<?php
class PatreonBridge extends BridgeAbstract {
	const NAME = 'Patreon Bridge';
	const URI = 'https://www.patreon.com/';
	const CACHE_TIMEOUT = 300; // 5min
	const DESCRIPTION = 'Returns posts by creators on Patreon';
	const MAINTAINER = 'Roliga';
	const PARAMETERS = array( array(
		'creator' => array(
			'name' => 'Creator',
			'type' => 'text',
			'required' => true,
			'title' => 'Creator name as seen in their page URL'
		)
	));

	public function collectData(){
		$html = getSimpleHTMLDOMCached($this->getURI(), 86400)
			or returnServerError('Failed to load creator page at ' . $this->getURI());
		$regex = '#/api/campaigns/([0-9]+)#';
		if(preg_match($regex, $html->save(), $matches) > 0) {
			$campaign_id = $matches[1];
		} else {
			returnServerError('Could not find campaign ID');
		}

		$query = array(
			'include' => implode(',', array(
				'user',
				'attachments',
				'user_defined_tags',
				//'campaign',
				//'poll.choices',
				//'poll.current_user_responses.user',
				//'poll.current_user_responses.choice',
				//'poll.current_user_responses.poll',
				//'access_rules.tier.null',
				//'images.null',
				//'audio.null'
			)),
			'fields' => array(
				'post' => implode(',', array(
					//'change_visibility_at',
					//'comment_count',
					'content',
					//'current_user_can_delete',
					//'current_user_can_view',
					//'current_user_has_liked',
					//'embed',
					'image',
					//'is_paid',
					//'like_count',
					//'min_cents_pledged_to_view',
					//'patreon_url',
					//'patron_count',
					//'pledge_url',
					//'post_file',
					//'post_metadata',
					//'post_type',
					'published_at',
					'teaser_text',
					//'thumbnail_url',
					'title',
					//'upgrade_url',
					'url',
					//'was_posted_by_campaign_owner'
				)),
				'user' => implode(',', array(
					//'image_url',
					'full_name',
					//'url'
				))
			),
			'filter' => array(
				'contains_exclusive_posts' => true,
				'is_draft' => false,
				'campaign_id' => $campaign_id
			),
			'sort' => '-published_at'
		);
		$posts = $this->apiGet('posts', $query);

		foreach($posts->data as $post) {
			$item = array(
				'uri' => $post->attributes->url,
				'title' => $post->attributes->title,
				'timestamp' => $post->attributes->published_at,
				'content' => '',
				'uid' => 'patreon.com/' . $post->id
			);

			$user = $this->findInclude($posts,
				'user',
				$post->relationships->user->data->id);
			$item['author'] = $user->full_name;

			if(isset($post->attributes->image))
				$item['content'] .= '<p><a href="'
					. $post->attributes->url
					. '"><img src="'
					. $post->attributes->image->thumb_url
					. '" /></a></p>';

			if(isset($post->attributes->content)) {
				$item['content'] .= $post->attributes->content;
			} elseif (isset($post->attributes->teaser_text)) {
				$item['content'] .= '<p>'
					. $post->attributes->teaser_text
					. '</p>';
			}

			if(isset($post->relationships->user_defined_tags)) {
				$item['categories'] = array();
				foreach($post->relationships->user_defined_tags->data as $tag) {
					$attrs = $this->findInclude($posts, 'post_tag', $tag->id);
					$item['categories'][] = $attrs->value;
				}
			}

			if(isset($post->relationships->attachments)) {
				$item['enclosures'] = array();
				foreach($post->relationships->attachments->data as $attachment) {
					$attrs = $this->findInclude($posts, 'attachment', $attachment->id);
					$item['enclosures'][] = $attrs->url;
				}
			}

			$this->items[] = $item;
		}
	}

	/*
	 * Searches the "included" array in an API response and returns attributes
	 * for the first match.
	 */
	private function findInclude($data, $type, $id) {
		foreach($data->included as $include)
			if($include->type === $type && $include->id === $id)
				return $include->attributes;
	}

	private function apiGet($endpoint, $query_data = array()) {
		$query_data['json-api-version'] = 1.0;
		$query_data['json-api-use-default-includes'] = 0;

		$url = 'https://www.patreon.com/api/'
			. $endpoint
			. '?'
			. http_build_query($query_data);

		/*
		 * Accept-Language header and the CURL cipher list are for bypassing the
		 * Cloudflare anti-bot protection on the Patreon API. If this ever breaks,
		 * here are some other project that also deal with this:
		 * https://github.com/mikf/gallery-dl/issues/342
		 * https://github.com/daemionfox/patreon-feed/issues/7
		 * https://www.patreondevelopers.com/t/api-returning-cloudflare-challenge/2025
		 * https://github.com/splitbrain/patreon-rss/issues/4
		 */
		$header = array(
			'Accept-Language: en-US',
			'Content-Type: application/json'
		);
		$opts = array(
			CURLOPT_SSL_CIPHER_LIST => implode(':', array(
				'DEFAULT',
				'!DHE-RSA-CHACHA20-POLY1305'
			))
		);

		$data = json_decode(getContents($url, $header, $opts))
			or returnServerError('API request to "' . $url . '" failed.');

		return $data;
	}

	public function getName(){
		if(!is_null($this->getInput('creator')))
			return $this->getInput('creator') . ' posts';

		return parent::getName();
	}

	public function getURI(){
		if(!is_null($this->getInput('creator')))
			return self::URI . $this->getInput('creator');

		return parent::getURI();
	}

	public function detectParameters($url){
		$params = array();

		// Matches e.g. https://www.patreon.com/SomeCreator
		$regex = '/^(https?:\/\/)?(www\.)?patreon\.com\/([^\/&?\n]+)/';
		if(preg_match($regex, $url, $matches) > 0) {
			$params['creator'] = urldecode($matches[3]);
			return $params;
		}

		return null;
	}
}