<?php

namespace classes;

/**
 * Ensures additive schema for the customer `invoice_email` field
 * (TRU-77 / DRIFT 16). The field is optional and stores an
 * e-mail address that should receive the customer's invoices
 * separately from the customer's primary `email`.
 */
class customer_invoice_email_schema_bootstrap
{
    private static bool $initialized = false;
    private const TABLE = 'users';
    private const COLUMN = 'invoice_email';

    public static function ensureSchema(): void
    {
        if (self::$initialized) {
            return;
        }

        global $db;
        if (!isset($db) || !is_object($db) || !method_exists($db, 'query')) {
            return;
        }

        self::ensureUsersTable($db);
        self::ensureInvoiceEmailColumn($db);

        self::$initialized = true;
    }

    private static function ensureUsersTable(object $db): void
    {
        $db->query(
            "CREATE TABLE IF NOT EXISTS users (
                id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
                customer_number INT NOT NULL,
                display_name VARCHAR(255) NULL,
                email VARCHAR(255) NULL,
                phone_country_code INT NULL,
                phone BIGINT NULL,
                password VARCHAR(255) NULL,
                group_id INT NOT NULL DEFAULT 0,
                xlvask_customer_id VARCHAR(255) NULL,
                sms_notifications_enabled TINYINT(1) NOT NULL DEFAULT 0,
                email_notifications_enabled TINYINT(1) NOT NULL DEFAULT 0,
                wash_certificate_email VARCHAR(255) NULL,
                invoice_email VARCHAR(255) NULL,
                two_factor_enabled TINYINT(1) NOT NULL DEFAULT 0,
                two_factor_secret VARCHAR(255) NULL,
                created_at DATETIME NULL DEFAULT CURRENT_TIMESTAMP,
                updated_at DATETIME NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
                deleted_at DATETIME NULL,
                KEY idx_users_customer_number (customer_number),
                KEY idx_users_group_id (group_id)
            ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci"
        );
    }

    private static function ensureInvoiceEmailColumn(object $db): void
    {
        if (!self::tableExists($db, self::TABLE)) {
            return;
        }
        if (self::columnExists($db, self::TABLE, self::COLUMN)) {
            return;
        }

        $safeTable = str_replace('`', '', self::TABLE);
        $db->query(
            "ALTER TABLE `{$safeTable}`
                ADD COLUMN " . self::COLUMN . " VARCHAR(255) NULL
                AFTER wash_certificate_email"
        );
    }

    private static function tableExists(object $db, string $table): bool
    {
        $safeTable = str_replace('`', '', $table);
        $result = $db->query("SHOW TABLES LIKE '{$safeTable}'");
        return $result && (int)$result->num_rows > 0;
    }

    private static function columnExists(object $db, string $table, string $column): bool
    {
        $safeTable = str_replace('`', '', $table);
        $safeColumn = str_replace("'", '', $column);
        $result = $db->query("SHOW COLUMNS FROM `{$safeTable}` LIKE '{$safeColumn}'");
        return $result && (int)$result->num_rows > 0;
    }
}