<?php
namespace Zadex\Editor;

defined('ABSPATH') || exit;

use Zadex\Assets;
use Zadex\Documents\Document;
use Zadex\Frontend\Templates;
use Zadex\Settings;
use Zadex\Widgets\WidgetRegistry;

/**
 * Handles the two editor URLs:
 *  ?zadex=edit     -> full-page editor shell (no theme), boots the Vue app.
 *  ?zadex=preview  -> the real theme page where the_content is replaced by the canvas mount point.
 */
final class EditorLoader
{
    private Assets $assets;
    private WidgetRegistry $widgets;
    private Settings $settings;

    public function __construct(Assets $assets, WidgetRegistry $widgets, Settings $settings)
    {
        $this->assets = $assets;
        $this->widgets = $widgets;
        $this->settings = $settings;
    }

    public function register(): void
    {
        add_action('template_redirect', [$this, 'maybe_handle'], 1);
    }

    /**
     * Editor route of the current request (`?zadex=edit|preview`, anything else is ''). It only selects which
     * screen is rendered; maybe_handle() checks the edit_post capability before either screen is shown, and
     * every change the editor makes goes through the nonce-checked REST API.
     */
    public static function mode(): string
    {
        $mode = isset($_GET['zadex']) ? sanitize_key(wp_unslash($_GET['zadex'])) : ''; // phpcs:ignore WordPress.Security.NonceVerification.Recommended
        return in_array($mode, ['edit', 'preview'], true) ? $mode : '';
    }

    /**
     * Post id of the editor route when WordPress has not resolved a queried object (draft previews:
     * `?p=ID` / `?page_id=ID`). Callers check edit_post on it before using it.
     */
    public static function requested_post_id(): int
    {
        // phpcs:disable WordPress.Security.NonceVerification.Recommended -- routing only, see above.
        $id = isset($_GET['p']) ? absint(wp_unslash($_GET['p'])) : 0;
        if ($id <= 0 && isset($_GET['page_id'])) {
            $id = absint(wp_unslash($_GET['page_id']));
        }
        // phpcs:enable WordPress.Security.NonceVerification.Recommended
        return $id;
    }

    public static function is_preview(): bool
    {
        return self::mode() === 'preview';
    }

    public function edit_url(int $post_id): string
    {
        return (string) get_preview_post_link($post_id, ['zadex' => 'edit']);
    }

    public function preview_url(int $post_id): string
    {
        return (string) get_preview_post_link($post_id, ['zadex' => 'preview']);
    }

    public function can_edit(int $post_id): bool
    {
        if (!$post_id || !current_user_can('edit_post', $post_id)) {
            return false;
        }
        $post_type = get_post_type($post_id);
        // `zadex/editor/post_types`: post types editable with Zadex besides the enabled ones (theme templates ...).
        $types = (array) apply_filters('zadex/editor/post_types', $this->settings->post_types());
        // `zadex/editor/can_edit` ($can, $post_id): e.g. the role manager's "No access" mode (T170).
        return $post_type && in_array($post_type, $types, true) && (bool) apply_filters('zadex/editor/can_edit', true, $post_id);
    }

    public function maybe_handle(): void
    {
        $mode = self::mode();
        if ($mode === '') {
            return;
        }
        $post_id = (int) get_queried_object_id();
        if (!$post_id) {
            $post_id = self::requested_post_id(); // access is checked by can_edit() below
        }
        if (!$this->can_edit($post_id)) {
            if (!is_user_logged_in()) {
                wp_safe_redirect(wp_login_url($this->edit_url($post_id)));
                exit;
            }
            wp_die(esc_html__('You are not allowed to edit this content with Zadex.', 'zadex'), 403);
        }
        if ($mode === 'edit') {
            $this->render_shell($post_id);
            exit;
        }
        $this->setup_preview($post_id);
    }

    private function setup_preview(int $post_id): void
    {
        show_admin_bar(false);
        add_filter('the_content', static function (string $content) use ($post_id): string {
            if (!in_the_loop() || !is_main_query() || get_the_ID() !== $post_id) {
                return $content;
            }
            return '<div id="zadex-canvas-root" class="zadex zadex-' . $post_id . '" data-zx-doc="' . $post_id . '"></div>';
        }, 9999);
        add_filter('body_class', static fn(array $c): array => array_merge($c, ['zadex-preview', 'zadex-page']));
        add_action('wp_enqueue_scripts', static function () use ($post_id): void {
            wp_register_script('zadex-preview', false, [], ZADEX_VERSION, false);
            wp_add_inline_script('zadex-preview', 'window.ZADEX_PREVIEW = ' . wp_json_encode(['postId' => (int) $post_id], JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_HEX_TAG | JSON_HEX_AMP) . ';');
            wp_enqueue_script('zadex-preview');
            wp_register_style('zadex-preview', false, [], ZADEX_VERSION);
            wp_add_inline_style('zadex-preview', 'html{margin-top:0!important}#zadex-canvas-root{min-height:40vh}');
            wp_enqueue_style('zadex-preview');
        }, 1);
        // Never cache or index preview pages.
        nocache_headers();
        add_filter('wp_robots', static fn(array $r): array => array_merge($r, ['noindex' => true, 'nofollow' => true]));
    }

    public function config(int $post_id): array
    {
        $post = get_post($post_id);
        $user = wp_get_current_user();
        $breakpoints = $this->settings->breakpoints();

        $config = [
            'version'       => ZADEX_VERSION,
            'dev'           => $this->assets->is_dev(),
            'postId'        => $post_id,
            'postTitle'     => $post ? $post->post_title : '',
            'postStatus'    => $post ? $post->post_status : 'draft',
            'postType'      => $post ? $post->post_type : 'page',
            'permalink'     => get_permalink($post_id),
            'previewUrl'    => $this->preview_url($post_id),
            'exitUrl'       => get_edit_post_link($post_id, 'raw') ?: admin_url(),
            'loginUrl'      => wp_login_url($this->edit_url($post_id)),
            'adminUrl'      => admin_url(),
            'siteUrl'       => home_url('/'),
            'pluginUrl'     => ZADEX_URL,
            'restUrl'       => esc_url_raw(rest_url('zadex/v1')),
            'nonce'         => wp_create_nonce('wp_rest'),
            'locale'        => get_user_locale(),
            'isRtl'         => is_rtl(),
            // Editor UI dictionary for t() (languages/zadex-<lang>.json); [] = English source strings.
            'i18n'          => (object) Translations::for_locale((string) get_user_locale()),
            'widgets'       => $this->widgets->for_editor(),
            'commonControls'=> $this->widgets->common_controls(),
            'breakpoints'   => $breakpoints,
            'global'        => $this->settings->global(),
            'globalCss'     => $this->settings->global_css(),
            'document'      => Document::get_data($post_id),
            'pageSettings'  => Document::get_page_settings($post_id),
            // Page template (_wp_page_template) as seen by the Page panel; '' = the theme's default layout.
            'template'      => Templates::get($post_id),
            'user'          => [
                'id'             => $user->ID,
                'name'           => $user->display_name,
                'manageOptions'  => current_user_can('manage_options'),
            ],
            'features'      => $this->settings->get('features', []),
            // Dynamic tags (T114): name, title, group, categories, controls for the picker.
            'dynamicTags'   => \Zadex\Dynamic\Registry::instance()->for_editor(),
            // Runtime option lists for `optionsFrom` selects (the Page panel's "Page layout" reads data.templates).
            'data'          => ['sidebars' => self::sidebar_options(), 'templates' => Templates::options()],
        ];
        return apply_filters('zadex/editor/config', $config, $post_id);
    }

    private function render_shell(int $post_id): void
    {
        nocache_headers();
        header('Content-Type: text/html; charset=' . get_option('blog_charset'));
        // The shell is not a theme page: drop the emoji/feed/theme hooks that would print into it
        // (print_emoji_styles is deprecated since WP 6.4 and would raise a notice under WP_DEBUG).
        remove_action('wp_print_styles', 'print_emoji_styles');
        remove_action('wp_head', 'print_emoji_detection_script', 7);
        remove_action('wp_head', 'wp_print_styles', 8);
        wp_enqueue_media(['post' => $post_id]);
        wp_enqueue_script('wp-i18n');
        $config = $this->config($post_id);
        $title = sprintf(/* translators: post title */ __('Editing: %s', 'zadex'), $config['postTitle']);
        ?>
<!DOCTYPE html>
<html <?php language_attributes(); ?> class="zadex-editor-html<?php echo is_rtl() ? ' rtl' : ''; ?>">
<head>
<meta charset="<?php echo esc_attr(get_option('blog_charset')); ?>">
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="robots" content="noindex, nofollow">
<title><?php echo esc_html($title); ?></title>
<?php
        wp_print_styles();
        wp_print_head_scripts();
        $this->assets->print_entry(Assets::ENTRY_EDITOR);
        // Icon font so the icon picker shows real glyphs.
        $this->assets->print_entry(Assets::ENTRY_ICONS);
        do_action('zadex/editor/head');
        ?>
</head>
<body class="zadex-editor-body">
<!-- impeccable direction (seed 18e8f929)
THESIS: A calm settings surface around a white sheet, the real page. Refuses the dark, crowded builder chrome; color lives only at edges.
OWN-WORLD: Grouped-inset panels on a cool light-gray ground; white rows with 1px hairlines and 10-12px radii; one system sans, hierarchy by size and weight; one blue accent confined to selection, active segment, focus, toggles and the single Publish button; unset settings drawn as ghost values.
STORY: A site owner sees the page as a sheet, presses + in the gap between sections, picks a column structure, drops widgets, edits in place, publishes.
FIRST VIEWPORT: 52px top bar (wordmark, icon rail | segmented devices | undo, status, Save, Publish); 336px grouped panel; the sheet on the ground with + lines between sections and an "Add section" strip at the end.
FORM: grouped-inset settings panels, candidate 7 of 7, seed 18e8f929.
FINISH: unreviewed and undocumented is unfinished; this build ends with the finish review, the verdict, DESIGN.md, and every shipping raster carrying its provenance.
-->
<div id="zadex-editor"></div>
<?php
        wp_register_script('zadex-editor-config', false, [], ZADEX_VERSION, true);
        wp_add_inline_script('zadex-editor-config', 'window.ZADEX = ' . wp_json_encode($config, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_HEX_TAG | JSON_HEX_AMP) . ';');
        wp_enqueue_script('zadex-editor-config');
        wp_print_footer_scripts();
        wp_print_media_templates();
        do_action('zadex/editor/footer');
        ?>
</body>
</html>
<?php
    }

    /**
     * JSON that is safe to embed in an inline script (wp_add_inline_script): `<`, `>` and `&` are hex-escaped so
     * a saved document containing a closing script tag in any text value can never end the script early.
     */
    public static function json_for_script(array $data): string
    {
        return (string) wp_json_encode($data, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_HEX_TAG | JSON_HEX_AMP);
    }

    /** Registered widget areas as select options (consumed by controls with `optionsFrom: "sidebars"`). */
    public static function sidebar_options(): array
    {
        $out = [['value' => '', 'label' => __('— Select —', 'zadex')]];
        foreach ((array) ($GLOBALS['wp_registered_sidebars'] ?? []) as $id => $sidebar) {
            $out[] = ['value' => (string) $id, 'label' => is_array($sidebar) && !empty($sidebar['name']) ? (string) $sidebar['name'] : (string) $id];
        }
        return $out;
    }

    /**
     * Collects all editable items on the current request:
     * - The singular post/page (if singular and user can edit it)
     * - The Header template (Theme Builder)
     * - Location template (single / archive / search / 404)
     * - The Footer template (Theme Builder)
     * - Popups (matching/active on this request)
     *
     * @return array<string, array{id: int, title: string, type: string, url: string}>
     */
    public function collect_editable_items(): array
    {
        if (function_exists('is_admin') && is_admin()) {
            return [];
        }

        $items = [];

        // 1. Current singular post or page
        if (function_exists('is_singular') && is_singular()) {
            $post_id = function_exists('get_queried_object_id') ? (int) get_queried_object_id() : 0;
            if ($post_id > 0 && $this->can_edit($post_id)) {
                $post = get_post($post_id);
                $title = $post && !empty($post->post_title) ? $post->post_title : (function_exists('get_the_title') ? (get_the_title($post_id) ?: __('(no title)', 'zadex')) : __('(no title)', 'zadex'));
                $post_type = get_post_type($post_id);
                $type_obj = function_exists('get_post_type_object') ? get_post_type_object($post_type) : null;
                $type_label = $type_obj && isset($type_obj->labels->singular_name) ? $type_obj->labels->singular_name : __('Page', 'zadex');
                $items['post'] = [
                    'id'    => $post_id,
                    'title' => $title,
                    'type'  => $type_label,
                    'url'   => $this->edit_url($post_id),
                ];
            }
        }

        // 2. Header template (Theme Builder)
        if (class_exists(\Zadex\Theme\Resolver::class)) {
            $header_id = \Zadex\Theme\Resolver::for_location('header');
            if ($header_id && $this->can_edit($header_id)) {
                $title = function_exists('get_the_title') ? (get_the_title($header_id) ?: __('Header', 'zadex')) : __('Header', 'zadex');
                $items['header'] = [
                    'id'    => $header_id,
                    'title' => $title,
                    'type'  => __('Header', 'zadex'),
                    'url'   => $this->edit_url($header_id),
                ];
            }
        }

        // 3. Location template: single / archive / search / 404 (Theme Builder)
        if (class_exists(\Zadex\Theme\Locations::class) && class_exists(\Zadex\Theme\Resolver::class)) {
            $location = \Zadex\Theme\Locations::location();
            if (is_string($location) && $location !== '') {
                foreach (\Zadex\Theme\Locations::candidates($location) as $cand) {
                    $cand_id = \Zadex\Theme\Resolver::for_location($cand);
                    if ($cand_id && $this->can_edit($cand_id)) {
                        if (isset($items['post']) && $items['post']['id'] === $cand_id) {
                            continue;
                        }
                        $labels = [
                            'single'  => __('Single Post', 'zadex'),
                            'archive' => __('Archive', 'zadex'),
                            'search'  => __('Search Results', 'zadex'),
                            '404'     => __('404 Error', 'zadex'),
                        ];
                        $type_label = $labels[$cand] ?? (ucfirst($cand) . ' ' . __('Template', 'zadex'));
                        $title = function_exists('get_the_title') ? (get_the_title($cand_id) ?: $type_label) : $type_label;
                        $items['location_' . $cand] = [
                            'id'    => $cand_id,
                            'title' => $title,
                            'type'  => $type_label,
                            'url'   => $this->edit_url($cand_id),
                        ];
                        break;
                    }
                }
            }
        }

        // 4. Footer template (Theme Builder)
        if (class_exists(\Zadex\Theme\Resolver::class)) {
            $footer_id = \Zadex\Theme\Resolver::for_location('footer');
            if ($footer_id && $this->can_edit($footer_id)) {
                $title = function_exists('get_the_title') ? (get_the_title($footer_id) ?: __('Footer', 'zadex')) : __('Footer', 'zadex');
                $items['footer'] = [
                    'id'    => $footer_id,
                    'title' => $title,
                    'type'  => __('Footer', 'zadex'),
                    'url'   => $this->edit_url($footer_id),
                ];
            }
        }

        // 5. Popups active on this page
        if (class_exists(\Zadex\Theme\Resolver::class)) {
            $popup_ids = \Zadex\Theme\Resolver::matching('popup');
            foreach ($popup_ids as $popup_id) {
                if ($this->can_edit((int) $popup_id)) {
                    $title = function_exists('get_the_title') ? (get_the_title((int) $popup_id) ?: __('Popup', 'zadex')) : __('Popup', 'zadex');
                    $items['popup_' . $popup_id] = [
                        'id'    => (int) $popup_id,
                        'title' => $title,
                        'type'  => __('Popup', 'zadex'),
                        'url'   => $this->edit_url((int) $popup_id),
                    ];
                }
            }
        }

        return (array) apply_filters('zadex/admin_bar/editable_items', $items);
    }

    /**
     * Adds "Edit with Zadex" and a dropdown list of all editable items (page, header, footer, templates, popups)
     * as shortcuts to the WordPress toolbar.
     *
     * @param \WP_Admin_Bar $bar
     */
    public function admin_bar_link($bar): void
    {
        if (!is_object($bar) || !method_exists($bar, 'add_node') || (function_exists('is_admin') && is_admin())) {
            return;
        }

        $items = $this->collect_editable_items();
        $can_manage_theme = current_user_can('edit_theme_options') || current_user_can('manage_options');

        if (empty($items) && !$can_manage_theme) {
            return;
        }

        // Determine primary URL and ID for the main button
        $primary_url = '';
        $primary_id = 0;
        if (!empty($items['post']['url'])) {
            $primary_url = $items['post']['url'];
            $primary_id = (int) $items['post']['id'];
        } else {
            foreach ($items as $item) {
                if (!empty($item['url'])) {
                    $primary_url = $item['url'];
                    $primary_id = (int) $item['id'];
                    break;
                }
            }
        }

        if ($primary_url === '' && $can_manage_theme) {
            $primary_url = admin_url('admin.php?page=zadex-theme-builder');
        }

        if ($primary_url === '') {
            return;
        }

        // 1. Top-level node
        $icon = '<span class="ab-icon dashicons dashicons-layout" style="font-family:dashicons;margin-top:2px;"></span>';
        $bar->add_node([
            'id'    => 'zadex-edit',
            'title' => $icon . '<span class="ab-label">' . esc_html__('Edit with Zadex', 'zadex') . '</span>',
            'href'  => $primary_url,
            'meta'  => [
                'title' => __('Edit with Zadex', 'zadex'),
            ],
        ]);

        // 2. Sub-nodes for each editable item
        foreach ($items as $key => $item) {
            if (strcasecmp($item['type'], $item['title']) === 0) {
                $label = $item['title'];
            } else {
                /* translators: 1: kind of editable item (e.g. "Header"), 2: its title. */
                $label = sprintf(__('%1$s: %2$s', 'zadex'), $item['type'], $item['title']);
            }
            $bar->add_node([
                'id'     => 'zadex-edit-' . $key,
                'parent' => 'zadex-edit',
                'title'  => esc_html($label),
                'href'   => $item['url'],
            ]);
        }

        // 3. Global shortcuts
        if ($can_manage_theme) {
            if (!empty($items)) {
                $bar->add_group([
                    'id'     => 'zadex-edit-tools-group',
                    'parent' => 'zadex-edit',
                    'meta'   => ['class' => 'ab-sub-secondary'],
                ]);
            }

            $parent = !empty($items) ? 'zadex-edit-tools-group' : 'zadex-edit';

            if ($primary_id > 0) {
                $bar->add_node([
                    'id'     => 'zadex-edit-site-settings',
                    'parent' => $parent,
                    'title'  => esc_html__('Site Settings', 'zadex'),
                    'href'   => add_query_arg(['zx_panel' => 'global'], $this->edit_url($primary_id)),
                ]);
            }

            $bar->add_node([
                'id'     => 'zadex-edit-theme-builder',
                'parent' => $parent,
                'title'  => esc_html__('Theme Builder', 'zadex'),
                'href'   => admin_url('admin.php?page=zadex-theme-builder'),
            ]);
        }
    }
}