<?php

namespace Illuminate\Pagination;

use Countable;
use ArrayAccess;
use JsonSerializable;
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\Paginator as PaginatorContract;

class Paginator extends AbstractPaginator implements Arrayable, ArrayAccess, Countable, IteratorAggregate, JsonSerializable, Jsonable, PaginatorContract
{
    /**
     * Determine if there are more items in the data source.
     *
     * @return bool
     */
    protected $hasMore;

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

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

        $this->checkForMorePages();
    }

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

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

    /**
     * Check for more pages. The last item will be sliced off.
     *
     * @return void
     */
    protected function checkForMorePages()
    {
        $this->hasMore = count($this->items) > ($this->perPage);

        $this->items = $this->items->slice(0, $this->perPage);
    }

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

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

    /**
     * Render the paginator using the given presenter.
     *
     * @param  \Illuminate\Contracts\Pagination\Presenter|null  $presenter
     * @return string
     */
    public function links(Presenter $presenter = null)
    {
        return $this->render($presenter);
    }

    /**
     * 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 = $presenter ?: new SimpleBootstrapThreePresenter($this);

        return $presenter->render();
    }

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

    /**
     * Convert the object into something JSON serializable.
     *
     * @return array
     */
    public function jsonSerialize()
    {
        return $this->toArray();
    }

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