<?php
declare(strict_types=1);

namespace ROITheme\Shared\Infrastructure\Logging;

/**
 * DeprecationLogger - Sistema de logging para código deprecated
 *
 * RESPONSABILIDAD: Registrar uso de código legacy para análisis y migración
 *
 * FEATURES:
 * - Log en archivo de texto
 * - Almacenamiento en base de datos para reportes
 * - Niveles de severidad
 * - Deduplicación de entradas
 *
 * @package ROITheme\Infrastructure\Logging
 */
final class DeprecationLogger
{
    private static ?self $instance = null;
    private string $logFile;
    private \wpdb $wpdb;
    private string $tableName;
    private bool $enabled = true;

    private function __construct()
    {
        global $wpdb;
        $this->wpdb = $wpdb;
        $this->tableName = $wpdb->prefix . 'roi_theme_deprecation_log';

        $uploadDir = wp_upload_dir();
        $logDir = $uploadDir['basedir'] . '/roi-theme-logs';

        if (!file_exists($logDir)) {
            wp_mkdir_p($logDir);
        }

        $this->logFile = $logDir . '/deprecation-' . date('Y-m-d') . '.log';

        // Asegurar que la tabla existe
        $this->ensureTableExists();
    }

    /**
     * Get singleton instance
     */
    public static function getInstance(): self
    {
        if (self::$instance === null) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    /**
     * Log deprecation use
     *
     * @param string $class Class name
     * @param string $method Method name
     * @param array $args Arguments passed
     * @param string $replacement Suggested replacement
     * @param string $version Version deprecated in
     * @return void
     */
    public function log(
        string $class,
        string $method,
        array $args = [],
        string $replacement = '',
        string $version = '2.0.0'
    ): void {
        if (!$this->enabled) {
            return;
        }

        $logEntry = [
            'timestamp' => current_time('mysql'),
            'class' => $class,
            'method' => $method,
            'args' => json_encode($args),
            'replacement' => $replacement,
            'version' => $version,
            'backtrace' => $this->getSimplifiedBacktrace(),
            'url' => $this->getCurrentUrl(),
            'user_id' => get_current_user_id()
        ];

        // Log to file
        $this->logToFile($logEntry);

        // Log to database (with deduplication)
        $this->logToDatabase($logEntry);

        // Trigger action for external monitoring
        do_action('roi_theme_deprecation_logged', $logEntry);
    }

    /**
     * Get deprecation statistics
     *
     * @param int $days Number of days to analyze
     * @return array Statistics
     */
    public function getStatistics(int $days = 7): array
    {
        $since = date('Y-m-d H:i:s', strtotime("-{$days} days"));

        $sql = $this->wpdb->prepare(
            "SELECT
                class,
                method,
                COUNT(*) as usage_count,
                MAX(timestamp) as last_used,
                replacement
            FROM {$this->tableName}
            WHERE timestamp >= %s
            GROUP BY class, method, replacement
            ORDER BY usage_count DESC",
            $since
        );

        return $this->wpdb->get_results($sql, ARRAY_A) ?: [];
    }

    /**
     * Get most used deprecated methods
     *
     * @param int $limit Number of results
     * @return array Top deprecated methods
     */
    public function getTopDeprecated(int $limit = 10): array
    {
        $sql = $this->wpdb->prepare(
            "SELECT
                class,
                method,
                COUNT(*) as usage_count,
                replacement
            FROM {$this->tableName}
            GROUP BY class, method, replacement
            ORDER BY usage_count DESC
            LIMIT %d",
            $limit
        );

        return $this->wpdb->get_results($sql, ARRAY_A) ?: [];
    }

    /**
     * Clear old logs
     *
     * @param int $days Keep logs newer than this many days
     * @return int Number of deleted entries
     */
    public function clearOldLogs(int $days = 30): int
    {
        $since = date('Y-m-d H:i:s', strtotime("-{$days} days"));

        $deleted = $this->wpdb->query(
            $this->wpdb->prepare(
                "DELETE FROM {$this->tableName} WHERE timestamp < %s",
                $since
            )
        );

        return (int) $deleted;
    }

    /**
     * Enable/disable logging
     *
     * @param bool $enabled
     */
    public function setEnabled(bool $enabled): void
    {
        $this->enabled = $enabled;
    }

    /**
     * Log to file
     *
     * @param array $entry Log entry
     */
    private function logToFile(array $entry): void
    {
        $message = sprintf(
            "[%s] %s::%s() deprecated in v%s - Use %s instead\n",
            $entry['timestamp'],
            $entry['class'],
            $entry['method'],
            $entry['version'],
            $entry['replacement'] ?: 'see documentation'
        );

        if (!empty($entry['backtrace'])) {
            $message .= "  Called from: {$entry['backtrace']}\n";
        }

        if (!empty($entry['url'])) {
            $message .= "  URL: {$entry['url']}\n";
        }

        $message .= "  ---\n";

        error_log($message, 3, $this->logFile);
    }

    /**
     * Log to database with deduplication
     *
     * @param array $entry Log entry
     */
    private function logToDatabase(array $entry): void
    {
        // Check if same call was logged in last hour (deduplication)
        $hash = md5($entry['class'] . $entry['method'] . $entry['url']);
        $oneHourAgo = date('Y-m-d H:i:s', strtotime('-1 hour'));

        $exists = $this->wpdb->get_var(
            $this->wpdb->prepare(
                "SELECT id FROM {$this->tableName}
                WHERE call_hash = %s
                AND timestamp > %s
                LIMIT 1",
                $hash,
                $oneHourAgo
            )
        );

        if ($exists) {
            // Update count instead of creating new entry
            $this->wpdb->query(
                $this->wpdb->prepare(
                    "UPDATE {$this->tableName}
                    SET usage_count = usage_count + 1,
                        timestamp = %s
                    WHERE id = %d",
                    $entry['timestamp'],
                    $exists
                )
            );
            return;
        }

        // Insert new entry
        $this->wpdb->insert(
            $this->tableName,
            [
                'timestamp' => $entry['timestamp'],
                'class' => $entry['class'],
                'method' => $entry['method'],
                'args' => $entry['args'],
                'replacement' => $entry['replacement'],
                'version' => $entry['version'],
                'backtrace' => $entry['backtrace'],
                'url' => $entry['url'],
                'user_id' => $entry['user_id'],
                'call_hash' => $hash,
                'usage_count' => 1
            ],
            ['%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%d', '%s', '%d']
        );
    }

    /**
     * Get simplified backtrace
     *
     * @return string Simplified backtrace
     */
    private function getSimplifiedBacktrace(): string
    {
        $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 5);

        // Skip first 3 frames (this method, log method, deprecated function)
        $relevant = array_slice($trace, 3, 2);

        $parts = [];
        foreach ($relevant as $frame) {
            if (isset($frame['file']) && isset($frame['line'])) {
                $file = basename($frame['file']);
                $parts[] = "{$file}:{$frame['line']}";
            }
        }

        return implode(' -> ', $parts);
    }

    /**
     * Get current URL
     *
     * @return string Current URL
     */
    private function getCurrentUrl(): string
    {
        if (!isset($_SERVER['REQUEST_URI'])) {
            return '';
        }

        $scheme = is_ssl() ? 'https' : 'http';
        $host = $_SERVER['HTTP_HOST'] ?? 'localhost';
        $uri = $_SERVER['REQUEST_URI'] ?? '';

        return $scheme . '://' . $host . $uri;
    }

    /**
     * Ensure database table exists
     */
    private function ensureTableExists(): void
    {
        $charset_collate = $this->wpdb->get_charset_collate();

        $sql = "CREATE TABLE IF NOT EXISTS {$this->tableName} (
            id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
            timestamp datetime NOT NULL,
            class varchar(255) NOT NULL,
            method varchar(255) NOT NULL,
            args text,
            replacement varchar(255) DEFAULT '',
            version varchar(20) DEFAULT '2.0.0',
            backtrace text,
            url varchar(500) DEFAULT '',
            user_id bigint(20) unsigned DEFAULT 0,
            call_hash varchar(32) NOT NULL,
            usage_count int(11) DEFAULT 1,
            PRIMARY KEY  (id),
            KEY class_method (class, method),
            KEY timestamp (timestamp),
            KEY call_hash (call_hash)
        ) $charset_collate;";

        require_once(ABSPATH . 'wp-admin/includes/upgrade.php');
        dbDelta($sql);
    }

    /**
     * Prevent cloning
     */
    private function __clone() {}

    /**
     * Prevent unserialization
     */
    public function __wakeup()
    {
        throw new \Exception('Cannot unserialize singleton');
    }
}