<?php
/**
 * Setup wizard state and input normalization.
 *
 * @package Leanmerce\CommerceCompliance
 */

namespace Leanmerce\CommerceCompliance\Application\Setup;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

use Leanmerce\CommerceCompliance\WooCommerce\Emails\WooEmailEligibility;

final class SetupService {
	public const TOTAL_STEPS = 7;

	public function __construct( private SettingsRepository $repository ) {}

	/**
	 * @return array<string,mixed>
	 */
	public function get_settings(): array {
		return $this->repository->get_settings();
	}

	/**
	 * @return array<string,mixed>
	 */
	public function get_state(): array {
		return $this->repository->get_setup_state();
	}

	/**
	 * Save one wizard step. Input must already be unslashed by the request controller.
	 *
	 * @param int                 $step Step number.
	 * @param array<string,mixed> $input Raw step input.
	 * @return array<string,mixed>
	 */
	public function save_step( int $step, array $input, bool $advance = true ): array {
		$step     = max( 1, min( self::TOTAL_STEPS, $step ) );
		$settings = $this->repository->get_settings();

		switch ( $step ) {
			case 1:
				$settings['languages'] = $this->sanitize_languages( $input );
				break;
			case 2:
				$settings['merchant'] = array_replace( $settings['merchant'], $this->sanitize_merchant( $input ) );
				break;
			case 3:
				// Preserve dev.1/stable free-form contacts until the merchant replaces them
				// with the structured dev.2 fields.
				$input['complaints_contact'] = $input['complaints_contact'] ?? $settings['sales']['complaints_contact'];
				$input['returns_contact']    = $input['returns_contact'] ?? $settings['sales']['returns_contact'];
				$input['returns_address']    = $input['returns_address'] ?? $settings['sales']['returns_address'];
				foreach ( array( 'returns_recipient', 'returns_street', 'returns_postcode', 'returns_city', 'returns_country' ) as $return_field ) {
					$input[ $return_field ] = $input[ $return_field ] ?? $settings['sales'][ $return_field ];
				}
				$settings['sales']    = array_replace( $settings['sales'], $this->sanitize_sales( $input ) );
				$settings['merchant'] = array_replace( $settings['merchant'], $this->sanitize_supplier( $input ) );
				break;
			case 4:
				$settings['terms'] = array_replace( $settings['terms'], $this->sanitize_terms( $input ) );
				break;
			case 5:
				$settings['delivery']                                        = array_replace( $settings['delivery'], $this->sanitize_delivery( $input ) );
				$settings['sales']['payment_delivery_information_confirmed'] = SetupInputSchema::boolean( $input['payment_delivery_information_confirmed'] ?? false );
				break;
			case 6:
				$settings['documents'] = array_replace( $settings['documents'], $this->sanitize_documents( $input ) );
				break;
			case 7:
				break;
		}

		$this->repository->save_settings( $settings );
		$this->repository->clear_audit_cache();

		$next_step = $advance ? min( self::TOTAL_STEPS, $step + 1 ) : $step;
		$state     = array(
			'current_step' => $next_step,
			'completed'    => $advance && 7 === $step,
			'updated_at'   => $this->now_mysql(),
		);
		$this->repository->save_setup_state( $state );

		return $settings;
	}

	/**
	 * Validate submitted step data without changing stored state.
	 *
	 * @param int                 $step Step number.
	 * @param array<string,mixed> $input Unslashed step input.
	 * @param bool                $for_completion Include merchant declarations required for readiness.
	 * @return array<int,array{field:string,code:string}>
	 */
	public function validate_step( int $step, array $input, bool $for_completion = false, array $facts = array() ): array {
		$errors = array();
		$step   = max( 1, min( self::TOTAL_STEPS, $step ) );

		if ( 1 === $step ) {
			$supported = array_keys( LanguageCatalog::supported() );
			foreach ( array( 'admin_language', 'default_document_language' ) as $field ) {
				if ( ! in_array( $this->text( $input[ $field ] ?? '' ), $supported, true ) ) {
					$errors[] = array(
						'field' => $field,
						'code'  => 'language',
					);
				}
			}
			$enabled = isset( $input['enabled_customer_languages'] ) && is_array( $input['enabled_customer_languages'] ) ? $input['enabled_customer_languages'] : array();
			if ( empty( array_intersect( $supported, array_map( array( $this, 'text' ), $enabled ) ) ) ) {
				$errors[] = array(
					'field' => 'enabled_customer_languages',
					'code'  => 'customer_languages',
				);
			}
		}

		if ( 2 === $step ) {
			foreach ( array( 'legal_name', 'registration_authority', 'address', 'city', 'postcode', 'phone', 'establishment' ) as $field ) {
				if ( '' === trim( $this->text( $input[ $field ] ?? '' ) ) ) {
					$errors[] = array(
						'field' => $field,
						'code'  => 'required',
					);
				}
			}
			foreach ( array( 'registration_number', 'tax_id' ) as $field ) {
				$value = trim( $this->text( $input[ $field ] ?? '' ) );
				if ( '' === $value ) {
					$errors[] = array(
						'field' => $field,
						'code'  => 'required',
					);
				} elseif ( ! preg_match( '/^[\p{L}\p{N} .\/\-]{2,64}$/u', $value ) ) {
					$errors[] = array(
						'field' => $field,
						'code'  => 'identifier',
					);
				}
			}
			$email = is_scalar( $input['email'] ?? null ) ? trim( (string) $input['email'] ) : '';
			if ( '' === $email ) {
				$errors[] = array(
					'field' => 'email',
					'code'  => 'required',
				);
			} elseif ( ! $this->is_valid_email( $email ) ) {
				$errors[] = array(
					'field' => 'email',
					'code'  => 'email',
				);
			}
			$site = is_scalar( $input['site'] ?? null ) ? trim( (string) $input['site'] ) : '';
			if ( '' !== $site && ! filter_var( $site, FILTER_VALIDATE_URL ) ) {
				$errors[] = array(
					'field' => 'site',
					'code'  => 'url',
				);
			}
			if ( SetupInputSchema::boolean( $input['vat_registered'] ?? false ) && '' === trim( $this->text( $input['vat_number'] ?? '' ) ) ) {
				$errors[] = array(
					'field' => 'vat_number',
					'code'  => 'required',
				);
			}
		}

		if ( 3 === $step ) {
			$complaints_email = trim( $this->text( $input['complaints_email'] ?? '' ) );
			$complaints_phone = trim( $this->text( $input['complaints_phone'] ?? '' ) );
			$legacy_complaint = trim( $this->text( $input['complaints_contact'] ?? '' ) );
			if ( '' === $complaints_email && '' === $complaints_phone && '' === $legacy_complaint ) {
				$errors[] = array(
					'field' => 'complaints_email',
					'code'  => 'complaints_channel',
				);
			} elseif ( '' !== $complaints_email && ! $this->is_valid_email( $complaints_email ) ) {
				$errors[] = array(
					'field' => 'complaints_email',
					'code'  => 'email',
				);
			}

			$same_returns    = SetupInputSchema::boolean( $input['returns_same_as_complaints'] ?? false );
			$returns_email   = trim( $this->text( $input['returns_email'] ?? '' ) );
			$returns_phone   = trim( $this->text( $input['returns_phone'] ?? '' ) );
			$returns_address = trim( $this->text( $input['returns_address'] ?? '' ) );
			$legacy_returns  = trim( $this->text( $input['returns_contact'] ?? '' ) );
			$use_merchant    = SetupInputSchema::boolean( $input['returns_use_merchant_address'] ?? false );
			$address_fields  = array( 'returns_recipient', 'returns_street', 'returns_postcode', 'returns_city', 'returns_country' );
			$address_values  = array();
			foreach ( $address_fields as $field ) {
				$address_values[ $field ] = trim( $this->text( $input[ $field ] ?? '' ) );
			}
			$has_structured_address = ! empty( array_filter( $address_values, static fn( string $value ): bool => '' !== $value ) );
			if ( $has_structured_address && ! $use_merchant ) {
				foreach ( $address_values as $field => $value ) {
					if ( '' === $value ) {
						$errors[] = array(
							'field' => $field,
							'code'  => 'required',
						);
					}
				}
			}
			if ( ! $same_returns && '' === $returns_email && '' === $returns_phone && '' === $returns_address && '' === $legacy_returns && ! $use_merchant && ! $has_structured_address ) {
				$errors[] = array(
					'field' => 'returns_email',
					'code'  => 'returns_channel',
				);
			} elseif ( '' !== $returns_email && ! $this->is_valid_email( $returns_email ) ) {
				$errors[] = array(
					'field' => 'returns_email',
					'code'  => 'email',
				);
			}
			$relationship = $this->text( $input['supplier_relationship'] ?? 'SAME_AS_MERCHANT' );
			if ( 'SEPARATE_CONTRACT_SUPPLIER' === $relationship ) {
				$name  = trim( $this->text( $input['separate_supplier_name'] ?? '' ) );
				$email = is_scalar( $input['separate_supplier_email'] ?? null ) ? trim( (string) $input['separate_supplier_email'] ) : '';
				if ( '' === $name || ! $this->is_valid_email( $email ) ) {
					$errors[] = array(
						'field' => 'separate_supplier_name',
						'code'  => 'supplier',
					);
				}
			}
			if ( $for_completion ) {
				foreach ( array( 'distance_sale_registration_confirmed', 'physical_goods_scope_confirmed', 'offer_validity_configured', 'warranty_information_configured' ) as $field ) {
					if ( ! SetupInputSchema::boolean( $input[ $field ] ?? false ) ) {
						$errors[] = array(
							'field' => $field,
							'code'  => 'declaration',
						);
					}
				}
			}
		}

		if ( 4 === $step ) {
			$mode = $this->text( $input['contract_formation_mode'] ?? '' );
			if ( ! empty( $facts ) && ( empty( $facts['terms_page_id'] ) || 'publish' !== (string) ( $facts['terms_page_status'] ?? '' ) || empty( $facts['terms_page_url_present'] ) ) ) {
				$errors[] = array(
					'field' => 'terms_page',
					'code'  => 'terms_page',
				);
			}
			$status   = $this->key( $input['contract_formation_status'] ?? '' );
			$statuses = isset( $facts['order_statuses'] ) && is_array( $facts['order_statuses'] ) ? $facts['order_statuses'] : array();
			if ( 'ORDER_STATUS' === $mode && '' === trim( $status ) ) {
				$errors[] = array(
					'field' => 'contract_formation_status',
					'code'  => 'contract_status',
				);
			} elseif ( 'ORDER_STATUS' === $mode && ! empty( $facts ) && ! isset( $statuses[ $status ] ) ) {
				$errors[] = array(
					'field' => 'contract_formation_status',
					'code'  => 'contract_status_missing',
				);
			}
			if ( 'CUSTOM_PROVIDER' === $mode && '' === trim( $this->key( $input['contract_formation_provider'] ?? '' ) ) ) {
				$errors[] = array(
					'field' => 'contract_formation_provider',
					'code'  => 'contract_provider',
				);
			}
			if ( $for_completion ) {
				foreach ( array( 'order_process_information_confirmed', 'terms_accessible_saveable_confirmed', 'rs_payment_obligation_confirmed' ) as $field ) {
					if ( ! SetupInputSchema::boolean( $input[ $field ] ?? false ) ) {
						$errors[] = array(
							'field' => $field,
							'code'  => 'declaration',
						);
					}
				}
			}
		}

		if ( 5 === $step ) {
			$email_id = $this->key( $input['customer_email_id'] ?? '' );
			if ( '' === trim( $email_id ) ) {
				$errors[] = array(
					'field' => 'customer_email_id',
					'code'  => 'required',
				);
			} elseif ( ! empty( $facts ) && ! $this->email_is_eligible( $email_id, (array) ( $facts['customer_emails'] ?? array() ) ) ) {
				$errors[] = array(
					'field' => 'customer_email_id',
					'code'  => 'email_route',
				);
			}
			if ( $for_completion && ! SetupInputSchema::boolean( $input['payment_delivery_information_confirmed'] ?? false ) ) {
				$errors[] = array(
					'field' => 'payment_delivery_information_confirmed',
					'code'  => 'declaration',
				);
			}
		}

		if ( 6 === $step && SetupInputSchema::boolean( $input['basic_pdf_enabled'] ?? false ) ) {
			$email_id = $this->key( $input['basic_pdf_email_id'] ?? '' );
			if ( '' === trim( $email_id ) ) {
				$errors[] = array(
					'field' => 'basic_pdf_email_id',
					'code'  => 'required',
				);
			} elseif ( ! empty( $facts ) && ! $this->email_is_eligible( $email_id, (array) ( $facts['customer_emails'] ?? array() ) ) ) {
				$errors[] = array(
					'field' => 'basic_pdf_email_id',
					'code'  => 'email_route',
				);
			}
		}

		return $errors;
	}

	/** @return array<int,array{field:string,code:string,step:int}> */
	public function validate_completion( array $facts = array() ): array {
		$settings = $this->repository->get_settings();
		$inputs   = $this->settings_as_step_inputs( $settings );
		$errors   = array();

		foreach ( range( 1, 6 ) as $step ) {
			foreach ( $this->validate_step( $step, $inputs[ $step ], true, $facts ) as $error ) {
				$error['step'] = $step;
				$errors[]      = $error;
			}
		}
		return $errors;
	}

	/** @return array<int,bool> Current server-authoritative completion state for steps 1-6. */
	public function step_completion( array $facts = array() ): array {
		$inputs = $this->settings_as_step_inputs( $this->repository->get_settings() );
		$status = array();
		foreach ( range( 1, 6 ) as $step ) {
			$status[ $step ] = empty( $this->validate_step( $step, $inputs[ $step ], true, $facts ) );
		}
		return $status;
	}

	/**
	 * Mark wizard complete after a successful final save/audit visit.
	 */
	public function mark_complete(): void {
		$state                 = $this->repository->get_setup_state();
		$state['current_step'] = self::TOTAL_STEPS;
		$state['completed']    = true;
		$state['updated_at']   = $this->now_mysql();
		$this->repository->save_setup_state( $state );
	}

	/**
	 * Seed safe convenience values from Woo/WordPress only when corresponding fields are empty.
	 * Legal identity fields remain merchant-confirmed inputs.
	 *
	 * @param array<string,mixed> $environment Detected environment facts.
	 */
	public function prefill_from_environment( array $environment, bool $persist = true ): array {
		$settings = $this->repository->get_settings();
		$changed  = false;

		$locale = isset( $environment['site_locale'] ) ? (string) $environment['site_locale'] : '';
		if ( '' !== $locale && empty( $settings['languages']['admin_language'] ) ) {
			$settings['languages']['admin_language'] = LanguageCatalog::normalize_locale( $locale );
			$changed                                 = true;
		}

		$prefills = array(
			'address'  => $environment['store_address'] ?? '',
			'city'     => $environment['store_city'] ?? '',
			'postcode' => $environment['store_postcode'] ?? '',
			'email'    => $environment['admin_email'] ?? '',
			'site'     => $environment['site_url'] ?? '',
		);

		foreach ( $prefills as $key => $value ) {
			if ( '' === (string) $settings['merchant'][ $key ] && '' !== (string) $value ) {
				$settings['merchant'][ $key ] = (string) $value;
				$changed                      = true;
			}
		}

		if ( $changed && $persist ) {
			$this->repository->save_settings( $settings );
		}
		return $settings;
	}

	/** @return array<string,mixed> */
	private function sanitize_languages( array $input ): array {
		$supported = array_keys( LanguageCatalog::supported() );
		$admin     = $this->choice( $input['admin_language'] ?? '', $supported, LanguageCatalog::BOSNIAN );
		if ( SetupInputSchema::boolean( $input['initialize_language_defaults'] ?? false ) ) {
			return array(
				'admin_language'             => $admin,
				'default_document_language'  => $admin,
				'enabled_customer_languages' => array( $admin ),
			);
		}
		$document = $this->choice( $input['default_document_language'] ?? '', $supported, LanguageCatalog::BOSNIAN );
		$enabled  = isset( $input['enabled_customer_languages'] ) && is_array( $input['enabled_customer_languages'] ) ? $input['enabled_customer_languages'] : array();
		$enabled  = array_values( array_unique( array_intersect( $supported, array_map( array( $this, 'text' ), $enabled ) ) ) );

		if ( empty( $enabled ) ) {
			$enabled = array( $document );
		}
		if ( ! in_array( $document, $enabled, true ) ) {
			$enabled[] = $document;
		}

		return array(
			'admin_language'             => $admin,
			'default_document_language'  => $document,
			'enabled_customer_languages' => $enabled,
		);
	}

	/** @return array<string,mixed> */
	private function sanitize_merchant( array $input ): array {
		$establishment = $this->choice( $input['establishment'] ?? '', array( 'FBIH', 'RS', 'BD' ), '' );
		return array(
			'legal_name'             => $this->text( $input['legal_name'] ?? '' ),
			'registered_name'        => $this->text( $input['registered_name'] ?? '' ),
			'registration_number'    => $this->text( $input['registration_number'] ?? '' ),
			'registration_authority' => $this->text( $input['registration_authority'] ?? '' ),
			'tax_id'                 => $this->text( $input['tax_id'] ?? '' ),
			'vat_registered'         => SetupInputSchema::boolean( $input['vat_registered'] ?? false ),
			'vat_number'             => $this->text( $input['vat_number'] ?? '' ),
			'address'                => $this->multiline( $input['address'] ?? '' ),
			'city'                   => $this->text( $input['city'] ?? '' ),
			'postcode'               => $this->text( $input['postcode'] ?? '' ),
			'country'                => 'BA',
			'phone'                  => $this->text( $input['phone'] ?? '' ),
			'email'                  => $this->email( $input['email'] ?? '' ),
			'site'                   => $this->url( $input['site'] ?? '' ),
			'establishment'          => $establishment,
		);
	}

	/** @return array<string,mixed> */
	private function sanitize_sales( array $input ): array {
		$complaints_email   = $this->email( $input['complaints_email'] ?? '' );
		$complaints_phone   = $this->text( $input['complaints_phone'] ?? '' );
		$legacy_complaint   = $this->text( $input['complaints_contact'] ?? '' );
		$complaints_contact = $this->join_contact( $complaints_email, $complaints_phone, '', $legacy_complaint );
		$same_returns       = SetupInputSchema::boolean( $input['returns_same_as_complaints'] ?? false );
		$returns_email      = $this->email( $input['returns_email'] ?? '' );
		$returns_phone      = $this->text( $input['returns_phone'] ?? '' );
		$returns_address    = $this->multiline( $input['returns_address'] ?? '' );
		$legacy_returns     = $this->text( $input['returns_contact'] ?? '' );
		$use_merchant       = SetupInputSchema::boolean( $input['returns_use_merchant_address'] ?? false );
		$returns_contact    = $same_returns ? $complaints_contact : $this->join_contact( $returns_email, $returns_phone, $returns_address, $legacy_returns );
		return array(
			'distance_sale_registration_confirmed' => SetupInputSchema::boolean( $input['distance_sale_registration_confirmed'] ?? false ),
			'physical_goods_scope_confirmed'       => SetupInputSchema::boolean( $input['physical_goods_scope_confirmed'] ?? false ),
			'complaints_contact'                   => $complaints_contact,
			'returns_contact'                      => $returns_contact,
			'complaints_email'                     => $complaints_email,
			'complaints_phone'                     => $complaints_phone,
			'returns_same_as_complaints'           => $same_returns,
			'returns_email'                        => $returns_email,
			'returns_phone'                        => $returns_phone,
			'returns_address'                      => $returns_address,
			'returns_use_merchant_address'         => $use_merchant,
			'returns_recipient'                    => $this->text( $input['returns_recipient'] ?? '' ),
			'returns_street'                       => $this->multiline( $input['returns_street'] ?? '' ),
			'returns_postcode'                     => $this->text( $input['returns_postcode'] ?? '' ),
			'returns_city'                         => $this->text( $input['returns_city'] ?? '' ),
			'returns_country'                      => $this->text( $input['returns_country'] ?? '' ),
			'offer_validity_configured'            => SetupInputSchema::boolean( $input['offer_validity_configured'] ?? false ),
			'warranty_information_configured'      => SetupInputSchema::boolean( $input['warranty_information_configured'] ?? false ),
			'sells_across_bih'                     => SetupInputSchema::boolean( $input['sells_across_bih'] ?? false ),
			'cross_entity_mode'                    => 'PRECAUTIONARY_UNION',
		);
	}

	/** @return array<string,mixed> */
	private function sanitize_supplier( array $input ): array {
		$relationship = $this->choice(
			$input['supplier_relationship'] ?? 'SAME_AS_MERCHANT',
			array( 'SAME_AS_MERCHANT', 'SEPARATE_CONTRACT_SUPPLIER' ),
			'SAME_AS_MERCHANT'
		);
		return array(
			'supplier_relationship'   => $relationship,
			'separate_supplier_name'  => $this->text( $input['separate_supplier_name'] ?? '' ),
			'separate_supplier_email' => $this->email( $input['separate_supplier_email'] ?? '' ),
		);
	}

	/** @return array<string,mixed> */
	private function sanitize_terms( array $input ): array {
		$mode = $this->choice(
			$input['contract_formation_mode'] ?? 'ORDER_CREATED',
			array( 'ORDER_CREATED', 'PAYMENT_COMPLETED', 'ORDER_STATUS', 'CUSTOM_PROVIDER' ),
			'ORDER_CREATED'
		);
		return array(
			'contract_formation_mode'             => $mode,
			'contract_formation_status'           => $this->key( $input['contract_formation_status'] ?? '' ),
			'contract_formation_provider'         => $this->key( $input['contract_formation_provider'] ?? '' ),
			'order_process_information_confirmed' => SetupInputSchema::boolean( $input['order_process_information_confirmed'] ?? false ),
			'terms_accessible_saveable_confirmed' => SetupInputSchema::boolean( $input['terms_accessible_saveable_confirmed'] ?? false ),
			'rs_payment_obligation_confirmed'     => SetupInputSchema::boolean( $input['rs_payment_obligation_confirmed'] ?? false ),
		);
	}

	/** @return array<string,mixed> */
	private function sanitize_delivery( array $input ): array {
		return array(
			'completed_means_dispatched' => SetupInputSchema::boolean( $input['completed_means_dispatched'] ?? false ),
			'customer_email_id'          => $this->key( $input['customer_email_id'] ?? 'customer_processing_order' ),
		);
	}

	/** @return array<string,mixed> */
	private function sanitize_documents( array $input ): array {
		return array(
			'basic_pdf_enabled'  => SetupInputSchema::boolean( $input['basic_pdf_enabled'] ?? false ),
			'basic_pdf_email_id' => $this->key( $input['basic_pdf_email_id'] ?? 'customer_processing_order' ),
		);
	}

	private function choice( $value, array $allowed, string $fallback ): string {
		$value = $this->text( $value );
		return in_array( $value, $allowed, true ) ? $value : $fallback;
	}

	private function text( $value ): string {
		$value = is_scalar( $value ) ? (string) $value : '';
		return sanitize_text_field( $value );
	}

	private function key( $value ): string {
		$value = is_scalar( $value ) ? (string) $value : '';
		if ( function_exists( 'sanitize_key' ) ) {
			return sanitize_key( $value );
		}
		return strtolower( preg_replace( '/[^a-zA-Z0-9_\-]/', '', $value ) ?? '' );
	}

	private function multiline( $value ): string {
		$value = is_scalar( $value ) ? (string) $value : '';
		if ( function_exists( 'sanitize_textarea_field' ) ) {
			return sanitize_textarea_field( $value );
		}
		// phpcs:ignore WordPress.WP.AlternativeFunctions.strip_tags_strip_tags -- Standalone service tests only; WordPress always provides sanitize_textarea_field.
		return strip_tags( $value );
	}

	private function email( $value ): string {
		$value = is_scalar( $value ) ? (string) $value : '';
		if ( function_exists( 'sanitize_email' ) ) {
			return sanitize_email( $value );
		}
		return filter_var( $value, FILTER_VALIDATE_EMAIL ) ? $value : '';
	}

	private function is_valid_email( string $value ): bool {
		if ( function_exists( 'is_email' ) ) {
			return false !== is_email( $value );
		}
		return false !== filter_var( $value, FILTER_VALIDATE_EMAIL );
	}

	private function email_is_eligible( string $id, array $emails ): bool {
		foreach ( $emails as $email ) {
			if ( is_array( $email ) && (string) ( $email['id'] ?? '' ) === $id ) {
				return WooEmailEligibility::facts_are_eligible( $email );
			}
		}
		return false;
	}

	private function join_contact( string $email, string $phone, string $address, string $legacy ): string {
		$parts = array_filter( array( $email, $phone, $address ), static fn( string $value ): bool => '' !== trim( $value ) );
		return empty( $parts ) ? $legacy : implode( ' · ', $parts );
	}

	/**
	 * Project stored settings back to the unchanged step input contract.
	 *
	 * @param array<string,mixed> $settings Stored settings.
	 * @return array<int,array<string,mixed>>
	 */
	private function settings_as_step_inputs( array $settings ): array {
		$languages = (array) $settings['languages'];
		$merchant  = (array) $settings['merchant'];
		$sales     = (array) $settings['sales'];
		$terms     = (array) $settings['terms'];
		$delivery  = (array) $settings['delivery'];
		$documents = (array) $settings['documents'];

		return array(
			1 => $languages,
			2 => $merchant,
			3 => array_merge( $sales, $merchant ),
			4 => $terms,
			5 => array_merge( $sales, $delivery ),
			6 => $documents,
		);
	}

	private function url( $value ): string {
		$value = is_scalar( $value ) ? (string) $value : '';
		if ( function_exists( 'esc_url_raw' ) ) {
			return esc_url_raw( $value );
		}
		return filter_var( $value, FILTER_VALIDATE_URL ) ? $value : '';
	}

	private function now_mysql(): string {
		if ( function_exists( 'current_time' ) ) {
			return (string) current_time( 'mysql' );
		}
		return gmdate( 'Y-m-d H:i:s' );
	}
}