class Gem::Uninstaller

# File lib/rubygems/uninstaller.rb, line 48
def initialize(gem, options = {})
  # TODO: document the valid options
  @gem                = gem
  @version            = options[:version] || Gem::Requirement.default
  @install_dir        = options[:install_dir]
  @gem_home           = File.realpath(@install_dir || Gem.dir)
  @user_dir           = File.exist?(Gem.user_dir) ? File.realpath(Gem.user_dir) : Gem.user_dir
  @force_executables  = options[:executables]
  @force_all          = options[:all]
  @force_ignore       = options[:ignore]
  @bin_dir            = options[:bin_dir]
  @format_executable  = options[:format_executable]
  @abort_on_dependent = options[:abort_on_dependent]

  # Indicate if development dependencies should be checked when
  # uninstalling. (default: false)
  #
  @check_dev = options[:check_dev]

  if options[:force]
    @force_all = true
    @force_ignore = true
  end

  # only add user directory if install_dir is not set
  @user_install = false
  @user_install = options[:user_install] unless @install_dir

  # Optimization: populated during #uninstall
  @default_specs_matching_uninstall_params = []
end

# File lib/rubygems/uninstaller.rb, line 310
def path_ok?(gem_dir, spec)
  full_path     = File.join gem_dir, "gems", spec.full_name
  original_path = File.join gem_dir, "gems", spec.original_name

  full_path == spec.full_gem_path || original_path == spec.full_gem_path
end

# File lib/rubygems/uninstaller.rb, line 300
def regenerate_plugins
  latest = specification_record.latest_spec_for(@spec.name)
  return if latest.nil?

  regenerate_plugins_for(latest, plugin_dir_for(@spec))
end

# File lib/rubygems/uninstaller.rb, line 241
def remove(spec)
  unless path_ok?(@gem_home, spec) ||
         (@user_install && path_ok?(@user_dir, spec))
    e = Gem::GemNotInHomeException.new \
      "Gem '#{spec.full_name}' is not installed in directory #{@gem_home}"
    e.spec = spec

    raise e
  end

  raise Gem::FilePermissionError, spec.base_dir unless
    File.writable?(spec.base_dir)

  full_gem_path = spec.full_gem_path
  exclusions = []

  if default_spec_matches?(spec) && spec.executables.any?
    exclusions = spec.executables.map {|exe| File.join(spec.bin_dir, exe) }
    exclusions << File.dirname(exclusions.last) until exclusions.last == full_gem_path
  end

  safe_delete { rm_r full_gem_path, exclusions: exclusions }
  safe_delete { FileUtils.rm_r spec.extension_dir }

  old_platform_name = spec.original_name

  gem = spec.cache_file
  gem = File.join(spec.cache_dir, "#{old_platform_name}.gem") unless
    File.exist? gem

  safe_delete { FileUtils.rm_r gem }

  begin
    Gem::RDoc.new(spec).remove
  rescue NameError
  end

  gemspec = spec.spec_file

  unless File.exist? gemspec
    gemspec = File.join(File.dirname(gemspec), "#{old_platform_name}.gemspec")
  end

  safe_delete { FileUtils.rm_r gemspec }
  announce_deletion_of(spec)
end

# File lib/rubygems/uninstaller.rb, line 234
def remove_all(list)
  list.each {|spec| uninstall_gem spec }
end

# File lib/rubygems/uninstaller.rb, line 180
def remove_executables(spec)
  return if spec.executables.empty? || default_spec_matches?(spec)

  executables = spec.executables.clone

  # Leave any executables created by other installed versions
  # of this gem installed.

  list = Gem::Specification.find_all do |s|
    s.name == spec.name && s.version != spec.version
  end

  list.each do |s|
    s.executables.each do |exe_name|
      executables.delete exe_name
    end
  end

  return if executables.empty?

  executables = executables.map {|exec| formatted_program_filename exec }

  remove = if @force_executables.nil?
    ask_yes_no("Remove executables:\n" \
               "\t#{executables.join ", "}\n\n" \
               "in addition to the gem?",
               true)
  else
    @force_executables
  end

  if remove
    bin_dir = @bin_dir || Gem.bindir(spec.base_dir)

    raise Gem::FilePermissionError, bin_dir unless File.writable? bin_dir

    executables.each do |exe_name|
      say "Removing #{exe_name}"

      exe_file = File.join bin_dir, exe_name

      safe_delete { FileUtils.rm exe_file }
      safe_delete { FileUtils.rm "#{exe_file}.bat" }
    end
  else
    say "Executables and scripts will remain installed."
  end
end

# File lib/rubygems/uninstaller.rb, line 376
def safe_delete(&block)
  block.call
rescue Errno::ENOENT
  nil
rescue Errno::EPERM
  e = Gem::UninstallError.new
  e.spec = @spec

  raise e
end

# File lib/rubygems/uninstaller.rb, line 84
def uninstall
  dependency = Gem::Dependency.new @gem, @version

  list = []

  specification_record.stubs.each do |spec|
    next unless dependency.matches_spec? spec

    list << spec
  end

  if list.empty?
    raise Gem::InstallError, "gem #{@gem.inspect} is not installed"
  end

  default_specs, list = list.partition(&:default_gem?)
  warn_cannot_uninstall_default_gems(default_specs - list)
  @default_specs_matching_uninstall_params = default_specs.map(&:to_spec)

  list, other_repo_specs = list.partition do |spec|
    @gem_home == spec.base_dir ||
      (@user_install && spec.base_dir == @user_dir)
  end

  list.sort!

  if list.empty?
    return unless other_repo_specs.any?

    other_repos = other_repo_specs.map(&:base_dir).uniq

    message = ["#{@gem} is not installed in GEM_HOME, try:"]
    message.concat other_repos.map {|repo|
      "\tgem uninstall -i #{repo} #{@gem}"
    }

    raise Gem::InstallError, message.join("\n")
  elsif @force_all
    remove_all list

  elsif list.size > 1
    gem_names = list.map(&:full_name_with_location)
    gem_names << "All versions"

    say
    _, index = choose_from_list "Select gem to uninstall:", gem_names

    if index == list.size
      remove_all list
    elsif index && index >= 0 && index < list.size
      uninstall_gem list[index]
    else
      say "Error: must enter a number [1-#{list.size + 1}]"
    end
  else
    uninstall_gem list.first
  end
end

# File lib/rubygems/uninstaller.rb, line 146
def uninstall_gem(stub)
  spec = stub.to_spec

  @spec = spec

  unless dependencies_ok? spec
    if abort_on_dependent? || !ask_if_ok(spec)
      raise Gem::DependencyRemovalException,
        "Uninstallation aborted due to dependent gem(s)"
    end
  end

  Gem.pre_uninstall_hooks.each do |hook|
    hook.call self
  end

  remove_executables @spec
  remove_plugins @spec
  remove @spec

  specification_record.remove_spec(stub)

  regenerate_plugins

  Gem.post_uninstall_hooks.each do |hook|
    hook.call self
  end

  @spec = nil
end

# File lib/rubygems/uninstaller.rb, line 399
def announce_deletion_of(spec)
  name = spec.full_name
  say "Successfully uninstalled #{name}"
  if default_spec_matches?(spec)
    say(
      "There was both a regular copy and a default copy of #{name}. The " \
        "regular copy was successfully uninstalled, but the default copy " \
        "was left around because default gems can't be removed."
    )
  end
end

# File lib/rubygems/uninstaller.rb, line 412
def default_spec_matches?(spec)
  !default_specs_that_match(spec).empty?
end

# File lib/rubygems/uninstaller.rb, line 417
def default_specs_that_match(spec)
  @default_specs_matching_uninstall_params.select {|default_spec| spec == default_spec }
end

# File lib/rubygems/uninstaller.rb, line 427
def plugin_dir_for(spec)
  Gem.plugindir(spec.base_dir)
end

# File lib/rubygems/uninstaller.rb, line 389
def rm_r(path, exclusions:)
  FileUtils::Entry_.new(path).postorder_traverse do |ent|
    ent.remove unless exclusions.include?(ent.path)
  end
end

# File lib/rubygems/uninstaller.rb, line 395
def specification_record
  @specification_record ||= @install_dir ? Gem::SpecificationRecord.from_path(@install_dir) : Gem::Specification.specification_record
end

# File lib/rubygems/uninstaller.rb, line 421
def warn_cannot_uninstall_default_gems(specs)
  specs.each do |spec|
    say "Gem #{spec.full_name} cannot be uninstalled because it is a default gem"
  end
end