<?php
namespace Sodino\Core;

/**
 * Cache Manager
 * Handles caching with WordPress transients and custom database cache
 */
class Cache {
    private static $instance = null;
    private $memory_cache = [];
    
    public static function getInstance() {
        if (self::$instance === null) {
            self::$instance = new self();
        }
        return self::$instance;
    }
    
    /**
     * Get cached value
     */
    public function get($key, $group = 'sodino') {
        $full_key = $this->buildKey($key, $group);
        
        // Check memory cache first
        if (isset($this->memory_cache[$full_key])) {
            return $this->memory_cache[$full_key];
        }
        
        // Check WordPress transient
        $value = get_transient($full_key);
        
        if ($value !== false) {
            $this->memory_cache[$full_key] = $value;
            return $value;
        }
        
        return false;
    }
    
    /**
     * Set cached value
     */
    public function set($key, $value, $expiration = 3600, $group = 'sodino') {
        $full_key = $this->buildKey($key, $group);
        
        // Set in memory cache
        $this->memory_cache[$full_key] = $value;
        
        // Set in WordPress transient
        return set_transient($full_key, $value, $expiration);
    }
    
    /**
     * Delete cached value
     */
    public function delete($key, $group = 'sodino') {
        $full_key = $this->buildKey($key, $group);
        
        // Remove from memory cache
        unset($this->memory_cache[$full_key]);
        
        // Remove from WordPress transient
        return delete_transient($full_key);
    }
    
    /**
     * Clear all cache for a group
     */
    public function clearGroup($group = 'sodino') {
        global $wpdb;
        
        // Clear memory cache for group
        foreach ($this->memory_cache as $key => $value) {
            if (strpos($key, "sodino_{$group}_") === 0) {
                unset($this->memory_cache[$key]);
            }
        }
        
        // Clear transients for group
        $wpdb->query(
            $wpdb->prepare(
                "DELETE FROM {$wpdb->options} WHERE option_name LIKE %s",
                $wpdb->esc_like('_transient_sodino_' . $group . '_') . '%'
            )
        );
        
        $wpdb->query(
            $wpdb->prepare(
                "DELETE FROM {$wpdb->options} WHERE option_name LIKE %s",
                $wpdb->esc_like('_transient_timeout_sodino_' . $group . '_') . '%'
            )
        );
        
        return true;
    }
    
    /**
     * Clear all Sodino cache
     */
    public function clearAll() {
        global $wpdb;
        
        // Clear memory cache
        $this->memory_cache = [];
        
        // Clear all Sodino transients
        $wpdb->query(
            "DELETE FROM {$wpdb->options} WHERE option_name LIKE '_transient_sodino_%' OR option_name LIKE '_transient_timeout_sodino_%'"
        );
        
        return true;
    }
    
    /**
     * Remember pattern - get from cache or execute callback
     */
    public function remember($key, $callback, $expiration = 3600, $group = 'sodino') {
        $value = $this->get($key, $group);
        
        if ($value !== false) {
            return $value;
        }
        
        $value = call_user_func($callback);
        $this->set($key, $value, $expiration, $group);
        
        return $value;
    }
    
    /**
     * Build cache key
     */
    private function buildKey($key, $group) {
        return "sodino_{$group}_{$key}";
    }
}