<?php
/**
  Really expensive algorithm
*/

/**
     * Get all project vacancies
     *
     * @return Collection of project vacancies
     */
    public function projectVacancies()
    {
        $vacancies = ProjectVacancy::available()->with('role', 'project')->get();

        return $vacancies->map(function ($item) {
            return "{$item->project_id},{$item->project_role_id}";
        })->unique()->values()->map(function ($item) use ($vacancies) {
            $ids = explode(',', $item);
            $project_id = (int) $ids[0];
            $project_role_id = (int) $ids[1];
            return $vacancies->first(function ($vacancy) use ($project_id, $project_role_id) {
                return $vacancy->project_id === $project_id && $vacancy->project_role_id === $project_role_id;
            });
        });
    }


/**
  Hash table implementation
*/
/**
     * Process vacancies (group by project&role, Caertification)
     *
     * @param array $vacancies
     * @return array
     */
    public function processVacancies($vacancies, $projects = true)
    {
        return $vacancies->reduce(function ($formatedVacancies, $vacancy) use ($projects){
            $formatedVacancies = $formatedVacancies ?: [];

            $groupId = $projects ? "{$vacancy->project_id}-{$vacancy->project_role_id}" : "{$vacancy->certification_id}";
            $formatedVacancy = $vacancy->toArray();
            if($projects) {
                unset($formatedVacancy['project']);
                unset($formatedVacancy['role']);
            }else {
                unset($formatedVacancy['certification']);
            }

            if (array_key_exists($groupId, $formatedVacancies)) {
                $key = $projects ? 'vacancies' : 'certification';
                array_push($formatedVacancies[$groupId][$key], $formatedVacancy);
            } else if($projects){
                $formatedVacancies[$groupId]['project'] = $vacancy->project->toArray();
                $formatedVacancies[$groupId]['role'] = $vacancy->role->toArray();
                $formatedVacancies[$groupId]['vacancies'] = [$formatedVacancy];
                $formatedVacancies[$groupId]['available_slots'] = 0;
            } else {
                $formatedVacancies[$groupId]['certification'] = $vacancy->certification->toArray();
                $formatedVacancies[$groupId]['available_slots'] = 0;
            }
            if (! $vacancy->fellow_id) {
                $formatedVacancies[$groupId]['available_slots']++;
            }
            return $formatedVacancies;
        });
    }