class Qi

@param captures_hash [Hash<Object, Integer>] a hash of captured pieces @param squares_hash [Hash<Object, Object>] A hash where the keys represent square

identifiers and the values represent the piece that will occupy each square.
Both the keys and values can be any type of Ruby object, such as integers, strings, symbols, etc.

@param turns [Array<Object>] a rotation of turns @param state [Hash<Symbol, Object>] a hash of game states

@example

captures = Hash.new(0)
north_captures = %w[r r b g g g g s n n n n p p p p p p p p p p p p p p p p p]
south_captures = %w[S]
(north_captures + south_captures).each { |piece| captures[piece] += 1 }
squares = { 3 => "s", 4 => "k", 5 => "s", 22 => "+P", 43 => "+B" }
Qi.new(captures, squares, [0, 1])

# File lib/qi.rb, line 45
def initialize(captures_hash, squares_hash, turns, **state)
  @captures_hash = ::Hash.new(0).merge(captures_hash.select { |_, v| v > 0 })
  @squares_hash = squares_hash.compact
  @turns = turns
  @state = state.transform_keys(&:to_sym)

  freeze
end

Return an array of captures containing piece names.

@return [Array<Object>] an array of captures @example

["S", "b", "g", "g", "g", "g", "n", "n", "n", "n", "p", "p", "p", "p", "p", "p", "p", "p", "p", "p", "p", "p", "p", "p", "p", "p", "p", "r", "r", "s"]

# File lib/qi.rb, line 59
def captures_array
  captures_hash.flat_map { |piece, count| ::Array.new(count, piece) }.sort
end

Commit a change to the game state and return a new Qi object.

@param add_captures_array [Array<Object>] an array of pieces to be added to captures @param del_captures_array [Array<Object>] an array of pieces to be deleted from captures @param edit_squares_hash [Hash<Object, Object>] A hash where the keys represent square

identifiers and the values represent the piece that will occupy each square.
Both the keys and values can be any type of Ruby object, such as integers, strings, symbols, etc.

@param state [Hash<Symbol, Object>] a hash of new game states @return [Qi] a new Qi object representing the updated game state @example

qi0.commit([], [], { D43: nil, B13: "+B" }, in_check: true)

# File lib/qi.rb, line 74
def commit(add_captures_array, del_captures_array, edit_squares_hash, **state)
  self.class.new(
    edit_captures_hash(add_captures_array.compact, del_captures_array.compact, **captures_hash),
    squares_hash.merge(edit_squares_hash),
    turns.rotate,
    **state
  )
end

Check if the current Qi object is equal to another Qi object.

@param other [Qi] another Qi object @return [Boolean] returns true if the captures_hash, squares_hash, turn, and state of both Qi objects are equal, false otherwise

# File lib/qi.rb, line 87
def eql?(other)
  return false unless other.captures_hash == captures_hash
  return false unless other.squares_hash == squares_hash
  return false unless other.turn == turn
  return false unless other.state == state

  true
end

Get the current turn.

@return [Object] the current turn

# File lib/qi.rb, line 100
def turn
  turns.fetch(0)
end

Edits the captures hash and returns it.

@param add_captures_array [Array<Object>] an array of pieces to be added to captures @param del_captures_array [Array<Object>] an array of pieces to be deleted from captures @param hash [Hash<Object, Integer>] the current captures hash @return [Hash<Object, Integer>] the updated captures hash

# File lib/qi.rb, line 112
def edit_captures_hash(add_captures_array, del_captures_array, **hash)
  add_captures_array.each { |piece_name| hash[piece_name] += 1 }
  del_captures_array.each { |piece_name| hash[piece_name] -= 1 }

  hash
end