module BoggleGrid

# File lib/boggle_grid.rb, line 43
def coerce_rng(rng, rand)
  return rng if rng.is_a?(Random)
  return Random.new if rand.nil?

  seed = rand.call(1_000_000)
  Random.new(seed)
end

# File lib/boggle_grid.rb, line 64
def path_from?(grid, letters, row, col, index, visited)
  return false if row.negative? || col.negative? || row >= grid.length || col >= grid[row].length

  key = [row, col]
  return false if visited[key]

  return false unless grid[row][col] == letters[index]

  return true if index == letters.length - 1

  visited = visited.merge(key => true)
  DIRECTIONS.any? do |dr, dc|
    path_from?(grid, letters, row + dr, col + dc, index + 1, visited)
  end
end

# File lib/boggle_grid.rb, line 36
def roll_grid(rng: nil, rand: nil)
  rng = coerce_rng(rng, rand)
  shuffled = DICE.shuffle(random: rng)
  faces = shuffled.map { |die| die[rng.rand(die.length)] }
  4.times.map { |row| faces[(row * 4)...(row * 4 + 4)] }
end

# File lib/boggle_grid.rb, line 52
def word_on_grid?(grid, word)
  letters = word.to_s.strip.downcase.chars
  return false if letters.empty?

  grid.each_with_index do |row, r|
    row.each_with_index do |cell, c|
      return true if path_from?(grid, letters, r, c, 0, {})
    end
  end
  false
end