package service

import (
	"exam_registration/internal/dao"
	"exam_registration/internal/model"
	"errors"
	"time"
)

type NoticeService struct{}

func (s *NoticeService) CreateNotice(notice *model.ExamNotice) error {
	notice.PublishTime = time.Now()
	return dao.DB.Create(notice).Error
}

func (s *NoticeService) GetNoticeByID(id uint64) (*model.ExamNotice, error) {
	var notice model.ExamNotice
	if err := dao.DB.Preload("Exam").First(&notice, id).Error; err != nil {
		return nil, errors.New("通知不存在")
	}
	return &notice, nil
}

func (s *NoticeService) GetNoticeList(examID, page, pageSize int) ([]model.ExamNotice, int64, error) {
	var notices []model.ExamNotice
	var total int64

	offset := (page - 1) * pageSize
	query := dao.DB.Model(&model.ExamNotice{}).Preload("Exam")

	if examID > 0 {
		query = query.Where("exam_id = ?", examID)
	}

	if err := query.Count(&total).Error; err != nil {
		return nil, 0, err
	}

	err := query.Offset(offset).Limit(pageSize).Order("id DESC").Find(&notices).Error
	return notices, total, err
}

func (s *NoticeService) UpdateNotice(id uint64, updates map[string]interface{}) error {
	return dao.DB.Model(&model.ExamNotice{}).Where("id = ?", id).Updates(updates).Error
}

func (s *NoticeService) DeleteNotice(id uint64) error {
	return dao.DB.Delete(&model.ExamNotice{}, id).Error
}