second step

src/Config/ContextServiceConfig.php

@@ -1,12 +1,55 @@
 <?php
 
+declare(strict_types=1);
+
 namespace App\Config;
 
-class ContextServiceConfig
+/**
+ * YAML-backed context configuration.
+ *
+ * This class intentionally has no PHP fallback values. Missing or invalid
+ * configuration must be fixed in config/retriex/*.yaml instead of being hidden
+ * by application defaults.
+ */
+final class ContextServiceConfig
 {
-    //Number of lines included in regular context. Intended for normal conversational continuity.
-    public const MAX_VISIBLE_REGULAR_LINES = 25;
+    /**
+     * @param array<string, mixed> $config
+     */
+    public function __construct(private readonly array $config)
+    {
+    }
 
-    //Number of lines included in full context. Intended for exceptional or diagnostic scenarios.
-    public const MAX_FULL_LINES = 500;
-}
+    public function getMaxVisibleRegularLines(): int
+    {
+        return $this->requiredPositiveInt('max_visible_regular_lines');
+    }
+
+    public function getMaxFullLines(): int
+    {
+        return $this->requiredPositiveInt('max_full_lines');
+    }
+
+    private function requiredPositiveInt(string $key): int
+    {
+        if (!array_key_exists($key, $this->config)) {
+            throw new \InvalidArgumentException(sprintf('Missing required RetrieX context config key "%s".', $key));
+        }
+
+        $value = $this->config[$key];
+
+        if (is_int($value)) {
+            $intValue = $value;
+        } elseif (is_string($value) && preg_match('/^-?\d+$/', trim($value)) === 1) {
+            $intValue = (int) trim($value);
+        } else {
+            throw new \InvalidArgumentException(sprintf('RetrieX context config key "%s" must be an integer.', $key));
+        }
+
+        if ($intValue <= 0) {
+            throw new \InvalidArgumentException(sprintf('RetrieX context config key "%s" must be greater than 0.', $key));
+        }
+
+        return $intValue;
+    }
+}