<?php

namespace AOP\App;

use AOP\App\Admin\AdminPages\SubpageCreate;
use AOP\App\Admin\AdminPages\SubpageEdit;
use AOP\App\Admin\AdminPages\SubpageMaster;

final class Enqueue
{
    use Singleton;

    private function __construct()
    {
        add_action('admin_enqueue_scripts', function () {
            $this->adminJs();
            $this->adminCss();
        });

        add_filter('admin_body_class', [self::class, 'bodyClass']);
    }

    /**
     * The screens of the editor (Add new and edit). Their ids depend on the translated menu title, so WordPress
     * builds them.
     *
     * @return string[]
     */
    public static function editorScreenIds(): array
    {
        return [
            get_plugin_page_hookname(SubpageCreate::SLUG, SubpageMaster::SLUG),
            'admin_page_' . SubpageEdit::SLUG,
        ];
    }

    /**
     * Mark the screens of the editor with a class of our own, so the CSS does not depend on a screen id (that
     * changes with the language of the menu title).
     *
     * @param string $classes The classes WordPress gives the body of an admin screen.
     */
    public static function bodyClass($classes): string
    {
        $screen = function_exists('get_current_screen') ? get_current_screen() : null;

        if ($screen && in_array($screen->id, self::editorScreenIds(), true)) {
            return $classes . ' aop-editor-screen';
        }

        return (string) $classes;
    }

    /**
     * Handles all the admin js files.
     */
    private function adminJs()
    {
        Data::adminPagesIds()->filter(function ($page) {
            return get_current_screen()->id === $page;
        })->each(function () {
            // window.aop.fields: the place where the built-in and add-on field types register (Field Types API).
            // The editor reads it, so it comes first.
            static::buildScript(Plugin::PREFIX . 'field-registry-js', 'field-registry');

            // The handle stays 'aop-app-js': the notices and the localized data address it.
            static::buildScript(Plugin::PREFIX . 'app-js', 'editor', [Plugin::PREFIX . 'field-registry-js']);
            static::scriptTranslations(Plugin::PREFIX . 'app-js');

            wp_localize_script(Plugin::PREFIX . 'app-js', Plugin::PREFIX_ . 'editor_config', static::editorConfig());

            wp_localize_script(Plugin::PREFIX . 'app-js', Plugin::PREFIX_ . 'script_data_js', Data::js()->toArray());

            wp_localize_script(Plugin::PREFIX . 'app-js', Plugin::PREFIX_ . 'dashicons_js', Dashicons::allIconsCollection()->toArray());

            /**
             * Enqueue the editor scripts of your field types here. Runs on the screens of the editor after the
             * scripts of the plugin were enqueued.
             *
             * @since 1.0.0
             */
            do_action('aop_enqueue_editor_assets');
        });
    }

    /**
     * What the React editor needs besides the page data: the fields of the form that WordPress always posted
     * with a page. They travel in a script, not in an attribute named nonce (analysis S14).
     *
     * @return array{nonceName: string, nonce: string, referer: string, svgUploads: bool}
     */
    public static function editorConfig(): array
    {
        list($nonceName, $nonce, $referer) = SubpageEdit::wpNonceFieldArray();

        return [
            'nonceName' => $nonceName,
            'nonce' => $nonce,
            'referer' => $referer,
            // WordPress blocks SVG uploads by default; the image field says so (a plugin like Safe SVG allows them).
            'svgUploads' => in_array('image/svg+xml', get_allowed_mime_types(), true),
        ];
    }

    /**
     * Handles all the admin css files.
     */
    private function adminCss()
    {
        Data::adminPagesIds()->filter(function ($page) {
            return get_current_screen()->id === $page && get_current_screen()->id !== 'toplevel_page_admin_options_pages_master';
        })->each(function () {
            static::buildStyle(Plugin::PREFIX . 'app-css', 'css/aop');
        });

        // The list of pages has its own WordPress table; only the dialog and the row link need styles.
        Data::adminPagesIds()->filter(function ($page) {
            return get_current_screen()->id === $page && get_current_screen()->id === 'toplevel_page_admin_options_pages_master';
        })->each(function () {
            static::buildStyle(Plugin::PREFIX . 'master-css', 'css/master');
        });

        wp_enqueue_style(Plugin::PREFIX . 'icon-css', Plugin::assetsUrl() . 'css/aop-icon.css', [], Plugin::releaseVersion(), 'all');
    }

    public static function version($file)
    {
        $path = Plugin::assetsDir() . $file;

        return file_exists($path) ? md5(filemtime($path)) : Plugin::releaseVersion();
    }

    /**
     * Dependencies and version of a wp-scripts entry, read from its generated <entry>.asset.php.
     *
     * @param string $entry Entry name, e.g. 'settings'.
     *
     * @return array{dependencies: string[], version: string}
     */
    public static function buildAsset($entry)
    {
        $file = Plugin::buildDir() . $entry . '.asset.php';

        if (is_readable($file)) {
            $asset = include $file;

            return [
                'dependencies' => (array) ($asset['dependencies'] ?? []),
                'version' => (string) ($asset['version'] ?? Plugin::releaseVersion()),
            ];
        }

        return ['dependencies' => [], 'version' => static::buildFileVersion($entry . '.js')];
    }

    /**
     * Version for a built file that has no .asset.php (the CSS files).
     *
     * @param string $file Path relative to includes/build/.
     *
     * @return string
     */
    public static function buildFileVersion($file)
    {
        $path = Plugin::buildDir() . $file;

        return file_exists($path) ? (string) filemtime($path) : Plugin::releaseVersion();
    }

    /**
     * Enqueue a wp-scripts JavaScript entry with the dependencies webpack found.
     *
     * @param string   $handle
     * @param string   $entry             Entry name, e.g. 'settings'.
     * @param string[] $extraDependencies Script handles webpack cannot detect (e.g. 'wp-api').
     */
    public static function buildScript($handle, $entry, array $extraDependencies = [])
    {
        $asset = static::buildAsset($entry);

        wp_enqueue_script(
            $handle,
            Plugin::buildUrl() . $entry . '.js',
            array_values(array_unique(array_merge($asset['dependencies'], $extraDependencies))),
            $asset['version'],
            true
        );
    }

    /**
     * Load the translations of a script: a language pack of translate.wordpress.org, otherwise the .json files
     * that ship with the plugin.
     *
     * @param string $handle
     */
    public static function scriptTranslations($handle): void
    {
        wp_set_script_translations($handle, 'admin-options-pages', Plugin::languagesDir());
    }

    /**
     * Enqueue a wp-scripts CSS entry.
     *
     * @param string   $handle
     * @param string   $entry Entry name, e.g. 'css/settings'.
     * @param string[] $dependencies Style handles.
     */
    public static function buildStyle($handle, $entry, array $dependencies = [])
    {
        wp_enqueue_style($handle, Plugin::buildUrl() . $entry . '.css', $dependencies, static::buildFileVersion($entry . '.css'));
    }
}