<?php

namespace Providers;

abstract class Provider {

    protected $_options = [];
    protected $_feed = NULL;
    protected $_cacheTimeout = '15 minutes';
    protected $_cacheTime;

    public function __construct($feed, $options=[]) {
        $this->_feed = $feed;
        $this->_options = $options;
    }

    abstract protected function _getCachePath();

    protected function _getCache($path) {
        return file_get_contents($path);
    }

    abstract protected function _fetchItems();

    abstract protected function _spamFilter($items);

    abstract protected function _mapItems($content);

    abstract protected function _sortContent($content);

    protected function _getItems() {
        $cacheFile = sprintf($this->_getCachePath(), $this->_feed);
        $this->_cacheTime = file_exists($cacheFile) ? filemtime($cacheFile) : PHP_INT_MIN;
        if ($this->_cacheTime > strtotime('-' . $this->_cacheTimeout)) {
            return unserialize($this->_getCache($cacheFile));
        } else {
            $content = $this->_fetchItems();
            if (empty($content) && file_exists($cacheFile)) {
                return unserialize($this->_getCache($cacheFile));
            }
            file_put_contents($cacheFile, serialize($content));
            $this->_cacheTime = time();
            return $content;
        }
    }

    protected function _filterItemContent($items) {
        if (in_array('noemoji', $this->_options)) {
            $dictionary = json_decode(file_get_contents('../config/emoji.json'), TRUE);
            $filtered = [];
            foreach ($items as $item) {
                foreach (['Title', 'Text'] as $field) {
                    $item->{$field} = strtr($item->{$field}, $dictionary);
                }
            }
        }
        if (array_key_exists('title', $this->_options)) {
            $keyword = strtolower($this->_options['title']);
            $items = array_filter($items, function($item) use($keyword) {
                return str_contains(strtolower($item->Title), $keyword);
            });
        }
        return $items;
    }

    public function get() {
        $items = $this->_getItems();
        if (isset($this->_options['spamfilter'])) {
            $items = $this->_spamFilter($items);
        }
        return $this->_sortContent(
            $this->_filterItemContent(
                $this->_mapItems($items)
            )
        );
    }

    public function cacheTime() {
        return $this->_cacheTime;
    }

    abstract public function title();

}

?>