(function (root, factory) {
    if (typeof define === 'function' && define.amd) {
        define([], factory)
    } else if (typeof module === 'object' && module.exports) {
        module.exports = factory()
    } else {
        root.coverArt = factory()
    }
}(this, function () {
    'use strict'

    var API_KEY = 'b6d34c3af91d62ab0ae00ab1b6fa8733'
    var API_SECRET = '2c631802c2285d5d5d1502462fe42a2b'

    var coverArt = {
        lastfm: new LastFM({
            apiKey: API_KEY,
            apiSecret: API_SECRET,
            cache: new LastFMCache()
        }),

        getCover: function (uri, images, size, mopidy) {
            var defUrl = 'images/default_cover.png'
            $(images).attr('src', defUrl)
            if (!uri) {
                return
            }
            mopidy.library.getImages({'uris': [uri]}).then(function (imageResults) {
                var uri = Object.keys(imageResults)[0]
                if (imageResults[uri].length > 0) {
                    $(images).attr('src', imageResults[uri][0].uri)
                } else {
                    // Also check deprecated 'album.images' in case backend does not
                    // implement mopidy.library.getImages yet...
                    coverArt.getCoverFromAlbum(uri, images, size, mopidy)
                }
            })
        },

        // Note that this approach has been deprecated in Mopidy
        // TODO: Remove when Mopidy no longer supports getting images
        //       with 'album.images'.
        getCoverFromAlbum: function (uri, images, size, mopidy) {
            var defUrl = 'images/default_cover.png'
            $(images).attr('src', defUrl)
            if (!uri) {
                return
            }
            mopidy.library.lookup({'uris': [uri]}).then(function (resultDict) {
                var uri = Object.keys(resultDict)[0]
                var track = resultDict[uri][0]
                if (track && track.album && track.album.images && track.album.images.length > 0) {
                    $(images).attr('src', track.album.images[0])
                } else if (track && (track.album || track.artist)) {
                    // Fallback to last.fm
                    coverArt.getCoverFromLastFm(track, images, size)
                } else {
                    return
                }
            })
        },

        getCoverFromLastFm: function (track, images, size) {
            var defUrl = 'images/default_cover.png'
            $(images).attr('src', defUrl)
            if (!track || !(track.album || track.artists)) {
                return
            }
            var albumname = (track.album && track.album.name) ? track.album.name : ''
            var artistname = ''
            if (track.album && track.album.artists && track.album.artists.length > 0) {
                // First look for the artist in the album
                artistname = track.album.artists[0].name
            } else if (track.artists && (track.artists.length > 0)) {
                // Fallback to using artists for specific track
                artistname = track.artists[0].name
            }

            this.lastfm.album.getInfo({artist: artistname, album: albumname}, {success: function (data) {
                for (var i = 0; i < data.album.image.length; i++) {
                    if (data.album.image[i].size === size) {
                        $(images).attr('src', data.album.image[i]['#text'] || defUrl)
                    }
                }
            }, error: function (code, message) {
                console.error('Error retrieving album info from last.fm', code, message)
            }})
        },

        getArtistImage: function (artist, images, size) {
            var defUrl = 'images/user_24x32.png'
            $(images).attr('src', defUrl)
            if (!artist || artist.length === 0) {
                return
            }
            this.lastfm.artist.getInfo({artist: artist}, {success: function (data) {
                for (var i = 0; i < data.artist.image.length; i++) {
                    if (data.artist.image[i].size === size) {
                        $(images).attr('src', data.artist.image[i]['#text'] || defUrl)
                    }
                }
            }, error: function (code, message) {
                console.error('Error retrieving artist info from last.fm', code, message)
            }})
        }
    }
    return coverArt
}))