Resolve "Remove all use of GLOBALS"

Closes #13

classes/Configuration.php

+<?php declare(strict_types=1);
+
+namespace uib\ub\loadspeakr;
+
+use Exception;
+use UnexpectedValueException;
+
+final class Configuration
+{
+    private array $configs;
+
+    /**
+     * @throws Exception
+     */
+    public function __construct(array $conf)
+    {
+        if (count($conf) === 0) {
+            throw new Exception(
+              'Empty configuration. Giving up.'
+            );
+        }
+
+        $this->configs['conf'] = $conf;
+    }
+
+    public function getConfigValue(string $type, $key)
+    {
+        if (!$key) {
+            throw new UnexpectedValueException(
+              'Configuration key missing : ' . $key
+            );
+        }
+        if (!isset($this->configs[$type][$key])) {
+            throw new UnexpectedValueException(
+              'Missing config: ' . $type . ' of key: ' . $key
+            );
+        }
+
+        return $this->configs[$type][$key];
+    }
+
+    public function getConfigValues($type): array
+    {
+        if (!isset($this->configs[$type])) {
+            throw new UnexpectedValueException(
+              'Unknown configuration type: ' . $type
+            );
+        }
+
+        return $this->configs[$type];
+    }
+
+    public function debugMode(): bool
+    {
+        return $this->configs['conf']['debug'];
+    }
+
+    public function add(string $name, array $config): Configuration
+    {
+        $copy = clone $this;
+        $copy->configs[$name] = $config;
+
+        return $copy;
+    }
+
+}