<?php

namespace App\Services;

use Exception;

class FileStorage
{
	private string $basePath;

	public function __construct(?string $basePath = null)
	{
		// Default base path is the 'data' directory in the project root
		if ($basePath === null) {
			$this->basePath = realpath(__DIR__ . '/../../data');
		} else {
			$this->basePath = realpath($basePath);
		}

		if (!$this->basePath || !is_dir($this->basePath)) {
			throw new Exception("Invalid base path for FileStorage.");
		}
	}

	/**
	 * Safely resolves and validates a path within the base directory.
	 * Prevents path traversal attacks.
	 */
	private function resolvePath(string $path): string
	{
		$fullPath = $this->basePath . DIRECTORY_SEPARATOR . ltrim($path, DIRECTORY_SEPARATOR);
		$realPath = realpath(dirname($fullPath));

		if ($realPath === false || strpos($realPath, $this->basePath) !== 0) {
			throw new Exception("Security Alert: Path traversal attempt detected or invalid path: " . $path);
		}

		return $fullPath;
	}

	/**
	 * Saves an array as a JSON file.
	 */
	public function put(string $path, array $data): bool
	{
		$fullPath = $this->resolvePath($path);

		$json = json_encode($data, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE | JSON_THROW_ON_ERROR);

		if (file_put_contents($fullPath, $json) === false) {
			return false;
		}

		return true;
	}

	/**
	 * Reads a JSON file and returns it as an associative array.
	 */
	public function get(string $path): ?array
	{
		$fullPath = $this->resolvePath($path);

		if (!file_exists($fullPath)) {
			return null;
		}

		try {
			$content = file_get_contents($fullPath);
			if ($content === false) {
				return null;
			}

			return json_decode($content, true, 512, JSON_THROW_ON_ERROR);
		} catch (Exception $e) {
			return null;
		}
	}

	/**
	 * Checks if a file exists.
	 */
	public function exists(string $path): bool
	{
		try {
			$fullPath = $this->resolvePath($path);
			return file_exists($fullPath);
		} catch (Exception $e) {
			return false;
		}
	}

	/**
	 * Deletes a file.
	 */
	public function delete(string $path): bool
	{
		$fullPath = $this->resolvePath($path);

		if (file_exists($fullPath)) {
			return unlink($fullPath);
		}

		return false;
	}
}