<?php
namespace Zadex\Components;

defined('ABSPATH') || exit;

use Zadex\Documents\Document;
use Zadex\Widgets\WidgetRegistry;

/**
 * The `zadex_component` post type (T168 / T210): components and global widgets.
 *
 * A component is a normal Zadex document (`_zadex_data` tree, `_zadex_css` generated by the editor with the
 * component's own element ids) plus:
 *  _zadex_component_kind   'component' | 'widget' (global widget: the root is one widget)
 *  _zadex_component_props  JSON list of exposed properties [{id, label, elementId, control}]
 *
 * Private (`public: false`, no admin UI of its own: "Zadex → Components" lists them) but publicly queryable so the
 * editor URLs (?zadex=edit / ?zadex=preview) resolve; visitors get a 404 on a component URL (Components::guard_single).
 */
final class ComponentPost
{
    public const POST_TYPE = 'zadex_component';
    public const META_KIND = '_zadex_component_kind';
    public const META_PROPS = '_zadex_component_props';
    public const KINDS = ['component', 'widget'];
    /** Page-settings key the editor keeps the exposed properties in while the component is the edited document. */
    public const PAGE_KEY = 'component_props';
    public const MAX_PROPS = 50;

    /** @var array<int, array> per-request cache of component trees */
    private static array $trees = [];

    public static function register(): void
    {
        register_post_type(self::POST_TYPE, [
            'labels'              => [
                'name'          => __('Components', 'zadex'),
                'singular_name' => __('Component', 'zadex'),
            ],
            'public'              => false,
            'publicly_queryable'  => true,
            'exclude_from_search' => true,
            'show_ui'             => false,
            'show_in_menu'        => false,
            'show_in_nav_menus'   => false,
            'show_in_rest'        => false,
            'has_archive'         => false,
            'rewrite'             => false,
            'query_var'           => false,
            'hierarchical'        => false,
            'supports'            => ['title', 'revisions', 'author'],
            'capability_type'     => 'post',
            'map_meta_cap'        => true,
        ]);
    }

    public static function is_component(int $post_id): bool
    {
        return $post_id > 0 && get_post_type($post_id) === self::POST_TYPE;
    }

    /** A component that is not trashed. */
    public static function exists(int $post_id): bool
    {
        $post = $post_id > 0 ? get_post($post_id) : null;
        return $post !== null && (string) ($post->post_type ?? '') === self::POST_TYPE && (string) ($post->post_status ?? '') !== 'trash';
    }

    /** Rendered on the live site only when published; editor previews show drafts too. */
    public static function renderable(int $post_id, bool $editor = false): bool
    {
        if (!self::exists($post_id)) {
            return false;
        }
        $status = (string) (get_post($post_id)->post_status ?? '');
        return $editor ? true : in_array($status, ['publish', 'private'], true);
    }

    public static function sanitize_kind($kind): string
    {
        return is_string($kind) && in_array($kind, self::KINDS, true) ? $kind : 'component';
    }

    public static function kind(int $post_id): string
    {
        return self::sanitize_kind(get_post_meta($post_id, self::META_KIND, true));
    }

    /** Global widget = one root element that is a widget (no children, not a container). */
    public static function kind_for(array $elements, WidgetRegistry $registry): string
    {
        if (count($elements) !== 1 || !is_array($elements[0] ?? null)) {
            return 'component';
        }
        $root = $elements[0];
        $manifest = $registry->get((string) ($root['type'] ?? ''));
        $container = !empty($manifest['isContainer']);
        return !$container && empty($root['children']) ? 'widget' : 'component';
    }

    /**
     * Valid, unique props (the same rules as `sanitizeProps()` in src/editor/core/components.ts).
     *
     * @return array<int, array{id:string, label:string, elementId:string, control:string}>
     */
    public static function sanitize_props($input): array
    {
        if (is_string($input) && $input !== '') {
            $input = json_decode($input, true);
        }
        if (!is_array($input)) {
            return [];
        }
        $out = [];
        $seen = [];
        foreach ($input as $raw) {
            if (!is_array($raw)) {
                continue;
            }
            $id = is_string($raw['id'] ?? null) ? (string) preg_replace('/[^a-zA-Z0-9_-]/', '', $raw['id']) : '';
            $element = is_string($raw['elementId'] ?? null) && preg_match('/^[a-z][a-z0-9]{2,15}$/', $raw['elementId']) ? $raw['elementId'] : '';
            $control = is_string($raw['control'] ?? null) && preg_match('/^[a-zA-Z_][a-zA-Z0-9_]*$/', $raw['control']) ? $raw['control'] : '';
            if ($id === '' || $element === '' || $control === '' || isset($seen[$id])) {
                continue;
            }
            $seen[$id] = true;
            $label = is_string($raw['label'] ?? null) ? trim(sanitize_text_field($raw['label'])) : '';
            $out[] = [
                'id'        => $id,
                'label'     => $label !== '' ? mb_substr($label, 0, 80) : $control,
                'elementId' => $element,
                'control'   => $control,
            ];
            if (count($out) >= self::MAX_PROPS) {
                break;
            }
        }
        return $out;
    }

    /** @return array<int, array{id:string, label:string, elementId:string, control:string}> */
    public static function props(int $post_id): array
    {
        return self::sanitize_props(get_post_meta($post_id, self::META_PROPS, true));
    }

    public static function set_props(int $post_id, $props): array
    {
        $clean = self::sanitize_props($props);
        update_post_meta($post_id, self::META_PROPS, wp_slash((string) wp_json_encode($clean, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES)));
        return $clean;
    }

    /** @return array<int, array> the component's elements (cached per request) */
    public static function tree(int $post_id): array
    {
        if (!isset(self::$trees[$post_id])) {
            $data = Document::get_data($post_id);
            self::$trees[$post_id] = is_array($data['elements'] ?? null) ? $data['elements'] : [];
        }
        return self::$trees[$post_id];
    }

    public static function reset_cache(?int $post_id = null): void
    {
        if ($post_id === null) {
            self::$trees = [];
        } else {
            unset(self::$trees[$post_id]);
        }
    }

    /** @return array<string, mixed> */
    public static function summary($post): array
    {
        $id = (int) $post->ID;
        return [
            'id'       => $id,
            'title'    => (string) $post->post_title,
            'kind'     => self::kind($id),
            'usage'    => Usage::count($id),
            'modified' => (string) ($post->post_modified_gmt ?? ''),
            'status'   => (string) ($post->post_status ?? ''),
        ];
    }

    /** Summary + elements, CSS and props (GET /components/{id}). */
    public static function full(int $post_id): ?array
    {
        if (!self::exists($post_id)) {
            return null;
        }
        $item = self::summary(get_post($post_id));
        $item['elements'] = self::tree($post_id);
        $item['css'] = Document::get_css($post_id);
        $item['props'] = self::props($post_id);
        return $item;
    }

    /** @return \WP_Post[] every component, newest first */
    public static function all(): array
    {
        return get_posts([
            'post_type'        => self::POST_TYPE,
            'post_status'      => ['publish', 'draft', 'pending', 'private', 'future'],
            'numberposts'      => 500,
            'orderby'          => 'modified',
            'order'            => 'DESC',
        ]);
    }
}