<?php

namespace AOP\App\ImportExport;

/**
 * Turns a stored page value back into the shape of the editor form (what `Input` reads from the request), so that an
 * imported menu goes through exactly the code that saves a menu in the editor: the same validation, the same
 * sanitizing per field type, the same storing.
 *
 * The inverse of `Input`. `PageValueToPostTest` checks page value → post → `Input` → page value for the fixtures.
 */
final class PageValueToPost
{
    /**
     * @param array $pageValue A page value as stored (or exported).
     *
     * @return array The payload of the editor form.
     */
    public static function convert(array $pageValue): array
    {
        $post = [
            'menu_id' => (string) ($pageValue['menu_id'] ?? ''),
            'side_bar_visible' => self::toggle($pageValue['side_bar_visible'] ?? true),
            'pages' => [],
        ];

        if (isset($pageValue['existing_menu'])) {
            $post['existing_menu'] = [
                'menu_name' => (string) ($pageValue['existing_menu']['menu_name'] ?? ''),
                'menu_slug' => (string) ($pageValue['existing_menu']['menu_slug'] ?? ''),
            ];
        } else {
            $menu = (array) ($pageValue['menu'] ?? []);

            $post['menu'] = [
                'menu_title' => (string) ($menu['menu_title'] ?? ''),
                'menu_icon' => (string) ($menu['icon_url'] ?? ''),
                'menu_position' => (string) ($menu['position'] ?? ''),
            ];
        }

        foreach (array_values((array) ($pageValue['pages'] ?? [])) as $key => $page) {
            $post['pages'][(string) $key] = self::page((array) $page);
        }

        return $post;
    }

    private static function page(array $page): array
    {
        $post = [
            'menu_title' => (string) ($page['menu_title'] ?? ''),
            'subpage_title' => (string) ($page['subpage_title'] ?? ''),
            'select_title' => (string) ($page['select_title'] ?? 'None'),
            'role' => ($page['capability'] ?? '') === 'edit_others_posts' ? 'editor' : 'administrator',
            'subpage_position' => isset($page['subpage_position']) ? (string) $page['subpage_position'] : '',
            'subpage_toggle' => self::toggle($page['subpage_toggle'] ?? true),
            'subpage_slug' => (string) ($page['menu_slug'] ?? ''),
            'subpage_slug_suffix' => (string) ($page['subpage_slug_suffix'] ?? ''),
            'fields' => [],
        ];

        // A page of 1.1 has its roles; a page of 1.0 posts its level, as the editor of 1.0 did.
        if (isset($page['roles']) && is_array($page['roles'])) {
            unset($post['role']);
            $post = self::insertAfter($post, 'select_title', ['roles' => array_values($page['roles'])]);
        }

        if (! empty($page['include_tab'])) {
            $post['subpage_tab'] = '1';
        }

        foreach (array_values((array) ($page['fields'] ?? [])) as $key => $field) {
            $post['fields'][(string) $key] = self::field((array) $field);
        }

        return $post;
    }

    /**
     * @param array  $array
     * @param string $key   The key to insert after.
     * @param array  $items
     */
    private static function insertAfter(array $array, string $key, array $items): array
    {
        $position = array_search($key, array_keys($array), true);

        return array_slice($array, 0, $position + 1, true) + $items + array_slice($array, $position + 1, null, true);
    }

    /**
     * A field posts what it stores, apart from its page, which the form calls `page_slug`. Values the editor never
     * posted (null) are left out.
     */
    private static function field(array $field): array
    {
        $post = [];

        foreach ($field as $key => $value) {
            if ($value === null) {
                continue;
            }

            // The form posts the autoload only when it is switched off; "yes" is what a missing value means.
            if ($key === 'toggle_autoload' && $value === 'yes') {
                continue;
            }

            if ($key === 'page_name') {
                $key = 'page_slug';
            }

            $post[$key] = is_bool($value) ? self::toggle($value) : (is_scalar($value) ? (string) $value : $value);
        }

        return $post;
    }

    private static function toggle($value): string
    {
        return $value === true || $value === 'true' ? 'true' : 'false';
    }
}