require 'curses'
require 'test/unit'

class Gravity
  attr_accessor :gravity

  None = 0
  Center = 1
  Top = 2
  Left = 3
  Right = 4
  Bottom = 5
  TopLeft = 6
  TopRight = 7
  BottomLeft = 8
  BottomRight = 9

  def initialize(gravity = Gravity::None)
    @gravity = gravity
  end

  def to_s
    case @gravity
    when None
      return "NoneGravity"
    when Center
      return "CenterGravity"
    when Top
      return "TopGravity"
    when Left
      return "LeftGravity"
    when Right
      return "RightGravity"
    when Bottom
      return "BottomGravity"
    when TopLeft
      return "TopLeftGravity"
    when TopRight
      return "TopRightGravity"
    when BottomLeft
      return "BottomLeftGravity"
    when BottomRight
      return "BottomRightGravity"
    end
  end

  def ==(other)
    @gravity == other.gravity
  end
end

class Border
  attr_accessor :left, :right, :top, :bottom, :titlebar_height

  def initialize(left, right, top, bottom, titlebar_height)
    @left = left
    @right = right
    @top = top
    @bottom = bottom
    @titlebar_height = titlebar_height
  end

  def width
    left + right
  end

  def height
    top + titlebar_height + bottom
  end
end

class Size
  attr_accessor :width
  attr_accessor :height

  def initialize(width, height)
    @width = width
    @height = height
  end
end

class Point
  attr_accessor :x
  attr_accessor :y

  def initialize(x, y)
    @x = x
    @y = y
  end
end

def gravity(size, border, point)
  return Gravity.new(Gravity::None) if point.x >= size.width or point.y >= size.height

  if point.x < border.left
    return Gravity.new(Gravity::TopLeft) if point.y < border.top + 10
    return Gravity.new(Gravity::BottomLeft) if point.y >= size.height - border.left - 10
    return Gravity.new(Gravity::Left)
  end

  if point.x >= (size.width - border.right) - 10
    return Gravity.new(Gravity::TopRight) if point.y < border.top
    return Gravity.new(Gravity::BottomRight) if point.y >= size.height - border.bottom
  end

  if point.x >= size.width - border.left
    return Gravity.new(Gravity::TopRight) if point.y < border.top + 10
    return Gravity.new(Gravity::BottomRight) if point.y >= size.height - border.left - 10
    return Gravity.new(Gravity::Right)
  end

  if point.x < border.left + 10
    return Gravity.new(Gravity::TopLeft) if point.y < border.top
    return Gravity.new(Gravity::BottomLeft) if point.y >= size.height - border.bottom
  end

  return Gravity.new(Gravity::Top) if point.y < border.top
  return Gravity.new(Gravity::Bottom) if point.y >= size.height - border.bottom
  return Gravity.new(Gravity::Center)
end

def draw
  Curses::init_screen
  Curses::nl
  Curses::noecho

  @border = Border.new(2, 2, 2, 2, 10)
  @size = Size.new(30, 30)

  0.upto(@size.width - 1) do |x|
    0.upto(@size.height - 1) do |y|
      Curses::setpos(y, x)

      if gravity(@size, @border, Point.new(x, y)) == Gravity.new(Gravity::Center)
        Curses::addstr " "
      elsif gravity(@size, @border, Point.new(x, y)) == Gravity.new(Gravity::TopLeft) or
          gravity(@size, @border, Point.new(x, y)) == Gravity.new(Gravity::TopRight) or
          gravity(@size, @border, Point.new(x, y)) == Gravity.new(Gravity::BottomLeft) or
          gravity(@size, @border, Point.new(x, y)) == Gravity.new(Gravity::BottomRight)
        Curses::addstr "+"
      else
        Curses::addstr "-"
      end
    end
  end

  Curses::refresh
  Curses::getch
  Curses::close_screen
end

draw
exit

class TestGravity < Test::Unit::TestCase
  def setup
    @border = Border.new(2, 2, 2, 2, 10)
    @size = Size.new(30, 30)
  end

  def test_edges
    assert gravity(@size, @border, Point.new(0, 0)) == Gravity.new(Gravity::TopLeft)
    assert gravity(@size, @border, Point.new(@size.width - 1, 0)) == Gravity.new(Gravity::TopRight)
    assert gravity(@size, @border, Point.new(0, @size.height - 1)) == Gravity.new(Gravity::BottomLeft)
    assert gravity(@size, @border, Point.new(@size.width - 1, @size.height - 1)) == Gravity.new(Gravity::BottomRight)
  end

  def test_sides
    (10 + @border.top).upto(@size.height - 10 - @border.bottom - 1) do |y|
      assert gravity(@size, @border, Point.new(0, y)) == Gravity.new(Gravity::Left)
    end

    (10 + @border.top).upto(@size.height - 10 - @border.bottom - 1) do |y|
      assert gravity(@size, @border, Point.new(@size.width - 1, y)) == Gravity.new(Gravity::Right)
    end

    (@border.left + 10).upto(@size.width - 10 - @border.right - 1) do |x|
      assert gravity(@size, @border, Point.new(x, 0)) == Gravity.new(Gravity::Top)
    end

    (@border.left + 10).upto(@size.width - 10 - @border.right - 1) do |x|
      assert gravity(@size, @border, Point.new(x, @size.height - 1)) == Gravity.new(Gravity::Bottom)
    end
  end

  def test_topleft
    0.upto(@border.left + 10 - 1) do |x|
      assert gravity(@size, @border, Point.new(x, 0)) == Gravity.new(Gravity::TopLeft)
    end

    0.upto(@border.top + 10 - 1) do |y|
      assert gravity(@size, @border, Point.new(0, y)) == Gravity.new(Gravity::TopLeft)
    end
  end

  def test_topright
    (@size.width - 10 - @border.right).upto(@size.width - 1) do |x|
      assert gravity(@size, @border, Point.new(x, 0)) == Gravity.new(Gravity::TopRight)
    end

    0.upto(@border.top + 10 - 1) do |y|
      assert gravity(@size, @border, Point.new(@size.width - 1, y)) == Gravity.new(Gravity::TopRight)
    end
  end
end