gistfile1.rb

require "rspec"

class Grid
  attr_reader :cells, :ships

  SIZE = 10

  def initialize
    @cells = SIZE.times.map { [nil] * SIZE }
    @ships = []
  end

  def display
    cells.map do |row|
      row.map do |cell|
        cell || '.'
      end.join + "\n"
    end.join
  end

  def place_ship(*coordinates)
    ships << Ship.new(*coordinates)
  end

  def shoot(x, y)
    if ship = ships.detect{|s| s.shoot(x, y)}
      if ship.sunk?
        ship.coordinates.each do |cx, cy|
          cells[cx][cy] = "X"
        end
      else
        cells[x][y] = "*"
      end
    else
      cells[x][y] = "O"
    end

    self
  end

  def game_over?
    ships.all? { |s| s.sunk? }
  end

  def valid?
    ships.all? do |ship|
      ship.coordinates.all? do |x, y|
        ships.all? do |other_ship|
          next true if ship == other_ship
          other_ship.coordinates.all? do |ox, oy|
            (x - ox).abs > 1 || (y - oy).abs > 1
          end
        end
      end
    end
  end
end

class Ship
  attr_reader :coordinates

  def initialize(*coordinates)
    @coordinates = coordinates
    @unshot = @coordinates.dup
  end

  def shoot(x, y)
    @unshot.delete([x, y])
  end

  def sunk?
    @unshot.empty?
  end

  def valid?
    @coordinates.all? do |x,y|
      0 <= x && x < Grid::SIZE &&
      0 <= y && y < Grid::SIZE
    end
  end
end

describe Grid do
  let(:grid) { Grid.new }

  context "with empty" do
    it "displays empty grid" do
      grid.display.should == <<-EOS
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
EOS
    end
  end

  context "when 1 single cell ship" do
    before do
      grid.place_ship([0,0])
    end

    describe "#shoot" do
      it "marks missed shot" do
        expect(grid.shoot(1,1).display).to eq(<<-EOS
..........
.O........
..........
..........
..........
..........
..........
..........
..........
..........
EOS
)
      end

      it "marks successful shot" do
        expect(grid.shoot(0,0).display).to eq(<<-EOS
X.........
..........
..........
..........
..........
..........
..........
..........
..........
..........
EOS
)
      end

      specify "game over when all ships shot" do
        grid.shoot(0,0)
        expect(grid.game_over?).to be_true
      end
    end
  end

  context "when 1 multiple cell ship" do
    before do
      grid.place_ship([0,0], [0, 1])
    end

    it "marks successful shot" do
      expect(grid.shoot(0,0).display).to eq(<<-EOS
*.........
..........
..........
..........
..........
..........
..........
..........
..........
..........
EOS
)
      end

    it "marks ship as sunk" do
      expect(grid.shoot(0,0).shoot(0,1).display).to eq(<<-EOS
XX........
..........
..........
..........
..........
..........
..........
..........
..........
..........
EOS
)
      end
  end

  describe "valid grid" do
    it "is valid with one ship" do
      grid.place_ship([0,0], [0, 1])

      expect(grid.valid?).to be_true
    end

    it "is not valid with overlaping ships" do
      grid.place_ship([0,0], [0, 1])
      grid.place_ship([0,1], [0, 2])

      expect(grid.valid?).to be_false
    end

    it "is valid with two distant ships" do
      grid.place_ship([0,0], [0, 1])
      grid.place_ship([7,0], [7, 1])

      expect(grid.valid?).to be_true

    end

    it "is not valid with ships that are too close" do
      grid.place_ship([0,0], [0, 1])
      grid.place_ship([1,2], [1, 3])

      expect(grid.valid?).to be_false
    end

  end

  describe "valid ship" do
    it "is valid with coordinates inside grid" do
      Ship.new([0,0], [0,1]).should be_valid
    end

    it "is not valid with coordinates outside grid" do
      Ship.new([0,0], [0,-1]).should_not be_valid
    end
  end

  context "when placing ships randomly" do
    before do
      # grid.palce_random_ship(3)
      # grid.palce_random_ship(2)
      # grid.palce_random_ship(3)
    end

    it "does something" do
    end
  end
end