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#
# Author:: Mathieu Sauve-Frankel <msf@kisoku.net>
# Copyright:: Copyright (c) 2009 Mathieu Sauve-Frankel.
# License:: Apache License, Version 2.0
#
# 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 "chef-config/path_helper"
require "chef-config/workstation_config_loader"
require_relative "../ohai"
require_relative "log"
require "mixlib/cli" unless defined?(Mixlib::CLI)
require "benchmark"

# The Application class is what is called by the Ohai CLI binary. It handles:
#  - CLI options and attribute arguments
#  - Collecting data via the Ohai::System class
#  - Printing the results returned via the Ohai::System class
class Ohai::Application
  include Mixlib::CLI

  option :config_file,
    short: "-c CONFIG",
    long: "--config CONFIG",
    description: "A configuration file to use",
    proc: lambda { |path| File.expand_path(path, Dir.pwd) }

  option :directory,
    short: "-d DIRECTORY",
    long: "--directory DIRECTORY",
    description: "A directory to add to the Ohai plugin search path. If passing multiple directories use this option more than once.",
    proc: lambda { |path, path_array|
      (path_array ||= []) << Ohai::Config.platform_specific_path(path)
      path_array
    }

  option :log_level,
    short: "-l LEVEL",
    long: "--log_level LEVEL",
    description: "Set the log level (debug, info, warn, error, fatal)",
    proc: lambda { |l| l.to_sym }

  option :log_location,
    short: "-L LOGLOCATION",
    long: "--logfile LOGLOCATION",
    description: "Set the log file location, defaults to STDOUT - recommended for daemonizing",
    proc: nil

  option :help,
    short: "-h",
    long: "--help",
    description: "Show this message",
    on: :tail,
    boolean: true,
    show_options: true,
    exit: 0

  option :version,
    short: "-v",
    long: "--version",
    description: "Show Ohai version",
    boolean: true,
    proc: lambda { |v| puts "Ohai: #{::Ohai::VERSION}" },
    exit: 0

  # the method called by the Ohai binary to actually run the whole application
  #
  # @return void
  def run
    elapsed = Benchmark.realtime do
      configure_ohai
      run_application
    end
    Ohai::Log.debug("Ohai took #{elapsed} total seconds to run.")
  end

  # parses the CLI options, loads the config file if present, and initializes logging
  #
  # @return void
  def configure_ohai
    @attributes = parse_options
    @attributes = nil if @attributes.empty?

    load_workstation_config

    Ohai::Log.init(Ohai.config[:log_location])
  end

  # Passes config and attributes arguments to Ohai::System then prints the results.
  # Called by the run method after config / logging have been initialized
  #
  # @return void
  def run_application
    config[:invoked_from_cli] = true
    config[:logger] = Ohai::Log.with_child
    ohai = Ohai::System.new(config)
    ohai.all_plugins(@attributes)

    if @attributes
      @attributes.each do |a|
        puts ohai.attributes_print(a)
      end
    else
      puts ohai.json_pretty_print
    end
  end

  class << self
    # Log a fatal error message to both STDERR and the Logger, exit the application
    # @param msg [String] the message to log
    # @param err [Integer] the exit code
    def fatal!(msg, err = -1)
      STDERR.puts("FATAL: #{msg}")
      Ohai::Log.fatal(msg)
      Process.exit err
    end

    # Log a debug message to the Logger and then exit the application
    # @param msg [String] the message to log
    # @param err [Integer] the exit code
    def exit!(msg, err = -1)
      Ohai::Log.debug(msg)
      Process.exit err
    end
  end

  private

  def load_workstation_config
    config_loader = ChefConfig::WorkstationConfigLoader.new(
      config[:config_file], Ohai::Log
    )
    begin
      config_loader.load
    rescue ChefConfig::ConfigurationError => config_error
      Ohai::Application.fatal!(config_error.message)
    end
  end
end