+++ /dev/null
-import Foundation
-import HTMLEntities
-
-// Given a track, attempts to fetch the lyrics from lyricswiki
-class LyricsEngine {
-
- // URL of the API endpoint to use
- private let apiURL = "https://lyrics.wikia.com/api.php?action=lyrics&func=getSong&fmt=realjson"
-
- // Method used to call the API
- private let apiMethod = "GET"
-
- // Regular expxression used to find the lyrics in the lyricswiki HTML
- private let lyricsMatcher = "class='lyricbox'>(.+)<div"
-
- // The track we'll be looking for
- private let track: Track
-
- // Fetches the lyrics and returns if found
- var lyrics: String? {
-
- var lyrics: String?
-
- // Encode the track artist and name and finish building the API call URL
-
- if let artist = track.artist.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed) {
- if let name: String = track.name.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed) {
- if let url = URL(string: "\(apiURL)&artist=\(artist)&song=\(name)") {
-
- // We'll lock until the async call is finished
-
- var requestFinished = false
- let asyncLock = NSCondition()
- asyncLock.lock()
-
- // Call the API and unlock when you're done
-
- fetchLyricsFromAPI(withURL: url, completionHandler: {lyricsResult -> Void in
- lyrics = lyricsResult
- requestFinished = true
- asyncLock.signal()
- })
-
- while !requestFinished {
- asyncLock.wait()
- }
- asyncLock.unlock()
- }
- }
- }
-
- return lyrics
- }
-
- // Initializes with a track
- init(withTrack targetTrack: Track) {
-
- track = targetTrack
- }
-
- // Fetch the lyrics URL from the API, triggers the request to fetch the
- // lyrics page
- private func fetchLyricsFromAPI(withURL url: URL, completionHandler: @escaping (String?) -> Void) {
-
- var apiRequest = URLRequest(url: url)
- apiRequest.httpMethod = "GET"
-
- let task = URLSession.shared.dataTask(with: apiRequest, completionHandler: {data, _, _ -> Void in
-
- // If the response is parseable JSON, and has a url, we'll look for
- // the lyrics in there
-
- if let data = data {
- if let jsonResponse = try? JSONSerialization.jsonObject(with: data) {
- if let jsonResponse = jsonResponse as? [String: Any] {
- if let lyricsUrlString = jsonResponse["url"] as? String {
- if let lyricsUrl = URL(string: lyricsUrlString) {
-
- // At this point we have a valid wiki url
- self.fetchLyricsFromPage(withURL: lyricsUrl, completionHandler: completionHandler)
- return
- }
- }
- }
- }
- }
-
- completionHandler(nil)
- })
- task.resume()
- }
-
- // Fetch the lyrics from the page and send it to the parser
- private func fetchLyricsFromPage(withURL url: URL, completionHandler: @escaping (String?) -> Void) {
-
- var pageRequest = URLRequest(url: url)
- pageRequest.httpMethod = "GET"
-
- let task = URLSession.shared.dataTask(with: pageRequest, completionHandler: {data, _, _ -> Void in
-
- // If the response is parseable JSON, and has a url, we'll look for
- // the lyrics in there
-
- if let data = data {
- if let htmlBody = String(data: data, encoding: String.Encoding.utf8) {
- self.parseHtmlBody(htmlBody, completionHandler: completionHandler)
- return
- }
- }
-
- completionHandler(nil)
- })
- task.resume()
- }
-
- // Parses the wiki to find the lyrics, decodes the lyrics object
- private func parseHtmlBody(_ body: String, completionHandler: @escaping (String?) -> Void) {
-
- // Look for the lyrics lightbox
-
- if let regex = try? NSRegularExpression(pattern: lyricsMatcher) {
- let matches = regex.matches(in: body, range: NSRange(location: 0, length: body.characters.count))
-
- for match in matches {
-
- let nsBody = body as NSString
- let range = match.rangeAt(1)
- let encodedLyrics = nsBody.substring(with: range)
-
- let decodedLyrics = decodeLyrics(encodedLyrics)
-
- completionHandler(decodedLyrics)
- return
- }
- }
-
- completionHandler(nil)
- }
-
- // Escapes the HTML entities
- private func decodeLyrics(_ lyrics: String) -> String {
-
- let unescapedLyrics = lyrics.htmlUnescape()
- return unescapedLyrics.replacingOccurrences(of: "<br />", with: "\n")
- }
-}