# encoding: utf-8
#
# This file is part of the bovem gem. Copyright (C) 2013 and above Shogun <shogun@cowtech.it>.
# Licensed under the MIT license, which can be found at http://www.opensource.org/licenses/mit-license.php.
#

module Bovem
  # This is the main class for a Bovem application.
  #
  # Basically is the same of a command, but it adds support for application version.
  #
  # @attribute version
  #   @return [String] The version of the application.
  # @attribute shell
  #   @return [Bovem::Shell] A shell helper.
  # @attribute console
  #   @return [Bovem::Console] A console helper.
  # @attribute skip_commands
  #   @return [Boolean] If to skip commands run via {#run}.
  # @attribute show_commands
  #   @return [Boolean] If to show command lines run via {#run}.
  # @attribute output_commands
  #   @return [Boolean] If to show the output of the commands run via {#run}.
  class Application < Bovem::Command
    attr_accessor :version
    attr_accessor :shell
    attr_accessor :console
    attr_accessor :skip_commands
    attr_accessor :show_commands
    attr_accessor :output_commands

    # Initializes a new Bovem application.
    #
    # In options, you can override the command line arguments with `:__args__`, and you can skip execution by specifying `run: false`.
    #
    # @see Command#setup_with
    #
    # @param options [Hash] The settings to initialize the application with.
    # @return [Application] The created application.
    def self.create(options = {}, &block)
      raise Bovem::Errors::Error.new(Bovem::Application, :missing_block, Bovem::Localizer.localize_on_locale(options[:locale], :missing_app_block)) if !block_given?
      run, args, options = setup_application_option(options)

      begin
        create_application(run, args, options, &block)
      rescue => e
        Kernel.puts(e.to_s)
        Kernel.exit(1)
      end
    end

    # Creates a new application.
    #
    # @param options [Hash] The settings to initialize the application with.
    def initialize(options = {}, &block)
      super(options, &block)

      @shell = Bovem::Shell.instance
      @console = @shell.console
      @skip_commands = false
      @show_commands = false
      @output_commands = false

      help_option
    end

    # Reads and optionally sets the version of this application.
    #
    # @param value [String|nil] The new version of this application.
    # @return [String|nil] The version of this application.
    def version(value = nil)
      @version = value.ensure_string if !value.nil?
      @version
    end

    # Executes this application.
    #
    # @param args [Array] The command line to pass to this application. Defaults to `ARGV`.
    def execute(args = nil)
      super(args || ARGV)
    end

    # Adds a help command and a help option to this application.
    def help_option
      command(:help, description: i18n.help_command_description) do
        action { |command| application.command_help(command) }
      end

      option(:help, [i18n.help_option_short_form, i18n.help_option_long_form], help: i18n.help_message){ |application, _| application.show_help }
    end

    # The name of the current executable.
    #
    # @return [String] The name of the current executable.
    def executable_name
      $0
    end

    # Shows a help about a command.
    #
    # @param command [Command] The command to show help for.
    def command_help(command)
      fetch_commands_for_help(command).each do |arg|
        # Find the command across
        next_command = Bovem::Parser.find_command(arg, command, [])

        if next_command then
          command = command.commands[next_command[:name]]
        else
          break
        end
      end

      command.show_help
    end

    # Runs a command into the shell.
    #
    # @param command [String] The string to run.
    # @param message [String] A message to show before running.
    # @param show_exit [Boolean] If show the exit status.
    # @param fatal [Boolean] If quit in case of fatal errors.
    # @return [Hash] An hash with `status` and `output` keys.
    def run(command, message = nil, show_exit = true, fatal = true)
      @shell.run(command, message, !@skip_commands, show_exit, @output_commands, @show_commands, fatal)
    end

    private
      # Setup options for application creation.
      #
      # @param options [Hash] The options to setups.
      # @return [Array] If to run the application, the arguments and the specified options.
      def self.setup_application_option(options)
        options = {name: Bovem::Localizer.localize_on_locale(options[:locale], :default_application_name), parent: nil, application: nil}.merge(options.ensure_hash)
        run = options.delete(:run)
        [(!run.nil? ? run : true).to_boolean, options.delete(:__args__), options]
      end

      # Create the application.
      #
      # @param run [Boolean ]If to run the application.
      # @param args [Hash] The arguments to use for running.
      # @param options [Hash] The options of the application.
      # @return [Application] The new application.
      def self.create_application(run, args, options, &block)
        application = new(options, &block)
        application.execute(args) if application && run
        application
      end

      # Fetch a command list for showing help.
      #
      # @param command [Command] The command to show help for.
      def fetch_commands_for_help(command)
        command.arguments.collect {|c| c.split(":") }.flatten.collect(&:strip).select(&:present?)
      end
  end
end