//
//  Track.swift
//  Tag for iTunes
//
//  Created by Kim Wittenburg on 30.05.15.
//  Copyright (c) 2015 Kim Wittenburg. All rights reserved.
//

import Cocoa

/// Represents a track of the
/// [Search API](https://www.apple.com/itunes/affiliates/resources/documentation/itunes-store-web-service-search-api.html).
public class Track: iTunesType {

    // MARK: Properties
    
    public let id: iTunesId
    
    public let name: String
    
    public let censoredName: String
    
    public let artistName: String
    
    public let releaseDate: NSDate
    
    public let trackNumber: Int
    
    public let trackCount: Int
    
    public let discNumber: Int
    
    public let discCount: Int
    
    public let genre: String
    
    public internal(set) weak var album: Album!
    
    /// These tracks will be changed, if `save()` is called.
    public var associatedTracks = [iTunesTrack]()
    
    // MARK: Initializers
    
    public required init(data: [iTunesAPI.Field: AnyObject]) {
        id = data[.TrackId] as! UInt
        name = data[.TrackName] as! String
        censoredName = data[.TrackCensoredName] as! String
        artistName = data[.ArtistName] as! String
        releaseDate = iTunesAPI.sharedDateFormatter.dateFromString(data[.ReleaseDate] as! String)!
        trackNumber = data[.TrackNumber] as! Int
        trackCount = data[.TrackCount] as! Int
        discNumber = data[.DiscNumber] as! Int
        discCount = data[.DiscCount] as! Int
        genre = data[.PrimaryGenreName] as! String
    }
    
    public static var requiredFields: [iTunesAPI.Field] {
        return [.TrackId, .TrackName, .TrackCensoredName, .ArtistName, .ReleaseDate, .TrackNumber, .TrackCount, .DiscNumber, .DiscCount, .PrimaryGenreName]
    }
    
    // MARK: Methods
    
    /// Saves the track. This means that its properties are applied to every
    /// `iTunesTrack` in its `associatedTracks`.
    ///
    /// This method respects the user's preferences (See `Preferences` class).
    public func save() {
        saveToTracks(associatedTracks)
    }
    
    /// Applies the receiver's properties to the specified tracks.
    ///
    /// This method respects the user's preferences (See `Preferences` class).
    public func saveToTracks(tracks: [iTunesTrack]) {
        for track in tracks {
            saveToTrack(track)
        }
    }
    
    /// Applies the receiver's properties to the specified `track`.
    ///
    /// This method respects the user's preferences (See `Preferences` class).
    public func saveToTrack(track: iTunesTrack) {
        let components = NSCalendar.currentCalendar().components(.Year, fromDate: releaseDate)
        track.name = name
        track.artist = artistName
        track.year = components.year
        track.trackNumber = trackNumber
        track.trackCount = trackCount
        track.discNumber = discNumber
        track.discCount = discCount
        track.genre = genre
        track.album = album?.name
        track.albumArtist = album?.artistName
        track.sortName = ""
        track.sortAlbum = ""
        track.sortAlbumArtist = ""
        track.sortArtist = ""
        track.composer = ""
        track.sortComposer = ""
        track.comment = ""
        track.artworks().removeAllObjects()
    }
    
    /// Returns `true` if all `associatedTrack`s contain the same values as the
    /// `Track` instance.
    public var saved: Bool {
        let components = NSCalendar.currentCalendar().components(.Year, fromDate: releaseDate)
        for track in associatedTracks {
            guard track.name == name && track.artist == artistName && track.year == components.year && track.trackNumber == trackNumber && track.trackCount == trackCount && track.discNumber == discNumber && track.discCount == discCount && track.genre == genre && track.album == album.name && track.albumArtist == album.artistName && track.composer == "" else {
                return false
            }
        }
        return true
    }

}

extension Track: Hashable {
    
    public var hashValue: Int {
        return Int(id)
    }
    
}

public func ==(lhs: Track, rhs: Track) -> Bool {
    return lhs.id == rhs.id
}