<?php
/**
 * Settings operations for the plugin.
 *
 * This class handles all settings operations, including getting and setting
 * plugin options.
 *
 * @package    QDR_Temporary_Shared_Storage
 * @since      1.0.0
 */
class QDR_TSS_Settings {

    /**
     * The single instance of the class.
     *
     * @var QDR_TSS_Settings
     * @since 1.0.0
     */
    protected static $_instance = null;

    /**
     * Option name for settings.
     *
     * @var string
     * @since 1.0.0
     */
    private $option_name = 'qdr_tss_settings';

    /**
     * Default settings.
     *
     * @var array
     * @since 1.0.0
     */
    private $defaults = array(
        'api_key' => '',
        'media_category' => 'shared-storage',
        'max_upload_size' => 1073741824, // 1GB default
    );

    /**
     * Current settings.
     *
     * @var array
     * @since 1.0.0
     */
    private $settings = array();

    /**
     * Main QDR_TSS_Settings Instance.
     *
     * Ensures only one instance of QDR_TSS_Settings is loaded or can be loaded.
     *
     * @since 1.0.0
     * @static
     * @return QDR_TSS_Settings - Main instance.
     */
    public static function instance() {
        if (is_null(self::$_instance)) {
            self::$_instance = new self();
        }
        return self::$_instance;
    }

    /**
     * QDR_TSS_Settings Constructor.
     */
    public function __construct() {
        $this->load_settings();
    }

    /**
     * Load settings from database.
     *
     * @since 1.0.0
     */
    public function load_settings() {
        $settings = get_option($this->option_name, array());
        
        // Generate API key if it doesn't exist
        if (empty($settings['api_key'])) {
            $settings['api_key'] = $this->generate_api_key();
        }
        
        $this->settings = wp_parse_args($settings, $this->defaults);
    }

    /**
     * Get all settings.
     *
     * @since 1.0.0
     * @return array The settings.
     */
    public function get_settings() {
        return $this->settings;
    }

    /**
     * Get a specific setting.
     *
     * @since 1.0.0
     * @param string $key     The setting key.
     * @param mixed  $default The default value if setting doesn't exist.
     * @return mixed The setting value.
     */
    public function get_setting($key, $default = null) {
        if (isset($this->settings[$key])) {
            return $this->settings[$key];
        }
        
        return $default !== null ? $default : (isset($this->defaults[$key]) ? $this->defaults[$key] : null);
    }

    /**
     * Update settings.
     *
     * @since 1.0.0
     * @param array $settings The settings to update.
     * @return bool True on success, false on failure.
     */
    public function update_settings($settings) {
        // Merge with existing settings
        $this->settings = wp_parse_args($settings, $this->settings);
        
        // Save to database
        $result = update_option($this->option_name, $this->settings);
        
        return $result;
    }

    /**
     * Update a specific setting.
     *
     * @since 1.0.0
     * @param string $key   The setting key.
     * @param mixed  $value The setting value.
     * @return bool True on success, false on failure.
     */
    public function update_setting($key, $value) {
        $this->settings[$key] = $value;
        
        // Save to database
        return update_option($this->option_name, $this->settings);
    }

    /**
     * Generate a random API key.
     *
     * @since 1.0.0
     * @return string The generated API key.
     */
    public function generate_api_key() {
        return wp_generate_password(32, false);
    }

    /**
     * Validate API key.
     *
     * @since 1.0.0
     * @param string $api_key The API key to validate.
     * @return bool True if valid, false otherwise.
     */
    public function validate_api_key($api_key) {
        return $api_key === $this->get_setting('api_key');
    }

    /**
     * Format bytes to human readable format.
     *
     * @since 1.0.0
     * @param int $bytes     The size in bytes.
     * @param int $precision The number of decimal places.
     * @return string Human readable size.
     */
    public function format_bytes($bytes, $precision = 2) {
        $units = array('B', 'KB', 'MB', 'GB', 'TB');
        
        $bytes = max($bytes, 0);
        $pow = floor(($bytes ? log($bytes) : 0) / log(1024));
        $pow = min($pow, count($units) - 1);
        
        $bytes /= pow(1024, $pow);
        
        return round($bytes, $precision) . ' ' . $units[$pow];
    }
}