<?php

/**
 * Matomo - free/libre analytics platform
 *
 * @link    https://matomo.org
 * @license https://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
 */

namespace Piwik\Category;

use Piwik\Container\StaticContainer;

/**
 * Holds the list of categories (with their subcategories) available in the Piwik reporting menu.
 *
 * This class is for now not exposed as public API until needed.
 */
class CategoryList
{
    /**
     * @var Category[] indexed by categoryId
     */
    private $categories = array();

    public function addCategory(Category $category)
    {
        $categoryId = $category->getId();

        if ($this->hasCategory($categoryId)) {
            throw new \Exception(sprintf('Category %s already exists', $categoryId));
        }

        $this->categories[$categoryId] = $category;
    }

    public function getCategories()
    {
        return $this->categories;
    }

    /**
     * Returns the reporting menu groups that do not require tracked data, collected across all
     * categories (it is a property of the group, so resolved globally rather than per category).
     *
     * @return string[]
     */
    public function getGroupsWithoutTrackingRequirement(): array
    {
        $groups = [];
        foreach ($this->categories as $category) {
            foreach ($category->getGroupsWithoutTrackingRequirement() as $group) {
                $groups[$group] = true;
            }
        }
        return array_keys($groups);
    }

    /**
     * @param string|null $categoryId
     * @return bool
     */
    public function hasCategory($categoryId)
    {
        return isset($this->categories[$categoryId]);
    }

    /**
     * Get the category having the given id, if possible.
     *
     * @param string|null $categoryId
     * @return Category|null
     */
    public function getCategory($categoryId)
    {
        if ($this->hasCategory($categoryId)) {
            return $this->categories[$categoryId];
        }

        return null;
    }

    /**
     * @return CategoryList
     */
    public static function get()
    {
        $list = new CategoryList();

        $categories = StaticContainer::get('Piwik\Plugin\Categories');

        foreach ($categories->getAllCategories() as $category) {
            $list->addCategory($category);
        }

        // move subcategories into categories
        foreach ($categories->getAllSubcategories() as $subcategory) {
            $categoryId = $subcategory->getCategoryId();

            if (!$categoryId) {
                continue;
            }

            if ($list->hasCategory($categoryId)) {
                $category = $list->getCategory($categoryId);
            } else {
                $category = new Category();
                $category->setId($categoryId);
                $list->addCategory($category);
            }

            $category->addSubcategory($subcategory);
        }

        return $list;
    }
}
