require 'fileutils'

module Educoder
  module Utils
    class << self
      # Returns the relative root url of the application
      def relative_url_root
        ActionController::Base.respond_to?('relative_url_root') ?
            ActionController::Base.relative_url_root.to_s :
            ActionController::Base.config.relative_url_root.to_s
      end

      # Sets the relative root url of the application
      def relative_url_root=(arg)
        if ActionController::Base.respond_to?('relative_url_root=')
          ActionController::Base.relative_url_root=arg
        else
          ActionController::Base.config.relative_url_root = arg
        end
      end

      # Generates a n bytes random hex string
      # Example:
      #   random_hex(4) # => "89b8c729"
      def random_hex(n)
        SecureRandom.hex(n)
      end

      def save_upload(upload, path)
        directory = File.dirname(path)
        unless File.exists?(directory)
          FileUtils.mkdir_p directory
        end
        File.open(path, "wb") do |f|
          if upload.respond_to?(:read)
            buffer = ""
            while (buffer = upload.read(8192))
              f.write(buffer)
              yield buffer if block_given?
            end
          else
            f.write(upload)
            yield upload if block_given?
          end
        end
      end

      def digest(diskfile)
        md5 = Digest::MD5.new
        File.open(diskfile, "rb") do |f|
          buffer = ""
          while (buffer = f.read(8192))
            md5.update(buffer)
          end
        end
        md5.hexdigest
      end
    end

    module Shell

      module_function

      def shell_quote(str)
        if Redmine::Platform.mswin?
          '"' + str.gsub(/"/, '\\"') + '"'
        else
          "'" + str.gsub(/'/, "'\"'\"'") + "'"
        end
      end

      def shell_quote_command(command)
        if Redmine::Platform.mswin? && RUBY_PLATFORM == 'java'
          command
        else
          shell_quote(command)
        end
      end
    end

    module DateCalculation
      # Returns the number of working days between from and to
      def working_days(from, to)
        days = (to - from).to_i
        if days > 0
          weeks = days / 7
          result = weeks * (7 - non_working_week_days.size)
          days_left = days - weeks * 7
          start_cwday = from.cwday
          days_left.times do |i|
            unless non_working_week_days.include?(((start_cwday + i - 1) % 7) + 1)
              result += 1
            end
          end
          result
        else
          0
        end
      end

      # Adds working days to the given date
      def add_working_days(date, working_days)
        if working_days > 0
          weeks = working_days / (7 - non_working_week_days.size)
          result = weeks * 7
          days_left = working_days - weeks * (7 - non_working_week_days.size)
          cwday = date.cwday
          while days_left > 0
            cwday += 1
            unless non_working_week_days.include?(((cwday - 1) % 7) + 1)
              days_left -= 1
            end
            result += 1
          end
          next_working_date(date + result)
        else
          date
        end
      end

      # Returns the date of the first day on or after the given date that is a working day
      def next_working_date(date)
        cwday = date.cwday
        days = 0
        while non_working_week_days.include?(((cwday + days - 1) % 7) + 1)
          days += 1
        end
        date + days
      end

      # Returns the index of non working week days (1=monday, 7=sunday)
      def non_working_week_days
        @non_working_week_days ||= begin
          days = Setting.non_working_week_days
          if days.is_a?(Array) && days.size < 7
            days.map(&:to_i)
          else
            []
          end
        end
      end
    end
  end
end