input-method.rb

# frozen_string_literal: false
#
#   irb/input-method.rb - input methods used irb
#   	by Keiju ISHITSUKA(keiju@ruby-lang.org)
#

require_relative 'completion'
require 'io/console'
require 'reline'

module IRB
  STDIN_FILE_NAME = "(line)" # :nodoc:
  class InputMethod

    # Creates a new input method object
    def initialize(file = STDIN_FILE_NAME)
      @file_name = file
    end
    # The file name of this input method, usually given during initialization.
    attr_reader :file_name

    # The irb prompt associated with this input method
    attr_accessor :prompt

    # Reads the next line from this input method.
    #
    # See IO#gets for more information.
    def gets
      fail NotImplementedError, "gets"
    end
    public :gets

    def winsize
      if instance_variable_defined?(:@stdout) && @stdout.tty?
        @stdout.winsize
      else
        [24, 80]
      end
    end

    # Whether this input method is still readable when there is no more data to
    # read.
    #
    # See IO#eof for more information.
    def readable_after_eof?
      false
    end

    def support_history_saving?
      false
    end

    # For debug message
    def inspect
      'Abstract InputMethod'
    end
  end

  class StdioInputMethod < InputMethod
    # Creates a new input method object
    def initialize
      super
      @line_no = 0
      @line = []
      @stdin = IO.open(STDIN.to_i, :external_encoding => IRB.conf[:LC_MESSAGES].encoding, :internal_encoding => "-")
      @stdout = IO.open(STDOUT.to_i, 'w', :external_encoding => IRB.conf[:LC_MESSAGES].encoding, :internal_encoding => "-")
    end

    # Reads the next line from this input method.
    #
    # See IO#gets for more information.
    def gets
      print @prompt
      line = @stdin.gets
      @line[@line_no += 1] = line
    end

    # Whether the end of this input method has been reached, returns +true+ if
    # there is no more data to read.
    #
    # See IO#eof? for more information.
    def eof?
      if @stdin.wait_readable(0.00001)
        c = @stdin.getc
        result = c.nil? ? true : false
        @stdin.ungetc(c) unless c.nil?
        result
      else # buffer is empty
        false
      end
    end

    # Whether this input method is still readable when there is no more data to
    # read.
    #
    # See IO#eof for more information.
    def readable_after_eof?
      true
    end

    # Returns the current line number for #io.
    #
    # #line counts the number of times #gets is called.
    #
    # See IO#lineno for more information.
    def line(line_no)
      @line[line_no]
    end

    # The external encoding for standard input.
    def encoding
      @stdin.external_encoding
    end

    # For debug message
    def inspect
      'StdioInputMethod'
    end
  end

  # Use a File for IO with irb, see InputMethod
  class FileInputMethod < InputMethod
    class << self
      def open(file, &block)
        begin
          io = new(file)
          block.call(io)
        ensure
          io&.close
        end
      end
    end

    # Creates a new input method object
    def initialize(file)
      super
      @io = file.is_a?(IO) ? file : File.open(file)
      @external_encoding = @io.external_encoding
    end
    # The file name of this input method, usually given during initialization.
    attr_reader :file_name

    # Whether the end of this input method has been reached, returns +true+ if
    # there is no more data to read.
    #
    # See IO#eof? for more information.
    def eof?
      @io.closed? || @io.eof?
    end

    # Reads the next line from this input method.
    #
    # See IO#gets for more information.
    def gets
      print @prompt
      @io.gets
    end

    # The external encoding for standard input.
    def encoding
      @external_encoding
    end

    # For debug message
    def inspect
      'FileInputMethod'
    end

    def close
      @io.close
    end
  end

  begin
    class ReadlineInputMethod < InputMethod
      def self.initialize_readline
        require "readline"
      rescue LoadError
      else
        include ::Readline
      end

      # Creates a new input method object using Readline
      def initialize
        self.class.initialize_readline
        if Readline.respond_to?(:encoding_system_needs)
          IRB.__send__(:set_encoding, Readline.encoding_system_needs.name, override: false)
        end
        super

        @line_no = 0
        @line = []
        @eof = false

        @stdin = IO.open(STDIN.to_i, :external_encoding => IRB.conf[:LC_MESSAGES].encoding, :internal_encoding => "-")
        @stdout = IO.open(STDOUT.to_i, 'w', :external_encoding => IRB.conf[:LC_MESSAGES].encoding, :internal_encoding => "-")

        if Readline.respond_to?("basic_word_break_characters=")
          Readline.basic_word_break_characters = IRB::InputCompletor::BASIC_WORD_BREAK_CHARACTERS
        end
        Readline.completion_append_character = nil
        Readline.completion_proc = IRB::InputCompletor::CompletionProc
      end

      # Reads the next line from this input method.
      #
      # See IO#gets for more information.
      def gets
        Readline.input = @stdin
        Readline.output = @stdout
        if l = readline(@prompt, false)
          HISTORY.push(l) if !l.empty?
          @line[@line_no += 1] = l + "\n"
        else
          @eof = true
          l
        end
      end

      # Whether the end of this input method has been reached, returns +true+
      # if there is no more data to read.
      #
      # See IO#eof? for more information.
      def eof?
        @eof
      end

      # Whether this input method is still readable when there is no more data to
      # read.
      #
      # See IO#eof for more information.
      def readable_after_eof?
        true
      end

      def support_history_saving?
        true
      end

      # Returns the current line number for #io.
      #
      # #line counts the number of times #gets is called.
      #
      # See IO#lineno for more information.
      def line(line_no)
        @line[line_no]
      end

      # The external encoding for standard input.
      def encoding
        @stdin.external_encoding
      end

      # For debug message
      def inspect
        readline_impl = (defined?(Reline) && Readline == Reline) ? 'Reline' : 'ext/readline'
        str = "ReadlineInputMethod with #{readline_impl} #{Readline::VERSION}"
        inputrc_path = File.expand_path(ENV['INPUTRC'] || '~/.inputrc')
        str += " and #{inputrc_path}" if File.exist?(inputrc_path)
        str
      end
    end
  end

  class RelineInputMethod < InputMethod
    HISTORY = Reline::HISTORY
    # Creates a new input method object using Reline
    def initialize
      IRB.__send__(:set_encoding, Reline.encoding_system_needs.name, override: false)
      super

      @line_no = 0
      @line = []
      @eof = false

      @stdin = ::IO.open(STDIN.to_i, :external_encoding => IRB.conf[:LC_MESSAGES].encoding, :internal_encoding => "-")
      @stdout = ::IO.open(STDOUT.to_i, 'w', :external_encoding => IRB.conf[:LC_MESSAGES].encoding, :internal_encoding => "-")

      Reline.basic_word_break_characters = IRB::InputCompletor::BASIC_WORD_BREAK_CHARACTERS
      Reline.completion_append_character = nil
      Reline.completer_quote_characters = ''
      Reline.completion_proc = IRB::InputCompletor::CompletionProc
      Reline.output_modifier_proc =
        if IRB.conf[:USE_COLORIZE]
          proc do |output, complete: |
            next unless IRB::Color.colorable?
            lvars = IRB.CurrentContext&.local_variables || []
            IRB::Color.colorize_code(output, complete: complete, local_variables: lvars)
          end
        else
          proc do |output|
            Reline::Unicode.escape_for_print(output)
          end
        end
      Reline.dig_perfect_match_proc = IRB::InputCompletor::PerfectMatchedProc
      Reline.autocompletion = IRB.conf[:USE_AUTOCOMPLETE]

      if IRB.conf[:USE_AUTOCOMPLETE]
        begin
          require 'rdoc'
          Reline.add_dialog_proc(:show_doc, SHOW_DOC_DIALOG, Reline::DEFAULT_DIALOG_CONTEXT)
        rescue LoadError
        end
      end
    end

    def check_termination(&block)
      @check_termination_proc = block
    end

    def dynamic_prompt(&block)
      @prompt_proc = block
    end

    def auto_indent(&block)
      @auto_indent_proc = block
    end

    SHOW_DOC_DIALOG = ->() {
      dialog.trap_key = nil
      alt_d = [
        [Reline::Key.new(nil, 0xE4, true)], # Normal Alt+d.
        [27, 100], # Normal Alt+d when convert-meta isn't used.
        [195, 164], # The "ä" that appears when Alt+d is pressed on xterm.
        [226, 136, 130] # The "∂" that appears when Alt+d in pressed on iTerm2.
      ]

      if just_cursor_moving and completion_journey_data.nil?
        return nil
      end
      cursor_pos_to_render, result, pointer, autocomplete_dialog = context.pop(4)
      return nil if result.nil? or pointer.nil? or pointer < 0
      name = result[pointer]
      name = IRB::InputCompletor.retrieve_completion_data(name, doc_namespace: true)

      options = {}
      options[:extra_doc_dirs] = IRB.conf[:EXTRA_DOC_DIRS] unless IRB.conf[:EXTRA_DOC_DIRS].empty?
      driver = RDoc::RI::Driver.new(options)

      if key.match?(dialog.name)
        begin
          driver.display_names([name])
        rescue RDoc::RI::Driver::NotFoundError
        end
      end

      begin
        name = driver.expand_name(name)
      rescue RDoc::RI::Driver::NotFoundError
        return nil
      rescue
        return nil # unknown error
      end
      doc = nil
      used_for_class = false
      if not name =~ /#|\./
        found, klasses, includes, extends = driver.classes_and_includes_and_extends_for(name)
        if not found.empty?
          doc = driver.class_document(name, found, klasses, includes, extends)
          used_for_class = true
        end
      end
      unless used_for_class
        doc = RDoc::Markup::Document.new
        begin
          driver.add_method(doc, name)
        rescue RDoc::RI::Driver::NotFoundError
          doc = nil
        rescue
          return nil # unknown error
        end
      end
      return nil if doc.nil?
      width = 40

      right_x = cursor_pos_to_render.x + autocomplete_dialog.width
      if right_x + width > screen_width
        right_width = screen_width - (right_x + 1)
        left_x = autocomplete_dialog.column - width
        left_x = 0 if left_x < 0
        left_width = width > autocomplete_dialog.column ? autocomplete_dialog.column : width
        if right_width.positive? and left_width.positive?
          if right_width >= left_width
            width = right_width
            x = right_x
          else
            width = left_width
            x = left_x
          end
        elsif right_width.positive? and left_width <= 0
          width = right_width
          x = right_x
        elsif right_width <= 0 and left_width.positive?
          width = left_width
          x = left_x
        else # Both are negative width.
          return nil
        end
      else
        x = right_x
      end
      formatter = RDoc::Markup::ToAnsi.new
      formatter.width = width
      dialog.trap_key = alt_d
      mod_key = RUBY_PLATFORM.match?(/darwin/) ? "Option" : "Alt"
      message = "Press #{mod_key}+d to read the full document"
      contents = [message] + doc.accept(formatter).split("\n")
      contents = contents.take(preferred_dialog_height)

      y = cursor_pos_to_render.y
      Reline::DialogRenderInfo.new(pos: Reline::CursorPos.new(x, y), contents: contents, width: width, bg_color: '49')
    }

    # Reads the next line from this input method.
    #
    # See IO#gets for more information.
    def gets
      Reline.input = @stdin
      Reline.output = @stdout
      Reline.prompt_proc = @prompt_proc
      Reline.auto_indent_proc = @auto_indent_proc if @auto_indent_proc
      if l = Reline.readmultiline(@prompt, false, &@check_termination_proc)
        Reline::HISTORY.push(l) if !l.empty?
        @line[@line_no += 1] = l + "\n"
      else
        @eof = true
        l
      end
    end

    # Whether the end of this input method has been reached, returns +true+
    # if there is no more data to read.
    #
    # See IO#eof? for more information.
    def eof?
      @eof
    end

    # Whether this input method is still readable when there is no more data to
    # read.
    #
    # See IO#eof for more information.
    def readable_after_eof?
      true
    end

    # Returns the current line number for #io.
    #
    # #line counts the number of times #gets is called.
    #
    # See IO#lineno for more information.
    def line(line_no)
      @line[line_no]
    end

    # The external encoding for standard input.
    def encoding
      @stdin.external_encoding
    end

    # For debug message
    def inspect
      config = Reline::Config.new
      str = "RelineInputMethod with Reline #{Reline::VERSION}"
      inputrc_path = File.expand_path(config.inputrc_path)
      str += " and #{inputrc_path}" if File.exist?(inputrc_path)
      str
    end

    def support_history_saving?
      true
    end
  end

  class ReidlineInputMethod < RelineInputMethod
    def initialize
      warn <<~MSG.strip
        IRB::ReidlineInputMethod is deprecated, please use IRB::RelineInputMethod instead.
      MSG
      super
    end
  end
end