#!/usr/bin/env python3
"""
数据库迁移脚本 - 添加PDF拆题相关字段
"""

import sqlite3
import os

def migrate_database():
    """迁移数据库，添加新字段"""
    db_path = "wordmaster.db"
    
    if not os.path.exists(db_path):
        print("❌ 数据库文件不存在")
        return False
    
    try:
        conn = sqlite3.connect(db_path)
        cursor = conn.cursor()
        
        print("🔄 开始数据库迁移...")
        
        # 检查是否已经存在新字段
        cursor.execute("PRAGMA table_info(questions)")
        columns = [column[1] for column in cursor.fetchall()]
        
        new_fields = [
            ('page_spans', 'JSON'),
            ('source_text', 'TEXT'),
            ('images', 'JSON'), 
            ('formula', 'JSON'),
            ('score', 'REAL'),
            ('question_number', 'VARCHAR'),
            ('auto_extracted', 'BOOLEAN DEFAULT FALSE')
        ]
        
        # 添加缺失的字段
        for field_name, field_type in new_fields:
            if field_name not in columns:
                sql = f"ALTER TABLE questions ADD COLUMN {field_name} {field_type}"
                print(f"  添加字段: {field_name}")
                cursor.execute(sql)
            else:
                print(f"  字段已存在: {field_name}")
        
        conn.commit()
        print("✅ 数据库迁移完成")
        
        # 验证新结构
        cursor.execute("PRAGMA table_info(questions)")
        new_columns = [column[1] for column in cursor.fetchall()]
        print(f"📊 当前字段数量: {len(new_columns)}")
        
        return True
        
    except Exception as e:
        print(f"❌ 迁移失败: {e}")
        return False
    finally:
        if 'conn' in locals():
            conn.close()

if __name__ == "__main__":
    success = migrate_database()
    if success:
        print("\n🎉 数据库迁移成功完成!")
    else:
        print("\n💔 数据库迁移失败!")