RSpec::Support.require_rspec_core "formatters/helpers"

module RSpec
  module Core
    module Formatters
      # @private
      class DeprecationFormatter
        Formatters.register self, :deprecation, :deprecation_summary

        attr_reader :count, :deprecation_stream, :summary_stream

        def initialize(deprecation_stream, summary_stream)
          @deprecation_stream = deprecation_stream
          @summary_stream = summary_stream
          @seen_deprecations = Set.new
          @count = 0
        end
        alias :output :deprecation_stream

        def printer
          @printer ||= case deprecation_stream
                       when File
                         ImmediatePrinter.new(FileStream.new(deprecation_stream),
                                              summary_stream, self)
                       when RaiseErrorStream
                         ImmediatePrinter.new(deprecation_stream, summary_stream, self)
                       else
                         DelayedPrinter.new(deprecation_stream, summary_stream, self)
                       end
        end

        def deprecation(notification)
          return if @seen_deprecations.include? notification

          @count += 1
          printer.print_deprecation_message notification
          @seen_deprecations << notification
        end

        def deprecation_summary(_notification)
          printer.deprecation_summary
        end

        def deprecation_message_for(data)
          if data.message
            SpecifiedDeprecationMessage.new(data)
          else
            GeneratedDeprecationMessage.new(data)
          end
        end

        RAISE_ERROR_CONFIG_NOTICE = <<-EOS.gsub(/^\s+\|/, '')
          |
          |If you need more of the backtrace for any of these deprecations to
          |identify where to make the necessary changes, you can configure
          |`config.raise_errors_for_deprecations!`, and it will turn the
          |deprecation warnings into errors, giving you the full backtrace.
        EOS

        DEPRECATION_STREAM_NOTICE = "Pass `--deprecation-out` or set " \
          "`config.deprecation_stream` to a file for full output."
        TOO_MANY_WARNINGS_NOTICE  = "Too many similar deprecation messages " \
          "reported, disregarding further reports. #{DEPRECATION_STREAM_NOTICE}"

        # @private
        SpecifiedDeprecationMessage = Struct.new(:type) do
          def initialize(data)
            @message = data.message
            super deprecation_type_for(data)
          end

          def to_s
            output_formatted @message
          end

          def too_many_warnings_message
            TOO_MANY_WARNINGS_NOTICE
          end

          private

          def output_formatted(str)
            return str unless str.lines.count > 1
            separator = '-' * 80
            "#{separator}\n#{str.chomp}\n#{separator}"
          end

          def deprecation_type_for(data)
            data.message.gsub(/(\w+\/)+\w+\.rb:\d+/, '')
          end
        end

        # @private
        GeneratedDeprecationMessage = Struct.new(:type) do
          def initialize(data)
            @data = data
            super data.deprecated
          end

          def to_s
            msg = String.new("#{@data.deprecated} is deprecated.")
            msg << " Use #{@data.replacement} instead." if @data.replacement
            msg << " Called from #{@data.call_site}."   if @data.call_site
            msg
          end

          def too_many_warnings_message
            "Too many uses of deprecated '#{type}'. #{DEPRECATION_STREAM_NOTICE}"
          end
        end

        # @private
        class ImmediatePrinter
          attr_reader :deprecation_stream, :summary_stream, :deprecation_formatter

          def initialize(deprecation_stream, summary_stream, deprecation_formatter)
            @deprecation_stream = deprecation_stream

            @summary_stream = summary_stream
            @deprecation_formatter = deprecation_formatter
          end

          def print_deprecation_message(data)
            deprecation_message = deprecation_formatter.deprecation_message_for(data)
            deprecation_stream.puts deprecation_message.to_s
          end

          def deprecation_summary
            return if deprecation_formatter.count.zero?
            deprecation_stream.summarize(summary_stream, deprecation_formatter.count)
          end
        end

        # @private
        class DelayedPrinter
          TOO_MANY_USES_LIMIT = 4

          attr_reader :deprecation_stream, :summary_stream, :deprecation_formatter

          def initialize(deprecation_stream, summary_stream, deprecation_formatter)
            @deprecation_stream = deprecation_stream
            @summary_stream = summary_stream
            @deprecation_formatter = deprecation_formatter
            @seen_deprecations = Hash.new { 0 }
            @deprecation_messages = Hash.new { |h, k| h[k] = [] }
          end

          def print_deprecation_message(data)
            deprecation_message = deprecation_formatter.deprecation_message_for(data)
            @seen_deprecations[deprecation_message] += 1

            stash_deprecation_message(deprecation_message)
          end

          def stash_deprecation_message(deprecation_message)
            if @seen_deprecations[deprecation_message] < TOO_MANY_USES_LIMIT
              @deprecation_messages[deprecation_message] << deprecation_message.to_s
            elsif @seen_deprecations[deprecation_message] == TOO_MANY_USES_LIMIT
              @deprecation_messages[deprecation_message] << deprecation_message.too_many_warnings_message
            end
          end

          def deprecation_summary
            return unless @deprecation_messages.any?

            print_deferred_deprecation_warnings
            deprecation_stream.puts RAISE_ERROR_CONFIG_NOTICE

            summary_stream.puts "\n#{Helpers.pluralize(deprecation_formatter.count, 'deprecation warning')} total"
          end

          def print_deferred_deprecation_warnings
            deprecation_stream.puts "\nDeprecation Warnings:\n\n"
            @deprecation_messages.keys.sort_by(&:type).each do |deprecation|
              messages = @deprecation_messages[deprecation]
              messages.each { |msg| deprecation_stream.puts msg }
              deprecation_stream.puts
            end
          end
        end

        # @private
        # Not really a stream, but is usable in place of one.
        class RaiseErrorStream
          def puts(message)
            raise DeprecationError, message
          end

          def summarize(summary_stream, deprecation_count)
            summary_stream.puts "\n#{Helpers.pluralize(deprecation_count, 'deprecation')} found."
          end
        end

        # @private
        # Wraps a File object and provides file-specific operations.
        class FileStream
          def initialize(file)
            @file = file

            # In one of my test suites, I got lots of duplicate output in the
            # deprecation file (e.g. 200 of the same deprecation, even though
            # the `puts` below was only called 6 times). Setting `sync = true`
            # fixes this (but we really have no idea why!).
            @file.sync = true
          end

          def puts(*args)
            @file.puts(*args)
          end

          def summarize(summary_stream, deprecation_count)
            path = @file.respond_to?(:path) ? @file.path : @file.inspect
            summary_stream.puts "\n#{Helpers.pluralize(deprecation_count, 'deprecation')} logged to #{path}"
            puts RAISE_ERROR_CONFIG_NOTICE
          end
        end
      end
    end

    # Deprecation Error.
    DeprecationError = Class.new(StandardError)
  end
end