//
//  Tag.swift
//  TagTunes
//
//  Created by Kim Wittenburg on 21.01.16.
//  Copyright © 2016 Kim Wittenburg. All rights reserved.
//

import Foundation

/// This enum contains cases for the different tags supported by TagTunes. Tags
/// may or may not be returned by the iTunes Store. Use the
/// `isReturnedBySearchAPI` property to query this information.
///
/// The `Tag` enum supports localization for displaying the name of a tag in the
/// user interface. Use the `localizedName` property for this purpose.
public enum Tag: String {
    case Name = "name", Artist = "artist", Year = "year", TrackNumber = "trackNumber", TrackCount = "trackCount", DiscNumber = "discNumber", DiscCount = "discCount", Genre = "genre", AlbumName = "album", AlbumArtist = "albumArtist", ReleaseDate = "releaseDate", Compilation = "compilation"
    case Artwork = "artwork"
    case SortName = "sortName", SortArtist = "sortArtist", SortAlbumName = "sortAlbum", SortAlbumArtist = "sortAlbumArtist", Composer = "composer", SortComposer = "sortComposer", Comment = "comment"
    
    /// Returns `true` for tags that are returned from the
    /// [Search API](https://www.apple.com/itunes/affiliates/resources/documentation/itunes-store-web-service-search-api.html).
    public var isReturnedBySearchAPI: Bool {
        switch self {
        case Name, Artist, Year, TrackNumber, TrackCount, DiscNumber, DiscCount, Genre, AlbumName, AlbumArtist, Compilation, ReleaseDate:
            return true
        case Artwork:
            return true
        case SortName, SortArtist, SortAlbumName, SortAlbumArtist, Composer, SortComposer, Comment:
            return false
        }
    }

    /// Returns a `AEKeyword` associated with the tag. This code can be used to
    /// work with Apple-Event properties of the `iTunesTrack` class.
    internal var code: AEKeyword {
        let keyword: String
        switch self {
        case Name: keyword = "pnam"
        case Artist: keyword = "pArt"
        case Year: keyword = "pYr "
        case TrackNumber: keyword = "pTrN"
        case TrackCount: keyword = "pTrC"
        case DiscNumber: keyword = "pDsN"
        case DiscCount: keyword = "pDsC"
        case Genre: keyword = "pGen"
        case AlbumName: keyword = "pAlb"
        case AlbumArtist: keyword = "pAlA"
        case Compilation: keyword = "pAnt"
        case ReleaseDate: keyword = "pRlD"
        case Artwork: keyword = "cArt"
        case SortName: keyword = "pSNm"
        case SortArtist: keyword = "pSAr"
        case SortAlbumName: keyword = "pSAl"
        case SortAlbumArtist: keyword = "pSAA"
        case Composer: keyword = "pCmp"
        case SortComposer: keyword = "pSCm"
        case Comment: keyword = "pCmt"
        }
        return AEKeyword(keyword)
    }

    /// Returns the localized name of the tag which can be displayed in the user
    /// interface.
    public var localizedName: String {
        return NSLocalizedString("Tag: \(self.rawValue)", comment: "")
    }

    // TODO: Order of tags should not be determined here.
    /// Returns an array of all tags. The tags are sorted by whether they are
    /// returned by the
    /// [Search API](https://www.apple.com/itunes/affiliates/resources/documentation/itunes-store-web-service-search-api.html).
    public static var allTags: [Tag] {
        return [.Name, .Artist, .Year, .TrackNumber, .TrackCount, .DiscNumber, .DiscCount, .Genre, .AlbumName, .AlbumArtist, .Compilation, .ReleaseDate, .Artwork, .SortName, .SortArtist, .SortAlbumName, .SortAlbumArtist, .Composer, .SortComposer, .Comment]
    }
    
}