import SwiftUI

class SettingsManager: ObservableObject {
  @AppStorage("detailViewType")
  var detailViewQuality: BooruPostFileType = .original

  @AppStorage("thumbnailQuality")
  var thumbnailQuality: BooruPostFileType = .preview

  @AppStorage("searchSuggestionsMode")
  var searchSuggestionsMode: SettingsSearchSuggestionsMode = .disabled

  @AppStorage("thumbnailGridColumns")
  var thumbnailGridColumns = 2

  @AppStorage("bookmarks")
  private var bookmarksData = Data()

  @AppStorage("preferredBooru")
  var preferredBooru: BooruProvider = .safebooru

  @AppStorage("enableShareShortcut")
  var enableShareShortcut = false

  @AppStorage("displayRatings")
  private var displayRatingsData = SettingsManager.defaultRatingsData()

  @AppStorage("blurRatings")
  private var blurRatingsData = SettingsManager.initializeRatingsData(
    enabledRatings: [.explicit]
  )

  @AppStorage("displayDetailsInformationBar")
  var displayDetailsInformationBar = true

  @AppStorage("searchHistory")
  private var searchHistoryData = Data()

  #if os(macOS)
    @AppStorage("saveTagsToFile")
    var saveTagsToFile = false
  #endif

  var bookmarks: [SettingsBookmark] {
    get {
      if let bookmarks = try? JSONDecoder().decode([SettingsBookmark].self, from: bookmarksData) {
        return bookmarks
      }

      return []
    }

    set {
      if let data = try? JSONEncoder().encode(newValue) {
        bookmarksData = data
      }
    }
  }

  var displayRatings: [BooruRating] {
    get { Self.decodeRatings(from: displayRatingsData) }
    set { if let data = Self.encodeRatings(newValue) { displayRatingsData = data } }
  }

  var blurRatings: [BooruRating] {
    get { Self.decodeRatings(from: blurRatingsData) }
    set { if let data = Self.encodeRatings(newValue) { blurRatingsData = data } }
  }

  var searchHistory: [BooruSearchQuery] {
    get {
      if let history = try? JSONDecoder().decode([BooruSearchQuery].self, from: searchHistoryData) {
        return history
      }

      return []
    }

    set {
      if let data = try? JSONEncoder().encode(newValue) {
        searchHistoryData = data
      }
    }
  }

  func appendToSearchHistory(_ query: BooruSearchQuery) {
    self.searchHistory.append(query)
  }

  func removeFromSearchHistory(_ query: BooruSearchQuery) {
    if let index = self.searchHistory.firstIndex(of: query) {
      self.searchHistory.remove(at: index)
    }
  }

  private static func defaultRatingsData() -> Data {
    initializeRatingsData(enabledRatings: BooruRating.allCases)
  }

  private static func initializeRatingsData(enabledRatings: [BooruRating]) -> Data {
    var ratings: [BooruRating] = []

    for rating in enabledRatings {
      ratings.append(rating)
    }

    do {
      return try JSONEncoder().encode(ratings)
    } catch {
      debugPrint("Settings.initializeRatingsData: \(error)")

      return Data()
    }
  }

  private static func decodeRatings(from data: Data) -> [BooruRating] {
    if let ratings = try? JSONDecoder().decode([BooruRating].self, from: data) {
      return ratings
    }

    return BooruRating.allCases
  }

  private static func encodeRatings(_ ratings: [BooruRating]) -> Data? {
    try? JSONEncoder().encode(ratings)
  }

  func resetToDefaults() {
    detailViewQuality = .original
    thumbnailQuality = .preview
    searchSuggestionsMode = .disabled
    thumbnailGridColumns = 2
    preferredBooru = .safebooru
    enableShareShortcut = false
    displayRatingsData = Self.defaultRatingsData()
    blurRatingsData = Self.initializeRatingsData(enabledRatings: [.explicit])
    displayDetailsInformationBar = true

    #if os(macOS)
      saveTagsToFile = false
    #endif
  }

  func addBookmark(provider: BooruProvider, tags: [String]) {
    var currentBookmarks = bookmarks

    currentBookmarks.append(SettingsBookmark(provider: provider, tags: tags.map { $0.lowercased() }))

    bookmarks = currentBookmarks
  }

  func removeBookmark(at index: IndexSet) {
    var currentBookmarks = bookmarks

    currentBookmarks.remove(atOffsets: index)

    bookmarks = currentBookmarks
  }

  func removeBookmark(withTags tags: [String]) {
    var currentBookmarks = bookmarks

    currentBookmarks.removeAll { bookmark in
      bookmark.tags.contains(where: tags.contains)
    }

    bookmarks = currentBookmarks
  }

  func removeBookmark(withID: UUID) {
    var currentBookmarks = bookmarks

    currentBookmarks.removeAll { bookmark in
      bookmark.id == withID
    }

    bookmarks = currentBookmarks
  }
}