# frozen_string_literal: true
module Stupidedi
  using Refinements

  module Versions
    module Common
      module ElementTypes
        #
        # Simple element definition for date elements
        #
        # @see DateVal
        # @see X222.pdf B.1.1.3.1.5 Date
        #
        class DT < SimpleElementDef
          def initialize(id, name, min_length, max_length, description = nil, parent = nil)
            super(id, name, min_length, max_length, description, parent)

            unless min_length == 6 or min_length == 8
              raise Exceptions::InvalidSchemaError,
                "min_length must be either 6 or 8"
            end

            unless max_length == 6 or max_length == 8
              raise Exceptions::InvalidSchemaError,
                "max_length must be either 6 or 8"
            end
          end

          def companion
            DateVal
          end
        end

        #
        # @see X222.pdf B.1.1.3.1.5 Date
        #
        class DateVal < Values::SimpleElementVal
          def date?
            true
          end

          def proper?
            false
          end

          def too_long?
            false
          end

          def too_short?
            false
          end

          #
          # Models invalid dates, either with a bad format or a date that
          # does not exist (eg Febuary 30th 2000)
          #
          class Invalid < DateVal
            # @return [Object]
            attr_reader :value

            def initialize(value, usage, position)
              super(usage, position)
              @value = value
            end

            def valid?
              false
            end

            def empty?
              false
            end

            # @return [DateVal]
            def map
              self
            end

            # @return [String]
            # :nocov:
            def inspect
              id = definition.bind do |d|
                "[#{"% 5s" % d.id}: #{d.name}]".bind do |s|
                  if usage.forbidden?
                    ansi.forbidden(s)
                  elsif usage.required?
                    ansi.required(s)
                  else
                    ansi.optional(s)
                  end
                end
              end

              ansi.element("DT.invalid#{id}") + "(#{ansi.invalid(@value.inspect)})"
            end
            # :nocov:

            # @return [String]
            def to_s
              ""
            end

            # @return [String]
            def to_x12(truncate = true)
              ""
            end

            # @return [Boolean]
            def ==(other)
              eql?(other)
            end

            # @return [Invalid]
            def copy(changes = {})
              self
            end
          end

          class Valid < DateVal
            def valid?
              true
            end

            # @return [DateVal]
            def map
              DateVal.value(yield(value), usage, position)
            end

            # @return [DateVal]
            def copy(changes = {})
              DateVal.value \
                changes.fetch(:value, value),
                changes.fetch(:usage, usage),
                changes.fetch(:position, position)
            end

            def coerce(other)
              return DateVal.value(other, usage, position), self
            end

            def ==(other)
              other = DateVal.value(other, usage, position)
              other.valid? and other.value == value
            end
          end

          #
          # Empty date value. Shouldn't be directly instantiated -- instead,
          # use the {DateVal.empty} constructor.
          #
          class Empty < Valid
            def value
              nil
            end

            def empty?
              true
            end

            # @return [String]
            # :nocov:
            def inspect
              id = definition.bind do |d|
                "[#{"% 5s" % d.id}: #{d.name}]".bind do |s|
                  if usage.forbidden?
                    ansi.forbidden(s)
                  elsif usage.required?
                    ansi.required(s)
                  else
                    ansi.optional(s)
                  end
                end
              end

              ansi.element("DT.empty#{id}")
            end
            # :nocov:

            # @return [String]
            def to_s
              ""
            end

            # @return [String]
            def to_x12(truncate = true)
              ""
            end
          end

          #
          # Date with a fully-specified year (with century). Shouldn't be
          # directly instantiated -- instead use the {DateVal.value} constructor
          #
          class Proper < Valid
            def_delegators :@value, :year, :month, :day, :cwday, :cweek,
              :downto, :upto, :step, :httpdate, :to_s, :to_i, :strftime,
              :iso8601, :rfc2822, :rfc3339, :rfc822, :leap?, :julian?,
              :gregorian?, :mday, :mon, :to_datetime, :to_int, :to_r, :to_c,
              :wday, :xmlschema, :yday, :start

            extend Operators::Wrappers
            wrappers :+, :<<, :>>, :next_day, :next_month, :next_year,
              :prev_day, :prev_month, :prev_year

            extend Operators::Unary
            unary_operators :next, :succ, :prev

            extend Operators::Relational
            relational_operators :<, :>, :<=, :>=, :<=>, :-, :coerce => :to_date

            attr_reader :value

            def initialize(value, usage, position)
              @value = value

              # Check that date is reasonably valid
              unless @value.year.between?(0, 9999) and @value.month.between?(1, 12) and @value.day.between?(1, 31)
                raise Exceptions::InvalidElementError,
                  "invalid date: year(#{year}) month(#{month}) day(#{day})"
              end

              super(usage, position)
            end

            def empty?
              false
            end

            def proper?
              true
            end

            # @return [Date]
            def to_date
              @value
            end

            # @return [Time]
            def to_time(hour = nil, minute = nil, second = nil)
              if minute.nil? and second.nil? and hour.respond_to?(:hour)
                if hour.respond_to?(:minute) and hour.respond_to?(:second)
                  hour, minute, second = hour.hour, hour.minute, hour.second
                elsif hour.respond_to?(:min) and hour.respond_to?(:sec)
                  hour, minute, second = hour.hour, hour.min, hour.sec
                end
              end

              if not second.nil?
                Time.utc(year, month, day, hour, minute, second)
              elsif not minute.nil?
                Time.utc(year, month, day, hour, minute)
              elsif not hour.nil?
                Time.utc(year, month, day, hour)
              else
                Time.utc(year, month, day)
              end
            end

            # @return [Proper] self
            def oldest(date)
              self
            end

            # @return [Proper] self
            def newest(date)
              self
            end

            # @return [Proper] self
            def future
              self
            end

            # @return [Proper] self
            def past
              self
            end

            # @return [String]
            # :nocov:
            def inspect
              id = definition.bind do |d|
                "[#{"% 5s" % d.id}: #{d.name}]".bind do |s|
                  if usage.forbidden?
                    ansi.forbidden(s)
                  elsif usage.required?
                    ansi.required(s)
                  else
                    ansi.optional(s)
                  end
                end
              end

              ansi.element("DT.value#{id}") + "(#{"%04d-%02d-%02d" % [year, month, day]})"
            end
            # :nocov:

            # @return [String]
            def to_x12(truncate = true)
              x12 =
                if definition.max_length < 8
                  "%02d%02d%02d" % [year % 100, month, day]
                else
                  "%04d%02d%02d" % [year % 10000, month, day]
                end

              if truncate
                x12.slice(-definition.max_length..-1)
              else
                x12
              end
            end

            def too_long?
              if definition.max_length < 8
                definition.max_length - 2 < year.to_s.length
              else
                definition.max_length - 4 < year.to_s.length
              end
            end
          end

          #
          # Date with a partially-specified year (two digits, missing century).
          # Shouldn't be directly instantiated -- instead, use the constuctor
          # method {DateVal.value}
          #
          class Improper < Valid
            # @return [Integer]
            attr_reader :year

            # @return [Integer]
            attr_reader :month

            # @return [Integer]
            attr_reader :day

            def initialize(year, month, day, usage, position)
              @year, @month, @day = year, month, day

              # Check that date is reasonably valid
              unless @year.between?(0, 99) and @month.between?(1, 12) and @day.between?(1, 31)
                raise Exceptions::InvalidElementError,
                  "invalid date: year(#{year}) month(#{month}) day(#{day})"
              end

              super(usage, position)
            end

            def value
              [@year, @month, @day]
            end

            def copy(changes = {})
              if [:year, :month, :day].any?{|k| changes.include?(k) }
                changes[:value] = [changes.fetch(:year, @year),
                                   changes.fetch(:month, @month),
                                   changes.fetch(:day, @day)]
              end

              super(changes)
            end

            def empty?
              false
            end

            def proper?
              false
            end

            def too_short?
              # Less than a 4-digit year means our max length is 7, but in
              # practice the definition min/max lengths are either 6 or 8
              definition.min_length > 6
            end

            def too_long?
              # We know month and day occupy four characters, but year *could*
              # occupy either three or two characters. If the max_length can't
              # accomodate a three-digit year, make sure we don't have one
              definition.max_length < 7 and @year > 99
            end

            # Create a proper date using the given century `cc`
            #
            # @example
            #   DateVal.value("501015").century(19) #=> DateVal.value("19501230")
            #
            # @return [Proper]
            def century(cc)
              date = ::Date.civil(100 * cc + @year, @month, @day)
              Proper.new(date, usage, position)
            end

            # Create a proper date which cannot be older than the given `date`
            # and cannot be newer than one year after the given `date`.
            #
            # @example
            #   DateVal.value("501015").oldest(Date.civil(1950, 10, 20)) #=> DateVal.value("20501015")
            #   DateVal.value("501015").oldest(Date.civil(1950, 10, 15)) #=> DateVal.value("19501015")
            #   DateVal.value("501015").oldest(Date.civil(1950, 10, 10)) #=> DateVal.value("19501015")
            #
            # @return [Proper]
            def oldest(date)
              cc, yy = date.year.divmod(100)

              if @year < yy
                century(cc + 1)
              elsif @year > yy
                century(cc)
              else
                if @month < date.month
                  century(cc + 1)
                elsif @month > date.month
                  century(cc)
                else
                  if @day < date.day
                    century(cc + 1)
                  else
                    century(cc)
                  end
                end
              end
            end

            # Create a proper date which cannot be newer than the given `date`
            # and cannot be older than one year before the given `date`.
            #
            # @example
            #   DateVal.value("501015").newest(Date.civil(1950, 10, 20)) #=> DateVal.value("19501015")
            #   DateVal.value("501015").newest(Date.civil(1950, 10, 15)) #=> DateVal.value("19501015")
            #   DateVal.value("501015").newest(Date.civil(1950, 10, 10)) #=> DateVal.value("18501015")
            #
            # @return [Proper]
            def newest(date)
              cc, yy = date.year.divmod(100)

              if @year < yy
                century(cc)
              elsif @year > yy
                century(cc - 1)
              else
                if @month < date.month
                  century(cc)
                elsif @month > date.month
                  century(cc - 1)
                else
                  if @day <= date.day
                    century(cc)
                  else
                    century(cc - 1)
                  end
                end
              end
            end

            # Create a proper date which cannot be newer than the current date
            #
            # @return [Proper]
            def past
              newest(Date.today)
            end

            # Create a proper date which cannot be older than the current date
            #
            # @return [Proper]
            def future
              oldest(Date.today)
            end

            # @return [String]
            # :nocov:
            def inspect
              id = definition.bind do |d|
                "[#{"% 5s" % d.id}: #{d.name}]".bind do |s|
                  if usage.forbidden?
                    ansi.forbidden(s)
                  elsif usage.required?
                    ansi.required(s)
                  else
                    ansi.optional(s)
                  end
                end
              end

              ansi.element("DT.value#{id}") + "(XX#{"%02d-%02d-%02d" % [@year, @month, @day]})"
            end
            # :nocov:

            # @return [String]
            def to_s
              "XX%02d%02d%02d" % [@year, @month, @day]
            end

            # @return [String]
            def to_x12(truncate = true)
              "%02d%02d%02d" % [@year, @month, @day]
            end
          end
        end

        class << DateVal
          # @group Constructors
          ###################################################################

          # @return [DateVal::Empty]
          def empty(usage, position)
            self::Empty.new(usage, position)
          end

          # @return [DateVal]
          def value(object, usage, position)
            if object.is_a?(DateVal)
              object#.copy(:usage => usage, :position => position)
            elsif object.blank?
              self::Empty.new(usage, position)
            elsif object.is_a?(String) or object.is_a?(StringVal)
              string = object.to_s

              if string.length < 6
                self::Invalid.new(object, usage, position)
              else
                day   = string.slice(-2, 2).to_i
                month = string.slice(-4, 2).to_i
                year  = string.slice( 0..-5)

                if year.length < 4
                  self::Improper.new(year.to_i, month, day, usage, position)
                else
                  self::Proper.new(date(year, month, day), usage, position)
                end
              end
            elsif object.respond_to?(:year) and object.respond_to?(:month) and object.respond_to?(:day)
              self::Proper.new(date(object.year, object.month, object.day), usage, position)
            elsif object.is_a?(Array) and object.length == 3
              if object[0] <= 99
                self::Improper.new(*object, usage, position)
              else
                self::Proper.new(date(*object), usage, position)
              end
            else
              self::Invalid.new(object, usage, position)
            end
          rescue Exceptions::InvalidElementError
            self::Invalid.new(object, usage, position)
          end

          # @endgroup
          ###################################################################

        private

          def date(year, month, day)
            ::Date.civil(year.to_i, month.to_i, day.to_i)
          rescue
            raise Exceptions::InvalidElementError,
              "invalid year(#{year}), month(#{month}), day(#{day})"
          end
        end

        # Prevent direct instantiation of abstract class DateVal
        DateVal.eigenclass.send(:protected, :new)
        DateVal::Empty.eigenclass.send(:public, :new)
        DateVal::Proper.eigenclass.send(:public, :new)
        DateVal::Invalid.eigenclass.send(:public, :new)
        DateVal::Improper.eigenclass.send(:public, :new)
      end
    end
  end
end
