/*
 *
 * Copyright (c) 2008-2010, Felix Bruns <felixbruns@web.de>
 *
 */
var crypto = require('crypto'),
    http = require('http'),
    querystring = require('querystring');

exports.LastFM = function LastFM(options){
	/* Set default values for required options. */
	var apiKey    = options.apiKey    || '';
	var apiSecret = options.apiSecret || '';
	var apiUrl    = options.apiUrl    || 'ws.audioscrobbler.com';
	var apiPort    = options.apiPort    || 80; 
    var apiVersion = options.apiVersion || '/2.0/';

	/* Set API key. */
	this.setApiKey = function(_apiKey){
		apiKey = _apiKey;
	};

	/* Set API key. */
	this.setApiSecret = function(_apiSecret){
		apiSecret = _apiSecret;
	};

	/* Set API URL. */
	this.setApiUrl = function(_apiUrl){
		apiUrl = _apiUrl;
	};


	/* Internal call (POST, GET). */
	var internalCall = function(params, callbacks, requestMethod){
        params.format = 'json';
        params = querystring.stringify(params);
        if (requestMethod == 'POST') {
            var options = {
                host: apiUrl,
                port: apiPort,
                path: apiVersion,
                method: requestMethod 
            }; 
            var request = http.request(options, dataHandler);
            request.on('error', errorHandler);
            request.setHeader('Content-Length', params.length);
            request.setHeader('Content-Type', 'application/x-www-form-urlencoded');
            request.end(params);
        } else {
            var options = {
                host: apiUrl,
                port: apiPort,
                path: apiVersion + '?' + params
            }; 
            http.get(options,dataHandler).on('error', errorHandler);
        }

        function errorHandler(e) {
            if(callbacks && (typeof(callbacks.error) === 'function')){
                callbacks.error(-1, e.message);
            }
        }

        function dataHandler(response) {
            var data = "";
            response.setEncoding('utf8');
            response.on('data', function(chunk) {
                if (response.statusCode == 200 && typeof(data.error) === 'undefined') {
                    data += chunk;
                }
            });
            response.on('end', function() {
                var statusCode = response.statusCode;
                if (statusCode != 200) {
                    if(callbacks && (typeof(callbacks.error) === 'function')){
                        callbacks.error(statusCode, data);
                    }
                } else if(typeof(data.error) !== 'undefined'){
                    if(callbacks && (typeof(callbacks.error) === 'function')){
                        callbacks.error(data.error, data.message);
                    }
                } else if(callbacks && (typeof(callbacks.success) === 'function')) {
                    callbacks.success(JSON.parse(data));
                }
            });
        }
	};

	/* Normal method call. */
	var call = function(method, params, callbacks, requestMethod){
		/* Set default values. */
		params        = params        || {};
		callbacks     = callbacks     || {};
		requestMethod = requestMethod || 'GET';

		/* Add parameters. */
		params.method  = method;
		params.api_key = apiKey;
		/* Call method. */
		internalCall(params, callbacks, requestMethod);
	};

	/* Signed method call. */
	var signedCall = function(method, params, session, callbacks, requestMethod){
		/* Set default values. */
		params        = params        || {};
		callbacks     = callbacks     || {};
		requestMethod = requestMethod || 'GET';

		/* Add parameters. */
		params.method  = method;
		params.api_key = apiKey;

		/* Add session key. */
		if(session && typeof(session.key) != 'undefined'){
			params.sk = session.key;
		}

		/* Get API signature. */
		params.api_sig = auth.getApiSignature(params);

		/* Call method. */
		internalCall(params, callbacks, requestMethod);
	};

	/* Album methods. */
	this.album = {
		addTags : function(params, session, callbacks){
			/* Build comma separated tags string. */
			if(typeof(params.tags) == 'object'){
				params.tags = params.tags.join(',');
			}

			signedCall('album.addTags', params, session, callbacks, 'POST');
		},

		getBuylinks : function(params, callbacks){
			call('album.getBuylinks', params, callbacks);
		},

		getInfo : function(params, callbacks){
			call('album.getInfo', params, callbacks);
		},

		getTags : function(params, session, callbacks){
			signedCall('album.getTags', params, session, callbacks);
		},

		removeTag : function(params, session, callbacks){
			signedCall('album.removeTag', params, session, callbacks, 'POST');
		},

		search : function(params, callbacks){
			call('album.search', params, callbacks);
		},

		share : function(params, session, callbacks){
			/* Build comma separated recipients string. */
			if(typeof(params.recipient) == 'object'){
				params.recipient = params.recipient.join(',');
			}

			signedCall('album.share', params, callbacks);
		}
	};

	/* Artist methods. */
	this.artist = {
		addTags : function(params, session, callbacks){
			/* Build comma separated tags string. */
			if(typeof(params.tags) == 'object'){
				params.tags = params.tags.join(',');
			}

			signedCall('artist.addTags', params, session, callbacks, 'POST');
		},

		getCorrection : function(params, callbacks){
			call('artist.getCorrection', params, callbacks);
		},

		getEvents : function(params, callbacks){
			call('artist.getEvents', params, callbacks);
		},

		getImages : function(params, callbacks){
			call('artist.getImages', params, callbacks);
		},

		getInfo : function(params, callbacks){
			call('artist.getInfo', params, callbacks);
		},

		getPastEvents : function(params, callbacks){
			call('artist.getPastEvents', params, callbacks);
		},

		getPodcast : function(params, callbacks){
			call('artist.getPodcast', params, callbacks);
		},

		getShouts : function(params, callbacks){
			call('artist.getShouts', params, callbacks);
		},

		getSimilar : function(params, callbacks){
			call('artist.getSimilar', params, callbacks);
		},

		getTags : function(params, session, callbacks){
			signedCall('artist.getTags', params, session, callbacks);
		},

		getTopAlbums : function(params, callbacks){
			call('artist.getTopAlbums', params, callbacks);
		},

		getTopFans : function(params, callbacks){
			call('artist.getTopFans', params, callbacks);
		},

		getTopTags : function(params, callbacks){
			call('artist.getTopTags', params, callbacks);
		},

		getTopTracks : function(params, callbacks){
			call('artist.getTopTracks', params, callbacks);
		},

		removeTag : function(params, session, callbacks){
			signedCall('artist.removeTag', params, session, callbacks, 'POST');
		},

		search : function(params, callbacks){
			call('artist.search', params, callbacks);
		},

		share : function(params, session, callbacks){
			/* Build comma separated recipients string. */
			if(typeof(params.recipient) == 'object'){
				params.recipient = params.recipient.join(',');
			}

			signedCall('artist.share', params, session, callbacks, 'POST');
		},

		shout : function(params, session, callbacks){
			signedCall('artist.shout', params, session, callbacks, 'POST');
		}
	};

	/* Auth methods. */
	this.auth = {
		getMobileSession : function(params, callbacks){
			/* Set new params object with authToken. */
			params = {
				username  : params.username,
				authToken : util.md5(params.username + util.md5(params.password))
			};

			signedCall('auth.getMobileSession', params, null, callbacks);
		},

		getSession : function(params, callbacks){
			signedCall('auth.getSession', params, null, callbacks);
		},

		getToken : function(callbacks){
			signedCall('auth.getToken', null, null, callbacks);
		},

		/* Deprecated. Security hole was fixed. */
		getWebSession : function(callbacks){
			/* Save API URL and set new one (needs to be done due to a cookie!). */
			var previuousApiUrl = apiUrl;

			apiUrl = 'http://ext.last.fm/2.0/';

			signedCall('auth.getWebSession', null, null, callbacks);

			/* Restore API URL. */
			apiUrl = previuousApiUrl;
		}
	};

	/* Chart methods. */
	this.chart = {
		getHypedArtists : function(params, session, callbacks){
			call('chart.getHypedArtists', params, callbacks);
		},

		getHypedTracks : function(params, session, callbacks){
			call('chart.getHypedTracks', params, callbacks);
		},

		getLovedTracks : function(params, session, callbacks){
			call('chart.getLovedTracks', params, callbacks);
		},

		getTopArtists : function(params, session, callbacks){
			call('chart.getTopArtists', params, callbacks);
		},

		getTopTags : function(params, session, callbacks){
			call('chart.getTopTags', params, callbacks);
		},

		getTopTracks : function(params, session, callbacks){
			call('chart.getTopTracks', params, callbacks);
		}
	};

	/* Event methods. */
	this.event = {
		attend : function(params, session, callbacks){
			signedCall('event.attend', params, session, callbacks, 'POST');
		},

		getAttendees : function(params, session, callbacks){
			call('event.getAttendees', params, callbacks);
		},

		getInfo : function(params, callbacks){
			call('event.getInfo', params, callbacks);
		},

		getShouts : function(params, callbacks){
			call('event.getShouts', params, callbacks);
		},

		share : function(params, session, callbacks){
			/* Build comma separated recipients string. */
			if(typeof(params.recipient) == 'object'){
				params.recipient = params.recipient.join(',');
			}

			signedCall('event.share', params, session, callbacks, 'POST');
		},

		shout : function(params, session, callbacks){
			signedCall('event.shout', params, session, callbacks, 'POST');
		}
	};

	/* Geo methods. */
	this.geo = {
		getEvents : function(params, callbacks){
			call('geo.getEvents', params, callbacks);
		},

		getMetroArtistChart : function(params, callbacks){
			call('geo.getMetroArtistChart', params, callbacks);
		},

		getMetroHypeArtistChart : function(params, callbacks){
			call('geo.getMetroHypeArtistChart', params, callbacks);
		},

		getMetroHypeTrackChart : function(params, callbacks){
			call('geo.getMetroHypeTrackChart', params, callbacks);
		},

		getMetroTrackChart : function(params, callbacks){
			call('geo.getMetroTrackChart', params, callbacks);
		},

		getMetroUniqueArtistChart : function(params, callbacks){
			call('geo.getMetroUniqueArtistChart', params, callbacks);
		},

		getMetroUniqueTrackChart : function(params, callbacks){
			call('geo.getMetroUniqueTrackChart', params, callbacks);
		},

		getMetroWeeklyChartlist : function(params, callbacks){
			call('geo.getMetroWeeklyChartlist', params, callbacks);
		},

		getMetros : function(params, callbacks){
			call('geo.getMetros', params, callbacks);
		},

		getTopArtists : function(params, callbacks){
			call('geo.getTopArtists', params, callbacks);
		},

		getTopTracks : function(params, callbacks){
			call('geo.getTopTracks', params, callbacks);
		}
	};

	/* Group methods. */
	this.group = {
		getHype : function(params, callbacks){
			call('group.getHype', params, callbacks);
		},

		getMembers : function(params, callbacks){
			call('group.getMembers', params, callbacks);
		},

		getWeeklyAlbumChart : function(params, callbacks){
			call('group.getWeeklyAlbumChart', params, callbacks);
		},

		getWeeklyArtistChart : function(params, callbacks){
			call('group.getWeeklyArtistChart', params, callbacks);
		},

		getWeeklyChartList : function(params, callbacks){
			call('group.getWeeklyChartList', params, callbacks);
		},

		getWeeklyTrackChart : function(params, callbacks){
			call('group.getWeeklyTrackChart', params, callbacks);
		}
	};

	/* Library methods. */
	this.library = {
		addAlbum : function(params, session, callbacks){
			signedCall('library.addAlbum', params, session, callbacks, 'POST');
		},

		addArtist : function(params, session, callbacks){
			signedCall('library.addArtist', params, session, callbacks, 'POST');
		},

		addTrack : function(params, session, callbacks){
			signedCall('library.addTrack', params, session, callbacks, 'POST');
		},

		getAlbums : function(params, callbacks){
			call('library.getAlbums', params, callbacks);
		},

		getArtists : function(params, callbacks){
			call('library.getArtists', params, callbacks);
		},

		getTracks : function(params, callbacks){
			call('library.getTracks', params, callbacks);
		}
	};

	/* Playlist methods. */
	this.playlist = {
		addTrack : function(params, session, callbacks){
			signedCall('playlist.addTrack', params, session, callbacks, 'POST');
		},

		create : function(params, session, callbacks){
			signedCall('playlist.create', params, session, callbacks, 'POST');
		},

		fetch : function(params, callbacks){
			call('playlist.fetch', params, callbacks);
		}
	};

	/* Radio methods. */
	this.radio = {
		getPlaylist : function(params, session, callbacks){
			signedCall('radio.getPlaylist', params, session, callbacks);
		},

		search : function(params, session, callbacks){
			signedCall('radio.search', params, session, callbacks);
		},

		tune : function(params, session, callbacks){
			signedCall('radio.tune', params, session, callbacks);
		}
	};

	/* Tag methods. */
	this.tag = {
		getInfo : function(params, callbacks){
			call('tag.getInfo', params, callbacks);
		},

		getSimilar : function(params, callbacks){
			call('tag.getSimilar', params, callbacks);
		},

		getTopAlbums : function(params, callbacks){
			call('tag.getTopAlbums', params, callbacks);
		},

		getTopArtists : function(params, callbacks){
			call('tag.getTopArtists', params, callbacks);
		},

		getTopTags : function(callbacks){
			call('tag.getTopTags', null, callbacks);
		},

		getTopTracks : function(params, callbacks){
			call('tag.getTopTracks', params, callbacks);
		},

		getWeeklyArtistChart : function(params, callbacks){
			call('tag.getWeeklyArtistChart', params, callbacks);
		},

		getWeeklyChartList : function(params, callbacks){
			call('tag.getWeeklyChartList', params, callbacks);
		},

		search : function(params, callbacks){
			call('tag.search', params, callbacks);
		}
	};

	/* Tasteometer method. */
	this.tasteometer = {
		compare : function(params, callbacks){
			call('tasteometer.compare', params, callbacks);
		},

		compareGroup : function(params, callbacks){
			call('tasteometer.compareGroup', params, callbacks);
		}
	};

	/* Track methods. */
	this.track = {
		addTags : function(params, session, callbacks){
			signedCall('track.addTags', params, session, callbacks, 'POST');
		},

		ban : function(params, session, callbacks){
			signedCall('track.ban', params, session, callbacks, 'POST');
		},

		getBuylinks : function(params, callbacks){
			call('track.getBuylinks', params, callbacks);
		},

		getCorrection : function(params, callbacks){
			call('track.getCorrection', params, callbacks);
		},

		getFingerprintMetadata : function(params, callbacks){
			call('track.getFingerprintMetadata', params, callbacks);
		},

		getInfo : function(params, callbacks){
			call('track.getInfo', params, callbacks);
		},

		getShouts : function(params, callbacks){
			call('track.getShouts', params, callbacks);
		},

		getSimilar : function(params, callbacks){
			call('track.getSimilar', params, callbacks);
		},

		getTags : function(params, session, callbacks){
			signedCall('track.getTags', params, session, callbacks);
		},

		getTopFans : function(params, callbacks){
			call('track.getTopFans', params, callbacks);
		},

		getTopTags : function(params, callbacks){
			call('track.getTopTags', params, callbacks);
		},

		love : function(params, session, callbacks){
			signedCall('track.love', params, session, callbacks, 'POST');
		},

		removeTag : function(params, session, callbacks){
			signedCall('track.removeTag', params, session, callbacks, 'POST');
		},

		scrobble : function(params, callbacks){
			/* Flatten an array of multiple tracks into an object with "array notation". */
			if(params.constructor.toString().indexOf("Array") != -1){
				var p = {};

				for(i in params){
					for(j in params[i]){
						p[j + '[' + i + ']'] = params[i][j];
					}
				}

				params = p;
			}

			signedCall('track.scrobble', params, session, callbacks, 'POST');
		},

		search : function(params, callbacks){
			call('track.search', params, callbacks);
		},

		share : function(params, session, callbacks){
			/* Build comma separated recipients string. */
			if(typeof(params.recipient) == 'object'){
				params.recipient = params.recipient.join(',');
			}

			signedCall('track.share', params, session, callbacks, 'POST');
		},

		unban : function(params, session, callbacks){
			signedCall('track.unban', params, session, callbacks, 'POST');
		},

		unlove : function(params, session, callbacks){
			signedCall('track.unlove', params, session, callbacks, 'POST');
		},

		updateNowPlaying : function(params, session, callbacks){
			signedCall('track.updateNowPlaying', params, session, callbacks, 'POST');
		}
	};

	/* User methods. */
	this.user = {
		getArtistTracks : function(params, callbacks){
			call('user.getArtistTracks', params, callbacks);
		},

		getBannedTracks : function(params, callbacks){
			call('user.getBannedTracks', params, callbacks);
		},

		getEvents : function(params, callbacks){
			call('user.getEvents', params, callbacks);
		},

		getFriends : function(params, callbacks){
			call('user.getFriends', params, callbacks);
		},

		getInfo : function(params, callbacks){
			call('user.getInfo', params, callbacks);
		},

		getLovedTracks : function(params, callbacks){
			call('user.getLovedTracks', params, callbacks);
		},

		getNeighbours : function(params, callbacks){
			call('user.getNeighbours', params, callbacks);
		},

		getNewReleases : function(params, callbacks){
			call('user.getNewReleases', params, callbacks);
		},

		getPastEvents : function(params, callbacks){
			call('user.getPastEvents', params, callbacks);
		},

		getPersonalTracks : function(params, callbacks){
			call('user.getPersonalTracks', params, callbacks);
		},

		getPlaylists : function(params, callbacks){
			call('user.getPlaylists', params, callbacks);
		},

		getRecentStations : function(params, session, callbacks){
			signedCall('user.getRecentStations', params, session, callbacks);
		},

		getRecentTracks : function(params, callbacks){
			call('user.getRecentTracks', params, callbacks);
		},

		getRecommendedArtists : function(params, session, callbacks){
			signedCall('user.getRecommendedArtists', params, session, callbacks);
		},

		getRecommendedEvents : function(params, session, callbacks){
			signedCall('user.getRecommendedEvents', params, session, callbacks);
		},

		getShouts : function(params, callbacks){
			call('user.getShouts', params, callbacks);
		},

		getTopAlbums : function(params, callbacks){
			call('user.getTopAlbums', params, callbacks);
		},

		getTopArtists : function(params, callbacks){
			call('user.getTopArtists', params, callbacks);
		},

		getTopTags : function(params, callbacks){
			call('user.getTopTags', params, callbacks);
		},

		getTopTracks : function(params, callbacks){
			call('user.getTopTracks', params, callbacks);
		},

		getWeeklyAlbumChart : function(params, callbacks){
			call('user.getWeeklyAlbumChart', params, callbacks);
		},

		getWeeklyArtistChart : function(params, callbacks){
			call('user.getWeeklyArtistChart', params, callbacks);
		},

		getWeeklyChartList : function(params, callbacks){
			call('user.getWeeklyChartList', params, callbacks);
		},

		getWeeklyTrackChart : function(params, callbacks){
			call('user.getWeeklyTrackChart', params, callbacks);
		},

		shout : function(params, session, callbacks){
			signedCall('user.shout', params, session, callbacks, 'POST');
		}
	};

	/* Venue methods. */
	this.venue = {
		getEvents : function(params, callbacks){
			call('venue.getEvents', params, callbacks);
		},

		getPastEvents : function(params, callbacks){
			call('venue.getPastEvents', params, callbacks);
		},

		search : function(params, callbacks){
			call('venue.search', params, callbacks);
		}
	};

	/* Private auth methods. */
	var auth = {
		getApiSignature : function(params){
			var keys   = [];
			var string = '';

			for(var key in params){
				keys.push(key);
			}

			keys.sort();

			for(var index in keys){
				var key = keys[index];

				string += key + params[key];
			}

			string += apiSecret;
            
            return util.md5(string);
		}
	};

    var util = {
        md5: function(string) {
            return crypto.createHash('md5').update(string).digest('hex');
        }
    };
}
