class TrustyCms::Geometry

def self.parse(value)
  return value if value.is_a?(Geometry)
  match = value.to_s.strip.match(/\A(\d*)x(\d*)([%<>#^!@])?\z/)
  raise StyleError, "Unrecognized geometry: #{value.inspect}" unless match
  width = match[1].to_s.empty? ? 0 : match[1].to_i
  height = match[2].to_s.empty? ? 0 : match[2].to_i
  modifier = match[3]
  new(width, height, modifier)
end

def ==(other)
  to_s == other.to_s
end

def =~(other)
  height.to_i == other.height.to_i && width.to_i == other.width.to_i
end

def aspect
  return nil if width.to_f == 0.0 || height.to_f == 0.0
  width.to_f / height.to_f
end

def horizontal?
  width.to_i > height.to_i
end

def initialize(width, height = nil, modifier = nil)
  @width = width.to_i
  @height = height.to_i
  @modifier = modifier
end

def scaled_by(other)
  if other.is_a?(Numeric)
    scaled_width = (width * other.fdiv(100)).round
    scaled_height = (height * other.fdiv(100)).round
    return Geometry.new(scaled_width, scaled_height)
  end
  other = Geometry.new("#{other}%") unless other.is_a?(Geometry)
  if other.height.positive?
    Geometry.new(width * other.width / 100, height * other.height / 100)
  else
    Geometry.new(width * other.width / 100, height * other.width / 100)
  end
end

def scaled_to_fit(other)
  if other.width.positive? && other.height.zero?
    Geometry.new(other.width, height * other.width / width)
  elsif other.width.zero? && other.height.positive?
    Geometry.new(width * other.height / height, other.height)
  else
    product_width = other.width * height
    product_height = other.height * width
    if product_width == product_height
      other.without_modifier
    elsif product_width > product_height
      scaled_width = (width * other.height.fdiv(height)).round
      Geometry.new(scaled_width, other.height)
    else
      scaled_height = (height * other.width.fdiv(width)).round
      Geometry.new(other.width, scaled_height)
    end
  end
end

def square?
  width.to_i == height.to_i
end

def to_s
  suffix = modifier.to_s
  "#{width}x#{height}#{suffix}"
end

def transformed_by(other)
  other = Geometry.parse(other)
  return other.without_modifier if self =~ other || ['#', '!', '^'].include?(other.modifier)
  raise TransformationError, 'geometry is not transformable without both width and height' if height.zero? || width.zero?
  case other.modifier
  when '>'
    (other.width < width || other.height < height) ? scaled_to_fit(other) : self
  when '<'
    (other.width > width && other.height > height) ? scaled_to_fit(other) : self
  when '%'
    scaled_by(other)
  when '@'
    scaled_by((other.width * 100).fdiv(width * height))
  else
    scaled_to_fit(other)
  end
end

def vertical?
  height.to_i > width.to_i
end

def without_modifier
  Geometry.new(width, height)
end