class PhotoGeometry
  attr_reader :mid_point, :x1, :y1, :x2, :y2, :rotation
  def initialize(h_pixels, v_pixels)
    reset(h_pixels, v_pixels)
  end
  
  def reset(h_pixels, v_pixels)
    @mid_point = [h_pixels.to_f / 2.0, v_pixels.to_f / 2.0]
    @rotation = 0
    @x1 = @x2 = mid_point[0]
    @y1 = @y2 = mid_point[1]
  end
  
  def rotate_90_clockwise
    @x1, @y1, @x2, @y2 = @y2, @x1, @y1, @x2 
    @rotation += 90
    @rotation -= 360 if @rotation >= 360
    @mid_point.reverse!
  end
  
  def rotate_90_counterclockwise
    @x1, @y1, @x2, @y2 = @y1, @x2, @y2, @x1
    @rotation -= 90
    @rotation += 360 if @rotation < 0
    @mid_point.reverse!
  end
  
  def crop(left_percent, top_percent, right_percent, bottom_percent)
    w = width
    h = height
    pixels = left_percent.to_f / 100 * w
    @x1 -= pixels
    pixels = top_percent.to_f / 100 * h
    @y1 -= pixels
    pixels = right_percent.to_f / 100 * w
    @x2 -= pixels
    pixels = bottom_percent.to_f / 100 * h
    @y2 -= pixels
  end
  
  def x_y_width_height
    return mid_point[0] - x1, mid_point[1] - y1, width, height
  end
  
  def x_y_width_height_before_rotation
    case @rotation
    when 90
      return mid_point[1] -  y1, mid_point[0] -  x2, height, width
    when 180
      return mid_point[0] -  x2, mid_point[1] - y2 , width, height
    when 270
      return mid_point[1] - y2, mid_point[0] - x1, height, width
    else
      return mid_point[0] - x1, mid_point[1] - y1, width, height
    end
  end
  
  def x_y_width_height_for(max_width, max_height)
    s = scale_factor_for(max_width, max_height)
    return (mid_point[0] - x1) * s, (mid_point[1] - y1) * s, width * s, height * s
  end
  
  def width
    x1 + x2
  end
  
  def height
    y1 + y2
  end
  
  def total_width
    2.0 * mid_point[0]
  end
  
  def total_height
    2.0 * mid_point[1]
  end
  
  def scale_factor_for(max_width, max_height)
    return [max_width.to_f / width, max_height.to_f / height].min
  end
  
  
  
end