#define MOVES_INTERNAL
#include "engine/moves.h"

void __forloop_bishop_moves_gen(
  moves_t* moves,
  bitboard_t friendly_type,
  bitboard_t friendly_pieces,
  bitboard_t enemy_pieces
) {
  bitboard_t all_occupied = friendly_pieces | enemy_pieces;
  while (friendly_type) {
    int from = __builtin_ctzll(friendly_type);
    friendly_type &= friendly_type - 1;
    bitboard_t attacks = get_bishop_attacks(from, all_occupied) & ~friendly_pieces;
    while (attacks) {
      int to = __builtin_ctzll(attacks);
      attacks &= attacks - 1;
      add_move(moves, from, to, .flags = ((enemy_pieces >> to) & 1) ? MOVE_CAPTURE : 0);
    }
  }
}

void get_bishop_moves(moves_t* moves, position_t position) {
  assert_valid_position(position);

  bitboard_t friendly_bishops;
  bitboard_t friendly_pieces;
  bitboard_t enemy_pieces;
  if (position.turn == WHITE_TURN) {
    friendly_pieces = whites(position);
    enemy_pieces = blacks(position);
    friendly_bishops = position.bitboards[WHITE_BISHOP];
  } else {
    friendly_pieces = blacks(position);
    enemy_pieces = whites(position);
    friendly_bishops = position.bitboards[BLACK_BISHOP];
  }
  
  __forloop_bishop_moves_gen(
    moves,
    friendly_bishops,
    friendly_pieces,
    enemy_pieces
  );
}