module AspectRatio

# File lib/aspect_ratio.rb, line 32
def self.crop(x, y, r)
  orient = r.split('!')[1]
  ratio  = r.split('!')[0].split(':').sort.map { |r| BigDecimal(r) }

  vertical = y > x
  rotate = y > x && orient == 'h' || x > y && orient == 'v'

  if (vertical || rotate) && !(vertical && rotate)
    x = x + y
    y = x - y
    x = x - y
  end

  xʹ = x
  yʹ = x * (ratio[1] / ratio[0])

  if (yʹ > y) || rotate && (yʹ > x)
    yʹ = y
    xʹ = y * (ratio[1] / ratio[0])

    if xʹ > x
      xʹ = x
      yʹ = x * (ratio[0] / ratio[1])
    end
  end

  delta_x = ((x - xʹ) / 2).to_f.floor
  delta_y = ((y - yʹ) / 2).to_f.floor

  if (vertical || rotate) && !(vertical && rotate)
    [
      delta_y,         # crop top left x
      delta_x,         # crop top left y
      y - delta_y * 2, # crop width
      x - delta_x * 2  # crop height
    ]
  else
    [
      delta_x.to_f,    # crop top left x
      delta_y,         # crop top left y
      x - delta_x * 2, # crop width
      y - delta_y * 2  # crop height
    ]
  end
end

# File lib/aspect_ratio.rb, line 4
def self.resize(x, y, x_max = nil, y_max = nil, enlarge = true)
  x = BigDecimal(x)
  y = BigDecimal(y)
  x_max = BigDecimal(x_max) if x_max
  y_max = BigDecimal(y_max) if y_max

  if x_max && y_max
    return [x.to_i, y.to_i] if !enlarge && x <= x_max && y <= y_max

    # Maximum values of height and width given, aspect ratio preserved.
    if y > x
      return [(y_max * x / y).round, y_max]
    else
      return [x_max, (x_max * y / x).round]
    end
  elsif x_max
    return [x.to_i, y.to_i] if !enlarge && x <= x_max

    # Width given, height automagically selected to preserve aspect ratio.
    return [x_max, (x_max * y / x).round]
  else
    return [x.to_i, y.to_i] if !enlarge && y <= y_max

    # Height given, width automagically selected to preserve aspect ratio.
    return [(y_max * x / y).round, y_max]
  end
end