<?php

/**
 * Collegamento al database di WordPress per The Newsletter.
 *
 * Usa un utente MySQL dedicato che può leggere/scrivere SOLO la tabella delle newsletter.
 * Variabili nel .env di YogiBook:
 *   WP_DB_HOST, WP_DB_NAME, WP_DB_USER, WP_DB_PASSWORD, WP_DB_PREFIX (default wp_),
 *   WP_ADMIN_URL (default https://yogasoul.it/wp-admin/)
 */
class NewsletterWp
{
    private static ?PDO $pdo = null;

    public static function isConfigured(): bool
    {
        return !empty($_ENV['WP_DB_NAME']) && !empty($_ENV['WP_DB_USER']);
    }

    public static function adminUrl(): string
    {
        return rtrim($_ENV['WP_ADMIN_URL'] ?? 'https://yogasoul.it/wp-admin/', '/') . '/admin.php?page=newsletter_emails_index';
    }

    private static function table(): string
    {
        $prefix = preg_replace('/[^a-zA-Z0-9_]/', '', $_ENV['WP_DB_PREFIX'] ?? 'wp_');
        return '`' . $prefix . 'newsletter_emails`';
    }

    private static function db(): PDO
    {
        if (!self::isConfigured()) {
            throw new RuntimeException('Collegamento a WordPress non configurato (manca WP_DB_* nel file .env).');
        }
        if (self::$pdo === null) {
            $host = $_ENV['WP_DB_HOST'] ?? 'localhost';
            $port = '3306';
            if (strpos($host, ':') !== false) {
                [$host, $port] = explode(':', $host, 2);
            }
            try {
                self::$pdo = new PDO(
                "mysql:host={$host};port={$port};dbname={$_ENV['WP_DB_NAME']};charset=utf8mb4",
                $_ENV['WP_DB_USER'],
                $_ENV['WP_DB_PASSWORD'] ?? '',
                [
                    PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
                    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
                    PDO::ATTR_TIMEOUT            => 5,
                ]
            );
            } catch (PDOException $e) {
                error_log('NewsletterWp: connessione fallita: ' . $e->getMessage());
                throw new RuntimeException('Collegamento al database di WordPress non riuscito: controlla WP_DB_* nel file .env.');
            }
        }
        return self::$pdo;
    }

    private static function unserializeOptions(?string $raw): array
    {
        if ($raw === null || $raw === '') return [];
        $o = @unserialize($raw, ['allowed_classes' => false]);
        return is_array($o) ? $o : [];
    }

    /** Ultime newsletter del plugin (per l'import e per lo stato). */
    public static function listEmails(int $limit = 30): array
    {
        $st = self::db()->prepare("SELECT id, subject, status, created, sent, total FROM " . self::table() . "
                                   WHERE type = 'message' ORDER BY id DESC LIMIT " . max(1, min(100, $limit)));
        $st->execute();
        return $st->fetchAll();
    }

    /** Stato di più newsletter in una sola query: [id => status]. */
    public static function statuses(array $ids): array
    {
        $ids = array_values(array_unique(array_filter(array_map('intval', $ids))));
        if (!$ids) return [];
        $ph = implode(',', array_fill(0, count($ids), '?'));
        $st = self::db()->prepare("SELECT id, status FROM " . self::table() . " WHERE id IN ($ph)");
        $st->execute($ids);
        $out = [];
        foreach ($st->fetchAll() as $r) $out[(int) $r['id']] = $r['status'];
        return $out;
    }

    /** Legge una newsletter del plugin e la converte in blocchi YogiBook. */
    public static function import(int $id): array
    {
        $st = self::db()->prepare("SELECT id, subject, message, options, editor FROM " . self::table() . " WHERE id = ?");
        $st->execute([$id]);
        $row = $st->fetch();
        if (!$row) {
            throw new RuntimeException('Newsletter non trovata in WordPress.');
        }

        $opts = self::unserializeOptions($row['options']);

        return [
            'subject'   => (string) $row['subject'],
            'preheader' => (string) ($opts['preheader'] ?? ''),
            'blocks'    => NewsletterRenderer::fromComposerHtml((string) $row['message']),
            'settings'  => NewsletterRenderer::settingsFromWpOptions($opts),
        ];
    }

    /**
     * Crea o aggiorna la bozza in The Newsletter.
     * Aggiorna solo se è ancora "new" (mai partita). Restituisce [id, created(bool)].
     */
    public static function push(?int $wpId, string $subject, string $preheader, string $html, string $text, array $settings): array
    {
        $db = self::db();
        $composerOpts = NewsletterRenderer::wpComposerOptions($settings);

        if ($wpId) {
            $st = $db->prepare("SELECT status, options FROM " . self::table() . " WHERE id = ?");
            $st->execute([$wpId]);
            $row = $st->fetch();

            if ($row) {
                if ($row['status'] !== 'new') {
                    throw new RuntimeException('In WordPress questa newsletter è già "' . $row['status'] . '": non la modifico. Duplica la bozza per crearne una nuova.');
                }

                // Mantiene tutto quello scelto in WordPress (liste, mittente, utm...)
                $opts = array_merge(self::unserializeOptions($row['options']), $composerOpts, ['preheader' => $preheader]);
                unset($opts['error_message']);

                $up = $db->prepare("UPDATE " . self::table() . "
                                    SET subject = ?, message = ?, message_text = ?, options = ?, editor = 2, updated = ?
                                    WHERE id = ? AND status = 'new'");
                $up->execute([$subject, $html, $text, serialize($opts), time(), $wpId]);

                return [$wpId, false];
            }
            // Cancellata in WordPress: la ricreiamo
        }

        // Nuova: il pubblico parte uguale all'ultima newsletter (si controlla in WordPress)
        $base = [];
        $last = $db->query("SELECT options FROM " . self::table() . " WHERE type = 'message' ORDER BY id DESC LIMIT 1")->fetchColumn();
        if ($last) {
            $prev = self::unserializeOptions($last);
            foreach (['status', 'wp_users', 'lists', 'lists_operator', 'lists_exclude', 'countries', 'regions', 'cities',
                      'sender_email', 'sender_name', 'text_message_mode', 'utm_source', 'utm_campaign', 'utm_medium', 'utm_term', 'utm_content'] as $k) {
                if (array_key_exists($k, $prev)) $base[$k] = $prev[$k];
            }
        }
        $opts = array_merge(['status' => 'C', 'wp_users' => '0', 'lists' => [], 'lists_operator' => 'or', 'lists_exclude' => []], $base, $composerOpts, ['preheader' => $preheader]);

        $ins = $db->prepare("INSERT INTO " . self::table() . "
            (language, subject, message, subject2, message2, name2, status, total, last_id, sent, track, list,
             type, query, editor, sex, theme, message_text, preferences, send_on, token, options, private, version, updated)
            VALUES ('', ?, ?, '', '', '', 'new', 0, 0, 0, 1, 0,
             'message', '', 2, '', '', ?, '', ?, '', ?, 0, '', ?)");
        $ins->execute([$subject, $html, $text, time(), serialize($opts), time()]);

        return [(int) $db->lastInsertId(), true];
    }
}