#
# Copyright:: 2016-2019, Chef Software, Inc.
# Author:: Tim Smith (<tsmith@chef.io>)
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

module RuboCop
  module Cop
    module Chef
      # Checks for incorrectly formatted copyright comments.
      #
      # @example
      #
      #   # bad (assuming current year is 2016)
      #   Copyright:: 2013-2016 Opscode, Inc.
      #   Copyright:: 2013-2016 Chef Inc.
      #   Copyright:: 2013-2016 Chef Software Inc.
      #   Copyright:: 2009-2010 2013-2016 Chef Software Inc.
      #   Copyright:: Chef Software Inc.
      #   Copyright:: Tim Smith
      #   Copyright:: Copyright (c) 2015-2016 Chef Software, Inc.
      #
      #   # good (assuming current year is 2016)
      #   Copyright:: 2013-2016 Chef Software, Inc.
      #   Copyright:: 2013-2016 Tim Smith
      #   Copyright:: 2016 37Signals, Inc.
      #
      class CopyrightCommentFormat < Cop
        require 'date'

        MSG = 'Properly format copyrights header comments'.freeze

        def investigate(processed_source)
          return unless processed_source.ast

          processed_source.comments.each do |comment|
            next unless comment.inline? # headers aren't in blocks

            if invalid_copyright_comment?(comment)
              add_offense(comment, location: comment.loc.expression, message: MSG, severity: :refactor)
            end
          end
        end

        def autocorrect(comment)
          correct_comment = "# Copyright:: #{copyright_date_range(comment)}, #{copyright_holder(comment)}"
          ->(corrector) { corrector.replace(comment.loc.expression, correct_comment) }
        end

        private

        def copyright_date_range(comment)
          dates = comment.text.scan(/([0-9]{4})/)

          # no copyright year present so return this year
          return Time.new.year if dates.empty?

          oldest_date = dates.min[0].to_i

          # Avoid returning THIS_YEAR - THIS_YEAR
          if oldest_date == Time.new.year
            oldest_date
          else
            "#{oldest_date}-#{Time.new.year}"
          end
        end

        def copyright_holder(comment)
          # Grab just the company / individual name w/o :: or dates
          match = /(?:.*[0-9]{4}|Copyright\W*)(?:,)?(?:\s)?(.*)/.match(comment.text)
          marketing_sanitizer(match.captures[0])
        end

        # Flush Opscode down the memory hole and Chef Inc is not a company
        def marketing_sanitizer(name)
          name.gsub('Opscode', 'Chef Software').gsub(/Chef(?:,)? Inc.*/, 'Chef Software, Inc.')
        end

        def invalid_copyright_comment?(comment)
          match = /# (?:Copyright\W*)(.*)/.match(comment.text)
          return false unless match # it's not even a copyright

          current_text = match.captures[0]
          desired_text = "#{copyright_date_range(comment)}, #{copyright_holder(comment)}"

          return true unless current_text == desired_text
        end
      end
    end
  end
end