// The main class, handles all the actions that the executable will call
class Lyricli {

    // Version of the application
    static var version = "2.0.1"

    // Flag that controls whether we should show the track artist and name before
    // the lyrics
    static var showTitle = false

    // Obtains the name of the current track from a source, fetches the lyrics
    // from an engine and prints them
    static func printLyrics() {

        let sourceManager = SourceManager()

        if let currentTrack = sourceManager.currentTrack {
            printLyrics(currentTrack)
        } else {
            print("No Artist/Song could be found :(")
        }
    }

    // fetches the lyrics from an engine and prints them
    static func printLyrics(_ currentTrack: Track) {
        let engine = LyricsEngine(withTrack: currentTrack)

        if showTitle {
            printTitle(currentTrack)
        }
        if let lyrics = engine.lyrics {
            print(lyrics)
        } else {
            print("Lyrics not found :(")
        }
    }

    // Print the currently available sources
    static func printSources() {
        let sourceManager = SourceManager()
        for (sourceName, _) in sourceManager.availableSources {
            if (Configuration.shared["enabled_sources"] as? [String] ?? []).contains(sourceName) {
                print("\(sourceName) (enabled)")
            } else {
                print(sourceName)
            }
        }
    }

    // Runs the enable method of a source and writes the configuration to set it
    // as enabled
    static func enableSource(_ sourceName: String) throws {
        let sourceManager = SourceManager()
        if let source = sourceManager.availableSources[sourceName] {
            if let enabledSources = Configuration.shared["enabled_sources"] as? [String] {
                if source.enable() == false {
                    throw SourceCouldNotBeEnabled()
                }
                if !enabledSources.contains(sourceName) {
                    Configuration.shared["enabled_sources"] = enabledSources + [sourceName]
                }
                return
            }
            throw ConfigurationCouldNotBeRead()
        }
        throw SourceNotAvailable()
    }

    // Remove a source from the enabled sources configuration
    static func disableSource(_ sourceName: String) throws {
        let sourceManager = SourceManager()
        if let source = sourceManager.availableSources[sourceName] {
            if let enabledSources = Configuration.shared["enabled_sources"] as? [String] {
                if source.disable() == false {
                    throw SourceCouldNotBeDisabled()
                }
                Configuration.shared["enabled_sources"] = enabledSources.filter { $0 != sourceName }
                return
            }
            throw ConfigurationCouldNotBeRead()
        }
        throw SourceNotAvailable()
    }

    // Removes any configuration for a source, and disables it
    static func resetSource(_ sourceName: String) throws {
        let sourceManager = SourceManager()
        if let source = sourceManager.availableSources[sourceName] {
            if source.reset() == false {
                throw SourceCouldNotBeReset()
            }
            try disableSource(sourceName)
            return
        }
        throw SourceNotAvailable()
    }

    // Prints the track artist and name
    private static func printTitle(_ track: Track) {
        print("\(track.artist) - \(track.name)")
    }
}