import random
import json
from docx import Document
from docx.shared import Pt

class ExamGenerator:
    def __init__(self, question_bank_file):
        self.questions = self.load_questions(question_bank_file)
        self.document = Document()
    
    def load_questions(self, filename):
        """从JSON文件加载题库"""
        with open(filename, 'r', encoding='utf-8') as f:
            return json.load(f)
    
    def select_questions(self, num_questions=10):
        """随机选择指定数量的题目"""
        return random.sample(self.questions, min(num_questions, len(self.questions)))
    
    def shuffle_options(self, question):
        """随机打乱选择题的选项顺序"""
        if 'options' in question:
            options = question['options']
            correct_answer = options[0]  # 假设第一个选项是正确答案
            random.shuffle(options)
            # 找到新位置中的正确答案索引
            question['correct_index'] = options.index(correct_answer) + 1
            question['options'] = options
        return question
    
    def generate_exam(self, output_file="exam.docx", num_questions=10):
        """生成试卷文档"""
        # 设置文档样式
        self.document = Document()
        style = self.document.styles['Normal']
        font = style.font
        font.name = 'Arial'
        font.size = Pt(12)
        
        # 添加标题
        self.document.add_heading('期末考试试卷', level=0)
        self.document.add_paragraph('姓名：__________  学号：__________  班级：__________')
        self.document.add_paragraph('\n')
        
        # 选择题目并生成试卷内容
        selected_questions = self.select_questions(num_questions)
        for i, question in enumerate(selected_questions, 1):
            # 随机打乱选项（如果是选择题）
            question = self.shuffle_options(question)
            
            # 添加题目
            self.document.add_paragraph(f'{i}. {question["question"]}')
            
            # 添加选项（如果是选择题）
            if 'options' in question:
                for j, option in enumerate(question['options'], 1):
                    self.document.add_paragraph(f"   {chr(64+j)}. {option}", style='ListBullet')
            
            self.document.add_paragraph('\n')
        
        # 保存文档
        self.document.save(output_file)
        print(f"试卷已生成: {output_file}")
    
    def generate_answer_sheet(self, output_file="answers.txt"):
        """生成答案文档"""
        with open(output_file, 'w', encoding='utf-8') as f:
            f.write("试卷答案：\n\n")
            for i, question in enumerate(self.questions, 1):
                if 'correct_index' in question:
                    f.write(f"{i}. 正确答案: {chr(64 + question['correct_index'])}\n")
                elif 'answer' in question:
                    f.write(f"{i}. 答案: {question['answer']}\n")
        print(f"答案已生成: {output_file}")

# 示例题库
question_bank = [
    {
        "question": "Python中如何创建一个空列表？",
        "options": ["a = list()", "a = []", "a = new list()", "a = list.new()"],
        "type": "choice"
    },
    {
        "question": "解释Python中的GIL",
        "type": "essay"
    },
    {
        "question": "Python中__init__方法的作用是什么？",
        "options": ["类的构造函数", "类的析构函数", "类的静态方法", "类的装饰器"],
        "type": "choice"
    },
    {
        "question": "使用列表推导式生成1-10的平方数",
        "answer": "[x**2 for x in range(1, 11)]",
        "type": "code"
    }
]

# 保存题库到文件
with open('questions.json', 'w', encoding='utf-8') as f:
    json.dump(question_bank, f, ensure_ascii=False, indent=2)

# 使用示例
generator = ExamGenerator('questions.json')
generator.generate_exam(num_questions=3)
generator.generate_answer_sheet()

1. Python中如何创建一个空列表？

• A. a = new list()
• B. a = []
• C. a = list()
• D. a = list.new()

2. 解释Python中的GIL

3. Python中__init__方法的作用是什么？

• A. 类的静态方法
• B. 类的构造函数
• C. 类的装饰器
• D. 类的析构函数

对于教育机构，建议采用以下架构：

1. 使用MySQL或MongoDB存储大型题库
2. 开发Web管理界面进行题目管理
3. 添加试卷难度平衡算法
4. 集成在线考试功能