module TextFileMutator
  
  def self.has_multiple_content_before?(file_content, content, before) 
    res = file_content =~ /(#{content}\s*#{content})\s*#{before}/
    !res.nil?
  end

  def self.has_content_before?(file_content, content, before) 
    res = file_content =~ /(#{content})\s*#{before}/
    !res.nil?
  end


  def self.has_multiple_content_after?(file_content, content, after)
    res = file_content =~ /#{after}\s*(#{content}\s*#{content})/
    !res.nil?
  end

  def self.has_content_after?(file_content, content, after)
    res = file_content =~ /#{after}\s*(#{content})/
    !res.nil?
  end
  
  
  def self.insert_before(file, line, txt_before, exist_check=true)
    content = File.read(file)
    if exist_check    
      return if has_content_before?(content, txt_before, line)
    end
    gsub_content_file content, file, /(#{Regexp.escape(line)})/ do |match|
      "#{txt_before}\n#{match}"
    end
  end

  def self.insert_after(file, line, txt_after, exist_check=true) 
    content = File.read(file)
    if exist_check    
      return if has_content_after?(content, txt_after, line)
    end
    gsub_content_file file, /(#{Regexp.escape(line)})/ do |match|
      "#{match}\n#{txt_after}"
    end
  end

  def self.remove_duplicate_lines(file)
    content = File.read(file)
    content.gsub!(/^(.*)(\r?\n\1)+$/, '\1')
    File.open(path, 'wb') { |file| file.write(content) }
  end


  def self.comment_gem_config(file, line)  
    gsub_file file, /^\s*[^#]\s*config.gem.+'#{Regexp.escape(line)}'$/ do |match|
      "# " + "#{match}"
    end
  end

  def self.remove_require(file, line)
    gsub_file file, /^\s*require\s+'#{Regexp.escape(line)}'$/ do |match|
      ""
    end
  end

  def self.comment_line(file, line)  
    gsub_file file, /^\s*[^#]\s*(#{Regexp.escape(line)}$)/i do |match|
      "# " + "#{match}"
    end
  end

  def self.remove_content(file, line)  
    gsub_file file, /(#{Regexp.escape(line)})/i do |match|
      ""
    end
  end

  def self.remove_line(file, line)  
    gsub_file file, /^.*#{Regexp.escape(line)}.*$)/i do |match|
      ""
    end
  end


protected
def self.gsub_content_file(content, path, regexp, *args, &block)
  content.gsub!(regexp, *args, &block)
  File.open(path, 'wb') { |file| file.write(content) }
end

  def self.gsub_file(path, regexp, *args, &block)
    content = File.read(path).gsub(regexp, *args, &block)
    File.open(path, 'wb') { |file| file.write(content) }
  end

end