require 'tempfile'
require 'shellwords'
require 'pry/default_commands/hist'

class Pry
  module DefaultCommands

    Editing = Pry::CommandSet.new do
      import Hist

      create_command "!", "Clear the input buffer. Useful if the parsing process goes wrong and you get stuck in the read loop.", :use_prefix => false do
        def process
          output.puts "Input buffer cleared!"
          eval_string.replace("")
        end
      end

      create_command "show-input", "Show the contents of the input buffer for the current multi-line expression." do
        def process
          output.puts Code.new(eval_string).with_line_numbers
        end
      end

      create_command "edit" do
        description "Invoke the default editor on a file."

        banner <<-BANNER
          Usage: edit [--no-reload|--reload] [--line LINE] [--temp|--ex|FILE[:LINE]|--in N]

          Open a text editor. When no FILE is given, edits the pry input buffer.
          Ensure Pry.config.editor is set to your editor of choice.

          e.g: `edit sample.rb`
          e.g: `edit sample.rb --line 105`
          e.g: `edit --ex`

          https://github.com/pry/pry/wiki/Editor-integration#wiki-Edit_command
        BANNER

        def options(opt)
          opt.on :e, :ex, "Open the file that raised the most recent exception (_ex_.file)", :optional_argument => true, :as => Integer
          opt.on :i, :in, "Open a temporary file containing the Nth input expression. N may be a range.", :optional_argument => true, :as => Range, :default => -1..-1
          opt.on :t, :temp, "Open an empty temporary file"
          opt.on :l, :line, "Jump to this line in the opened file", :argument => true, :as => Integer
          opt.on :n, :"no-reload", "Don't automatically reload the edited code"
          opt.on :c, :"current", "Open the current __FILE__ and at __LINE__ (as returned by `whereami`)."
          opt.on :r, :reload, "Reload the edited code immediately (default for ruby files)"
        end

        def process
          if [opts.present?(:ex), opts.present?(:temp), opts.present?(:in), !args.empty?].count(true) > 1
            raise CommandError, "Only one of --ex, --temp, --in and FILE may be specified."
          end

          if !opts.present?(:ex) && !opts.present?(:current) && args.empty?
            # edit of local code, eval'd within pry.
            process_local_edit
          else
            # edit of remote code, eval'd at top-level
            process_remote_edit
          end
        end

        def process_i
          case opts[:i]
          when Range
            (_pry_.input_array[opts[:i]] || []).join
          when Fixnum
            _pry_.input_array[opts[:i]] || ""
          else
            return output.puts "Not a valid range: #{opts[:i]}"
          end
        end

        def process_local_edit
          content = case
            when opts.present?(:temp)
              ""
            when opts.present?(:in)
              process_i
            when eval_string.strip != ""
              eval_string
            else
              _pry_.input_array.reverse_each.find{ |x| x && x.strip != "" } || ""
          end

          line = content.lines.count

          temp_file do |f|
            f.puts(content)
            f.flush
            reload = !opts.present?(:'no-reload') && !Pry.config.disable_auto_reload
            f.close(false)
            invoke_editor(f.path, line, reload)
            if reload
              silence_warnings do
                eval_string.replace(File.read(f.path))
              end
            end
          end
        end

        def process_remote_edit
          if opts.present?(:ex)
            if _pry_.last_exception.nil?
              raise CommandError, "No exception found."
            end

            ex = _pry_.last_exception
            bt_index = opts[:ex].to_i

            ex_file, ex_line = ex.bt_source_location_for(bt_index)
            if ex_file && RbxPath.is_core_path?(ex_file)
              file_name = RbxPath.convert_path_to_full(ex_file)
            else
              file_name = ex_file
            end

            line = ex_line

            if file_name.nil?
              raise CommandError, "Exception has no associated file."
            end

            if Pry.eval_path == file_name
              raise CommandError, "Cannot edit exceptions raised in REPL."
            end
          elsif opts.present?(:current)
            file_name = target.eval("__FILE__")
            line = target.eval("__LINE__")
          else

            # break up into file:line
            file_name = File.expand_path(args.first)
            line = file_name.sub!(/:(\d+)$/, "") ? $1.to_i : 1
          end

          if not_a_real_file?(file_name)
            raise CommandError, "#{file_name} is not a valid file name, cannot edit!"
          end

          line = opts[:l].to_i if opts.present?(:line)

          reload = opts.present?(:reload) || ((opts.present?(:ex) || file_name.end_with?(".rb")) && !opts.present?(:'no-reload')) && !Pry.config.disable_auto_reload

          # Sanitize blanks.
          sanitized_file_name = Shellwords.escape(file_name)

          invoke_editor(sanitized_file_name, line, reload)
          set_file_and_dir_locals(sanitized_file_name)

          if reload
            silence_warnings do
              TOPLEVEL_BINDING.eval(File.read(file_name), file_name)
            end
          end
        end
      end

      create_command "edit-method" do
        description "Edit the source code for a method."

        banner <<-BANNER
          Usage: edit-method [OPTIONS] [METH]

          Edit the method METH in an editor.
          Ensure Pry.config.editor is set to your editor of choice.

          e.g: `edit-method hello_method`
          e.g: `edit-method Pry#rep`
          e.g: `edit-method`

          https://github.com/pry/pry/wiki/Editor-integration#wiki-Edit_method
        BANNER

        command_options :shellwords => false

        def options(opt)
          method_options(opt)
          opt.on :n, "no-reload", "Do not automatically reload the method's file after editing."
          opt.on "no-jump", "Do not fast forward editor to first line of method."
          opt.on :p, :patch, "Instead of editing the method's file, try to edit in a tempfile and apply as a monkey patch."
        end

        def process
          if !Pry.config.editor
            raise CommandError, "No editor set!\nEnsure that #{text.bold("Pry.config.editor")} is set to your editor of choice."
          end

          begin
            @method = method_object
          rescue MethodNotFound => err
          end

          if opts.present?(:patch) || (@method && @method.dynamically_defined?)
            if err
              raise err # can't patch a non-method
            end

            process_patch
          else
            if err && !File.exist?(target.eval('__FILE__'))
              raise err # can't edit a non-file
            end

            process_file
          end
        end

        def process_patch
          lines = @method.source.lines.to_a

          lines[0] = definition_line_for_owner(lines[0])

          temp_file do |f|
            f.puts lines
            f.flush
            f.close(false)
            invoke_editor(f.path, 0, true)

            source = wrap_for_nesting(wrap_for_owner(File.read(f.path)))

            if @method.alias?
              with_method_transaction(original_name, @method.owner) do
                Pry.new(:input => StringIO.new(source)).rep(TOPLEVEL_BINDING)
                Pry.binding_for(@method.owner).eval("alias #{@method.name} #{original_name}")
              end
            else
              Pry.new(:input => StringIO.new(source)).rep(TOPLEVEL_BINDING)
            end
          end
        end

        def process_file
          file, line = extract_file_and_line

          reload = !opts.present?(:'no-reload') && !Pry.config.disable_auto_reload
          invoke_editor(file, opts["no-jump"] ? 0 : line, reload)
          silence_warnings do
            load file if reload
          end
        end

        protected
          def extract_file_and_line
            if @method
              if @method.source_type == :c
                raise CommandError, "Can't edit a C method."
              else
                [@method.source_file, @method.source_line]
              end
            else
              [target.eval('__FILE__'), target.eval('__LINE__')]
            end
          end

          # Run some code ensuring that at the end target#meth_name will not have changed.
          #
          # When we're redefining aliased methods we will overwrite the method at the
          # unaliased name (so that super continues to work). By wrapping that code in a
          # transation we make that not happen, which means that alias_method_chains, etc.
          # continue to work.
          #
          # @param [String] meth_name  The method name before aliasing
          # @param [Module] target  The owner of the method
          def with_method_transaction(meth_name, target)
            target = Pry.binding_for(target)
            temp_name = "__pry_#{meth_name}__"

            target.eval("alias #{temp_name} #{meth_name}")
            yield
            target.eval("alias #{meth_name} #{temp_name}")
          ensure
            target.eval("undef #{temp_name}") rescue nil
          end

          # The original name of the method, if it's not present raise an error telling
          # the user why we don't work.
          #
          def original_name
            @method.original_name or raise CommandError, "Pry can only patch methods created with the `def` keyword."
          end

          # Update the definition line so that it can be eval'd directly on the Method's
          # owner instead of from the original context.
          #
          # In particular this takes `def self.foo` and turns it into `def foo` so that we
          # don't end up creating the method on the singleton class of the singleton class
          # by accident.
          #
          # This is necessarily done by String manipulation because we can't find out what
          # syntax is needed for the argument list by ruby-level introspection.
          #
          # @param String   The original definition line. e.g. def self.foo(bar, baz=1)
          # @return String  The new definition line. e.g. def foo(bar, baz=1)
          def definition_line_for_owner(line)
            if line =~ /^def (?:.*?\.)?#{Regexp.escape(original_name)}(?=[\(\s;]|$)/
              "def #{original_name}#{$'}"
            else
              raise CommandError, "Could not find original `def #{original_name}` line to patch."
            end
          end

          # Update the source code so that when it has the right owner when eval'd.
          #
          # This (combined with definition_line_for_owner) is backup for the case that
          # wrap_for_nesting fails, to ensure that the method will stil be defined in
          # the correct place.
          #
          # @param [String] source  The source to wrap
          # @return [String]
          def wrap_for_owner(source)
            Thread.current[:__pry_owner__] = @method.owner
            source = "Thread.current[:__pry_owner__].class_eval do\n#{source}\nend"
          end

          # Update the new source code to have the correct Module.nesting.
          #
          # This method uses syntactic analysis of the original source file to determine
          # the new nesting, so that we can tell the difference between:
          #
          #   class A; def self.b; end; end
          #   class << A; def b; end; end
          #
          # The resulting code should be evaluated in the TOPLEVEL_BINDING.
          #
          # @param [String] source  The source to wrap.
          # @return [String]
          def wrap_for_nesting(source)
            nesting = Pry::Code.from_file(@method.source_file).nesting_at(@method.source_line)

            (nesting + [source] + nesting.map{ "end" } + [""]).join("\n")
          rescue Pry::Indent::UnparseableNestingError => e
            source
          end
      end

      create_command(/amend-line(?: (-?\d+)(?:\.\.(-?\d+))?)?/) do
        description "Amend a line of input in multi-line mode."
        command_options :interpolate => false, :listing => "amend-line"

        banner <<-'BANNER'
          Amend a line of input in multi-line mode. `amend-line N`, where the N in `amend-line N` represents line to replace.

          Can also specify a range of lines using `amend-line N..M` syntax. Passing '!' as replacement content deletes the line(s) instead.
          e.g amend-line 1 puts 'hello world! # replace line 1'
          e.g amend-line 1..4 !               # delete lines 1..4
          e.g amend-line 3 >puts 'goodbye'    # insert before line 3
          e.g amend-line puts 'hello again'   # no line number modifies immediately preceding line
        BANNER

        def process
          start_line_number, end_line_number, replacement_line = *args

          if eval_string.empty?
            raise CommandError, "No input to amend."
          end

          replacement_line = "" if !replacement_line
          input_array = eval_string.each_line.to_a

          end_line_number = start_line_number.to_i if !end_line_number
          line_range = start_line_number ? (one_index_number(start_line_number.to_i)..one_index_number(end_line_number.to_i))  : input_array.size - 1

          # delete selected lines if replacement line is '!'
          if arg_string == "!"
            input_array.slice!(line_range)
          elsif arg_string.start_with?(">")
            insert_slot = Array(line_range).first
            input_array.insert(insert_slot, arg_string[1..-1] + "\n")
          else
            input_array[line_range] = arg_string + "\n"
          end
          eval_string.replace input_array.join
          run "show-input"
        end
      end

      create_command "play" do
        include Helpers::DocumentationHelpers

        description "Play back a string variable or a method or a file as input."

        banner <<-BANNER
          Usage: play [OPTIONS] [--help]

          The play command enables you to replay code from files and methods as
          if they were entered directly in the Pry REPL. Default action (no
          options) is to play the provided string variable

          e.g: `play -i 20 --lines 1..3`
          e.g: `play -m Pry#repl --lines 1..-1`
          e.g: `play -f Rakefile --lines 5`

          https://github.com/pry/pry/wiki/User-Input#wiki-Play
        BANNER

        attr_accessor :content

        def setup
          self.content   = ""
        end

        def options(opt)
          opt.on :m, :method, "Play a method's source.", :argument => true do |meth_name|
            meth = get_method_or_raise(meth_name, target, {})
            self.content << meth.source
          end
          opt.on :d, :doc, "Play a method's documentation.", :argument => true do |meth_name|
            meth = get_method_or_raise(meth_name, target, {})
            text.no_color do
              self.content << process_comment_markup(meth.doc)
            end
          end
          opt.on :c, :command, "Play a command's source.", :argument => true do |command_name|
            command = find_command(command_name)
            block = Pry::Method.new(command.block)
            self.content << block.source
          end
          opt.on :f, :file, "Play a file.", :argument => true do |file|
            self.content << File.read(File.expand_path(file))
          end
          opt.on :l, :lines, "Only play a subset of lines.", :optional_argument => true, :as => Range, :default => 1..-1
          opt.on :i, :in, "Play entries from Pry's input expression history. Takes an index or range. Note this can only replay pure Ruby code, not Pry commands.", :optional_argument => true,
          :as => Range, :default => -5..-1 do |range|
            input_expressions = _pry_.input_array[range] || []
            Array(input_expressions).each { |v| self.content << v }
          end
          opt.on :o, "open", 'When used with the -m switch, it plays the entire method except the last line, leaving the method definition "open". `amend-line` can then be used to modify the method.'
        end

        def process
          perform_play
          run "show-input" unless Pry::Code.complete_expression?(eval_string)
        end

        def process_non_opt
          args.each do |arg|
            begin
              self.content << target.eval(arg)
            rescue Pry::RescuableException
              raise CommandError, "Problem when evaling #{arg}."
            end
          end
        end

        def perform_play
          process_non_opt

          if opts.present?(:lines)
            self.content = restrict_to_lines(self.content, opts[:l])
          end

          if opts.present?(:open)
            self.content = restrict_to_lines(self.content, 1..-2)
          end

          eval_string << self.content
        end
      end
    end
  end
end