<?php

namespace bff\modules\seo;

use bff;
use Url;
use Lang;
use HTML;

class Canonical
{
    /** @var Template */
    public $template;
    /** @var string url */
    public $url;
    /** @var array url query */
    public $query = [];
    /** @var bool Add pages to index */
    public $pagesCanonical = true;
    /** @var array meta cache */
    protected $meta = [];

    public function __construct(Template $template, string $url, array $query = [])
    {
        $this->template = $template;

        $this->setUrl($url, $query);

        $this->pagesCanonical = bff::config('seo.pages.canonical', true, TYPE_BOOL);
    }

    /**
     * @param string $url
     * @param array $query
     */
    public function setUrl(string $url, array $query = [])
    {
        $this->url = $url;
        $this->query = $query;
    }

    /**
     * @param array $query
     * @param string $url
     * @return string
     */
    public function queryToString(array $query, string $url): string
    {
        if (empty($query)) {
            return '';
        }

        # Skip first 'page' and 'total' pages counter
        foreach ($query as $key => $value) {
            if (empty($value) || ($key == 'page' && $value < 2) || $key === 'total') {
                unset($query[$key]);
            }
        }

        # Exclude 'page' from canonical url
        if (! $this->pagesCanonical) {
            unset($query['page']);
        }

        return Url::query($query, [], (strpos($url, '?') === false ? '?' : '&'));
    }

    /**
     * Get final meta tags
     * @param string $language
     * @param bool|array $landing active landing page or false
     * @return array
     */
    public function getMeta(string $language, $landing): array
    {
        if ($this->meta) {
            return $this->meta;
        }

        # Use landing uri
        if ($landing !== false) {
            $url = $landing['landing_uri'];
            if (Lang::getLanguageUrlPrefix() !== '/') {
                # {sitehost}/(lang1|lang2|...)/.* => {sitehost}/
                $url = preg_replace(
                    '/' . preg_quote(Url::HOST_PLACEHOLDER) . '\/(' . join('|', Lang::getLanguages()) . ')\/.*/U',
                    Url::HOST_PLACEHOLDER . '/',
                    $url
                );
            }
            if (empty($landing['joined'])) {
                $this->template->index();
            }
        } else {
            $url = $this->url;
        }

        # Noindex => no meta
        if (! $this->template->index) {
            return $this->meta;
        }

        # Add query
        $url .= $this->queryToString($this->query, $url);

        # Dynamic url => final url
        if (Url::isDynamic($url)) {
            $scheme = (bff::config('https.canonical', false) ? 'https' : false);
            $languages = Lang::getLanguages(true, Lang::getHiddenLocalesList());
            if (sizeof($languages) > 1) {
                foreach ($languages as $lng) {
                    # alternate meta
                    $tag = [
                        'rel' => 'alternate',
                        'hreflang' => $lng,
                        'href' => Url::dynamic($url, [], ['lang' => $lng, 'scheme' => $scheme]),
                    ];
                    $this->meta['link-alternate-' . $lng] = array_merge($tag, [
                        'tag' => 'link',
                        'html' => '<link' . HTML::attributes($tag) . ' />',
                    ]);
                }
            }
            $url = Url::dynamic($url, [], ['lang' => $language, 'scheme' => $scheme]);
        }

        # canonical meta
        $tag = [
            'rel' => 'canonical',
            'href' => $url,
        ];
        $this->meta['link-canonical'] = array_merge($tag, [
            'tag' => 'link',
            'html' => '<link' . HTML::attributes($tag) . ' />',
        ]);

        return $this->meta;
    }
}