require_relative 'human_duration/constants'
require_relative 'human_duration/overloads'
require_relative 'human_duration/version'

#
# docs to do
#
module HumanDuration
    #
    # docs to do
    #
    class Duration
        $time_values = {}
        $item_count = 0
        $output_buffer = ''

        $type = 'compact'

        def self.display_type(type = 'compact')
            raise ArgumentError.new('Invalid type - Valid options are:- compact, short and full') unless VALID_TYPES.include? type

            $type = type
        end

        def self.human_duration(seconds)
            reset

            return 'negative' if seconds < 0
            return 'now' if seconds.zero?

            split_seconds(seconds)
            count_items
            generate_output

            $output_buffer
        end

        def self.reset
            $time_values = {}
            $item_count = 0
            $output_buffer = ''
        end

        def self.pluralize(number)
            return 's' unless number == 1

            ''
        end

        def self.comma_or_not(count)
            return ', ' if count > 1
            return ' & ' if count == 1 && $type == 'short'
            return ' and ' if count == 1

            ''
        end

        def self.add_time(value, name, plural = true)
            return if value < 1 && $type != 'full'

            $output_buffer << if plural
                                  format('%<value>s %<name>s%<plural>s', value: value, name: name, plural: pluralize(value))
                              else
                                  format('%<value>s %<name>s', value: value, name: name)
                              end
            $item_count -= 1
            $output_buffer << comma_or_not($item_count)
        end

        def self.split_seconds(seconds)
            SPLIT_TYPES.map do |count, name|
                if seconds > 0
                    seconds, n = seconds.divmod(count)
                    $time_values[name] = n
                else
                    $time_values[name] = 0
                end
            end
        end

        def self.count_items
            $time_values.each do |_name, value|
                $item_count += 1 if value > 0 || $type == 'full'
            end
        end

        def self.add_time_long
            $time_values.reverse_each do |name, value|
                add_time(value, name)
            end
        end

        def self.add_time_short
            $time_values.reverse_each do |name, value|
                add_time(value, SHORT_NAME_MAP[name], false)
            end
        end

        def self.generate_output
            if $type == 'short'
                add_time_short
            else
                add_time_long
            end
        end
    end
end