module BattleshipAi

# File lib/battleship_ai.rb, line 22
def hunt_coord(shots)
  hits = shots.select { |_, result| %i[hit sunk].include?(result) }.keys
  hits.each do |coord|
    index = BattleshipBoard.coord_to_index(coord)
    BattleshipBoard.neighbors(index).each do |neighbor|
      neighbor_coord = BattleshipBoard.index_to_coord(neighbor)
      return neighbor_coord unless shots.key?(neighbor_coord)
    end
  end
  nil
end

# File lib/battleship_ai.rb, line 10
def pick_shot(game:, rand: ->(max) { Random.rand(0...max) })
  player = AI_OPPONENT
  shots = game["shots"][player] || {}
  hunt = hunt_coord(shots)
  return hunt if hunt

  untried = (0...(BattleshipBoard::SIZE * BattleshipBoard::SIZE)).reject do |index|
    shots.key?(BattleshipBoard.index_to_coord(index))
  end
  BattleshipBoard.index_to_coord(untried[rand.call(untried.length)])
end