<?php

/**
 * Settings storage and sanitisation.
 *
 * @package SugarCalc
 */
declare (strict_types = 1);
namespace SugarCalc;

if ( !defined( 'ABSPATH' ) ) {
    exit;
}
/**
 * Manages the sugarcalc_settings option: defaults, retrieval, sanitisation,
 * and persistence for the fields this build owns (credit display and
 * uninstall data-deletion). Unknown stored keys round-trip untouched.
 */
class Settings {
    public const OPTION_KEY = 'sugarcalc_settings';

    /**
     * Return the default settings used when no saved value exists.
     *
     * @return array<string, string>
     */
    public static function defaults() : array {
        return array(
            'delete_all_data' => 'no',
            'show_credit'     => 'default',
        );
    }

    /**
     * Return the active settings, merged over defaults.
     *
     * @return array<string, string>
     */
    public static function get() : array {
        $saved = get_option( self::OPTION_KEY, array() );
        if ( !is_array( $saved ) ) {
            $saved = array();
        }
        return array_merge( self::defaults(), $saved );
    }

    /**
     * Whether the "Powered by SugarCalc" credit should display on the front-end.
     *
     * The credit is optional and defaults to not showing on the site's front
     * end (issue 00032 / WP Guideline 10); it displays only when enabled for
     * the installation.
     *
     * @return bool
     */
    public static function show_credit() : bool {
        // Free build: explicit opt-in only, off by default.
        return 'yes' === (string) (self::get()['show_credit'] ?? 'default');
    }

    /**
     * Sanitise and persist settings. Only the fields present in $data that
     * this class owns are written; every other stored key round-trips
     * untouched, so a settings save in one build never discards values
     * written by another.
     *
     * @param array<string, mixed> $data Raw field values keyed by field name.
     */
    public static function save( array $data ) : void {
        $saved = get_option( self::OPTION_KEY, array() );
        if ( !is_array( $saved ) ) {
            $saved = array();
        }
        update_option( self::OPTION_KEY, array_merge( $saved, self::sanitise( $data ) ) );
    }

    /**
     * Sanitise the owned fields present in $data.
     *
     * @param array<string, mixed> $data Raw input data to sanitise.
     * @return array<string, string>
     */
    public static function sanitise( array $data ) : array {
        $clean = array();
        if ( array_key_exists( 'delete_all_data', $data ) ) {
            $clean['delete_all_data'] = ( 'yes' === $data['delete_all_data'] ? 'yes' : 'no' );
        }
        if ( array_key_exists( 'show_credit', $data ) ) {
            $show_credit = (string) $data['show_credit'];
            $clean['show_credit'] = ( in_array( $show_credit, array('yes', 'no', 'default'), true ) ? $show_credit : 'default' );
        }
        return $clean;
    }

}