<?php

namespace Illuminate\Pagination;

use Countable;
use ArrayAccess;
use IteratorAggregate;
use Illuminate\Support\Collection;
use Illuminate\Contracts\Support\Jsonable;
use Illuminate\Contracts\Support\Arrayable;
use Illuminate\Contracts\Pagination\Presenter;
use Illuminate\Contracts\Pagination\LengthAwarePaginator as LengthAwarePaginatorContract;

class LengthAwarePaginator extends AbstractPaginator implements Arrayable, ArrayAccess, Countable, IteratorAggregate, Jsonable, LengthAwarePaginatorContract
{
    /**
     * The total number of items before slicing.
     *
     * @var int
     */
    protected $total;

    /**
     * The last available page.
     *
     * @var int
     */
    protected $lastPage;

    /**
     * Create a new paginator instance.
     *
     * @param  mixed  $items
     * @param  int  $total
     * @param  int  $perPage
     * @param  int|null  $currentPage
     * @param  array  $options (path, query, fragment, pageName)
     * @return void
     */
    public function __construct($items, $total, $perPage, $currentPage = null, array $options = [])
    {
        foreach ($options as $key => $value) {
            $this->{$key} = $value;
        }

        $this->total = $total;
        $this->perPage = $perPage;
        $this->lastPage = (int) ceil($total / $perPage);
        $this->path = $this->path != '/' ? rtrim($this->path, '/') : $this->path;
        $this->currentPage = $this->setCurrentPage($currentPage, $this->lastPage);
        $this->items = $items instanceof Collection ? $items : Collection::make($items);
    }

    /**
     * Get the current page for the request.
     *
     * @param  int  $currentPage
     * @param  int  $lastPage
     * @return int
     */
    protected function setCurrentPage($currentPage, $lastPage)
    {
        $currentPage = $currentPage ?: static::resolveCurrentPage();

        // The page number will get validated and adjusted if it either less than one
        // or greater than the last page available based on the count of the given
        // items array. If it's greater than the last, we'll give back the last.
        if (is_numeric($currentPage) && $currentPage > $lastPage) {
            return $lastPage > 0 ? $lastPage : 1;
        }

        return $this->isValidPageNumber($currentPage) ? (int) $currentPage : 1;
    }

    /**
     * Get the URL for the next page.
     *
     * @return string|null
     */
    public function nextPageUrl()
    {
        if ($this->lastPage() > $this->currentPage()) {
            return $this->url($this->currentPage() + 1);
        }
    }

    /**
     * Determine if there are more items in the data source.
     *
     * @return bool
     */
    public function hasMorePages()
    {
        return $this->currentPage() < $this->lastPage();
    }

    /**
     * Get the total number of items being paginated.
     *
     * @return int
     */
    public function total()
    {
        return $this->total;
    }

    /**
     * Get the last page.
     *
     * @return int
     */
    public function lastPage()
    {
        return $this->lastPage;
    }

    /**
     * Render the paginator using the given presenter.
     *
     * @param  \Illuminate\Contracts\Pagination\Presenter|null  $presenter
     * @return string
     */
    public function render(Presenter $presenter = null)
    {
        if (is_null($presenter) && static::$presenterResolver) {
            $presenter = call_user_func(static::$presenterResolver, $this);
        }

        $presenter = $presenter ?: new BootstrapThreePresenter($this);

        return $presenter->render();
    }

    /**
     * Get the instance as an array.
     *
     * @return array
     */
    public function toArray()
    {
        return [
            'total'         => $this->total(),
            'per_page'      => $this->perPage(),
            'current_page'  => $this->currentPage(),
            'last_page'     => $this->lastPage(),
            'next_page_url' => $this->nextPageUrl(),
            'prev_page_url' => $this->previousPageUrl(),
            'from'          => $this->firstItem(),
            'to'            => $this->lastItem(),
            'data'          => $this->items->toArray(),
        ];
    }

    /**
     * Convert the object to its JSON representation.
     *
     * @param  int  $options
     * @return string
     */
    public function toJson($options = 0)
    {
        return json_encode($this->toArray(), $options);
    }
}
