/** @class This class implement a serializer for the JSON-Cinelab format

    @params DataLoader a dataloader reference

    @url the url from which to get our cinelab

 */

IriSP.JSONSerializer = function(DataLoader, url) {

  IriSP.Serializer.call(this, DataLoader, url);

};

IriSP.JSONSerializer.prototype = new IriSP.Serializer();

/** serialize data */

IriSP.JSONSerializer.prototype.serialize = function(data) {

  return JSON.stringify(data);

};

/** deserialize data */

IriSP.JSONSerializer.prototype.deserialize = function(data) {

  return JSON.parse(data);

};

/** load JSON-cinelab data and also sort the annotations by start time

    @param callback function to call when the data is ready.

 */

IriSP.JSONSerializer.prototype.sync = function(callback) {

  /* we don't have to do much because jQuery handles json for us */

  var self = this;

  var fn = function(data) {      

      self._data = data;      

      // sort the data too     

      self._data["annotations"].sort(function(a, b) 

          { var a_begin = +a.begin;

            var b_begin = +b.begin;

            return a_begin - b_begin;

          });

      callback(data);      

  };

  this._DataLoader.get(this._url, fn);

};

/** @return the metadata about the media being read FIXME: always return the first media. */

IriSP.JSONSerializer.prototype.currentMedia = function() {  

  return this._data.medias[0]; /* FIXME: don't hardcode it */

};

/** searches for an annotation which matches title, description and keyword 

   "" matches any field. 

   Note: it ignores tweets.

   @return a list of matching ids.

*/    

IriSP.JSONSerializer.prototype.searchAnnotations = function(title, description, keyword) {

    /* we can have many types of annotations. We want search to only look for regular segments */

    /* the next two lines are a bit verbose because for some test data, _serializer.data.view is either

       null or undefined.

    */

    var view;

    if (typeof(this._data.views) !== "undefined" && this._data.views !== null)

       view = this._data.views[0];

    var searchViewType = "";

    if(typeof(view) !== "undefined" && typeof(view.annotation_types) !== "undefined" && view.annotation_types.length > 1) {

            searchViewType = view.annotation_types[0];

    }

    var filterfn = function(annotation) {

      if( searchViewType  != "" && 

          typeof(annotation.meta) !== "undefined" && 

          typeof(annotation.meta["id-ref"]) !== "undefined" &&

          annotation.meta["id-ref"] !== searchViewType) {

        return true; // don't pass

      } else {

          return false;

      }

    };

    return this.searchAnnotationsFilter(title, description, keyword, filterfn);

};

/* only look for tweets */

IriSP.JSONSerializer.prototype.searchTweets = function(title, description, keyword) {

    /* we can have many types of annotations. We want search to only look for regular segments */

    /* the next two lines are a bit verbose because for some test data, _serializer.data.view is either

       null or undefined.

    */

    var view;

    if (typeof(this._data.views) !== "undefined" && this._data.views !== null)

       view = this._data.views[0];

    var searchViewType = "";

    if(typeof(view) !== "undefined" && typeof(view.annotation_types) !== "undefined" && view.annotation_types.length > 1) {

            searchViewType = view.annotation_types[0];

    }

    var filterfn = function(annotation) {

      if( searchViewType  != "" && 

          typeof(annotation.meta) !== "undefined" && 

          typeof(annotation.meta["id-ref"]) !== "undefined" &&

          annotation.meta["id-ref"] !== searchViewType) {

        return false; // pass

      } else {

          return true;

      }

    };

    return this.searchAnnotationsFilter(title, description, keyword, filterfn);

};

/**

  search an annotation according to its title, description and keyword

  @param filter a function to filter the results with. Used to select between annotation types.

 */    

IriSP.JSONSerializer.prototype.searchAnnotationsFilter = function(title, description, keyword, filter) {

    var rTitle;

    var rDescription;

    var rKeyword;

    /* match anything if given the empty string */

    if (title == "")

      title = ".*";

    if (description == "")

      description = ".*";

    if (keyword == "")

      keyword = ".*";

    rTitle = new RegExp(title, "i");  

    rDescription = new RegExp(description, "i");  

    rKeyword = new RegExp(keyword, "i");  

    var ret_array = [];

    var i;

    for (i in this._data.annotations) {

      var annotation = this._data.annotations[i];

      /* filter the annotations whose type is not the one we want */

      if (filter(annotation)) {

          continue;

      }

      if (rTitle.test(annotation.content.title) && 

          rDescription.test(annotation.content.description)) {

          /* FIXME : implement keyword support */

          ret_array.push(annotation);

      }

    }

    return ret_array;

};

/** breaks a string in words and searches each of these words. Returns an array

   of objects with the id of the annotation and its number of occurences.

   @param searchString a string of words.

   FIXME: optimize ? seems to be n^2 in the worst case.

*/

IriSP.JSONSerializer.prototype.searchOccurences = function(searchString) {

  var ret = { };

  var keywords = searchString.split(/\s+/);

  for (var i in keywords) {

    var keyword = keywords[i];

    // search this keyword in descriptions and title

    var found_annotations = []

    found_annotations = found_annotations.concat(this.searchAnnotations(keyword, "", ""));

    found_annotations = found_annotations.concat(this.searchAnnotations("", keyword, ""));

    for (var j in found_annotations) {

      var current_annotation = found_annotations[j];

      if (!ret.hasOwnProperty(current_annotation.id)) {

        ret[current_annotation.id] = 1;

      } else {

        ret[current_annotation.id] += 1;

      }

    }

  };

  return ret;

};

/** breaks a string in words and searches each of these words. Returns an array

   of objects with the id of the annotation and its number of occurences.

   FIXME: optimize ? seems to be n^2 in the worst case.

*/

IriSP.JSONSerializer.prototype.searchTweetsOccurences = function(searchString) {

  var ret = { };

  var keywords = searchString.split(/\s+/);

  for (var i in keywords) {

    var keyword = keywords[i];

    // search this keyword in descriptions and title

    var found_annotations = []

    found_annotations = found_annotations.concat(this.searchTweets(keyword, "", ""));

    found_annotations = found_annotations.concat(this.searchTweets("", keyword, ""));

    for (var j in found_annotations) {

      var current_annotation = found_annotations[j];

      if (!ret.hasOwnProperty(current_annotation.id)) {

        ret[current_annotation.id] = 1;

      } else {

        ret[current_annotation.id] += 1;

      }

    }

  };

  return ret;

};

/** returns all the annotations that are displayable at the moment 

   NB: only takes account the first type of annotations - ignores tweets 

   currentTime is in seconds.

   @param currentTime the time at which we search.

 */

IriSP.JSONSerializer.prototype.currentAnnotations = function(currentTime) {

  var view;

  var currentTimeMs = 1000 * currentTime;

  var ret_array = [];

  var i;

  for (i in this._data.annotations) {

    var annotation = this._data.annotations[i];

      ret_array.push(annotation);

  }

  return ret_array;

};

/** returns a list of ids of tweet lines (aka: groups in cinelab) */

IriSP.JSONSerializer.prototype.getTweetIds = function() {

  if (typeof(this._data.lists) === "undefined" || this._data.lists === null)

    return [];

  var tweetsId = [];

  /* first get the list containing the tweets */

  var tweets = IriSP.underscore.filter(this._data.lists, function(entry) { return entry.id.indexOf("tweet") !== -1 });

  // FIXME: collect tweets from multiple sources ?

  tweetsId = IriSP.underscore.pluck(tweets[0].items, "id-ref");

  return tweetsId;

};

/** this function returns a list of lines which are not tweet lines */

IriSP.JSONSerializer.prototype.getNonTweetIds = function() {

  if (typeof(this._data.lists) === "undefined" || this._data.lists === null)

    return [];

  var illegal_values = this.getTweetIds();

  return IriSP.underscore.difference(ids, illegal_values);

};