#--
# Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
# All rights reserved.
# See LICENSE.txt for permissions.
#++

require 'yaml'
require 'rubygems'

# Store the gem command options specified in the configuration file.  The
# config file object acts much like a hash.

class Gem::ConfigFile

  DEFAULT_BACKTRACE = false
  DEFAULT_BENCHMARK = false
  DEFAULT_BULK_THRESHOLD = 1000
  DEFAULT_VERBOSITY = true
  DEFAULT_UPDATE_SOURCES = true

  ##
  # For Ruby packagers to set configuration defaults.  Set in
  # rubygems/defaults/operating_system.rb

  OPERATING_SYSTEM_DEFAULTS = {}

  ##
  # For Ruby implementers to set configuration defaults.  Set in
  # rubygems/defaults/#{RUBY_ENGINE}.rb

  PLATFORM_DEFAULTS = {}

  system_config_path = 
    begin
      require 'Win32API'

      CSIDL_COMMON_APPDATA = 0x0023
      path = 0.chr * 260
      SHGetFolderPath = Win32API.new 'shell32', 'SHGetFolderPath', 'LLLLP', 'L'
      SHGetFolderPath.call 0, CSIDL_COMMON_APPDATA, 0, 1, path

      path.strip
    rescue LoadError
      '/etc'
    end

  SYSTEM_WIDE_CONFIG_FILE = File.join system_config_path, 'gemrc'
  
  # List of arguments supplied to the config file object.
  attr_reader :args

  # Where to look for gems
  attr_accessor :path

  # True if we print backtraces on errors.
  attr_writer :backtrace

  # True if we are benchmarking this run.
  attr_accessor :benchmark

  # Bulk threshold value.  If the number of missing gems are above
  # this threshold value, then a bulk download technique is used.
  attr_accessor :bulk_threshold

  # Verbose level of output:
  # * false -- No output
  # * true -- Normal output
  # * :loud -- Extra output
  attr_accessor :verbose

  # True if we want to update the SourceInfoCache every time, false otherwise
  attr_accessor :update_sources

  # Create the config file object.  +args+ is the list of arguments
  # from the command line.
  #
  # The following command line options are handled early here rather
  # than later at the time most command options are processed.
  #
  # * --config-file and --config-file==NAME -- Obviously these need
  #   to be handled by the ConfigFile object to ensure we get the
  #   right config file.
  #
  # * --backtrace -- Backtrace needs to be turned on early so that
  #   errors before normal option parsing can be properly handled.
  #
  # * --debug -- Enable Ruby level debug messages.  Handled early
  #   for the same reason as --backtrace.
  #
  def initialize(arg_list)
    @config_file_name = nil
    need_config_file_name = false

    arg_list = arg_list.map do |arg|
      if need_config_file_name then
        @config_file_name = arg
        need_config_file_name = false
        nil
      elsif arg =~ /^--config-file=(.*)/ then
        @config_file_name = $1
        nil
      elsif arg =~ /^--config-file$/ then
        need_config_file_name = true
        nil
      else
        arg
      end
    end.compact

    @backtrace = DEFAULT_BACKTRACE
    @benchmark = DEFAULT_BENCHMARK
    @bulk_threshold = DEFAULT_BULK_THRESHOLD
    @verbose = DEFAULT_VERBOSITY
    @update_sources = DEFAULT_UPDATE_SOURCES

    operating_system_config = Marshal.load Marshal.dump(OPERATING_SYSTEM_DEFAULTS)
    platform_config = Marshal.load Marshal.dump(PLATFORM_DEFAULTS)
    system_config = load_file SYSTEM_WIDE_CONFIG_FILE
    user_config = load_file config_file_name.dup.untaint

    @hash = operating_system_config.merge platform_config
    @hash = @hash.merge system_config
    @hash = @hash.merge user_config

    # HACK these override command-line args, which is bad
    @backtrace = @hash[:backtrace] if @hash.key? :backtrace
    @benchmark = @hash[:benchmark] if @hash.key? :benchmark
    @bulk_threshold = @hash[:bulk_threshold] if @hash.key? :bulk_threshold
    Gem.sources = @hash[:sources] if @hash.key? :sources
    @verbose = @hash[:verbose] if @hash.key? :verbose
    @update_sources = @hash[:update_sources] if @hash.key? :update_sources
    @path = @hash[:gempath]

    handle_arguments arg_list
  end

  def load_file(filename)
    begin
      YAML.load(File.read(filename)) if filename and File.exist?(filename)
    rescue ArgumentError
      warn "Failed to load #{config_file_name}"
    rescue Errno::EACCES
      warn "Failed to load #{config_file_name} due to permissions problem."
    end or {}
  end

  # True if the backtrace option has been specified, or debug is on.
  def backtrace
    @backtrace or $DEBUG
  end

  # The name of the configuration file.
  def config_file_name
    @config_file_name || Gem.config_file
  end

  # Delegates to @hash
  def each(&block)
    hash = @hash.dup
    hash.delete :update_sources
    hash.delete :verbose
    hash.delete :benchmark
    hash.delete :backtrace
    hash.delete :bulk_threshold

    yield :update_sources, @update_sources
    yield :verbose, @verbose
    yield :benchmark, @benchmark
    yield :backtrace, @backtrace
    yield :bulk_threshold, @bulk_threshold

    yield 'config_file_name', @config_file_name if @config_file_name

    hash.each(&block)
  end

  # Handle the command arguments.
  def handle_arguments(arg_list)
    @args = []

    arg_list.each do |arg|
      case arg
      when /^--(backtrace|traceback)$/ then
        @backtrace = true
      when /^--bench(mark)?$/ then
        @benchmark = true
      when /^--debug$/ then
        $DEBUG = true
      else
        @args << arg
      end
    end
  end

  # Really verbose mode gives you extra output.
  def really_verbose
    case verbose
    when true, false, nil then false
    else true
    end
  end

  # to_yaml only overwrites things you can't override on the command line.
  def to_yaml # :nodoc:
    yaml_hash = {}
    yaml_hash[:backtrace] = @hash.key?(:backtrace) ? @hash[:backtrace] :
      DEFAULT_BACKTRACE
    yaml_hash[:benchmark] = @hash.key?(:benchmark) ? @hash[:benchmark] :
      DEFAULT_BENCHMARK
    yaml_hash[:bulk_threshold] = @hash.key?(:bulk_threshold) ?
      @hash[:bulk_threshold] : DEFAULT_BULK_THRESHOLD
    yaml_hash[:sources] = Gem.sources
    yaml_hash[:update_sources] = @hash.key?(:update_sources) ?
      @hash[:update_sources] : DEFAULT_UPDATE_SOURCES
    yaml_hash[:verbose] = @hash.key?(:verbose) ? @hash[:verbose] :
      DEFAULT_VERBOSITY

    keys = yaml_hash.keys.map { |key| key.to_s }
    keys << 'debug'
    re = Regexp.union(*keys)

    @hash.each do |key, value|
      key = key.to_s
      next if key =~ re
      yaml_hash[key.to_s] = value
    end

    yaml_hash.to_yaml
  end

  # Writes out this config file, replacing its source.
  def write
    File.open config_file_name, 'w' do |fp|
      fp.write self.to_yaml
    end
  end

  # Return the configuration information for +key+.
  def [](key)
    @hash[key.to_s]
  end

  # Set configuration option +key+ to +value+.
  def []=(key, value)
    @hash[key.to_s] = value
  end

  def ==(other) # :nodoc:
    self.class === other and
    @backtrace == other.backtrace and
    @benchmark == other.benchmark and
    @bulk_threshold == other.bulk_threshold and
    @verbose == other.verbose and
    @update_sources == other.update_sources and
    @hash == other.hash
  end

  protected

  attr_reader :hash

end