//
//  Preferences.swift
//  TagTunes
//
//  Created by Kim Wittenburg on 29.08.15.
//  Copyright © 2015 Kim Wittenburg. All rights reserved.
//

import Cocoa

/// Internal class to be used in IB to bind to the shared preferences.
@objc internal class PreferencesSingleton: NSObject {
    
    internal dynamic var sharedPreferences: Preferences {
        return Preferences.sharedPreferences
    }
    
}

/// A custom interface for the `NSUserDefaults`. It is recommended to use this
/// class insted of accessing the user defaults directly to prevent errors due
/// to misspelled strings.
///
/// All properties in this class are KCO compliant.
@objc public class Preferences: NSObject {

    // MARK: Types
    
    internal struct UserDefaultsConstants {
        
        static let numberOfSearchResultsKey = "Number of Search Results"
        
        static let iTunesStoreKey = "iTunes Store"
        
        static let useEnglishTagsKey = "Use English Tags"
        
        static let removeSavedItemsKey = "Remove Saved Items"
        
        static let useCensoredNamesKey = "Use Censored Names"
        
        static let caseSensitiveKey = "Case Sensitive"
        
        static let tagSavingBehaviorsKey = "Tag Saving Behaviors"
    }
    
    /// Specifies the way a tag is saved to iTunes.
    public enum TagSavingBehavior: String {
        
        /// Sets the tag's value to the value returned from the Search API.
        case Save = "save"
        
        /// Sets the tag's value to an empty string.
        case Clear = "clear"
        
        /// Does not alter the tag's value.
        case Ignore = "ignore"
        
    }
        
    // MARK: Initialization
    
    public static var sharedPreferences = Preferences()
    
    /// Initializes the default preferences. This method must be called the very
    /// first time the application is launched. It is perfectly valid to call
    /// this method every time the application launches. Existing values are not
    /// overridden.
    public func initializeDefaultValues() {
        NSUserDefaults.standardUserDefaults().registerDefaults([
            UserDefaultsConstants.numberOfSearchResultsKey: 10,
            UserDefaultsConstants.iTunesStoreKey: NSLocale.currentLocale().objectForKey(NSLocaleCountryCode)!,
            UserDefaultsConstants.useEnglishTagsKey: false,
            UserDefaultsConstants.removeSavedItemsKey: false,
            UserDefaultsConstants.useCensoredNamesKey: false,
            UserDefaultsConstants.caseSensitiveKey: true
            ])
        if NSUserDefaults.standardUserDefaults().dictionaryForKey(UserDefaultsConstants.tagSavingBehaviorsKey) == nil {
            tagSavingBehaviors = [:]
        }
        var savingBehaviors = tagSavingBehaviors
        for tag in Tag.allTags {
            if savingBehaviors[tag] == nil {
                savingBehaviors[tag] = tag.isReturnedBySearchAPI ? .Save : .Clear
            }
        }
        tagSavingBehaviors = savingBehaviors
    }
    
    // MARK: General Preferences
    
    /// The number of search results that should be displayed.
    public dynamic var numberOfSearchResults: Int {
        set {
            NSUserDefaults.standardUserDefaults().setInteger(newValue, forKey: UserDefaultsConstants.numberOfSearchResultsKey)
        }
        get {
            return NSUserDefaults.standardUserDefaults().integerForKey(UserDefaultsConstants.numberOfSearchResultsKey)
        }
    }
    
    /// The iTunes Store from which the metadata should be loaded.
    ///
    /// The value of this property must be a valid two-letter ISO country code.
    public dynamic var iTunesStore: String {
        set {
            NSUserDefaults.standardUserDefaults().setObject(newValue, forKey: UserDefaultsConstants.iTunesStoreKey)
        }
        get {
            return NSUserDefaults.standardUserDefaults().stringForKey(UserDefaultsConstants.iTunesStoreKey)!
        }
    }

    /// If `true` the Search API Request adds the "lang=en" option.
    public dynamic var useEnglishTags: Bool {
        set {
            NSUserDefaults.standardUserDefaults().setBool(newValue, forKey: UserDefaultsConstants.useEnglishTagsKey)
        }
        get {
            return NSUserDefaults.standardUserDefaults().boolForKey(UserDefaultsConstants.useEnglishTagsKey)
        }
    }
    
    /// If `true` all saved items are removed from the list after saving.
    public dynamic var removeSavedItems: Bool {
        set {
            NSUserDefaults.standardUserDefaults().setBool(newValue, forKey: UserDefaultsConstants.removeSavedItemsKey)
        }
        get {
            return NSUserDefaults.standardUserDefaults().boolForKey(UserDefaultsConstants.removeSavedItemsKey)
        }
    }
    
    // MARK: Tag Preferences
    
    /// If `true` TagTunes displays and saves censored names instead of the
    /// original names.
    public dynamic var useCensoredNames: Bool {
        set {
            NSUserDefaults.standardUserDefaults().setBool(newValue, forKey: UserDefaultsConstants.useCensoredNamesKey)
        }
        get {
            return NSUserDefaults.standardUserDefaults().boolForKey(UserDefaultsConstants.useCensoredNamesKey)
        }
    }
    
    /// If `true` TagTunes ignores cases when comparing track titles and albums.
    public dynamic var caseSensitive: Bool {
        set {
            NSUserDefaults.standardUserDefaults().setBool(newValue, forKey: UserDefaultsConstants.caseSensitiveKey)
        }
        get {
            return NSUserDefaults.standardUserDefaults().boolForKey(UserDefaultsConstants.caseSensitiveKey)
        }
    }
        
    /// The ways different tags are saved (or not saved).
    public var tagSavingBehaviors: [Tag: TagSavingBehavior] {
        set {
            let savableData = newValue.map { ($0.rawValue, $1.rawValue) }
            NSUserDefaults.standardUserDefaults().setObject(savableData, forKey: UserDefaultsConstants.tagSavingBehaviorsKey)
        }
        get {
            let savableData = NSUserDefaults.standardUserDefaults().dictionaryForKey(UserDefaultsConstants.tagSavingBehaviorsKey)!
            return savableData.map { (Tag(rawValue: $0)!, TagSavingBehavior(rawValue: $1 as! String)!) }
        }
    }
    
}