/*
 * Keyman is copyright (C) SIL Global. MIT License.
 *
 * Created by Shawn Schantz on 2026-02-24
 *
 * Object that represents a Keyman keyboard
 * Each keyboard can be marked as enabled/disabled
 *
 */

import Foundation
import AppKit

public class Keyboard: Identifiable, Hashable, Equatable {
  
  public var id = UUID()
  public var enabled: Bool
  public var name: String
  public var keyboardId: String
  // the directory we are reading the keyboard from
  public var keyboardDirectoryUrl: URL
  // the URL of the .kmx file for the package
  public let kmxFileUrl: URL
  // a key to uniquely identify the keyboard
  // in the UserDefaults this key is used for the selected Keyboard and enabled keyboards properties
  // the key is in the form "/[package directory]/[package name].kmx"
  // for example, "/khmer_angkor/khmer_angkor.kmx"
  public let keyboardKey: String
  
  public init(keyboardSource: KeyboardSource, directoryUrl: URL) {
    self.enabled = true
    self.name = keyboardSource.name
    self.keyboardId = keyboardSource.id
    self.keyboardDirectoryUrl = directoryUrl
    self.kmxFileUrl = Keyboard.deriveKmxFileUrl(from: self.keyboardDirectoryUrl, keyboardId: self.keyboardId)
    self.keyboardKey = Keyboard.deriveKeyboardSettingsKey(from: self.keyboardDirectoryUrl, keyboardId: self.keyboardId)
    
//    print("keyboard created for: \(keyboardSource.id) \r   with kmxFileUrl: \(self.kmxFileUrl) \r   and settingsKey: \(self.keyboardKey)")
  }
  
  /**
   * initializer that does not rely on package source -- provided to create unit test data
   */
  public init(name: String, keyboardId: String, keyboardDirectoryUrl: URL, enabled: Bool) {
    self.name = name
    self.keyboardId = keyboardId
    self.keyboardDirectoryUrl = keyboardDirectoryUrl
    self.kmxFileUrl = Keyboard.deriveKmxFileUrl(from: self.keyboardDirectoryUrl, keyboardId: self.keyboardId)
    self.enabled = enabled
    self.keyboardKey = Keyboard.deriveKeyboardSettingsKey(from: self.keyboardDirectoryUrl, keyboardId: self.keyboardId)
  }
  
  /**
   * provided for Equatable conformance
   */
  public static func == (lhs: Keyboard, rhs: Keyboard) -> Bool {
    return lhs.keyboardId == rhs.keyboardId && lhs.enabled == rhs.enabled
  }
  
  /**
   * provided for Hashable conformance
   */
  public func hash(into hasher: inout Hasher) {
    hasher.combine(keyboardId)
  }
  
  /**
   * generate the url for the keyboard's kmx file
   */
  static func deriveKmxFileUrl(from keyboardDirectory: URL, keyboardId: String) -> URL {
    return keyboardDirectory.appendingPathComponent("\(keyboardId).kmx")
  }
  
  /**
   * generate the keyboard's key
   * see the above comment for `keyboardKey` for a description of the format of the key
   */
 static func deriveKeyboardSettingsKey(from keyboardDirectory: URL, keyboardId: String) -> String {
    // get parent directory
    let parentDirectoryName = keyboardDirectory.lastPathComponent
    
    // get filename from keyboardId
    let kmxFilename = "\(keyboardId).kmx"
    
    let settingsKey = "/\(parentDirectoryName)/\(kmxFilename)"
    
    return settingsKey
  }
  
  /**
   * validate whether a corresponding kmx file exists for this keyboard
   */
  public func validateKmxFile() throws {
    if !FileManager.default.fileExists(atPath: self.kmxFileUrl.path) {
      print("** error: could not find kmx file \(self.kmxFileUrl.path)")
      throw LoadPackageError.missingKmxFile
    }
  }
}