class MonthlyCalendar

# File lib/monthly_calendar.rb, line 12
def initialize(options = {})
  @start_date = (options[:start_date] && Date.parse(options[:start_date])) ||
                Date.today
  @pages_count = options[:pages] || 1

  @pdf = Prawn::Document.new(page_layout: :landscape, top_margin: 1.in, skip_page_creation: true)
  create
end

# File lib/monthly_calendar.rb, line 21
def save(file_name = "calendar.pdf")
  pdf.render_file File.expand_path(file_name)
end

# File lib/monthly_calendar.rb, line 25
def stream
  yield(to_s)
end

# File lib/monthly_calendar.rb, line 29
def to_s
  pdf.render
end

# File lib/monthly_calendar.rb, line 64
def calendar_contents
  months = []

  current_month = @start_date

  @pages_count.times do |page_index|
    month_text = current_month.strftime("%B %Y")

    days_in_month = Date.new(current_month.year, current_month.month, -1).mday
    first_day_of_week = Date.new(current_month.year, current_month.month, 1).wday

    weeks_count = ((days_in_month + first_day_of_week) / 7.0).ceil

    days = []
    days << [] until days.count == weeks_count

    first_day_of_week.times do
      days[0] << nil
    end

    days_in_month.times do |day|
      week = (day + first_day_of_week) / 7
      days[week] << day + 1
    end

    days[4] << nil until days[4].count == 7

    unless days[5].nil?
      days[5] << nil until days[5].count == 7
    end

    months << [month_text, days]
    current_month = current_month.next_month
  end

  months
end

# File lib/monthly_calendar.rb, line 35
def create
  calendar_contents.each do |(month, weeks)|
    pdf.start_new_page

    days_in_month = weeks.flatten.compact.max
    first_day_of_week = weeks[0].index(1)

    weeks_count = ((days_in_month + first_day_of_week) / 7.0).ceil

    pdf.define_grid(rows: weeks_count, columns: 7)

    draw_header(month)

    weeks.each_with_index do |week, week_index|
      draw_notes(week_index,
                 find_nil_cells(week),
                 weeks_count == 6 ? :close : :far)

      week.each_with_index do |day, day_index|
        draw_day_square(week_index, day_index, day)
      end
    end

    # The last thing drawn on each page isn't rendered for some reason so this
    # just "flushes the queue" (causes the last thing previous to be drawn)
    pdf.stroke
  end
end

# File lib/monthly_calendar.rb, line 102
def find_nil_cells(week)
  { start: week.index(nil), count: week.count(nil) }
end