module Gitlab
  module Utils
    extend self

    # Run system command without outputting to stdout.
    #
    # @param  cmd [Array<String>]
    # @return [Boolean]
    def system_silent(cmd)
      Popen.popen(cmd).last.zero?
    end

    def force_utf8(str)
      str.force_encoding(Encoding::UTF_8)
    end

    # A slugified version of the string, suitable for inclusion in URLs and
    # domain names. Rules:
    #
    #   * Lowercased
    #   * Anything not matching [a-z0-9-] is replaced with a -
    #   * Maximum length is 63 bytes
    #   * First/Last Character is not a hyphen
    def slugify(str)
      return str.downcase
        .gsub(/[^a-z0-9]/, '-')[0..62]
        .gsub(/(\A-+|-+\z)/, '')
    end

    # Converts newlines into HTML line break elements
    def nlbr(str)
      ActionView::Base.full_sanitizer.sanitize(str, tags: []).gsub(/\r?\n/, '<br>').html_safe
    end

    def remove_line_breaks(str)
      str.gsub(/\r?\n/, '')
    end

    def to_boolean(value)
      return value if [true, false].include?(value)
      return true if value =~ /^(true|t|yes|y|1|on)$/i
      return false if value =~ /^(false|f|no|n|0|off)$/i

      nil
    end

    def boolean_to_yes_no(bool)
      if bool
        'Yes'
      else
        'No'
      end
    end

    def random_string
      Random.rand(Float::MAX.to_i).to_s(36)
    end

    # See: http://stackoverflow.com/questions/2108727/which-in-ruby-checking-if-program-exists-in-path-from-ruby
    # Cross-platform way of finding an executable in the $PATH.
    #
    #   which('ruby') #=> /usr/bin/ruby
    def which(cmd, env = ENV)
      exts = env['PATHEXT'] ? env['PATHEXT'].split(';') : ['']

      env['PATH'].split(File::PATH_SEPARATOR).each do |path|
        exts.each do |ext|
          exe = File.join(path, "#{cmd}#{ext}")
          return exe if File.executable?(exe) && !File.directory?(exe)
        end
      end

      nil
    end

    def bytes_to_megabytes(bytes)
      bytes.to_f / Numeric::MEGABYTE
    end

    # Used in EE
    # Accepts either an Array or a String and returns an array
    def ensure_array_from_string(string_or_array)
      return string_or_array if string_or_array.is_a?(Array)

      string_or_array.split(',').map(&:strip)
    end
  end
end
