#
# Copyright:: 2011-2016, Heavy Water Software Inc.
# Copyright:: Copyright (c) Chef Software Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

require_relative "../resource"
require "chef-utils/dist" unless defined?(ChefUtils::Dist)

class Chef
  class Resource
    class Locale < Chef::Resource
      provides :locale

      description "Use the **locale** resource to set the system's locale on Debian and Windows systems. Windows support was added in Chef Infra Client 16.0"
      introduced "14.5"

      examples <<~DOC
      Set the lang to 'en_US.UTF-8'

      ```ruby
        locale 'set system locale' do
          lang 'en_US.UTF-8'
        end
      ```
      DOC

      LC_VARIABLES ||= %w{LC_ADDRESS LC_COLLATE LC_CTYPE LC_IDENTIFICATION LC_MEASUREMENT LC_MESSAGES LC_MONETARY LC_NAME LC_NUMERIC LC_PAPER LC_TELEPHONE LC_TIME}.freeze
      LOCALE_CONF ||= "/etc/locale.conf".freeze
      LOCALE_REGEX ||= /\A\S+/.freeze
      LOCALE_PLATFORM_FAMILIES ||= %w{debian windows}.freeze

      property :lang, String,
        description: "Sets the default system language.",
        regex: [LOCALE_REGEX],
        validation_message: "The provided lang is not valid. It should be a non-empty string without any leading whitespace."

      property :lc_env, Hash,
        description: "A Hash of LC_* env variables in the form of `({ 'LC_ENV_VARIABLE' => 'VALUE' })`.",
        default: {},
        coerce: proc { |h|
          if h.respond_to?(:keys)
            invalid_keys = h.keys - LC_VARIABLES
            unless invalid_keys.empty?
              error_msg = "Key of option lc_env must be equal to one of: \"#{LC_VARIABLES.join('", "')}\"!  You passed \"#{invalid_keys.join(", ")}\"."
              raise Chef::Exceptions::ValidationFailed, error_msg
            end
          end
          unless h.values.all? { |x| x =~ LOCALE_REGEX }
            error_msg = "Values of option lc_env should be non-empty string without any leading whitespace."
            raise Chef::Exceptions::ValidationFailed, error_msg
          end
          h
        }

      # @deprecated Use {#lc_env} instead of this property.
      #   {#lc_env} uses Hash with specific LC var as key.
      # @raise [Chef::Deprecated]
      #
      def lc_all(arg = nil)
        unless arg.nil?
          Chef.deprecated(:locale_lc_all, "Changing LC_ALL can break #{ChefUtils::Dist::Infra::PRODUCT}'s parsing of command output in unexpected ways.\n Use one of the more specific LC_ properties as needed.")
        end
      end

      load_current_value do
        if windows?
          lang get_system_locale_windows
        else
          begin
            old_content = ::File.read(LOCALE_CONF)
            locale_values = Hash[old_content.split("\n").map { |v| v.split("=") }]
            lang locale_values["LANG"]
          rescue Errno::ENOENT => e
            false
          end
        end
      end

      # Gets the System-locale setting for the current computer.
      # @see https://docs.microsoft.com/en-us/powershell/module/international/get-winsystemlocale
      # @return [String] the current value of the System-locale setting.
      #
      def get_system_locale_windows
        powershell_exec("Get-WinSystemLocale").result["Name"]
      end

      action :update, description: "Update the system's locale." do
        converge_if_changed do
          set_system_locale
        end
      end

      action_class do
        # Avoid running this resource on platforms that don't use /etc/locale.conf
        #
        def define_resource_requirements
          requirements.assert(:all_actions) do |a|
            a.assertion { LOCALE_PLATFORM_FAMILIES.include?(node[:platform_family]) }
            a.failure_message(Chef::Exceptions::ProviderNotFound, "The locale resource is not supported on platform family: #{node[:platform_family]}")
          end

          requirements.assert(:all_actions) do |a|
            # RHEL/CentOS type platforms don't have locale-gen
            a.assertion { which("locale-gen") }
            a.failure_message(Chef::Exceptions::ProviderNotFound, "The locale resource requires the locale-gen tool")
          end
        end

        # Generates the localization files from templates using locale-gen.
        # @see http://manpages.ubuntu.com/manpages/cosmic/man8/locale-gen.8.html
        # @raise [Mixlib::ShellOut::ShellCommandFailed] not a supported language or locale
        #
        def generate_locales
          shell_out!("locale-gen #{unavailable_locales.join(" ")}", timeout: 1800)
        end

        # Sets the system locale for the current computer.
        #
        def set_system_locale
          if windows?
            # Sets the system locale for the current computer.
            # @see https://docs.microsoft.com/en-us/powershell/module/internationalcmdlets/set-winsystemlocale
            #
            response = powershell_exec("Set-WinSystemLocale -SystemLocale #{new_resource.lang}")
            raise response.errors.join(" ") if response.error?
          else
            generate_locales unless unavailable_locales.empty?
            update_locale
          end
        end

        # Updates system locale by appropriately writing them in /etc/locale.conf
        # @note This locale change won't affect the current run. At this time it is an exercise
        # left to the user to restart or reboot if the locale change is required at
        # later part of the client run.
        # @see https://wiki.archlinux.org/index.php/locale#Setting_the_system_locale
        #
        def update_locale
          file "Updating system locale" do
            path LOCALE_CONF
            content new_content
          end
        end

        # @return [Array<String>] Locales that user wants to set but are not available on
        #   the system. They are required to be generated.
        #
        def unavailable_locales
          @unavailable_locales ||= begin
            available = shell_out!("locale -a").stdout.split("\n")
            required = [new_resource.lang, new_resource.lc_env.values].flatten.compact.uniq
            required - available
          end
        end

        # @return [String] Contents that are required to be
        #   updated in /etc/locale.conf
        #
        def new_content
          @new_content ||= begin
            content = {}
            content = new_resource.lc_env.dup if new_resource.lc_env
            content["LANG"] = new_resource.lang if new_resource.lang
            content.sort.map { |t| t.join("=") }.join("\n") + "\n"
          end
        end
      end
    end
  end
end
