<?php

namespace EasyCorp\Bundle\EasyAdminBundle\Configuration;

/**
 * Processes the main menu configuration defined in the "design.menu"
 * option or creates the default config for the menu if none is defined.
 *
 * @author Javier Eguiluz <javier.eguiluz@gmail.com>
 */
class MenuConfigPass implements ConfigPassInterface
{
    public function process(array $backendConfig)
    {
        // process 1st level menu items
        $menuConfig = $backendConfig['design']['menu'];
        $menuConfig = $this->normalizeMenuConfig($menuConfig, $backendConfig);
        $menuConfig = $this->processMenuConfig($menuConfig, $backendConfig);

        $backendConfig['design']['menu'] = $menuConfig;

        // process 2nd level menu items (i.e. submenus)
        foreach ($backendConfig['design']['menu'] as $i => $itemConfig) {
            if (empty($itemConfig['children'])) {
                continue;
            }

            $submenuConfig = $itemConfig['children'];
            $submenuConfig = $this->normalizeMenuConfig($submenuConfig, $backendConfig, $i);
            $submenuConfig = $this->processMenuConfig($submenuConfig, $backendConfig, $i);

            $backendConfig['design']['menu'][$i]['children'] = $submenuConfig;
        }

        return $backendConfig;
    }

    /**
     * Normalizes the different shortcut notations of the menu config to simplify
     * further processing.
     *
     * @param array $menuConfig
     * @param array $backendConfig
     * @param int   $parentItemIndex The index of the parent item for this menu item (allows to treat submenus differently)
     *
     * @return array
     */
    private function normalizeMenuConfig(array $menuConfig, array $backendConfig, $parentItemIndex = -1)
    {
        // if the backend doesn't define the menu configuration: create a default
        // menu configuration to display all its entities
        if (empty($menuConfig)) {
            foreach ($backendConfig['entities'] as $entityName => $entityConfig) {
                $menuConfig[] = ['entity' => $entityName, 'label' => $entityConfig['label']];
            }
        }

        // replaces the short config syntax:
        //   design.menu: ['Product', 'User']
        // by the expanded config syntax:
        //   design.menu: [{ entity: 'Product' }, { entity: 'User' }]
        foreach ($menuConfig as $i => $itemConfig) {
            if (\is_string($itemConfig)) {
                $itemConfig = ['entity' => $itemConfig];
            }

            $menuConfig[$i] = $itemConfig;
        }

        foreach ($menuConfig as $i => $itemConfig) {
            // normalize icon configuration
            if (!\array_key_exists('icon', $itemConfig)) {
                $itemConfig['icon'] = ($parentItemIndex > -1) ? '' : 'fa-folder-open';
            } elseif (empty($itemConfig['icon'])) {
                $itemConfig['icon'] = null;
            } else {
                $itemConfig['icon'] = 'fa-'.$itemConfig['icon'];
            }

            // normalize css_class configuration
            if (!\array_key_exists('css_class', $itemConfig)) {
                $itemConfig['css_class'] = '';
            }

            // normalize submenu configuration (only for main menu items)
            if (-1 === $parentItemIndex && !isset($itemConfig['children'])) {
                $itemConfig['children'] = [];
            }

            // normalize 'default' option, which sets the menu item used as the backend index
            if (!\array_key_exists('default', $itemConfig)) {
                $itemConfig['default'] = false;
            } else {
                $itemConfig['default'] = (bool) $itemConfig['default'];
            }

            // normalize 'target' option, which allows to open menu items in different windows or tabs
            if (!\array_key_exists('target', $itemConfig)) {
                $itemConfig['target'] = false;
            } else {
                $itemConfig['target'] = (string) $itemConfig['target'];
            }

            // normalize 'rel' option, which adds html5 rel attribute (https://developer.mozilla.org/en-US/docs/Web/HTML/Link_types)
            if (!\array_key_exists('rel', $itemConfig)) {
                $itemConfig['rel'] = \array_key_exists('url', $itemConfig) ? 'noreferrer' : false;
            } else {
                $itemConfig['rel'] = (string) $itemConfig['rel'];
            }

            // normalize 'permission' option, which allows to set the security permission needed to see the menu item
            $itemConfig['permission'] = $itemConfig['permission'] ?? null;

            $menuConfig[$i] = $itemConfig;
        }

        return $menuConfig;
    }

    private function processMenuConfig(array $menuConfig, array $backendConfig, $parentItemIndex = -1)
    {
        foreach ($menuConfig as $i => $itemConfig) {
            // these options are needed to find the active menu/submenu item in the template
            $itemConfig['menu_index'] = (-1 === $parentItemIndex) ? $i : $parentItemIndex;
            $itemConfig['submenu_index'] = (-1 === $parentItemIndex) ? -1 : $i;

            // 1st level priority: if 'entity' is defined, link to the given entity
            if (isset($itemConfig['entity'])) {
                $itemConfig['type'] = 'entity';
                $entityName = $itemConfig['entity'];

                if (!\array_key_exists($entityName, $backendConfig['entities'])) {
                    throw new \RuntimeException(sprintf('The "%s" entity included in the "menu" option is not managed by EasyAdmin. The menu can only include any of these entities: %s.', $entityName, implode(', ', array_keys($backendConfig['entities']))));
                }

                if (!isset($itemConfig['label'])) {
                    $itemConfig['label'] = $backendConfig['entities'][$entityName]['label'];
                }

                if (!isset($itemConfig['params'])) {
                    $itemConfig['params'] = [];
                }
            }

            // 2nd level priority: if 'url' is defined, link to the given absolute/relative URL
            elseif (isset($itemConfig['url'])) {
                $itemConfig['type'] = 'link';

                if (!isset($itemConfig['label'])) {
                    throw new \RuntimeException(sprintf('The configuration of the menu item with "url = %s" must define the "label" option.', $itemConfig['url']));
                }
            }

            // 3rd level priority: if 'route' is defined, link to the path generated with the given route
            elseif (isset($itemConfig['route'])) {
                $itemConfig['type'] = 'route';

                if (!isset($itemConfig['label'])) {
                    throw new \RuntimeException(sprintf('The configuration of the menu item with "route = %s" must define the "label" option.', $itemConfig['route']));
                }

                if (!isset($itemConfig['params'])) {
                    $itemConfig['params'] = [];
                }
            }

            // 4th level priority: if 'label' is defined (and not the previous options),
            // this is a menu divider of a submenu title
            elseif (isset($itemConfig['label'])) {
                if (empty($itemConfig['children'])) {
                    // if the item doesn't define a submenu, this is a menu divider
                    $itemConfig['type'] = 'divider';
                } else {
                    // if the item defines a submenu, this is the title of that submenu
                    $itemConfig['type'] = 'empty';
                }
            } else {
                throw new \RuntimeException(sprintf('The configuration of the menu item in the position %d (being 0 the first item) must define at least one of these options: entity, url, route, label.', $i));
            }

            $menuConfig[$i] = $itemConfig;
        }

        return $menuConfig;
    }
}