# frozen_string_literal: true
require 'rubygems/command'
require 'rubygems/version_option'
require 'rubygems/uninstaller'
require 'fileutils'

##
# Gem uninstaller command line tool
#
# See `gem help uninstall`

class Gem::Commands::UninstallCommand < Gem::Command

  include Gem::VersionOption

  def initialize
    super 'uninstall', 'Uninstall gems from the local repository',
          :version => Gem::Requirement.default, :user_install => true,
          :check_dev => false, :vendor => false

    add_option('-a', '--[no-]all',
      'Uninstall all matching versions'
    ) do |value, options|
      options[:all] = value
    end

    add_option('-I', '--[no-]ignore-dependencies',
               'Ignore dependency requirements while',
               'uninstalling') do |value, options|
      options[:ignore] = value
    end

    add_option('-D', '--[no-]check-development',
               'Check development dependencies while uninstalling',
               '(default: false)') do |value, options|
      options[:check_dev] = value
    end

    add_option('-x', '--[no-]executables',
                 'Uninstall applicable executables without',
                 'confirmation') do |value, options|
      options[:executables] = value
    end

    add_option('-i', '--install-dir DIR',
               'Directory to uninstall gem from') do |value, options|
      options[:install_dir] = File.expand_path(value)
    end

    add_option('-n', '--bindir DIR',
               'Directory to remove executables from') do |value, options|
      options[:bin_dir] = File.expand_path(value)
    end

    add_option('--[no-]user-install',
               'Uninstall from user\'s home directory',
               'in addition to GEM_HOME.') do |value, options|
      options[:user_install] = value
    end

    add_option('--[no-]format-executable',
               'Assume executable names match Ruby\'s prefix and suffix.') do |value, options|
      options[:format_executable] = value
    end

    add_option('--[no-]force',
               'Uninstall all versions of the named gems',
               'ignoring dependencies') do |value, options|
      options[:force] = value
    end

    add_option('--[no-]abort-on-dependent',
               'Prevent uninstalling gems that are',
               'depended on by other gems.') do |value, options|
      options[:abort_on_dependent] = value
    end

    add_version_option
    add_platform_option

    add_option('--vendor',
               'Uninstall gem from the vendor directory.',
               'Only for use by gem repackagers.') do |value, options|
      unless Gem.vendor_dir
        raise OptionParser::InvalidOption.new 'your platform is not supported'
      end

      alert_warning 'Use your OS package manager to uninstall vendor gems'
      options[:vendor] = true
      options[:install_dir] = Gem.vendor_dir
    end
  end

  def arguments # :nodoc:
    "GEMNAME       name of gem to uninstall"
  end

  def defaults_str # :nodoc:
    "--version '#{Gem::Requirement.default}' --no-force " +
    "--user-install"
  end

  def description # :nodoc:
    <<-EOF
The uninstall command removes a previously installed gem.

RubyGems will ask for confirmation if you are attempting to uninstall a gem
that is a dependency of an existing gem.  You can use the
--ignore-dependencies option to skip this check.
    EOF
  end

  def usage # :nodoc:
    "#{program_name} GEMNAME [GEMNAME ...]"
  end

  def check_version # :nodoc:
    if options[:version] != Gem::Requirement.default and
         get_all_gem_names.size > 1
      alert_error "Can't use --version with multiple gems. You can specify multiple gems with" \
                  " version requirements using `gem uninstall 'my_gem:1.0.0' 'my_other_gem:~>2.0.0'`"
      terminate_interaction 1
    end
  end

  def execute
    check_version

    if options[:all] and not options[:args].empty?
      uninstall_specific
    elsif options[:all]
      uninstall_all
    else
      uninstall_specific
    end
  end

  def uninstall_all
    specs = Gem::Specification.reject { |spec| spec.default_gem? }

    specs.each do |spec|
      options[:version] = spec.version
      uninstall_gem spec.name
    end

    alert "Uninstalled all gems in #{options[:install_dir]}"
  end

  def uninstall_specific
    deplist = Gem::DependencyList.new
    original_gem_version = {}

    get_all_gem_names_and_versions.each do |name, version|
      original_gem_version[name] = version || options[:version]

      gem_specs = Gem::Specification.find_all_by_name(name, original_gem_version[name])

      say("Gem '#{name}' is not installed") if gem_specs.empty?
      gem_specs.each do |spec|
        deplist.add spec
      end
    end

    deps = deplist.strongly_connected_components.flatten.reverse

    gems_to_uninstall = {}

    deps.each do |dep|
      unless gems_to_uninstall[dep.name]
        gems_to_uninstall[dep.name] = true

        unless original_gem_version[dep.name] == Gem::Requirement.default
          options[:version] = dep.version
        end

        uninstall_gem(dep.name)
      end
    end
  end

  def uninstall_gem(gem_name)
    uninstall(gem_name)
  rescue Gem::GemNotInHomeException => e
    spec = e.spec
    alert("In order to remove #{spec.name}, please execute:\n" +
          "\tgem uninstall #{spec.name} --install-dir=#{spec.installation_path}")
  rescue Gem::UninstallError => e
    spec = e.spec
    alert_error("Error: unable to successfully uninstall '#{spec.name}' which is " +
          "located at '#{spec.full_gem_path}'. This is most likely because" +
          "the current user does not have the appropriate permissions")
    terminate_interaction 1
  end

  def uninstall(gem_name)
    Gem::Uninstaller.new(gem_name, options).uninstall
  end

end