Detect missing Paper world defaults file

lang/en.json

@@ -112,5 +112,7 @@
   "event-listener-missing-class-problem": "The plugin '{{plugin-name}}' could not register the event listener '{{listener}}', because the class '{{missing-class}}' it references does not exist.",
   "client-only-mod-problem": "The mod '{{mod-name}}' cannot run on a server. It is either a client-only mod or uses client-only code.",
   "circular-plugin-dependency-problem": "Circular plugin dependencies detected: {{cycle}}.",
-  "restricted-plugin-name-problem": "A plugin has a name that is not allowed."
+  "restricted-plugin-name-problem": "A plugin has a name that is not allowed.",
+  "paper-world-defaults-missing-problem": "The file '{{path}}' with the default world settings does not exist. Paper cannot load new worlds without it.",
+  "paper-world-defaults-restore-solution": "Restore the file '{{path}}' from a backup or restart the server to create it again with default values."
 }

src/Analyser/PaperAnalyser.php

@@ -15,6 +15,7 @@
 use Aternos\Codex\Minecraft\Analysis\Problem\Paper\EventListenerMissingClassProblem;
 use Aternos\Codex\Minecraft\Analysis\Problem\Paper\CircularPluginDependencyProblem;
 use Aternos\Codex\Minecraft\Analysis\Problem\Paper\RestrictedPluginNameProblem;
+use Aternos\Codex\Minecraft\Analysis\Problem\Paper\WorldDefaultsMissingProblem;
 
 class PaperAnalyser extends BukkitAnalyser
 {
@@ -34,5 +35,6 @@ public function __construct()
         $this->addPossibleInsightClass(EventListenerMissingClassProblem::class);
         $this->addPossibleInsightClass(CircularPluginDependencyProblem::class);
         $this->addPossibleInsightClass(RestrictedPluginNameProblem::class);
+        $this->addPossibleInsightClass(WorldDefaultsMissingProblem::class);
     }
 }

src/Analysis/Problem/Bukkit/PluginRuntimeProblem.php

@@ -2,6 +2,7 @@
 
 namespace Aternos\Codex\Minecraft\Analysis\Problem\Bukkit;
 
+use Aternos\Codex\Minecraft\Analysis\Problem\Paper\WorldDefaultsMissingProblem;
 use Aternos\Codex\Minecraft\Translator\Translator;
 
 class PluginRuntimeProblem extends PluginProblem
@@ -15,13 +16,19 @@ public function getMessage(): string
     }
 
     /**
+     * Matches exceptions in event handlers and scheduled tasks of a plugin, for example:
+     * Task #15 for Multiverse-Core v4.3.1 generated an exception
+     *
+     * Tasks that fail because Paper's world defaults file is missing are skipped,
+     * because {@see WorldDefaultsMissingProblem} reports the actual cause.
+     *
      * @inheritDoc
      */
     public static function getPatterns(): array
     {
         return [
             '/Could not pass event \w+ to (' . static::PLUGIN_NAME . ') .*/',
-            '/Task \S+ for (' . static::PLUGIN_NAME . ') \S+ generated an exception/'
+            '/Task \S+ for (' . static::PLUGIN_NAME . ') \S+ generated an exception(?!\n' . WorldDefaultsMissingProblem::EXCEPTION . ')/'
         ];
     }
 }

src/Analysis/Problem/Paper/WorldDefaultsMissingProblem.php

@@ -0,0 +1,74 @@
+<?php
+
+namespace Aternos\Codex\Minecraft\Analysis\Problem\Paper;
+
+use Aternos\Codex\Analysis\InsightInterface;
+use Aternos\Codex\Minecraft\Analysis\Solution\Paper\WorldDefaultsRestoreSolution;
+use Aternos\Codex\Minecraft\Translator\Translator;
+
+/**
+ * Paper could not create the configuration of a world, because config/paper-world-defaults.yml does not exist.
+ *
+ * Paper creates the file on startup and on /paper reload, so it is usually missing because it was
+ * removed while the server was running, and a plugin then created a new world.
+ */
+class WorldDefaultsMissingProblem extends PaperProblem
+{
+    /**
+     * Start of the exception Paper throws when the world defaults file is missing, for example:
+     * java.lang.IllegalStateException: World defaults configuration file 'config/paper-world-defaults.yml' doesn't exist
+     *
+     * Used to keep generic plugin problems from reporting the plugin that created the world.
+     */
+    public const string EXCEPTION = "java\.lang\.IllegalStateException: World defaults configuration file '";
+
+    protected string $path;
+
+    /**
+     * @inheritDoc
+     */
+    public function getMessage(): string
+    {
+        return Translator::getInstance()->getTranslation("paper-world-defaults-missing-problem", [
+            "path" => $this->path
+        ]);
+    }
+
+    /**
+     * Matches the exception Paper throws when it creates a world configuration without the defaults file, for example:
+     * java.lang.IllegalStateException: World defaults configuration file 'config/paper-world-defaults.yml' doesn't exist
+     *
+     * @inheritDoc
+     */
+    public static function getPatterns(): array
+    {
+        return ["/World defaults configuration file '(?<path>[^'\n]+)' doesn't exist/"];
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function setMatches(array $matches, mixed $patternKey): void
+    {
+        $this->path = $matches["path"];
+        $this->addSolution(new WorldDefaultsRestoreSolution($this->path));
+    }
+
+    /**
+     * @return string
+     */
+    public function getPath(): string
+    {
+        return $this->path;
+    }
+
+    /**
+     * @param InsightInterface $insight
+     * @return bool
+     */
+    public function isEqual(InsightInterface $insight): bool
+    {
+        return $insight instanceof static
+            && $this->getPath() === $insight->getPath();
+    }
+}

src/Analysis/Solution/Paper/WorldDefaultsRestoreSolution.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace Aternos\Codex\Minecraft\Analysis\Solution\Paper;
+
+use Aternos\Codex\Minecraft\Translator\Translator;
+
+/**
+ * Restore the missing world defaults file, either from a backup or by restarting the server,
+ * which creates it again with default values.
+ */
+class WorldDefaultsRestoreSolution extends PaperSolution
+{
+    /**
+     * @param string $path
+     */
+    public function __construct(protected string $path)
+    {
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function getMessage(): string
+    {
+        return Translator::getInstance()->getTranslation("paper-world-defaults-restore-solution", [
+            "path" => $this->path
+        ]);
+    }
+
+    /**
+     * @return string
+     */
+    public function getPath(): string
+    {
+        return $this->path;
+    }
+}