<?php
/**
* RssBridgeTwitchApi
* Returns the newest broadcasts or highlights. Be aware that Twitch deletes broadcasts after
* 14 days: http://blog.twitch.tv/2014/08/important-reminder-past-broadcasts-removed-today/
*
* @name Twitch API Bridge
* @homepage http://www.twitch.tv
* @description Returns the newest broadcasts or highlights by channel name using the Twitch API (v3)
* @maintainer logmanoriginal
* @update 2015-07-14
* @use1(text|channel="Channel", list|broadcasts="Show broadcasts=>true;Don't show broadcasts=>false")
* @use2(text|channel="Channel", text|limit="Limit", list|broadcasts="Show broadcasts=>true;Don't show broadcasts=>false")
*
* Description for the API is available on GitHub: https://github.com/justintv/twitch-api
*/

define(TWITCH_LIMIT, 10); // The default limit
define(TWITCH_BROADCASTS, 'false'); // The default flag for broadcasts

class TwitchApiBridge extends BridgeAbstract{
    
	// for use in the getName function!
	private $channel;
    
	public function collectData(array $param){

		/* In accordance with API description: 
		 * "When specifying a version for a request to the Twitch API, set the Accept HTTP header to the API version you prefer." 
		 * Now we prefer v3 right now and need to build the context options. */
		$opts = array('https' =>
			array(
				'method'  => 'GET',
				'header'  => 'Accept: application/vnd.twitchtv.v3+json'
			)
		);
		
		$context = stream_context_create($opts);
		
		$channel = '';
		$limit = TWITCH_LIMIT;
		$broadcasts = TWITCH_BROADCASTS;
		$requests = 1;
		
		if(isset($param['channel'])) {
			$channel = $param['channel'];
		} else {
			$this->returnError('You must specify a valid channel name! Received: &channel=' . $param['channel'], 400);
		}
		
		$this->channel = $channel;
		
		if(isset($param['limit'])) {
			try {
				$limit = (int)$param['limit'];
			} catch (Exception $e){
				$this->returnError('The limit you specified is not valid! Received: &limit=' . $param['limit'] . ' Expected: &limit=<num> where <num> is any integer number.', 400);
			}
		} else {
			$limit = TWITCH_LIMIT;
		}
		
		// The Twitch API allows a limit between 1 .. 100. Therefore any value below must be set to 1, any greater must result in multiple requests.
		if($limit < 1) { $limit = 1; }
		if($limit > 100) { 
			$requests = (int)($limit / 100); 
			if($limit % 100 != 0) { $requests++; }
		}
		
		if(isset($param['broadcasts']) && ($param['broadcasts'] == 'true' || $param['broadcasts'] == 'false')) {
			$broadcasts = $param['broadcasts'];
		} else {
			$this->returnError('The value for broadcasts you specified is not valid! Received: &broadcasts=' . $param['broadcasts'] . ' Expected: &broadcasts=false or &broadcasts=true', 400);
		}
		
		// Build the initial request, see also: https://github.com/justintv/Twitch-API/blob/master/v3_resources/videos.md#get-channelschannelvideos
		$request = '';
		
		if($requests == 1) {
			$request = 'https://api.twitch.tv/kraken/channels/' . $channel . '/videos?limit=' . $limit . '&broadcasts=' . $broadcasts;
		} else {
			$request = 'https://api.twitch.tv/kraken/channels/' . $channel . '/videos?limit=100&broadcasts=' . $broadcasts;
		}
		
		/* Finally we're ready to request data from the API. Each response provides information for the next request. */
		for($i = 0; $i < $requests; $i++) {
			$response = file_get_contents($request, false, $context);
			
			if($response == false) { 
				$this->returnError('Request failed! Check if the channel name is valid!', 400); 
			}
			
			$data = json_decode($response);
			
			foreach($data->videos as $video) {
				$item = new \Item();
				$item->id = $video->_id;
				$item->uri = $video->url;
				$item->thumbnailUri = $video->preview;
				$item->title = htmlspecialchars($video->title);
				$item->timestamp = strtotime($video->recorded_at);
				$item->content = '<a href="' . $item->uri . '"><img src="' . $item->thumbnailUri . '" /></a><br><a href="' . $item->uri . '">' . $item->title . '</a>';
				$this->items[] = $item;
				
				// Stop once the number of requested items is reached
				if(count($this->items) >= $limit) {
					break;
				}
			}
			
			// Get next request (if available)
			if(isset($data->_links->next)) {
				$request = $data->_links->next;
			} else {
				break;
			}
		}
	}

	public function getName(){
		return (!empty($this->channel) ? $this->channel . ' - ' : '') . 'Twitch API Bridge';
	}

	public function getURI(){
		return 'https://www.twitch.tv';
	}

	public function getCacheDuration(){
		return 10800; // 3 hours
	}
}
?>