<?php
/**
 * Error Handler & Monitoring
 *
 * Catches, logs, and reports errors to both local WP and remote backend.
 */

if (!defined('ABSPATH')) {
    exit;
}

class WPQuotePro_Error_Handler {

    private static $instance = null;
    private $error_count = 0;
    private $api_failures = [];

    public static function get_instance() {
        if (null === self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    public function __construct() {
        add_action('wp_loaded', [$this, 'register_error_handlers']);
    }

    public function register_error_handlers() {
        // 1.0.9: geen set_error_handler() en set_exception_handler() meer. Die
        // werkten voor de hele site: elke niet-afgevangen exception, ook van een
        // andere plugin of het thema, kwam hier terecht. PHP zag dan geen fatale
        // fout, dus WordPress toonde zijn pagina "Er is een kritieke fout" en de
        // herstelmodus niet; de bezoeker kreeg een lege pagina. Fouten van onze
        // eigen API-aanroepen komen er via log_api_failure() nog steeds in.

        // Admin notices for critical issues
        add_action('admin_notices', [$this, 'show_admin_notices']);
    }

    /**
     * Log API failure
     */
    public function log_api_failure($endpoint, $status_code, $error_message, $api_key = null) {
        $this->api_failures[] = [
            'timestamp' => current_time('mysql'),
            'endpoint' => $endpoint,
            'status_code' => $status_code,
            'error' => $error_message,
            'api_key' => $api_key ? substr($api_key, 0, 8) . '...' : null,
        ];

        // Keep only last 10 failures
        if (count($this->api_failures) > 10) {
            array_shift($this->api_failures);
        }

        // Log to local error log
        $this->log_error([
            'type' => 'api_failure',
            'level' => 'warn',
            'endpoint' => $endpoint,
            'status_code' => $status_code,
            'error' => $error_message,
        ]);

        // Report to backend if 3+ failures
        if (count($this->api_failures) >= 3) {
            $this->report_to_backend([
                'type' => 'api_failures',
                'count' => count($this->api_failures),
                'last_error' => end($this->api_failures),
            ]);
        }

        // Store in transient for admin notice
        set_transient('wpquotepro_api_error', [
            'endpoint' => $endpoint,
            'status' => $status_code,
            'message' => $error_message,
            'time' => current_time('mysql'),
        ], 12 * HOUR_IN_SECONDS);
    }

    /**
     * Generic error logging
     */
    private function log_error($data) {
        $this->error_count++;

        // Write to WordPress error log
        wpquotepro_log($data);

        // Store in transient for admin dashboard
        $errors = get_transient('wpquotepro_recent_errors') ?: [];
        array_push($errors, [
            'data' => $data,
            'time' => current_time('mysql'),
        ]);

        // Keep only last 20 errors
        if (count($errors) > 20) {
            array_shift($errors);
        }

        set_transient('wpquotepro_recent_errors', $errors, 24 * HOUR_IN_SECONDS);
    }

    /**
     * Report error to backend
     */
    public function report_to_backend($error_data) {
        $api_key = get_option('wpquotepro_api_key');
        $site_url = get_option('wpquotepro_site_url');

        if (!$api_key || !$site_url) {
            return;
        }

        $endpoint = WPQUOTEPRO_BACKEND_BASE . '/api/v1/plugin/report-error';
        if (!$endpoint) {
            return;
        }

        $body = array_merge([
            'api_key' => $api_key,
            'site_url' => $site_url,
            'plugin_version' => WPQUOTEPRO_VERSION,
            'php_version' => PHP_VERSION,
            'wordpress_version' => get_bloginfo('version'),
            'timestamp' => current_time('mysql'),
        ], $error_data);

        wp_remote_post($endpoint, [
            'timeout' => 5,
            'sslverify' => true,
            'body' => json_encode($body),
            'headers' => ['Content-Type' => 'application/json'],
            'blocking' => false,
        ]);
    }

    /**
     * Show admin notices for critical issues
     */
    public function show_admin_notices() {
        if (!current_user_can('manage_options')) {
            return;
        }

        // API error notice
        $api_error = get_transient('wpquotepro_api_error');
        if ($api_error) {
            ?>
            <div class="notice notice-error is-dismissible">
                <p>
                    <strong>GresQuote:</strong>
                    <?php
                    /* translators: %s: address of the GresQuote backend */
                    echo esc_html(sprintf(__('Cannot connect to the GresQuote backend (%s).', 'gresquote'), $api_error['endpoint']));
                    ?>
                    <?php esc_html_e('Status:', 'gresquote'); ?> <?php echo esc_html($api_error['status']); ?>
                </p>
            </div>
            <?php
        }

        // Configuration warning
        $api_key = get_option('wpquotepro_api_key');
        $site_url = get_option('wpquotepro_site_url');

        if (!$api_key) {
            ?>
            <div class="notice notice-warning is-dismissible">
                <p>
                    <strong>GresQuote:</strong>
                    <?php esc_html_e('API key not set.', 'gresquote'); ?>
                    <a href="<?php echo esc_url(admin_url('admin.php?page=wpquotepro-settings')); ?>"><?php esc_html_e('Settings →', 'gresquote'); ?></a>
                </p>
            </div>
            <?php
        }

        if (!$site_url) {
            ?>
            <div class="notice notice-warning is-dismissible">
                <p>
                    <strong>GresQuote:</strong>
                    <?php esc_html_e('Site URL not set.', 'gresquote'); ?>
                    <a href="<?php echo esc_url(admin_url('admin.php?page=wpquotepro-settings')); ?>"><?php esc_html_e('Settings →', 'gresquote'); ?></a>
                </p>
            </div>
            <?php
        }
    }

    /**
     * Get recent errors for diagnostics
     */
    public function get_recent_errors($limit = 10) {
        $errors = get_transient('wpquotepro_recent_errors') ?: [];
        return array_slice($errors, -$limit);
    }

    /**
     * Get API failure history
     */
    public function get_api_failures() {
        return $this->api_failures;
    }

    /**
     * Clear error history
     */
    public function clear_error_history() {
        delete_transient('wpquotepro_recent_errors');
        delete_transient('wpquotepro_api_error');
        $this->api_failures = [];
    }
}

// Initialize globally
WPQuotePro_Error_Handler::get_instance();