#!/usr/bin/env python3
"""
更新数据库外键约束，添加级联删除
"""

from app import create_app
from app.models import db
from sqlalchemy import text

def update_foreign_keys():
    app = create_app()
    
    with app.app_context():
        try:
            print("正在更新数据库外键约束...")
            
            # 删除现有的外键约束并重新创建带级联删除的约束
            queries = [
                # 删除现有外键约束
                "ALTER TABLE weekly_attendance DROP FOREIGN KEY weekly_attendance_ibfk_1",
                "ALTER TABLE daily_attendance_details DROP FOREIGN KEY daily_attendance_details_ibfk_1", 
                "ALTER TABLE daily_attendance_details DROP FOREIGN KEY daily_attendance_details_ibfk_2",
                "ALTER TABLE leave_records DROP FOREIGN KEY leave_records_ibfk_1",
                "ALTER TABLE students DROP FOREIGN KEY students_ibfk_1",
                
                # 重新创建带级联删除的外键约束
                "ALTER TABLE weekly_attendance ADD CONSTRAINT weekly_attendance_ibfk_1 FOREIGN KEY (student_number) REFERENCES students (student_number) ON DELETE CASCADE",
                "ALTER TABLE daily_attendance_details ADD CONSTRAINT daily_attendance_details_ibfk_1 FOREIGN KEY (weekly_record_id) REFERENCES weekly_attendance (record_id) ON DELETE CASCADE",
                "ALTER TABLE daily_attendance_details ADD CONSTRAINT daily_attendance_details_ibfk_2 FOREIGN KEY (student_number) REFERENCES students (student_number) ON DELETE CASCADE",
                "ALTER TABLE leave_records ADD CONSTRAINT leave_records_ibfk_1 FOREIGN KEY (student_number) REFERENCES students (student_number) ON DELETE CASCADE",
                "ALTER TABLE students ADD CONSTRAINT students_ibfk_1 FOREIGN KEY (student_number) REFERENCES users (student_number) ON DELETE CASCADE",
            ]
            
            for query in queries:
                try:
                    db.session.execute(text(query))
                    print(f"执行成功: {query}")
                except Exception as e:
                    print(f"执行失败 (可能约束不存在): {query}")
                    print(f"错误: {e}")
                    continue
            
            db.session.commit()
            print("数据库外键约束更新完成！")
            
        except Exception as e:
            db.session.rollback()
            print(f"更新失败: {e}")

if __name__ == '__main__':
    update_foreign_keys()