/**
 * Tae Won Ha - http://taewon.de - @hataewon
 * See LICENSE
 */

import Cocoa
import RxSwift

private class PrefKeys {

  static let editorFontName = "editor-font-name"
  static let editorFontSize = "editor-font-size"
  static let editorUsesLigatures = "editor-uses-ligatures"

  static let openNewWindowWhenLaunching = "open-new-window-when-launching"
  static let openNewWindowOnReactivation = "open-new-window-on-reactivation"
}

class PrefStore: Store {

  private static let compatibleVersion = "38"
  private static let defaultEditorFont = NeoVimView.defaultFont
  static let minimumEditorFontSize = NeoVimView.minFontSize
  static let maximumEditorFontSize = NeoVimView.maxFontSize

  private let source: Observable<Any>
  private let disposeBag = DisposeBag()

  private let subject = PublishSubject<Any>()
  var sink: Observable<Any> {
    return self.subject.asObservable()
  }

  private let userDefaults = NSUserDefaults.standardUserDefaults()
  private let fontManager = NSFontManager.sharedFontManager()

  var data = PrefData(
    general: GeneralPrefData(openNewWindowWhenLaunching: true, openNewWindowOnReactivation: true),
    appearance: AppearancePrefData(editorFont: PrefStore.defaultEditorFont, editorUsesLigatures: false)
  )

  init(source: Observable<Any>) {
    self.source = source

    if let prefs = self.userDefaults.dictionaryForKey(PrefStore.compatibleVersion) {
      self.data = self.prefDataFromDict(prefs)
    } else {
      self.userDefaults.setValue(self.prefsDict(self.data), forKey: PrefStore.compatibleVersion)
    }

    self.addReactions()
  }

  deinit {
    self.subject.onCompleted()
  }

  private func prefDataFromDict(prefs: [String: AnyObject]) -> PrefData {

    let editorFontName = prefs[PrefKeys.editorFontName] as? String ?? PrefStore.defaultEditorFont.fontName
    let editorFontSize = CGFloat(
      (prefs[PrefKeys.editorFontSize] as? NSNumber)?.floatValue ?? Float(PrefStore.defaultEditorFont.pointSize)
    )
    let editorFont = self.saneFont(editorFontName, fontSize: editorFontSize)
    
    let usesLigatures = (prefs[PrefKeys.editorUsesLigatures] as? NSNumber)?.boolValue ?? false
    let openNewWindowWhenLaunching = (prefs[PrefKeys.openNewWindowWhenLaunching] as? NSNumber)?.boolValue ?? true
    let openNewWindowOnReactivation = (prefs[PrefKeys.openNewWindowOnReactivation] as? NSNumber)?.boolValue ?? true

    return PrefData(
      general: GeneralPrefData(
        openNewWindowWhenLaunching: openNewWindowWhenLaunching,
        openNewWindowOnReactivation: openNewWindowOnReactivation
      ),
      appearance: AppearancePrefData(editorFont: editorFont, editorUsesLigatures: usesLigatures)
    )
  }

  private func saneFont(fontName: String, fontSize: CGFloat) -> NSFont {
    var editorFont = NSFont(name: fontName, size: fontSize) ?? PrefStore.defaultEditorFont
    if !editorFont.fixedPitch {
      editorFont = fontManager.convertFont(PrefStore.defaultEditorFont, toSize: editorFont.pointSize)
    }
    if editorFont.pointSize < PrefStore.minimumEditorFontSize
      || editorFont.pointSize > PrefStore.maximumEditorFontSize {
      editorFont = fontManager.convertFont(editorFont, toSize: PrefStore.defaultEditorFont.pointSize)
    }

    return editorFont
  }

  private func prefsDict(prefData: PrefData) -> [String: AnyObject] {
    let appearanceData = prefData.appearance
    let prefs: [String: AnyObject] = [
      PrefKeys.editorFontName: appearanceData.editorFont.fontName,
      PrefKeys.editorFontSize: appearanceData.editorFont.pointSize,
      PrefKeys.editorUsesLigatures: appearanceData.editorUsesLigatures
    ]
    return prefs
  }

  private func addReactions() {
    self.source
      .filter { $0 is PrefData }
      .map { $0 as! PrefData }
      .subscribeNext { [unowned self] prefData in
        self.data = prefData
        self.userDefaults.setValue(self.prefsDict(prefData), forKey: PrefStore.compatibleVersion)
        self.subject.onNext(prefData)
      }
      .addDisposableTo(self.disposeBag)
  }
}