Initialize Nest configuration library.

.gitignore

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+# IDEA
+.idea/
+*.iml
+
+# Composer
+vendor/

composer.json

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+{
+	"version": "1.0",
+	"name": "nest/configuration",
+	"description": "Nest configuration service.",
+	"type": "library",
+	"authors": [
+		{
+			"name": "Madeorsk",
+			"email": "madeorsk@protonmail.com"
+		}
+	],
+	"autoload": {
+		"psr-4": {
+			"Nest\\Configuration\\": "src/"
+		}
+	},
+	"repositories": [
+		{
+			"type": "vcs",
+			"url": "https://code.zeptotech.net/Nest/Core"
+		}
+	],
+	"require": {
+		"php": "^8.3",
+		"nest/core": "dev-main"
+	}
+}

composer.lock

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+{
+    "_readme": [
+        "This file locks the dependencies of your project to a known state",
+        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
+        "This file is @generated automatically"
+    ],
+    "content-hash": "456694be683ba1dd09042acde50b7e2a",
+    "packages": [
+        {
+            "name": "nest/core",
+            "version": "dev-main",
+            "source": {
+                "type": "git",
+                "url": "https://code.zeptotech.net/Nest/Core",
+                "reference": "22296b8d7c8b528089189a8d9500395424cb6468"
+            },
+            "require": {
+                "php": "^8.3"
+            },
+            "default-branch": true,
+            "type": "library",
+            "autoload": {
+                "psr-4": {
+                    "Nest\\": "src/"
+                },
+                "files": [
+                    "src/Utils/Array.php",
+                    "src/Utils/Paths.php",
+                    "src/Utils/Reflection.php",
+                    "src/Utils/String.php"
+                ]
+            },
+            "authors": [
+                {
+                    "name": "Madeorsk",
+                    "email": "madeorsk@protonmail.com"
+                }
+            ],
+            "description": "Nest framework core.",
+            "time": "2024-11-08T11:12:38+00:00"
+        }
+    ],
+    "packages-dev": [],
+    "aliases": [],
+    "minimum-stability": "stable",
+    "stability-flags": {
+        "nest/core": 20
+    },
+    "prefer-stable": false,
+    "prefer-lowest": false,
+    "platform": {
+        "php": "^8.3"
+    },
+    "platform-dev": {},
+    "plugin-api-version": "2.6.0"
+}

src/Configuration.php

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+<?php
+
+namespace Nest\Configuration;
+
+use Nest\Application;
+use Nest\Configuration\Exceptions\ConfigurationValueNotFoundException;
+use function Nest\Utils\path_join;
+
+/**
+ * Nest configuration manager.
+ */
+class Configuration
+{
+	/**
+	 * Loaded files array.
+	 * @var string[]
+	 */
+	protected array $loadedFiles;
+
+	/**
+	 * The configuration main associative array.
+	 * @var array<string, mixed>
+	 */
+	protected array $config;
+
+	/**
+	 * Create a new configuration manager for the given application.
+	 * @param Application $application The application.
+	 */
+	public function __construct(protected Application $application)
+	{
+		$this->reload();
+	}
+
+	/**
+	 * Scan a configuration directory.
+	 * @param string $path The configuration directory path.
+	 * @param string|null $globalContextIdentifier The global context identifier to look for, if there is one.
+	 * @return void
+	 */
+	private function scanDirectory(string $path, ?string $globalContextIdentifier = null): void
+	{
+		// Get all files in the config path.
+		$files = scandir($path);
+
+		foreach ($files as $file)
+		{
+			if (is_file(path_join($path, $file)) && str_ends_with($file, ".php"))
+				// If it looks like a configuration file, we try to load it.
+				$this->loadedFiles[] = path_join($path, $file);
+
+			if (!empty($globalContextIdentifier) && is_dir(path_join($path, $file)) && $globalContextIdentifier == $file)
+			{ // If it looks like the global context custom configuration directory: we try to load all configuration files in it.
+				$this->scanDirectory(path_join($path, $file));
+			}
+		}
+	}
+
+	/**
+	 * Reload all configuration files in the configuration path.
+	 * @return void
+	 */
+	public function reload(): void
+	{
+		// Initialize loaded files array.
+		$this->loadedFiles = [];
+
+		// Scan the main configuration directory, searching for config files or global context custom config directory.
+		$this->scanDirectory($this->application->paths()->getConfigPath(), $this->application->getGlobalContextIdentifier());
+		sort($this->loadedFiles); // Sort files alphabetically.
+
+		// Reset configuration.
+		$this->config = [];
+
+		// Read all sorted configuration files.
+		foreach ($this->loadedFiles as $configFile)
+			$this->readConfigFile($configFile);
+	}
+
+	/**
+	 * Read a configuration file and merge it with the current configuration state.
+	 * @param string $filePath The configuration file path.
+	 * @return $this
+	 */
+	public function readConfigFile(string $filePath): static
+	{
+		// Read the configuration file.
+		$config = require $filePath;
+		// Merge the main configuration with the configuration we just read.
+		$this->config = array_merge($this->config, $config);
+
+		return $this;
+	}
+
+
+	/**
+	 * Recursive function to get a configuration value.
+	 * @param array $configuration Configuration array where to find the key.
+	 * @param string[] $key Configuration key to find the value.
+	 * @param string $fullKey Full configuration key.
+	 * @return mixed The configuration value for the given key.
+	 * @throws ConfigurationValueNotFoundException
+	 */
+	private static function _getValue(array $configuration, array $key, string $fullKey): mixed
+	{
+		// Get the currently looked key.
+		$currentKey = array_shift($key);
+
+		if (array_key_exists($currentKey, $configuration))
+		{ // Configuration key exists.
+			if (empty($key))
+			{ // We reached the value, returning it.
+				return $configuration[$currentKey];
+			}
+			else
+			{ // We must continue to search for the configuration value.
+
+				if (!is_array($configuration[$currentKey]))
+					// Cannot continue to search because currently pointed configuration value is not an array.
+					throw new ConfigurationValueNotFoundException($fullKey);
+
+				// Recursive call to get the requested value.
+				return static::_getValue($configuration[$currentKey], $key, $fullKey);
+			}
+		}
+		else
+		{ // Configuration key is missing.
+			throw new ConfigurationValueNotFoundException($fullKey);
+		}
+	}
+
+	/**
+	 * Get a value from the loaded configuration.
+	 * Throw an exception if the value is not present in configuration array.
+	 * @param string $key Full configuration key, with "." to explore the configuration tree.
+	 * @return mixed The value corresponding to the given key.
+	 * @throws ConfigurationValueNotFoundException
+	 */
+	public function getValue(string $key): mixed
+	{
+		// Split the key.
+		$explodedKey = explode(".", $key);
+		// Call recursive retrieval of the value.
+		return static::_getValue($this->config, $explodedKey, $key);
+	}
+
+	/**
+	 * Get a value from the loaded configuration.
+	 * @param string $key Full configuration key, with "." to explore the configuration tree.
+	 * @param mixed|null $default The default value, if there is none in the loaded configuration.
+	 * @return mixed The value corresponding to the given key.
+	 */
+	public function val(string $key, mixed $default = null): mixed
+	{
+		try
+		{ // Trying to get the value corresponding to the given key.
+			return $this->getValue($key);
+		}
+		catch (ConfigurationValueNotFoundException $exception)
+		{ // Value could not be found, returning the default value.
+			return $default;
+		}
+	}
+}

src/ConfigurationService.php

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+<?php
+
+namespace Nest\Configuration;
+
+/**
+ * Nest configuration service.
+ */
+trait ConfigurationService
+{
+	/**
+	 * The configuration instance.
+	 * @var Configuration
+	 */
+	private Configuration $configuration;
+
+	protected function __nest__ConfigurationService(): void
+	{
+		// Initialize the configuration instance.
+		$this->configuration = new Configuration($this);
+	}
+
+	/**
+	 * Configuration service.
+	 * @return Configuration The configuration manager.
+	 */
+	public function configuration(): Configuration
+	{
+		return $this->configuration;
+	}
+}

src/Exceptions/ConfigurationException.php

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+<?php
+
+namespace Nest\Configuration\Exceptions;
+
+use Nest\Exceptions\Exception;
+
+class ConfigurationException extends Exception
+{
+}

src/Exceptions/ConfigurationValueNotFoundException.php

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+<?php
+
+namespace Nest\Configuration\Exceptions;
+
+use Throwable;
+
+/**
+ * Exception thrown when a configuration value does not exists in configuration array.
+ */
+class ConfigurationValueNotFoundException extends ConfigurationException
+{
+	/**
+	 * @param string $key The configuration key not found.
+	 * @param int $code [optional] The Exception code.
+	 * @param null|Throwable $previous [optional] The previous throwable used for the exception chaining.
+	 */
+	public function __construct(public string $key, int $code = 0, ?Throwable $previous = null)
+	{
+		parent::__construct("Cannot find a configuration value for key \"$this->key\".", $code, $previous);
+	}
+}