var query = require( 'querystring' ),
	http = require( 'http' );

var client = http.createClient( 80, "search.twitter.com" );

var TwitterSearch = function ( refreshInterval ) {
	this.events = {};

	this.timeoutFn = undefined;

	this.searchPath = "/search.json";

	this.refreshInterval = refreshInterval || 5000;

	this.searchRegistry = {};

	this.tweetRegistry = {};

	this.defaultSearch = {};

	this.nextSearch = undefined;
};

TwitterSearch.prototype = {
	search : function ( searchTerm ) {
		clearTimeout( this.timeoutFn );
		this.raiseEvent( "search.init", searchTerm );
		this.defaultSearch = {
			q : searchTerm,
			result_type : "recent",
			rpp : 100
		};
		this.nextSearch = undefined;
		this.searchRegistry = {};
		this.tweetRegistry = {};
		this.runSearch();
	},
	on : function ( eventName, callback ) {
		if ( !this.events[ eventName ] ) {
			this.events[ eventName ] = [];
		}
		this.events[ eventName ].push( callback );
		return function () {
			this.events[ eventName ] = _.without( this.events[ eventName ], callback );
		}.bind( this );
	},
	raiseEvent : function ( eventName, data ) {
		if ( this.events[ eventName ] ) {
			this.events[ eventName ].forEach( function ( callback ) {
				callback( data );
			} );
		}
	},
	buildUrl : function () {
		var srchQry;
		if ( this.nextSearch ) {
			srchQry = this.nextSearch;
		}
		else {
			if ( !this.defaultSearch.since_id ) {
				delete this.defaultSearch.since_id;
			}
			srchQry = "?" + query.stringify( this.defaultSearch );
		}
		return this.searchPath + srchQry;
	},

	runSearch : function () {
		var url = this.buildUrl();
		if ( !this.searchRegistry[url] ) {
			this.searchRegistry[url] = true;
			this.raiseEvent( "search.current", { url : url } );
			var request = client.request( "GET", url, {"host" : "search.twitter.com"} );
			request.addListener( "response", function ( response ) {
				var body = "";
				response.addListener( "data", function ( data ) {
					body += data;
				} );

				response.addListener( "end", function () {
					this.onSearched( JSON.parse( body ) );
				}.bind( this ) );
				this.timeoutFn = setTimeout( this.runSearch.bind( this ), this.refreshInterval );
			}.bind( this ) );
			request.end();
		}
		else {
			this.raiseEvent( "search.nodata", { url : url } );
			this.timeoutFn = setTimeout( this.runSearch.bind( this ), this.refreshInterval );
		}
	},
	onSearched : function ( payload ) {
		// sift out errors
		if ( !payload.error ) {
			if ( payload.results.length > 0 ) {
				this.processTweets( payload.results );
			}
			// do we have a next page option?  If so, let's use it
			if ( payload.next_page ) {
				this.nextSearch = payload.next_page;
			}
			if ( payload.max_id ) {
				this.defaultSearch.since_id = payload.max_id;
			}
		}
		else {
			this.nextSearch = undefined;
		}
	},
	processTweets : function ( tweets ) {
		var newTweets = tweets.filter( function ( t ) {
			return !this.tweetRegistry[t];
		}, this );
		newTweets.forEach( function ( tweet ) {
			if ( !this.tweetRegistry[tweet.id] ) {
				this.tweetRegistry[tweet.id] = true;
			}
			// deal with the images that consistently fail from twitter...
			if ( tweet.profile_image_url === "http://twitter.com/images/default_profile_normal.png" ||
			     tweet.profile_image_url === "http://static.twitter.com/images/default_profile_normal.png" ) {
				tweet.profile_image_url = "templates/images/default_profile_1_normal.png";
			}
		}, this );
		this.raiseEvent( "newTweets", newTweets );
	}
};


module.exports = TwitterSearch;