import java.util.Random;

/**
 * 小学题目生成器
 */
public class PrimaryQuestionGenerator extends AbstractQuestionGenerator {
    
    @Override
    public String generateQuestion(int[] operands, Random random) {
        StringBuilder question = new StringBuilder();
        
        // 小学题目：只能有+,-,*,/和()，严格按照附表-2要求
        question.append(operands[0]);
        for (int i = 1; i < operands.length; i++) {
            String op = BASIC_OPERATORS[random.nextInt(BASIC_OPERATORS.length)];
            // 随机添加括号，确保括号内也有运算符
            if (i < operands.length - 1 && random.nextBoolean()) {
                question.append(" ").append(op).append(" (").append(operands[i]);
                if (i + 1 < operands.length) {
                    op = BASIC_OPERATORS[random.nextInt(BASIC_OPERATORS.length)];
                    question.append(" ").append(op).append(" ").append(operands[++i]).append(")");
                } else {
                    question.append(")");
                }
            } else {
                question.append(" ").append(op).append(" ").append(operands[i]);
            }
        }
        
        return question.toString();
    }
}