class Pry
  class Commands
    attr_accessor :out
    
    def initialize(out)
      @out = out
    end
    
    def commands
      @commands ||= {
        "!" => proc do |opts|
          out.puts "Refreshed REPL"
          opts[:eval_string].clear
        end,
        ["exit_program", "quit_program"] => proc do
          exit
        end,
        "help" => proc do |opts|
          self.show_help
          opts[:eval_string].clear
        end,
        "nesting" => proc do |opts|
          self.show_nesting(opts[:nesting])
          opts[:eval_string].clear
        end,
        "status" => proc do |opts|
          self.show_status(opts[:nesting], opts[:target])
          opts[:eval_string].clear
        end,
        "exit_all" => proc do
          throw(:breakout, 0)
        end,
        ["exit", "quit", "back", "cd .."] => proc do |opts|
          throw(:breakout, opts[:nesting].level)
        end,
        "ls" => proc do |opts|
          out.puts "#{opts[:target].eval('Pry.view(local_variables + instance_variables)')}"
          opts[:eval_string].clear
        end,
        /^cat\s+(.+)/ => proc do |opts|
          obj = opts[:captures].first
          out.puts opts[:target].eval("#{obj}.inspect")
          opts[:eval_string].clear
        end,
        /^cd\s+(.+)/ => proc do |opts|
          obj = opts[:captures].first
          opts[:target].eval("#{obj}.pry")
          opts[:eval_string].clear
        end,
        /^show_doc\s*(.+)/ => proc do |opts|
          meth_name = opts[:captures].first
          doc = opts[:target].eval("method(:#{meth_name})").comment
          out.puts doc
          opts[:eval_string].clear
        end,
        /^show_idoc\s*(.+)/ => proc do |opts|
          meth_name = opts[:captures].first
          doc = opts[:target].eval("instance_method(:#{meth_name})").comment
          opts[:eval_string].clear
        end,
        /^show_method\s*(.+)/ => proc do |opts|
          meth_name = opts[:captures].first
          code = opts[:target].eval("method(:#{meth_name})").source
          out.puts code
          opts[:eval_string].clear
        end,
        /^show_imethod\s*(.+)/ => proc do |opts|
          meth_name = opts[:captures].first
          code = opts[:target].eval("instance_method(:#{meth_name})").source
          opts[:eval_string].clear
        end,
        /^jump_to\s*(\d*)/ => proc do |opts|
          break_level = opts[:captures].first.to_i
          nesting = opts[:nesting]

          case break_level
          when nesting.level
            out.puts "Already at nesting level #{nesting.level}"
            opts[:eval_string].clear
          when (0...nesting.level)
            throw(:breakout, break_level + 1)
          else
            max_nest_level = nesting.level - 1
            out.puts "Invalid nest level. Must be between 0 and #{max_nest_level}. Got #{break_level}."
            opts[:eval_string].clear
          end
        end
      }
    end

    def command_info
      @command_info ||= {
        "!" => "Refresh the REPL.",
        ["exit_program", "quit_program"] => "end
the current program.",
        "help" => "This menu.",
        "nesting" => "Show nesting information.",
        "status" => "Show status information.",
        "exit_all" => "End all nested Pry sessions",
        ["exit", "quit", "back", "cd .."] => "End the current Pry session.",
        "ls" => "Show the list of vars in the current scope.",
        "cat" => "Show output of <var>.inspect",
        "cd" => "Start a Pry session on <var> (use `cd ..` to go back)",
        "show_doc" => "Show the comments above <methname>",
        "show_idoc" => "Show the comments above instance method <methname>",
        "show_method" => "Show sourcecode for method <methname>",
        "show_imethod" => "Show sourcecode for instance method <methname>",
        "jump_to" => "Jump to a Pry session further up the stack, exiting all sessions below."
      }
    end

    def refresh
    end

    def show_help
      out.puts "Command list:"
      out.puts "--"
      out.puts "help                             This menu"
      out.puts "status                           Show status information"
      out.puts "!                                Refresh the REPL"
      out.puts "nesting                          Show nesting information"
      out.puts "ls                               Show the list of variables in the current scope"
      out.puts "cat <var>                        Show output of <var>.inspect"
      out.puts "cd <var>                         Start a Pry session on <var> (use `cd ..` to go back)"
      out.puts "show_method <methname>           Show the sourcecode for the method <methname>"
      out.puts "show_imethod <methname>          Show the sourcecode for the instance method <method_name>"
      out.puts "show_doc <methname>              Show the comments above <methname>"
      out.puts "show_idoc <methname>             Show the comments above instance method <methname>"
      out.puts "exit/quit/back                   End the current Pry session"
      out.puts "exit_all                         End all nested Pry sessions"
      out.puts "exit_program/quit_program        End the current program"
      out.puts "jump_to <level>                  Jump to a Pry session further up the stack, exiting all sessions below"
    end

    def show_nesting(nesting)
      out.puts "Nesting status:"
      out.puts "--"
      nesting.each do |level, obj|
        if level == 0
          out.puts "#{level}. #{Pry.view(obj)} (Pry top level)"
        else
          out.puts "#{level}. #{Pry.view(obj)}"
        end
      end
    end

    def show_status(nesting, target)
      out.puts "Status:"
      out.puts "--"
      out.puts "Receiver: #{Pry.view(target.eval('self'))}"
      out.puts "Nesting level: #{nesting.level}"
      out.puts "Local variables: #{target.eval('Pry.view(local_variables)')}"
      out.puts "Last result: #{Pry.view(Pry.last_result)}"
    end
  end
end