git-multi

#!/usr/bin/env ruby
# frozen_string_literal: true

#
# INSTALLATION
#
# ln -s ${PWD}/git-multi $(brew --prefix)/bin/
# sudo ln -s ${PWD}/git-multi /usr/local/bin/
#

# stdlib dependencies
require 'English'
require 'tempfile'
require 'fileutils'
require 'shellwords'
require 'io/console'
require 'forwardable'

# gem dependencies
begin
  require 'octokit'
rescue LoadError
  nil # it's optional
end

# rubocop:disable Style/TrailingCommaInArrayLiteral
# rubocop:disable Style/TrailingCommaInArguments
# rubocop:disable Style/NestedTernaryOperator
# rubocop:disable Style/EmptyCaseCondition
# rubocop:disable Style/SingleLineMethods
# rubocop:disable Style/CharacterLiteral
# rubocop:disable Style/BlockDelimiters
# rubocop:disable Style/FormatString

module Wordiness # :nodoc:
  module WordinessMethods # :nodoc:
    def quiet!() @quiet = true; end
    def verbose!() @verbose = true; end

    def quiet?() !!@quiet; end
    def verbose?() !!@verbose; end
  end

  def self.included(base)
    base.extend(WordinessMethods)
    base.instance_variable_set(:@quiet, false)
    base.instance_variable_set(:@verbose, false)
  end
end

class String # :nodoc:
  # https://en.wikipedia.org/wiki/ANSI_escape_code
  def colorize(color_code) "\e[#{color_code}m#{self}\e[0m"; end

  def bold()      colorize('1'); end
  def faint()     colorize('2'); end
  def italic()    colorize('3'); end
  def underline() colorize('4'); end
  def invert()    colorize('7'); end
  def strike()    colorize('9'); end

  def red()   colorize('31'); end
  def green() colorize('32'); end
  def blue()  colorize('34'); end
  def cyan()  colorize('36'); end
end

module Spinner # :nodoc:
  ANIMATION = [
    '[     ]',
    '[.    ]',
    '[..   ]',
    '[ .   ]',
    '[ ..  ]',
    '[  .  ]',
    '[  .. ]',
    '[   . ]',
    '[   ..]',
    '[    .]',
    '[     ]',
    '[    .]',
    '[   ..]',
    '[   . ]',
    '[  .. ]',
    '[  .  ]',
    '[ ..  ]',
    '[ .   ]',
    '[..   ]',
    '[.    ]',
  ].map(&:blue).freeze

  private_constant :ANIMATION

  module_function

  def animator_for(task)
    animation = ANIMATION.cycle
    loop do
      IO.console.print(?\r, task, ' ', animation.next)
      sleep 0.1
    end
  end

  private_class_method :animator_for

  def report_duration(task, start_at, finish_at)
    duration = format('(%.3f seconds)', finish_at - start_at)
    IO.console.print(?\r, task.strike, ' ', "\e[0K", duration.green, ?\n)
  end

  private_class_method :report_duration

  def spinner_for(task, &block)
    animator = Thread.new { animator_for(task) }
    block.call
  ensure
    animator.kill
  end

  private_class_method :spinner_for

  def timer_for(task, &block)
    start_at = Time.now
    block.call
  ensure
    finish_at = Time.now
    report_duration(task, start_at, finish_at)
  end

  private_class_method :timer_for

  def for(task, &block)
    timer_for(task) do
      spinner_for(task) do
        block.call
      end
    end
  end
end

class IO # :nodoc:
  def self.identical_ios?(stdout, stderr)
    # see also: ruby/ruby/lib/fileutils.rb
    out_stat = stdout.stat
    err_stat = stderr.stat
    (out_stat.dev == err_stat.dev) && (out_stat.ino == err_stat.ino)
  end
end

class Tempfile # :nodoc:
  def prefixed_lines_to(io, prefix = '')
    rewind
    lines = readlines
    lines.each_with_object(prefix, &:prepend)

    io.puts(lines)
    io.flush
  end
end

module Git # :nodoc:
  module Config # :nodoc:
    include Wordiness

    module_function

    def git(command, path = nil)
      git = path ? "git -C #{path}" : 'git'
      IO.console.puts "CMD: #{git} #{command}" if verbose?
      `#{git} #{command}`.split($RS).each(&:strip!)
    end
    private_class_method :git

    def git_var(name)
      git("var #{name}").sample
    end

    def editor
      @editor ||= git_var('GIT_EDITOR')
    end

    def git_config(options, file: nil)
      source = file && File.file?(file) ? "--file #{file}" : '--global'
      git("config #{source} #{options}")
    end
    private_class_method :git_config

    def get_options(name, file: nil)
      git_config("--get-all #{name}", file: file)
    end

    def delete_options(name, file: nil)
      git_config("--unset-all #{name}", file: file)
    end

    def add_options(name, options, file: nil)
      options.each do |option|
        git_config("--add #{name} #{option}", file: file)
      end
    end

    def replace_options(name, options, file: nil)
      delete_options(name, file: file)
      add_options(name, options, file: file)
    end

    def get_option(name, file: nil)
      git_config("--get #{name}", file: file).first
    end

    def get_list(name, file: nil)
      get_option(name, file: file).split(',')
    end
  end

  module Hub # :nodoc:
    module_function

    def access_token
      Config.get_option('github.token') || ENV['GITHUB_TOKEN']
    end
    private_class_method :access_token

    def client
      @client ||= ::Octokit::Client.new(
        access_token: access_token,
        auto_paginate: true,
      )
    end
    private_class_method :client

    USER_REPOSITORIES_FOR = Hash.new { |repos, (user, type)|
      repos[[user, type]] = Spinner.for('Fetching user repos') do
        client.repositories(user, type: type)
      end
    }
    private_constant :USER_REPOSITORIES_FOR

    ORGANIZATION_REPOSITORIES_FOR = Hash.new { |repos, (org, type)|
      repos[[org, type]] = Spinner.for('Fetching org repos') do
        client.organization_repositories(org, type: type)
      end
    }
    private_constant :ORGANIZATION_REPOSITORIES_FOR

    # rubocop:disable Metrics/MethodLength
    def repositories_for(owner, type = :owner)
      case client.user(owner).type
      when 'User'
        # type can be one of: all, owner, member
        USER_REPOSITORIES_FOR[[owner, type]]
      when 'Organization'
        # type can be one of: all, public, private, forks, sources, member
        ORGANIZATION_REPOSITORIES_FOR[[owner, type]]
      end
    rescue NameError
      raise unless $ERROR_INFO.message == 'uninitialized constant Octokit'

      IO.console.puts '(please run `gem install octokit` first)'.red
      [] # octokit gem not installed
    rescue ::Octokit::NotFound
      IO.console.puts "(user/org \"#{owner}\" doesn't exist)".red
      [] # user/org doesn't exist
    end
    # rubocop:enable Metrics/MethodLength
  end

  module Multi # :nodoc:
    CONFIG_DIR = File.join(Dir.home, '.config', 'git', 'multi')

    module_function

    def config_file_for(name)
      File.join(CONFIG_DIR, "#{name}.config")
    end

    def superprojects
      @superprojects ||= Config.get_list('git.multi.superprojects')
    end

    def default_workarea
      @default_workarea ||= Config.get_option('git.multi.workarea')
    end

    def default_exclusions
      @default_exclusions ||= Config.get_options('git.multi.exclude')
    end

    def workarea_for(name)
      key = "superproject.#{name}.workarea"
      workarea = Config.get_option(key, file: config_file_for(name))
      workarea || default_workarea
    end

    def exclusions_for(name)
      key = "superproject.#{name}.exclude"
      exclusions = Config.get_options(key, file: config_file_for(name))
      exclusions + default_exclusions
    end

    def repos_for(name)
      key = "superproject.#{name}.repo"
      Config.get_options(key, file: config_file_for(name))
    end

    def add_repos_to(name, repos)
      Config.add_options("superproject.#{name}.repo", repos, file: config_file_for(name))
    end

    def replace_repos_for(name, repos)
      Config.replace_options("superproject.#{name}.repo", repos, file: config_file_for(name))
    end

    def set_repos_for(name, repos)
      FileUtils.touch(config_file_for(name)) # ensure config file exists
      replace_repos_for(name, repos)
    end

    def diff(base, head)
      added = head - base
      removed = base - head

      (base + head).uniq.sort.map { |entry|
        case
        when added.include?(entry) then "(+) #{entry}".green
        when removed.include?(entry) then "(-) #{entry}".red
        else "    #{entry}"
        end
      }
    end

    def compare_repos_to(name, repos)
      IO.console.puts(
        if (base = repos_for(name)) == repos
          'Lists of repos are identical'
        else
          diff(base, repos)
        end
      )
    end

    class Repo # :nodoc:
      attr_reader :full_name

      def initialize(full_name, workarea, fractional_index, excluded = nil)
        @full_name = full_name
        @workarea = workarea
        @fractional_index = fractional_index
        @excluded = !!excluded
      end

      def work_tree() File.join(@workarea, full_name); end
      def git_dir() @git_dir ||= File.join(work_tree, '.git'); end

      def excluded?() @excluded; end
      def exists?() @exists ||= File.directory?(git_dir); end
      def missing?() !excluded? && !exists?; end

      TICK  = "\u2714".green.freeze
      CROSS = "\u2718".red.freeze
      ARROW = "\u2794".blue.freeze
      EXCLUDE = "\u233D".cyan.freeze

      def icon
        @icon ||= excluded? ? EXCLUDE : exists? ? TICK : CROSS
      end

      def to_s
        @to_s ||= "(#{@fractional_index} - #{@full_name})"
      end

      def label
        @label ||= "#{to_s.invert} #{icon}"
      end

      def report
        full_name = exists? ? @full_name : @full_name.strike
        IO.console.puts "#{icon} #{full_name}"
      end

      def gh_clone_cmd
        "gh repo clone #{full_name} #{work_tree}"
      end
    end

    module Exec # :nodoc:
      include Wordiness

      module_function

      # rubocop:disable Metrics/CyclomaticComplexity
      # rubocop:disable Metrics/PerceivedComplexity
      # rubocop:disable Metrics/MethodLength
      # rubocop:disable Metrics/AbcSize
      def do_it(args, prefix: '')
        IO.console.puts "CMD: #{args.join(' ')}" if verbose?

        prefix += ': ' unless prefix.empty?

        stdout_tty = (stdout = $stdout).tty?
        stderr_tty = (stderr = $stderr).tty?

        temp_out = temp_err = temp_ios = nil

        out, err = if stdout_tty && stderr_tty
                     [stdout, stderr]
                   elsif !stdout_tty && !stderr_tty
                     if IO.identical_ios?(stdout, stderr)
                       temp_ios = Tempfile.new('temp_ios_')
                       [temp_ios, temp_ios]
                     else
                       temp_out = Tempfile.new('temp_out_')
                       temp_err = Tempfile.new('temp_err_')
                       [temp_out, temp_err]
                     end
                   elsif stdout_tty
                     temp_err = Tempfile.new('temp_err_')
                     [stdout, temp_err]
                   elsif stderr_tty
                     temp_out = Tempfile.new('temp_out_')
                     [temp_out, stderr]
                   else
                     raise 'FIX ME!'
                   end

        system(*args, out: out, err: err)
      ensure
        temp_out&.prefixed_lines_to(stdout, prefix)
        temp_out&.close

        temp_err&.prefixed_lines_to(stderr, prefix)
        temp_err&.close

        temp_ios&.prefixed_lines_to([stdout, stderr].sample, prefix)
        temp_ios&.close
      end
      # rubocop:enable Metrics/AbcSize
      # rubocop:enable Metrics/MethodLength
      # rubocop:enable Metrics/PerceivedComplexity
      # rubocop:enable Metrics/CyclomaticComplexity

      private_class_method :do_it

      def git_in(repo, args)
        IO.console.puts(repo.label) unless quiet?
        args = args.dup.unshift('git', '-C', repo.work_tree, '--no-pager')
        do_it(args, prefix: repo.full_name)
      end

      def shell_in(repo, args)
        IO.console.puts(repo.label) unless quiet?
        args = args.dup.unshift(ENV.fetch('SHELL', '/bin/sh'), '-l')
        Dir.chdir(repo.work_tree) { do_it(args, prefix: repo.full_name) }
      end

      def raw_in(repo, args)
        IO.console.puts(repo.label) unless quiet?
        args = args.dup # no changes!
        Dir.chdir(repo.work_tree) { do_it(args, prefix: repo.full_name) }
      end

      def editor_for(file)
        editor = Config.editor
        IO.console.puts "CMD: #{editor} #{file}" if verbose?
        system("#{editor} #{file}")
      end
    end

    class SuperProject # :nodoc:
      @all = {}

      def self.for(name, repos, workarea, exclusions = [])
        @all[name] = new(name, repos, workarea, exclusions)
      end

      def self.all
        @all.values
      end

      def self.named(name)
        @all[name]
      end

      attr_reader :name, :workarea, :repos

      def initialize(name, repos, workarea, exclusions = [])
        @name = name
        @workarea = workarea
        @repos = repos.each_with_index.map { |full_name, index|
          excluded = exclusions.include?(full_name)
          fractional_index = "#{@name}: ##{index + 1}/#{repos.count}"
          Repo.new(full_name, workarea, fractional_index, excluded)
        }
      end

      private :initialize

      def to_s
        @to_s ||= "[#{name}: ##{repos.count} repos]"
      end

      def config_file
        Git::Multi.config_file_for(name)
      end

      def edit_config_file
        Exec.editor_for(config_file)
      end

      extend Forwardable
      def_delegators :@repos, :size

      def exec_git(args)
        each_repo(filter: :exists?, & ->(repo) { Exec.git_in(repo, args) })
      end

      def exec_shell(args)
        each_repo(filter: :exists?, & ->(repo) { Exec.shell_in(repo, args) })
      end

      def exec_raw(args)
        each_repo(filter: :exists?, & ->(repo) { Exec.raw_in(repo, args) })
      end

      def each_repo(filter: :itself, &block)
        @repos.select(&filter).each(&block)
      end
    end

    class ForEach # :nodoc:
      include Wordiness

      def self.in(superprojects)
        new(superprojects)
      end

      def initialize(superprojects)
        @superprojects = superprojects
      end
      private :initialize

      def each(format: '[%s: %d-repo superproject]')
        @superprojects.each do |superproject|
          title = sprintf(format, superproject.name, superproject.size)
          IO.console.puts(title.invert.bold) unless self.class.quiet?
          yield superproject
        end
      end
      private :each

      def edit_config_file
        each(&:edit_config_file)
      end

      def report_repo_status
        each { |superproject| superproject.each_repo(&:report) }
      end

      def list_all_repos
        each { |superproject| superproject.each_repo { puts _1.full_name } }
      end

      def list_repo_paths
        each { |superproject| superproject.each_repo { puts _1.work_tree } }
      end

      def list_existing_repos
        each(format: '[%s: existing repos]') { |superproject|
          superproject.each_repo(filter: :exists?, & -> { puts _1.full_name })
        }
      end

      def list_excluded_repos
        each(format: '[%s: excluded repos]') { |superproject|
          superproject.each_repo(filter: :excluded?, & -> { puts _1.full_name })
        }
      end

      def list_missing_repos
        each(format: '[%s: missing repos]') { |superproject|
          superproject.each_repo(filter: :missing?, & -> { puts _1.full_name })
        }
      end

      def clone_missing_repos
        each(format: '[%s: clone repos]') { |superproject|
          puts 'export GITHUB_TOKEN=$(git config --global --get github.token)'
          superproject.each_repo(filter: :missing?, & -> { puts _1.gh_clone_cmd })
        }
      end

      def run_git_command(args)
        each { _1.exec_git(args) }
      end

      def run_shell_command(args)
        each { _1.exec_shell(args) }
      end

      def run_raw_command(args)
        each { _1.exec_raw(args) }
      end
    end
  end
end

# rubocop:enable Style/FormatString
# rubocop:enable Style/BlockDelimiters
# rubocop:enable Style/CharacterLiteral
# rubocop:enable Style/SingleLineMethods
# rubocop:enable Style/EmptyCaseCondition
# rubocop:enable Style/NestedTernaryOperator
# rubocop:enable Style/TrailingCommaInArguments
# rubocop:enable Style/TrailingCommaInArrayLiteral

superprojects = begin
  project_list = []

  SuperProject = Git::Multi::SuperProject

  unless $stdin.tty?
    # read list of repo names from $stdin
    repos = $stdin.readlines.map(&:strip)
    # reopen $stdin (to ensure `Kernel.system` works correctly)
    $stdin.reopen('/dev/tty')
    # get default workarea & exclusions from git config
    workarea = Git::Multi.default_workarea
    exclusions = Git::Multi.default_exclusions
    # add "pseudo" superproject to the list
    project_list << SuperProject.for('$stdin', repos, workarea, exclusions)
  end

  ARGV.find_all { |arg| arg.start_with?('++') }.each do |name|
    # remove "++#{name}" from ARGV
    ARGV.delete(name)
    # remove prefix from "++#{name}"
    name = name.delete_prefix('++')
    # get list of repo names from git config
    repos = Git::Multi.repos_for(name)
    # get workarea & exclusions from git config
    workarea = Git::Multi.workarea_for(name)
    exclusions = Git::Multi.exclusions_for(name)
    # add "real" superproject to the list
    project_list << SuperProject.for(name, repos, workarea, exclusions)
  end

  ARGV.find_all { |arg| arg.start_with?('@@') }.each do |owner|
    # remove "@@#{owner}" from ARGV
    ARGV.delete(owner)
    # remove prefix from "@@#{owner}"
    owner = owner.delete_prefix('@@')
    # get list of repo names from the GitHub API
    repos = Git::Hub.repositories_for(owner).map(&:full_name)
    # get superproject workarea & exclusions from git config
    workarea = Git::Multi.workarea_for(owner)
    exclusions = Git::Multi.exclusions_for(owner)
    # add "real" superproject to the list
    project_list << SuperProject.for(owner, repos, workarea, exclusions)
  end

  if project_list.empty?
    # default to *all* superprojects defined in ~/.gitconfig
    Git::Multi.superprojects.each do |name|
      # get list of repo names from ~/.gitconfig
      repos = Git::Multi.repos_for(name)
      # get superproject workarea & exclusions from git config
      workarea = Git::Multi.workarea_for(name)
      exclusions = Git::Multi.exclusions_for(name)
      # add "real" superproject to the list
      project_list << SuperProject.for(name, repos, workarea, exclusions)
    end
  end

  project_list
end

if __FILE__ == $PROGRAM_NAME
  # rubocop:disable Lint/AssignmentInCondition

  global_options = %w[--quiet --verbose].freeze

  while global_options.include? ARGV.first
    case option = ARGV.shift
    when '--quiet'
      Git::Config.quiet!
      Git::Multi::Exec.quiet!
      Git::Multi::ForEach.quiet!
    when '--verbose'
      Git::Config.verbose!
      Git::Multi::Exec.verbose!
      Git::Multi::ForEach.verbose!
    else
      raise "Unsupported option: #{option}"
    end
  end

  if custom = Git::Multi::SuperProject.named('$stdin')
    list = custom.repos.map(&:full_name)

    # FIXME: this is a hack to get the name of the superproject
    name = (superprojects.map(&:name) - ['$stdin']).sample

    case cmd = ARGV.shift
    when '--diff' then Git::Multi.compare_repos_to(name, list)
    when '--update' then Git::Multi.add_repos_to(name, list)
    when '--create' then Git::Multi.set_repos_for(name, list)
    when '--replace' then Git::Multi.replace_repos_for(name, list)
    else raise "Unknown command: #{cmd}"
    end
  end

  each_superproject = Git::Multi::ForEach.in(superprojects)

  while ARGV.first&.start_with?('--')
    case ARGV.shift
    when '--edit' then each_superproject.edit_config_file
    when '--report' then each_superproject.report_repo_status
    when '--list' then each_superproject.list_all_repos
    when '--paths' then each_superproject.list_repo_paths
    when '--existing' then each_superproject.list_existing_repos
    when '--excluded' then each_superproject.list_excluded_repos
    when '--missing' then each_superproject.list_missing_repos
    when '--clone' then each_superproject.clone_missing_repos
    when '--git' then each_superproject.run_git_command(ARGV.shift(ARGV.size))
    when '--shell' then each_superproject.run_shell_command(ARGV.shift(ARGV.size))
    when '--raw' then each_superproject.run_raw_command(ARGV.shift(ARGV.size))
    end
  end

  each_superproject.run_git_command(ARGV) if ARGV.any?

  # rubocop:enable Lint/AssignmentInCondition
end

# That's all Folks!