<?php

namespace Providers;

require_once('HtmlFeed.php');
require_once('Item.php');

class Pagediff extends \Providers\HtmlFeed {

    protected $_cacheTimeout = '1 hour';

    public function __construct($feed, $options=[]) {
        $config = json_decode(file_get_contents('../config/pagediff.json'), TRUE);
        if (!isset($config[$feed])) {
            throw new \Exception(sprintf('Feed %s not configured', $feed));
        }
        $this->_config = $config[$feed];
        parent::__construct($feed, $options);
    }

    protected function _getCachePath() {
        return '../cache/pagediff.%s';
    }

    protected function _getFeedUrl($feed) {
        return $this->_config['url'];
    }

    private function _getItemCachePath() {
        return sprintf('../cache/pagediff.items.%s', $this->_feed);
    }

    private function _getCachedContent() {
        if (!file_exists($this->_getItemCachePath())) {
            return [];
        }
        return unserialize(
            file_get_contents(
                $this->_getItemCachePath()
            )
        );
    }

    private function _saveCachedContent($content) {
        return file_put_contents(
            $this->_getItemCachePath(),
            serialize($content)
        );
    }

    private function _getContentFromSelector($tree, $selector) {
        $node = $tree->find($selector['node']);
        if ($node->count() == 0) {
            return NULL;
        }
        if ($node->count() != 1) {
            if (isset($selector['index'])) {
                $node = $node->eq($selector['index']);
            } else {
                $node = $node->first();
            }
        }
        if (isset($selector['html'])) {
            return $node->innerHTML();
        }
        if (isset($selector['attr'])) {
            $text = $node->attr()[$selector['attr']];
        } else {
            $text = $node->text();
        }
        if (isset($selector['transform'])) {
            $text = sprintf($selector['transform'], $text);
        }
        return $text;
    }

    protected function _parseFeedContent($tree) {
        $selectors = $this->_config['selectors'];
        $items = $this->_getCachedContent();
        $currentItem = [];
        foreach (['id', 'link', 'name', 'text'] as $type) {
            $currentItem[$type] = $this->_getContentFromSelector($tree, $selectors[$type]);
        }
        $currentItem['time'] = date('Y-m-d H:i:s');
        if (!count($items) || $currentItem['id'] != $items[0]['id']) {
            $items = array_merge([$currentItem], $items);
            $this->_saveCachedContent($items);
        }
        return $items;
    }

    protected function _mapItems($items) {
        return array_map(function($item) {
            $i = new Item();
            $i->ID = $item['id'];
            $i->Title = $item['name'];
            $i->Time = $item['time'];
            $i->Text = $item['text'];
            $i->Link = $item['link'];
            return $i;
        }, $items);
    }

    public function title() {
        return $this->_config['title'];
    }

}

?>