<?php

namespace SiteSync;

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

/**
 * Handles Site Sync plugin settings and options.
 */
class Settings {
    public const OPTION_KEY         = 'site_sync_settings';
    private const DEFAULT_META_KEYS = array( '_thumbnail_id' );

    /**
     * Default settings for the Site Sync plugin.
     *
     * @var array
     */
    private $defaults = array(
        'site_uuid'      => '',
        'shared_key'     => '',
        'peer_site_key'  => '',
        'peer_url'       => '',
        'enabled'        => false,
        'sync_interval'  => 'site_sync_5min',
        'post_meta_keys' => self::DEFAULT_META_KEYS,
    );

    /**
     * Retrieves the merged plugin settings, applying defaults and normalizing meta keys.
     *
     * @return array The merged and normalized settings array.
     */
    public function get_settings(): array {
        $stored   = get_option( self::OPTION_KEY, array() );
        $settings = is_array( $stored ) ? $stored : array();

        $merged                   = array_merge( $this->defaults, $settings );
        $merged['post_meta_keys'] = $this->normalize_meta_keys( $merged['post_meta_keys'] );

        return $merged;
    }

    /**
     * Retrieves a specific setting value by key.
     *
     * @param string $key     The setting key to retrieve.
     * @param mixed  $default The default value to return if the key does not exist.
     * @return mixed The value of the setting or the default value.
     */
    public function get( string $key, $default = null ) { // phpcs:ignore
        $settings = $this->get_settings();

        return $settings[ $key ] ?? $default;
    }

    /**
     * Updates the plugin settings with provided data, sanitizing and normalizing values.
     *
     * @param array $data The settings data to update.
     * @return void
     */
    public function update( array $data ): void {
        $settings = $this->get_settings();

        $settings['peer_url']       = isset( $data['peer_url'] ) ? esc_url_raw( $data['peer_url'] ) : '';
        $settings['peer_site_key']  = isset( $data['peer_site_key'] ) ? sanitize_text_field( $data['peer_site_key'] ) : '';
        $settings['shared_key']     = isset( $data['shared_key'] ) ? sanitize_text_field( $data['shared_key'] ) : $settings['shared_key'];
        $settings['site_uuid']      = isset( $data['site_uuid'] ) ? sanitize_text_field( $data['site_uuid'] ) : $settings['site_uuid'];
        $settings['enabled']        = ! empty( $data['enabled'] );
        $metaKeys                   = $data['post_meta_keys'] ?? $settings['post_meta_keys'];
        $settings['post_meta_keys'] = $this->normalize_meta_keys( $metaKeys );

        $interval                  = isset( $data['sync_interval'] ) ? sanitize_text_field( $data['sync_interval'] ) : $settings['sync_interval'];
        $settings['sync_interval'] = $interval ? $interval : 'site_sync_5min';

        update_option( self::OPTION_KEY, $settings );
    }

    /**
     * Ensures that default values for 'site_uuid' and 'shared_key' are set if missing.
     *
     * @return array The updated settings array.
     */
    public function ensure_defaults(): array {
        $settings = $this->get_settings();
        $changed  = false;

        if ( empty( $settings['site_uuid'] ) ) {
            $settings['site_uuid'] = wp_generate_uuid4();
            $changed               = true;
        }

        if ( empty( $settings['shared_key'] ) ) {
            $settings['shared_key'] = wp_generate_password( 32, false, false );
            $changed                = true;
        }

        if ( $changed ) {
            update_option( self::OPTION_KEY, $settings );
        }

        return $settings;
    }

    /**
     * Retrieves the post meta keys to be synchronized.
     *
     * @return array The array of post meta keys.
     */
    public function get_post_meta_keys(): array {
        return $this->get_settings()['post_meta_keys'];
    }

    /**
     * Normalizes the post meta keys input into a sanitized array of unique keys.
     *
     * @param mixed $value The input value, either a string or array of meta keys.
     * @return array The sanitized and unique array of meta keys.
     */
    private function normalize_meta_keys( $value ): array {
        if ( is_string( $value ) ) {
            $parts = preg_split( '/[\s,]+/', $value );
        } elseif ( is_array( $value ) ) {
            $parts = $value;
        } else {
            $parts = array();
        }

        $keys = array();
        foreach ( $parts as $part ) {
            $sanitized = ltrim( sanitize_text_field( (string) $part ) );
            if ( $sanitized !== '' ) {
                $keys[] = $sanitized;
            }
        }

        if ( empty( $keys ) ) {
            $keys = self::DEFAULT_META_KEYS;
        }

        return array_values( array_unique( $keys ) );
    }
}