# frozen_string_literal: true

class Pry
  class Command
    class ShowInfo < Pry::ClassCommand
      extend Pry::Helpers::BaseHelpers

      command_options shellwords: false, interpolate: false

      def initialize(*)
        super

        @used_super = nil
      end

      def options(opt)
        opt.on :s, :super, "Select the 'super' method. Can be repeated to " \
                           "traverse the ancestors", as: :count
        opt.on :l, "line-numbers", "Show line numbers"
        opt.on :b, "base-one", "Show line numbers but start numbering at 1 " \
                               "(useful for `amend-line` and `play` commands)"
        opt.on :a, :all, "Show all definitions and monkeypatches of the " \
                         "module/class"
      end

      def process
        code_object = Pry::CodeObject.lookup(obj_name, pry_instance, super: opts[:super])
        raise CommandError, no_definition_message unless code_object

        @original_code_object = code_object

        if !obj_name && code_object.c_module? && !opts[:all]
          result = "You're inside an object, whose class is defined by means of " \
                   "the C Ruby API.\nPry cannot display the information for this " \
                   "class."
          if code_object.candidates.any?
            result += "\nHowever, you can view monkey-patches applied to this " \
                      "class.\n.Just execute the same command with the '--all' " \
                      "switch."
          end
        elsif show_all_modules?(code_object)
          # show all monkey patches for a module

          result = content_and_headers_for_all_module_candidates(code_object)
        else
          # show a specific code object
          co = code_object_with_accessible_source(code_object)
          result = content_and_header_for_code_object(co)
        end

        set_file_and_dir_locals(code_object.source_file)
        pry_instance.pager.page result
      end

      # This method checks whether the `code_object` is a WrappedModule, if it
      # is, then it returns the first candidate (monkeypatch) with accessible
      # source (or docs). If `code_object` is not a WrappedModule (i.e a method
      # or a command) then the `code_object` itself is just returned.
      #
      # @return [Pry::WrappedModule, Pry::Method, Pry::Command]
      def code_object_with_accessible_source(code_object)
        return code_object unless code_object.is_a?(WrappedModule)

        candidate = code_object.candidates.find(&:source)
        return candidate if candidate

        raise CommandError, no_definition_message unless valid_superclass?(code_object)

        @used_super = true
        code_object_with_accessible_source(code_object.super)
      end

      def valid_superclass?(code_object)
        code_object.super && code_object.super.wrapped != Object
      end

      def content_and_header_for_code_object(code_object)
        header(code_object) + content_for(code_object)
      end

      def content_and_headers_for_all_module_candidates(mod)
        result = "Found #{mod.number_of_candidates} candidates for " \
                 "`#{mod.name}` definition:\n"
        mod.number_of_candidates.times do |v|
          candidate = mod.candidate(v)
          begin
            result += "\nCandidate #{v + 1}/#{mod.number_of_candidates}: " \
                      "#{candidate.source_file}:#{candidate.source_line}\n"
            content = content_for(candidate)

            result += "Number of lines: #{content.lines.count}\n\n" + content
          rescue Pry::RescuableException
            result += "\nNo content found.\n"
            next
          end
        end
        result
      end

      def no_definition_message
        "Couldn't locate a definition for #{obj_name}"
      end

      # Generate a header (meta-data information) for all the code
      # object types: methods, modules, commands, procs...
      def header(code_object)
        file_name, line_num = file_and_line_for(code_object)
        content = content_for(code_object)

        h = "\n#{bold('From:')} #{file_name}"
        h += code_object_header(code_object, line_num)
        h += "\n#{bold('Number of lines:')} " + "#{content.lines.count}\n\n"
        if @used_super
          h += bold('** Warning:')
          h += " Cannot find code for #{@original_code_object.nonblank_name}. " \
               "Showing superclass #{code_object.nonblank_name} instead. **\n\n"
        end

        if content.lines.none?
          h += bold('** Warning:')
          h += " Cannot find code for '#{code_object.name}' (source_location is nil)"
        end

        h
      end

      def code_object_header(code_object, line_num)
        if code_object.real_method_object?
          method_header(code_object, line_num)

          # It sucks we have to test for both Pry::WrappedModule and
          # WrappedModule::Candidate, probably indicates a deep refactor needs
          # to happen in those classes.
        elsif code_object.is_a?(Pry::WrappedModule) ||
              code_object.is_a?(Pry::WrappedModule::Candidate)
          module_header(code_object, line_num)
        else
          ""
        end
      end

      def method_header(code_object, line_num)
        h = ""
        h += (code_object.c_method? ? ' (C Method):' : ":#{line_num}:")
        h += method_sections(code_object)[:owner]
        h += method_sections(code_object)[:visibility]
        h += method_sections(code_object)[:signature]
        h
      end

      def module_header(code_object, line_num)
        h = ""
        h += ":#{line_num}\n"
        h += bold(code_object.module? ? "Module" : "Class")
        h += " #{bold('name:')} #{code_object.nonblank_name}"

        if code_object.number_of_candidates > 1
          h += bold("\nNumber of monkeypatches: ")
          h += code_object.number_of_candidates.to_s
          h += ". Use the `-a` option to display all available monkeypatches"
        end
        h
      end

      def method_sections(code_object)
        {
          owner: "\n#{bold('Owner:')} #{code_object.owner || 'N/A'}\n",
          visibility: "#{bold('Visibility:')} #{code_object.visibility}",
          signature: "\n#{bold('Signature:')} #{code_object.signature}"
        }.merge(header_options) { |_key, old, new| (new && old).to_s }
      end

      def header_options
        {
          owner: true,
          visibility: true,
          signature: nil
        }
      end

      def show_all_modules?(code_object)
        code_object.is_a?(Pry::WrappedModule) && opts.present?(:all)
      end

      def obj_name
        @obj_name ||= args.empty? ? nil : args.join(' ')
      end

      def use_line_numbers?
        opts.present?(:b) || opts.present?(:l)
      end

      def start_line_for(code_object)
        if opts.present?(:'base-one')
          1
        else
          code_object.source_line || 1
        end
      end

      # takes into account possible yard docs, and returns yard_file / yard_line
      # Also adjusts for start line of comments (using start_line_for), which it
      # has to infer by subtracting number of lines of comment from start line
      # of code_object
      def file_and_line_for(code_object)
        if code_object.module_with_yard_docs?
          [code_object.yard_file, code_object.yard_line]
        else
          [code_object.source_file, start_line_for(code_object)]
        end
      end

      def complete(input)
        if input =~ /([^ ]*)#([a-z0-9_]*)\z/
          prefix = Regexp.last_match(1)
          search = Regexp.last_match(2)
          methods =
            begin
              # rubocop:disable Security/Eval
              Pry::Method.all_from_class(binding.eval(prefix))
              # rubocop:enable Security/Eval
            rescue RescuableException
              return super
            end
          methods.map do |method|
            [prefix, method.name].join('#') if method.name.start_with?(search)
          end.compact
        else
          super
        end
      end
    end
  end
end