import groovy.json.JsonSlurper

import org.serviio.library.metadata.*
import org.serviio.library.online.*

/**
 * YouTube.com content URL extractor plugin. 
 * 
 * It uses YouTube API v3 for retrieving playlists. 
 * 
 * @see http://en.wikipedia.org/wiki/Youtube#Quality_and_codecs
 *  
 * @author Petr Nejedly
 *
 */
class YouTube extends WebResourceUrlExtractor {

    final VALID_RESOURCE_URL = '^https?://www.googleapis.com/youtube/.*$'
	/* Listed in order of quality */
    final availableFormats = ['37', '46', '22', '45', '35', '34', '18', '44', '43', '6', '5']
    
    String getExtractorName() {
        return getClass().getName()
    }
    
    boolean extractorMatches(URL feedUrl) {
        return feedUrl ==~ VALID_RESOURCE_URL
    }
	
	public int getVersion() {
		return 3;
	}
	
	@Override
	WebResourceContainer extractItems(URL resourceUrl, int maxItemsToRetrieve) {
      final user_agent = "Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; Trident/6.0)"
      final api_key = "AIzaSyAPeRAlHMSa_WQMbarc_ffse7-t0-DOuVQ" // this is Serviio API key, don't use it for anything else please, they are easy to get

      if (maxItemsToRetrieve == -1) maxItemsToRetrieve = 50
	  
	  if (resourceUrl.toString().contains("channels")){
		def channelUrl = new URL(resourceUrl.toString() + "&part=contentDetails" + "&maxResults=" + maxItemsToRetrieve + "&key=" + api_key)  
		def channeljson = new JsonSlurper().parseText(openURL(channelUrl, user_agent))
		def uploadPlaylist = channeljson.items[0].contentDetails.relatedPlaylists.uploads
			 
		resourceUrl = new URL("https://www.googleapis.com/youtube/v3/playlistItems?playlistId=$uploadPlaylist")
	  }	  
	   	  
      def apiUrl = new URL(resourceUrl.toString() + "&part=snippet" + "&maxResults=" + maxItemsToRetrieve + "&key=" + api_key)

      def json = new JsonSlurper().parseText(openURL(apiUrl, user_agent))

      def items = []

      json.items.each() {
         if (it.snippet.title != "Deleted video") {
            items.add(new WebResourceItem(title : it.snippet.title, 
										  additionalInfo : ['videoId' : it.snippet.resourceId.videoId, 'thumb' : it.snippet.thumbnails.high.url]))
         }
      }
	  
	  def containerThumbnailUrl = items?.find { it -> it.additionalInfo['thumb'] != null }?.additionalInfo['thumb']

      return new WebResourceContainer(items: items, thumbnailUrl: containerThumbnailUrl)
    }

	@Override
	protected ContentURLContainer extractUrl(WebResourceItem wrItem, PreferredQuality requestedQuality) {
		
        def contentUrl
		def expiryDate
		def expiresImmediately
		def cacheKey
		
        def videoId = wrItem.additionalInfo['videoId']
		def thumbnailUrl = wrItem.additionalInfo['thumb']
		
        for (elType in ['&el=embedded', '&el=detailpage', '&el=vevo', '']) {           
            def videoInfoUrl = "http://www.youtube.com/get_video_info?&video_id=$videoId$elType&ps=default&eurl=&gl=US&hl=en"
            //log("Loading video info: $videoInfoUrl")
            def videoInfoWebPage = new URL(videoInfoUrl).getText()
            def parameters = [:]
        
            videoInfoWebPage.split('&').each{item -> addParameter(item, parameters, '=')}
            if(parameters.containsKey('token')) {		
	            def formatUrlMapString = parameters['fmt_url_map']    
				def urlEncodedUrlMapString = parameters['url_encoded_fmt_stream_map']
				def adaptiveFormatsMapString = parameters['adaptive_fmts']
				def allFormatUrlMap = [:]
				
				def test = URLDecoder.decode(adaptiveFormatsMapString,'UTF-8').split(',').each{item -> addParameter(item, allFormatUrlMap, '\\|')}
				
				if (formatUrlMapString != null && formatUrlMapString.length() > 0 ) {
					URLDecoder.decode(formatUrlMapString,'UTF-8').split(',').each{item -> addParameter(item, allFormatUrlMap, '\\|')}						
				} else {				 
					if (urlEncodedUrlMapString != null && urlEncodedUrlMapString.length() > 0 ) { 					
						processStreamData(urlEncodedUrlMapString, allFormatUrlMap)
					}	
					if (adaptiveFormatsMapString != null && adaptiveFormatsMapString.length() > 0 ) {
						processStreamData(adaptiveFormatsMapString, allFormatUrlMap)
					}
				}
			   // get available formats for requested quality, sorted by quality from highest
			   def formatUrlMap = new LinkedHashMap()
			   if(requestedQuality == PreferredQuality.HIGH) {
				   // best quality, get the first from the list
				   sortAvailableFormatUrls(availableFormats, allFormatUrlMap, formatUrlMap)
				   def selectedUrl = formatUrlMap.entrySet().toList().head()
				   contentUrl = selectedUrl.getValue()
				   cacheKey = getCacheKey(videoId, selectedUrl.getKey())
			   } else if (requestedQuality == PreferredQuality.MEDIUM) {
				   // work with subset of available formats, starting at the position of format 35 and then take the best quality from there
				   sortAvailableFormatUrls(availableFormats.getAt(4..availableFormats.size-1), allFormatUrlMap, formatUrlMap)
				   def selectedUrl = formatUrlMap.entrySet().toList().head()
				   contentUrl = selectedUrl.getValue()
				   cacheKey = getCacheKey(videoId, selectedUrl.getKey())
			   } else {
				   // worst quality, take the last url
				   sortAvailableFormatUrls(availableFormats, allFormatUrlMap, formatUrlMap)
				   def selectedUrl = formatUrlMap.entrySet().toList().last()
				   contentUrl = selectedUrl.getValue()
				   cacheKey = getCacheKey(linkUrl, selectedUrl.getKey())
			   }			  
			   if(contentUrl != null) {
				   expiresImmediately = true
				   if(contentUrl.startsWith('http')) {
					   // http URL
					   def contentUrlParameters = [:]
					   contentUrl.split('&').each{item -> addParameter(item, contentUrlParameters, '=')}
					   if( contentUrlParameters['expire'] != null ) {   
						   //log(Long.parseLong(contentUrlParameters['expire']).toString())
						   expiryDate = new Date(Long.parseLong(contentUrlParameters['expire'])*1000)
						   expiresImmediately = false
					   }
				   } else {
				   		// rtmp URL
				   		def rtmpMatcher = contentUrl =~ 'rtmpe?://.*?/(.*)'
						def app = rtmpMatcher[0][1]
						// TODO load swf player URL from the HTML page
				   		contentUrl = "$contentUrl app=$app swfUrl=http://s.ytimg.com/yt/swfbin/watch_as3-vflg0Q-LP.swf swfVfy=1"
				   }	
			   }
                
                break
            }
        }    
        return new ContentURLContainer(fileType: MediaFileType.VIDEO, contentUrl: contentUrl, thumbnailUrl: thumbnailUrl, expiresOn: expiryDate, expiresImmediately: expiresImmediately, cacheKey: cacheKey)
    }
 
    def addParameter(parameterString, parameters, separator) {
        def values = parameterString.split(separator)
        if( values.length == 2 ) {    
             parameters.put(values[0], values[1])
        }
    }   
	
	def processStreamData(String urlEncodedUrlMapString, Map streamsMap ) {
		URLDecoder.decode(urlEncodedUrlMapString,'UTF-8').split(',').each{item ->
			def streamParams = [:]
			item.split('&').each{item2 -> addParameter(item2, streamParams, '=')}
			String urlKeyName = streamParams.containsKey('url') ? 'url' : 'conn'
			//String stream = URLDecoder.decode(streamParams['stream'],'UTF-8') //TODO stream is playpath
			String streamUrl = URLDecoder.decode(streamParams[urlKeyName],'UTF-8')
			String signature = streamParams['sig']
			if(signature) streamUrl = streamUrl + "&signature=" + signature
			streamsMap.put(streamParams['itag'], streamUrl )
		}
	}

	def String getCacheKey(String videoId, String qualityId) {
		"youtube_${videoId}_${qualityId}"
	}
		
	def sortAvailableFormatUrls(List formatIds, Map sourceMap, Map targetMap) {
		formatIds.each{formatId ->
			if(sourceMap.containsKey(formatId) ) {				
				 targetMap.put(formatId, sourceMap.get(formatId))
			}
		}
	}
    
    static void main(args) {
		// this is just to test
        YouTube extractor = new YouTube()
		
		assert extractor.extractorMatches( new URL("https://www.googleapis.com/youtube/v3/playlistItems?playlistId=YOUR_PLAYLIST_ID_HERE") )
		assert !extractor.extractorMatches( new URL("http://google.com/feeds/api/standardfeeds/top_rated?time=today") )
		
		
		WebResourceContainer container = extractor.extractItems( new URL("https://www.googleapis.com/youtube/v3/playlistItems?playlistId=PL5D6FB3CCE0053D01"), 10)
		println container
		ContentURLContainer result = extractor.extractUrl(container.getItems()[2], PreferredQuality.MEDIUM)
		println result
		
    }

}