module CommercialWeeks

# File lib/commercial_weeks.rb, line 26
def self.calculate_weeks(start_date, end_date, year)
  (start_date..end_date).collect{ |week_num| week_dates(week_num, year) }
end

# File lib/commercial_weeks.rb, line 41
def self.compute_weeks(year=Time.now.year)
  number_of_weeks = weeks_count(year)
  previous_half_year_weeks(year - 1) | get_first_week(year) | calculate_weeks(1, number_of_weeks, year) | next_half_year_weeks(year + 1)
end

# File lib/commercial_weeks.rb, line 46
def self.current_week(current_date)
  current_date = Date.today if current_date.blank?
  end_date = current_date.next_year.year == current_date.sunday.year ? current_date.end_of_year : current_date.sunday
  end_date = end_date.strftime('%d %b, %Y')
  start_date = current_date.strftime('%d %b, %Y')
  [start_date, end_date].join(' - ')
end

# File lib/commercial_weeks.rb, line 20
def self.get_first_week(year=Time.now.year)
  return [] if Date.new(year).wday == 1
  weeks = []
  weeks << [Date.civil(year, 1, 1).strftime('%d %b, %Y'), Date.civil(year, 1, 1).sunday.strftime('%d %b, %Y')].join(' - ')
end

# File lib/commercial_weeks.rb, line 36
def self.next_half_year_weeks(year)
  week_number = Date.parse("#{year}-6-30").cweek
  get_first_week(year) | calculate_weeks(1, week_number, year)
end

# File lib/commercial_weeks.rb, line 30
def self.previous_half_year_weeks(year)
  week_number = Date.parse("#{year}-7-1").strftime("%V").to_i
  total_weeks = weeks_count(year)
  calculate_weeks(week_number, total_weeks, year)
end

# File lib/commercial_weeks.rb, line 54
def self.start_date_of_week(date)
  date.year == date.monday.year ? date.monday : date.beginning_of_year
end

# File lib/commercial_weeks.rb, line 8
def self.week_dates(week_num, year)
  week_start = Date.commercial(year, week_num, 1)
  week_end = Date.commercial(year, week_num, 7)
  week_end = Date.new(year).end_of_year if week_end.year > week_start.year
  [week_start.strftime('%d %b, %Y'), week_end.strftime('%d %b, %Y')].join(' - ')
end

# File lib/commercial_weeks.rb, line 15
def self.weeks_count(year)
  last_day = Date.new(year).end_of_year
  last_day.cweek == 1 ? last_day.prev_week.cweek : last_day.cweek
end