class Utils::Grepper

def initialize(opts = {})
  @args  = opts[:args] || {}
  @roots = opts[:roots] || []
  @config = opts[:config] || Utils::Config::ConfigFile.new
  if n = @args.values_at(*%w[A B C]).compact.first
    if n.to_s =~ /\A\d+\Z/ and (n = n.to_i) >= 1
      @queue = Queue.new n
    else
      raise ArgumentError, "needs to be an integer number >= 1"
    end
  end
  @pathes  = []
  pattern_opts = opts.subhash(:pattern) | {
    :cset  => @args['a'],
    :icase => @args['i'],
  }
  @pattern = @args['R'] ?
    FuzzyPattern.new(pattern_opts) :
    RegexpPattern.new(pattern_opts)
  @name_pattern =
    if name_pattern = @args['N']
      RegexpPattern.new(:pattern => name_pattern)
    elsif name_pattern = @args['n']
      FuzzyPattern.new(:pattern => name_pattern)
    end
  @skip_pattern =
    if skip_pattern = @args['S']
      RegexpPattern.new(:pattern => skip_pattern)
    elsif skip_pattern = @args['s']
      FuzzyPattern.new(:pattern => skip_pattern)
    end
end

def match(filename)
  @filename = filename
  @output = []
  bn, s = File.basename(filename), File.stat(filename)
  if s.directory? && @config.search.prune?(bn)
    $DEBUG and warn "Pruning #{filename.inspect}."
    Utils::Find.prune
  end
  if s.file? && !@config.search.skip?(bn) && (!@name_pattern || @name_pattern.match(bn))
    File.open(filename, 'rb') do |file|
      if file.binary? != true
        $DEBUG and warn "Matching #{filename.inspect}."
        match_lines file
      else
        $DEBUG and warn "Skipping binary file #{filename.inspect}."
      end
    end
  else
    $DEBUG and warn "Skipping #{filename.inspect}."
  end
  unless @output.empty?
    case
    when @args['l'], @args['e']
      @output.uniq!
      @pathes.concat @output
    else
      STDOUT.puts @output
    end
    @output.clear
  end
  self
rescue SystemCallError => e
  warn "Caught #{e.class}: #{e}"
  nil
end

def match_lines(file)
  for line in file
    if m = @pattern.match(line)
      @skip_pattern and @skip_pattern =~ line and next
      line[m.begin(0)...m.end(0)] = black on_white m[0]
      @queue and @queue << line
      if @args['l']
        @output << @filename
      elsif @args['L']
        @output << "#{@filename}:#{file.lineno}"
      elsif @args['e']
        @output << "#{@filename}:#{file.lineno}"
        break
      else
        @output << red("#{@filename}:#{file.lineno}")
        if @args['B'] or @args['C']
          @output.concat @queue.data
        else
          @output << line
        end
        if @args['A'] or @args['C']
          where = file.tell
          lineno = file.lineno
          @queue.max_size.times do
            file.eof? and break
            line = file.readline
            @queue << line
            @output << line
          end
          file.seek where
          file.lineno = lineno
        end
      end
    else
      @queue and @queue << line
    end
  end
end

def search
  @suffix = @args['I']
  for dir in @roots
    Utils::Find.find(dir) do |filename|
      if !@suffix || @suffix == File.extname(filename)[1..-1]
        match(filename)
      end
    end
  end
  if @args['L'] or @args['e']
    @pathes = @pathes.sort_by do |path|
      pair = path.split(':')
      pair[1] = pair[1].to_i
      pair
    end
  else
    @pathes.sort!
  end
  self
end