<?php

namespace App\Datatables;

use Illuminate\Support\Collection;

/**
 * Class MakesActionMenu
 * @package App\Datatables
 */
trait MakesActionMenu
{
    /**
     * Returns all possible datatable actions 
     * this list will be the single source of truth
     * for all Select Actions
     * 
     * @return Collection collection instance of action items
     */
	public function actions() :Collection
	{

    return collect([
		['action' => 'view_client_client_id', 'permission' => 'view_client', 'route' => 'clients.show', 'key' => 'client_id', 'name' => ctrans('texts.view')],
        ['action' => 'edit_client_client_id', 'permission' => 'edit_client', 'route' => 'clients.edit', 'key' => 'client_id', 'name' => ctrans('texts.edit')],
        ['action' => 'create_task_client_id', 'permission' => 'create_task', 'route' => 'tasks.create', 'key' => 'client_id', 'name' => ctrans('texts.new_task')],
        ['action' => 'create_invoice_client_id', 'permission' => 'create_invoice', 'route' => 'invoices.create', 'key' => 'client_id', 'name' => ctrans('texts.new_invoice')],
        ['action' => 'enter_payment_client_id', 'permission' => 'create_payment', 'route' => 'payments.create', 'key' => 'client_id', 'name' => ctrans('texts.enter_payment')], 
        ['action' => 'enter_credit_client_id', 'permission' => 'create_credit', 'route' => 'credits.create', 'key' => 'client_id', 'name' => ctrans('texts.enter_credit')],
        ['action' => 'enter_expense_client_id', 'permission' => 'create_expense', 'route' => 'expenses.create', 'key' => 'client_id', 'name' => ctrans('texts.enter_expense')]
    ]);

	}

    /**
     * To allow fine grained permissions we need to push the rows through a 
     * permissions/actions sieve.
     *
     * Complicating the calculation is the fact we allow a user who has 
     * create_entity permissions to also view/edit entities they have created.
     *
     * This must persist even if we later remove their create_entity permissions.
     *
     * The only clean way is to push each row through the sieve and push in view/edit permissions
     * onto the users permissions array on a per-row basis. 
     * 
     * @param  array $requested_actions - array of requested actions for menu
     * @param  stdClass $rows - requested $rows for datatable
     * @param  Class::class - need so we can harvest entity string
     * @return stdClass
     */
    public function processActions(array $requested_actions, $rows, $entity)
    {

        $rows->map(function ($row) use ($requested_actions, $entity){

            $row->actions = $this->createActionCollection($requested_actions, $row, $entity);

            return $row;

        });

        return $rows;

    }

    /**
     * Builds the actions for a single row of a datatable
     * 
     * @param  array $requested_actions - array of requested actions for menu
     * @param  stdClass $row - single $row for datatable
     * @param  Class::class - need so we can harvest entity string
     * @return Collection
     */
    private function createActionCollection($requested_actions, $row, $entity) : Collection
    {
        $permissions = auth()->user()->permissions();

        if(auth()->user()->owns($row))
            array_push($permissions, 'view_' . strtolower(class_basename($entity)), 'edit_' .strtolower(class_basename($entity))); 

        $updated_actions = $this->filterActions($requested_actions, $permissions, auth()->user()->isAdmin())->map(function ($action) use($row){

            $action['url'] = route($action['route'], [$action['key'] => $this->encodePrimaryKey($row->id)]);
            return $action;

        });

        return $updated_actions;   

    }

    /**
     * Filters the main actions collection down to the requested
     * actions for this menu
     * 
     * @param  array  $actions     Array of actions requested
     * @param  array  $permissions Array of user permissions
     * @param  bool   $isAdmin    Boolean isAdmin
     * @return Collection collection of filtered actions available to the user
     */
    public function filterActions(array $actions, array $permissions, bool $is_admin) :Collection
    {

    	return $this->checkPermissions($this->actions()->whereIn('action', $actions), $permissions, $is_admin);

    }

    /**
     * Checks the user permissions against the collection and returns
     * a Collection of available actions.
     * 
     * @param  Collection $actions  collection of possible actions
     * @param  bool       $isAdmin boolean defining if user is an administrator
     * @return Collection collection of filtered actions
     * 
     */
    private function checkPermissions(Collection $actions, array $permissions, bool $is_admin) :Collection
    {

        if($is_admin === TRUE)
            return $actions;

        return $actions->whereIn('permission', $permissions);
        
    }
}