module Ecom
  module Core
    class CrewTime < ApplicationRecord
      # Time Ranges
      MORNING = 'Morning'.freeze
      AFTERNOON = 'Afternoon'.freeze
      BOTH = 'Both'.freeze

      TIME_RANGE = {
        MORNING => {start: Time.zone.parse('5:00 AM'), end: Time.zone.parse('9:00 AM')},
        AFTERNOON => {start: Time.zone.parse('10:00 AM'), end: Time.zone.parse('2:00 PM')},
        BOTH => {start: Time.zone.parse('5:00 AM'), end: Time.zone.parse('2:00 PM')}
      }.freeze

      belongs_to :attendance_sheet_entry
      belongs_to :revision_to, class_name: 'Ecom::Core::CrewTime', optional: true
      belongs_to :created_by, class_name: 'Ecom::Core::User'
      has_one :revision, class_name: 'Ecom::Core::CrewTime', foreign_key: :revision_to_id

      validates :checkin_time, presence: true, if: :checkout_time

      before_save :calculate_hours
      after_save :calculate_total

      def calculate_hours
        self.hours = if checkout_time.nil? || checkin_time.nil?
                       0
                     else
                       compute_hours
                     end
      end

      def calculate_total
        compute_total_for_entry if saved_change_to_hours?
      end

      def compute_total_for_entry
        attendance_sheet_entry.total_hours = Ecom::Core::CrewTime.where(
          attendance_sheet_entry: attendance_sheet_entry,
          revised: false
        ).sum(:hours)
        attendance_sheet_entry.save
      end

      # A method to check if checkin and checkout range falls in the morning,
      # afternoon, or both.
      def find_range(start, finish)
        if start.before?(TIME_RANGE[MORNING][:end]) && finish.before?(TIME_RANGE[AFTERNOON][:start])
          MORNING
        elsif start.after?(TIME_RANGE[MORNING][:end]) && finish.after?(TIME_RANGE[AFTERNOON][:start])
          AFTERNOON
        else
          BOTH
        end
      end

      # A method to adjust time ranges by trimming any time value outside
      # of the defined morning and afternoon ranges
      def compute_hours
        # Reparse time to avoid errors caused by date differences
        start = Time.zone.parse(checkin_time.strftime('%I:%M%p'))
        finish = Time.zone.parse(checkout_time.strftime('%I:%M%p'))
        range = find_range(start, finish)
        left = start.before?(TIME_RANGE[range][:start]) ? TIME_RANGE[range][:start] : start
        right = finish.after?(TIME_RANGE[range][:end]) ? TIME_RANGE[range][:end] : finish
        time = (right - left) / 1.hour
        time -= 1 if range == BOTH
        time
      end
    end
  end
end