Detect unwritable Paper configuration files

lang/en.json

@@ -121,5 +121,6 @@
   "paper-world-config-reset-solution": "Back up and delete the file 'paper-world.yml' of the world '{{world-name}}'. Paper creates it again with default settings.",
   "paper-install-newer-version-solution": "Install the newer Paper version that created this config file.",
   "mod-fabric-loader-version-problem": "The mod '{{mod-name}}' requires Fabric Loader version {{loader-version}} or later, but version {{installed-version}} is installed.",
-  "fabric-loader-update-solution": "Update Fabric Loader to version {{loader-version}} or later."
+  "fabric-loader-update-solution": "Update Fabric Loader to version {{loader-version}} or later.",
+  "paper-config-not-writable-problem": "The configuration file '{{path}}' could not be saved. Settings missing from the file use their default values."
 }

src/Analyser/PaperAnalyser.php

@@ -16,6 +16,7 @@
 use Aternos\Codex\Minecraft\Analysis\Problem\Paper\CircularPluginDependencyProblem;
 use Aternos\Codex\Minecraft\Analysis\Problem\Paper\RestrictedPluginNameProblem;
 use Aternos\Codex\Minecraft\Analysis\Problem\Paper\NewerConfigVersionProblem;
+use Aternos\Codex\Minecraft\Analysis\Problem\Paper\ConfigNotWritableProblem;
 
 class PaperAnalyser extends BukkitAnalyser
 {
@@ -36,5 +37,6 @@ public function __construct()
         $this->addPossibleInsightClass(CircularPluginDependencyProblem::class);
         $this->addPossibleInsightClass(RestrictedPluginNameProblem::class);
         $this->addPossibleInsightClass(NewerConfigVersionProblem::class);
+        $this->addPossibleInsightClass(ConfigNotWritableProblem::class);
     }
 }

src/Analysis/Problem/Paper/ConfigNotWritableProblem.php

@@ -0,0 +1,68 @@
+<?php
+
+namespace Aternos\Codex\Minecraft\Analysis\Problem\Paper;
+
+use Aternos\Codex\Analysis\InsightInterface;
+use Aternos\Codex\Minecraft\Analysis\Solution\Paper\PaperCheckPermissionsSolution;
+use Aternos\Codex\Minecraft\Translator\Translator;
+
+/**
+ * Paper could not save one of its configuration files because access was denied.
+ * Settings that are missing from the file only exist in memory with their default values.
+ *
+ * Paper only logs this message for an AccessDeniedException, other save errors are thrown instead.
+ */
+class ConfigNotWritableProblem extends PaperProblem
+{
+    protected string $path;
+
+    /**
+     * @inheritDoc
+     */
+    public function getMessage(): string
+    {
+        return Translator::getInstance()->getTranslation("paper-config-not-writable-problem", [
+            "path" => $this->path
+        ]);
+    }
+
+    /**
+     * Matches the warning Paper logs when saving a configuration file fails, for example:
+     * [16:52:55 WARN]: [Configurations] Could not save config/paper-global.yml: Paper could not persist the full set of configuration settings in the configuration file.
+     *
+     * @inheritDoc
+     */
+    public static function getPatterns(): array
+    {
+        return ['/Could not save (?<path>[^:\n]+): Paper could not persist the full set of configuration settings/'];
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function setMatches(array $matches, mixed $patternKey): void
+    {
+        $this->path = $matches["path"];
+        // Configurate saves atomically through a temporary file next to the configuration file,
+        // so the file and its folder both need to be writable.
+        $this->addSolution(new PaperCheckPermissionsSolution($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();
+    }
+}