module ReanimatedUtils
  module_function

  def try_to_parse_react_native_package_json(react_native_dir)
    react_native_package_json_path = File.join(react_native_dir, 'package.json')
    if !File.exist?(react_native_package_json_path)
      return nil
    end
    return JSON.parse(File.read(react_native_package_json_path))
  end

  def find_config()
    result = {
      :is_reanimated_example_app => nil,
      :react_native_version => nil,
      :react_native_dir => nil,
      :react_native_common_dir => nil,
    }

    react_native_dir = File.dirname(`cd "#{Pod::Config.instance.installation_root.to_s}" && node --print "require.resolve('react-native/package.json')"`)
    react_native_json = try_to_parse_react_native_package_json(react_native_dir)

    if react_native_json == nil
      # user configuration, just in case
      node_modules_dir = ENV["REACT_NATIVE_NODE_MODULES_DIR"]
      react_native_json = try_to_parse_react_native_package_json(File.join(node_modules_dir, 'react-native'))
    end

    if react_native_json == nil
      raise '[Reanimated] Unable to recognize your `react-native` version. Please set environmental variable with `react-native` location: `export REACT_NATIVE_NODE_MODULES_DIR="<path to react-native>" && pod install`.'
    end

    validate_worklets_script = File.expand_path(File.join(__dir__, 'validate-worklets-build.js'))
    unless system("node \"#{validate_worklets_script}\"")
      abort("[Reanimated] Failed to validate worklets version")
    end


    result[:is_reanimated_example_app] = ENV["IS_REANIMATED_EXAMPLE_APP"] != nil
    result[:react_native_version] = react_native_json['version']
    result[:react_native_dir] = File.expand_path(react_native_dir)

    pods_root = Pod::Config.instance.project_pods_root
    react_native_common_dir_absolute = File.join(react_native_dir, 'ReactCommon')
    react_native_common_dir_relative = Pathname.new(react_native_common_dir_absolute).relative_path_from(pods_root).to_s
    result[:react_native_common_dir] = react_native_common_dir_relative

    return result
  end

  def assert_minimal_react_native_version(config)
    validate_react_native_version_script = File.expand_path(File.join(__dir__, 'validate-react-native-version.js'))
    unless system("node \"#{validate_react_native_version_script}\" #{config[:react_native_version]}")
      raise "[Reanimated] Your installed version of React Native is not compatible with installed version of Reanimated. See the documentation for the list of supported versions: https://docs.swmansion.com/react-native-reanimated/docs/guides/compatibility/"
    end
  end

  def assert_conflicting_feature_flags(feature_flags)
    ios_sync_ui_props = feature_flags['IOS_SYNCHRONOUSLY_UPDATE_UI_PROPS'] == 'true'
    shared_element_transitions = feature_flags['ENABLE_SHARED_ELEMENT_TRANSITIONS'] == 'true'

    if ios_sync_ui_props && shared_element_transitions
      raise "[Reanimated] The feature flags `IOS_SYNCHRONOUSLY_UPDATE_UI_PROPS` and `ENABLE_SHARED_ELEMENT_TRANSITIONS` cannot be enabled simultaneously. Please disable one of them in your package.json"
    end
  end

  def get_static_feature_flags()
    feature_flags = {}

    static_feature_flags_path = File.path('./src/featureFlags/staticFlags.json')
    if !File.exist?(static_feature_flags_path)
      raise "[Reanimated] Feature flags file not found at #{static_feature_flags_path}."
    end
    static_feature_flags_json = JSON.parse(File.read(static_feature_flags_path))
    static_feature_flags_json.each do |key, value|
      feature_flags[key] = value.to_s
    end

    package_json_path = File.join(Pod::Config.instance.installation_root.to_s, '..', 'package.json')
    if File.exist?(package_json_path)
      package_json = JSON.parse(File.read(package_json_path))
      if package_json['reanimated'] && package_json['reanimated']['staticFeatureFlags']
        feature_flags_json = package_json['reanimated']['staticFeatureFlags']
        feature_flags_json.each do |key, value|
          feature_flags[key] = value.to_s
        end
      end
    end

    assert_conflicting_feature_flags(feature_flags)

    return feature_flags.map { |key, value| "[#{key}:#{value}]" }.join('')
  end
end