# frozen_string_literal: true

####
# Thanks for all the help SimpleCov https://github.com/colszowka/simplecov
# initial version pulled into Coverband from Simplecov 12/04/2018
#
# Representation of a source file including it's coverage data, source code,
# source lines and featuring helpers to interpret that data.
####
module Coverband
  module Utils
    class SourceFile
      include Coverband::Utils::FilePathHelper
      # Representation of a single line in a source file including
      # this specific line's source code, line_number and code coverage,
      # with the coverage being either nil (coverage not applicable, e.g. comment
      # line), 0 (line not covered) or >1 (the amount of times the line was
      # executed)
      class Line
        # The source code for this line. Aliased as :source
        attr_reader :src
        # The line number in the source file. Aliased as :line, :number
        attr_reader :line_number
        # The coverage data for this line: either nil (never), 0 (missed) or >=1 (times covered)
        attr_reader :coverage
        # Whether this line was skipped
        attr_reader :skipped

        # Lets grab some fancy aliases, shall we?
        alias source src
        alias line line_number
        alias number line_number

        def initialize(src, line_number, coverage)
          raise ArgumentError, 'Only String accepted for source' unless src.is_a?(String)
          raise ArgumentError, 'Only Integer accepted for line_number' unless line_number.is_a?(Integer)
          raise ArgumentError, 'Only Integer and nil accepted for coverage' unless coverage.is_a?(Integer) || coverage.nil?
          @src         = src
          @line_number = line_number
          @coverage    = coverage
          @skipped     = false
        end

        # Returns true if this is a line that should have been covered, but was not
        def missed?
          !never? && !skipped? && coverage.zero?
        end

        # Returns true if this is a line that has been covered
        def covered?
          !never? && !skipped? && coverage > 0
        end

        # Returns true if this line is not relevant for coverage
        def never?
          !skipped? && coverage.nil?
        end

        # Flags this line as skipped
        def skipped!
          @skipped = true
        end

        # Returns true if this line was skipped, false otherwise. Lines are skipped if they are wrapped with
        # # :nocov: comment lines.
        def skipped?
          !!skipped
        end

        # The status of this line - either covered, missed, skipped or never. Useful i.e. for direct use
        # as a css class in report generation
        def status
          return 'skipped' if skipped?
          return 'never' if never?
          return 'missed' if missed?
          return 'covered' if covered?
        end
      end

      # The full path to this source file (e.g. /User/colszowka/projects/simplecov/lib/simplecov/source_file.rb)
      attr_reader :filename
      # The array of coverage data received from the Coverage.result
      attr_reader :coverage

      # the date this version of the file first started to record coverage
      attr_reader :first_updated_at
      # the date this version of the file last saw any coverage activity
      attr_reader :last_updated_at
      NOT_AVAILABLE = 'not available'

      def initialize(filename, file_data)
        @filename = filename
        if file_data.is_a?(Hash)
          @coverage = file_data['data']
          @first_updated_at = @last_updated_at = NOT_AVAILABLE
          @first_updated_at = Time.at(file_data['first_updated_at']) if file_data['first_updated_at']
          @last_updated_at =  Time.at(file_data['last_updated_at']) if file_data['last_updated_at']
        else
          @coverage = file_data
          @first_updated_at = NOT_AVAILABLE
          @last_updated_at = NOT_AVAILABLE
        end
      end

      # The path to this source file relative to the projects directory
      def project_filename
        @filename.sub(/^#{Coverband.configuration.root}/, '')
      end

      # The source code for this file. Aliased as :source
      def src
        # We intentionally read source code lazily to
        # suppress reading unused source code.
        @src ||= File.open(filename, 'rb', &:readlines)
      end
      alias source src

      # Returns all source lines for this file as instances of SimpleCov::SourceFile::Line,
      # and thus including coverage data. Aliased as :source_lines
      def lines
        @lines ||= build_lines
      end
      alias source_lines lines

      def build_lines
        coverage_exceeding_source_warn if coverage.size > src.size

        lines = src.map.with_index(1) do |src, i|
          Coverband::Utils::SourceFile::Line.new(src, i, coverage[i - 1])
        end

        process_skipped_lines(lines)
      end

      # Warning to identify condition from Issue #56
      def coverage_exceeding_source_warn
        warn "Warning: coverage data from Coverage [#{coverage.size}] exceeds line count in #{filename} [#{src.size}]"
      end

      # Access SimpleCov::SourceFile::Line source lines by line number
      def line(number)
        lines[number - 1]
      end

      # The coverage for this file in percent. 0 if the file has no relevant lines
      def covered_percent
        return 100.0 if no_lines?

        return 0.0 if relevant_lines.zero?

        Float(covered_lines.size * 100.0 / relevant_lines.to_f)
      end

      def covered_strength
        return 0.0 if relevant_lines.zero?

        round_float(lines_strength / relevant_lines.to_f, 1)
      end

      def no_lines?
        lines.length.zero? || (lines.length == never_lines.size)
      end

      def lines_strength
        lines.map(&:coverage).compact.reduce(:+)
      end

      def relevant_lines
        lines.size - never_lines.size - skipped_lines.size
      end

      # Returns all covered lines as SimpleCov::SourceFile::Line
      def covered_lines
        @covered_lines ||= lines.select(&:covered?)
      end

      # Returns all lines that should have been, but were not covered
      # as instances of SimpleCov::SourceFile::Line
      def missed_lines
        @missed_lines ||= lines.select(&:missed?)
      end

      # Returns all lines that are not relevant for coverage as
      # SimpleCov::SourceFile::Line instances
      def never_lines
        @never_lines ||= lines.select(&:never?)
      end

      # Returns all lines that were skipped as SimpleCov::SourceFile::Line instances
      def skipped_lines
        @skipped_lines ||= lines.select(&:skipped?)
      end

      # Returns the number of relevant lines (covered + missed)
      def lines_of_code
        covered_lines.size + missed_lines.size
      end

      # Will go through all source files and mark lines that are wrapped within # :nocov: comment blocks
      # as skipped.
      def process_skipped_lines(lines)
        skipping = false

        lines.each do |line|
          if Coverband::Utils::LinesClassifier.no_cov_line?(line.src)
            skipping = !skipping
            line.skipped!
          elsif skipping
            line.skipped!
          end
        end
      end

      # a bug that existed in simplecov was not checking that root
      # was at the start of the file name
      # I had previously patched this in my local Rails app
      def short_name
        filename.sub(/^#{Coverband.configuration.root}/, '.')
                .sub(%r{^.*\/gems}, '.')
                .gsub(%r{^\.\/}, '')
      end

      def relative_path
        full_path_to_relative(filename)
      end

      def gem?
        filename =~ %r{^.*\/gems\/}
      end

      def gem_name
        gem? ? short_name.split('/').first : nil
      end

      private

      # ruby 1.9 could use Float#round(places) instead
      # @return [Float]
      def round_float(float, places)
        factor = Float(10 * places)
        Float((float * factor).round / factor)
      end
    end
  end
end