddonDescription {
         this.authors = authors;
     }
 
+    /**
+     * @return the loadAfter
+     */
+    public List<String> getDependencies() {
+        return depend;
+    }
+
+    /**
+     * @param loadAfter the loadAfter to set
+     */
+    public void setLoadAfter(List<String> loadAfter) {
+        this.depend = loadAfter;
+    }
+
     public String getName() {
         return name;
     }
@@ -103,6 +120,11 @@ public final class AddonDescription {
             return this;
         }
 
+        public AddonDescriptionBuilder withDepend(List<String> addons) {
+            description.setLoadAfter(addons);
+            return this;
+        }
+
         public AddonDescription build(){
             return description;
         }

src/main/java/world/bentobox/bentobox/managers/AddonsManager.java

@@ -8,14 +8,18 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Enumeration;
 import java.util.HashMap;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
 
 import org.bukkit.Bukkit;
+import org.bukkit.configuration.InvalidConfigurationException;
 import org.bukkit.configuration.file.YamlConfiguration;
 
 import world.bentobox.bentobox.BentoBox;
@@ -29,7 +33,6 @@ import world.bentobox.bentobox.api.events.addon.AddonEvent;
  */
 public class AddonsManager {
 
-    private static final boolean DEBUG = false;
     private static final String LOCALE_FOLDER = "locales";
     private List<Addon> addons;
     private List<AddonClassLoader> loader;
@@ -40,21 +43,30 @@ public class AddonsManager {
         this.plugin = plugin;
         addons = new ArrayList<>();
         loader = new ArrayList<>();
+        loadAddonsFromFile();
     }
 
-    /**
+    public void loadAddonsFromFile() {
-     * Loads all the addons from the addons folder
-     */
-    public void loadAddons() {
         plugin.log("Loading addons...");
         File f = new File(plugin.getDataFolder(), "addons");
         if (!f.exists() && !f.mkdirs()) {
             plugin.logError("Cannot make addons folder!");
             return;
         }
-
         Arrays.stream(Objects.requireNonNull(f.listFiles())).filter(x -> !x.isDirectory() && x.getName().endsWith(".jar")).forEach(this::loadAddon);
-        addons.forEach(Addon::onLoad);
+        sortAddons();
+    }
+
+    /**
+     * Loads all the addons from the addons folder
+     */
+    public void loadAddons() {
+        // Run each onLoad
+        addons.forEach(addon -> {
+            addon.onLoad();
+            Bukkit.getPluginManager().callEvent(AddonEvent.builder().addon(addon).reason(AddonEvent.Reason.LOAD).build());
+            plugin.log("Loading " + addon.getDescription().getName() + "...");
+        });
         plugin.log("Loaded " + addons.size() + " addons.");
     }
 
@@ -81,24 +93,25 @@ public class AddonsManager {
         return addons.stream().filter(a -> a.getDescription().getName().contains(name)).findFirst();
     }
 
-    private void loadAddon(File f) {
+    private YamlConfiguration addonDescription(JarFile jar) throws InvalidAddonFormatException, IOException, InvalidConfigurationException {
-        try {
-            Addon addon;
-            // Check that this is a jar
-            if (!f.getName().endsWith(".jar")) {
-                throw new IOException("Filename must end in .jar. Name is '" + f.getName() + "'");
-            }
-            try (JarFile jar = new JarFile(f)) {
         // Obtain the addon.yml file
         JarEntry entry = jar.getJarEntry("addon.yml");
         if (entry == null) {
-                    throw new InvalidAddonFormatException("Addon '" + f.getName() + "' doesn't contains addon.yml file");
+            throw new InvalidAddonFormatException("Addon '" + jar.getName() + "' doesn't contains addon.yml file");
         }
         // Open a reader to the jar
         BufferedReader reader = new BufferedReader(new InputStreamReader(jar.getInputStream(entry)));
         // Grab the description in the addon.yml file
         YamlConfiguration data = new YamlConfiguration();
         data.load(reader);
+        return data;
+    }
+
+    private void loadAddon(File f) {
+        Addon addon;
+        try (JarFile jar = new JarFile(f)) {
+            // Get description in the addon.yml file
+            YamlConfiguration data = addonDescription(jar);
             // Load the addon
             AddonClassLoader addonClassLoader = new AddonClassLoader(this, data, f, this.getClass().getClassLoader());
             // Add to the list of loaders
@@ -120,18 +133,9 @@ public class AddonsManager {
             Bukkit.getPluginManager().callEvent(AddonEvent.builder().addon(addon).reason(AddonEvent.Reason.LOAD).build());
             // Add it to the list of addons
             addons.add(addon);
-
-                // Inform the console
-                plugin.log("Loaded addon " + addon.getDescription().getName() + "...");
         } catch (Exception e) {
             plugin.log(e.getMessage());
         }
-
-        } catch (Exception e) {
-            if (DEBUG) {
-                plugin.log(f.getName() + " is not a jarfile, ignoring...");
-            }
-        }
     }
 
     /**
@@ -212,4 +216,41 @@ public class AddonsManager {
         }
         return result;
     }
+
+    private void sortAddons() {
+        Map<String,Addon> sortedAddons = new LinkedHashMap<>();
+        Map<Addon, List<String>> remaining = new HashMap<>();
+        // Start with nodes with no dependencies
+        addons.stream().filter(a -> a.getDescription().getDependencies().isEmpty()).forEach(a -> sortedAddons.put(a.getDescription().getName(), a));
+        // Fill remaining
+        addons.stream().filter(a -> !a.getDescription().getDependencies().isEmpty()).forEach(a -> remaining.put(a, a.getDescription().getDependencies()));
+        // Run through remaining addons
+        int index = 0;
+        while (index < 10 && !remaining.isEmpty()) {
+            index++;
+            Iterator<Entry<Addon, List<String>>> it = remaining.entrySet().iterator();
+            while (it.hasNext()) {
+                Entry<Addon, List<String>> a = it.next();
+                // If the dependent addon is loaded
+                List<String> deps = new ArrayList<>(a.getValue());
+                Iterator<String> depIt = deps.iterator();
+                while(depIt.hasNext()) {
+                    String dep = depIt.next();
+                    if (sortedAddons.containsKey(dep)) {
+                        depIt.remove();
+                    }
+                }
+                if (deps.isEmpty()) {
+                    // Add addons loaded
+                    sortedAddons.put(a.getKey().getDescription().getName(), a.getKey());
+                    it.remove();
+                }
+            }
+        }
+        if (index == 10) {
+            plugin.logError("Circular dependency reference when loading addons");
+        }
+        addons.clear();
+        sortedAddons.values().forEach(addons::add);
+    }
 }