package model

import (
	"time"

	"gorm.io/gorm"
)

type Announcement struct {
	Id          int        `json:"id" gorm:"primaryKey;autoIncrement"`
	Title       string     `json:"title" gorm:"type:varchar(255);not null"`
	Content     string     `json:"content" gorm:"type:text;not null"`
	ContentHtml string     `json:"content_html" gorm:"type:text"`
	Status      string     `json:"status" gorm:"type:varchar(16);not null;default:'draft';index"`
	NotifyMode  string     `json:"notify_mode" gorm:"type:varchar(16);not null;default:'silent'"`
	JsonRules   string     `json:"json_rules" gorm:"type:text"`
	StartsAt    *time.Time `json:"starts_at" gorm:"index"`
	EndsAt      *time.Time `json:"ends_at" gorm:"index"`
	CreatedBy   int        `json:"created_by" gorm:"not null;default:0"`
	CreatedAt   time.Time  `json:"created_at"`
	UpdatedAt   time.Time  `json:"updated_at"`
}

func (Announcement) TableName() string {
	return "announcements"
}

func (a *Announcement) Insert() error {
	return DB.Create(a).Error
}

func (a *Announcement) Update() error {
	return DB.Save(a).Error
}

func GetAnnouncementByID(id int) (*Announcement, error) {
	var announcement Announcement
	err := DB.First(&announcement, "id = ?", id).Error
	return &announcement, err
}

func GetAnnouncements(page int, pageSize int, status string) ([]Announcement, int64, error) {
	var announcements []Announcement
	var total int64
	query := DB.Model(&Announcement{})
	if status != "" {
		query = query.Where("status = ?", status)
	}
	if err := query.Count(&total).Error; err != nil {
		return nil, 0, err
	}
	if page < 1 {
		page = 1
	}
	if pageSize < 1 {
		pageSize = 20
	}
	err := query.Order("id DESC").Offset((page - 1) * pageSize).Limit(pageSize).Find(&announcements).Error
	return announcements, total, err
}

func GetActiveAnnouncements() ([]Announcement, error) {
	var announcements []Announcement
	err := activeAnnouncementQuery().
		Order("id DESC").
		Find(&announcements).Error
	return announcements, err
}

func GetUnreadAnnouncements(userId int) ([]Announcement, error) {
	var announcements []Announcement
	readSubQuery := DB.Model(&AnnouncementRead{}).
		Select("announcement_id").
		Where("user_id = ?", userId)
	err := activeAnnouncementQuery().
		Where("id NOT IN (?)", readSubQuery).
		Order("id DESC").
		Find(&announcements).Error
	return announcements, err
}

func DeleteAnnouncementByID(id int) error {
	return DB.Delete(&Announcement{}, id).Error
}

func activeAnnouncementQuery() *gorm.DB {
	now := time.Now()
	return DB.Model(&Announcement{}).
		Where("status = ?", "active").
		Where("(starts_at IS NULL OR starts_at <= ?)", now).
		Where("(ends_at IS NULL OR ends_at >= ?)", now)
}