package model

import (
	"database/sql/driver"
	"encoding/json"
	"errors"
	"time"

	"gorm.io/gorm"

	"carrot_bbs/internal/pkg/utils"
)

// SystemNotificationType 系统通知类型
type SystemNotificationType string

const (
	// 互动通知
	SysNotifyLikePost     SystemNotificationType = "like_post"     // 点赞帖子
	SysNotifyLikeComment  SystemNotificationType = "like_comment"  // 点赞评论
	SysNotifyComment      SystemNotificationType = "comment"       // 评论
	SysNotifyReply        SystemNotificationType = "reply"         // 回复
	SysNotifyFollow       SystemNotificationType = "follow"        // 关注
	SysNotifyMention      SystemNotificationType = "mention"       // @提及
	SysNotifyFavoritePost SystemNotificationType = "favorite_post" // 收藏帖子
	SysNotifyLikeReply    SystemNotificationType = "like_reply"    // 点赞回复

	// 系统消息
	SysNotifySystem            SystemNotificationType = "system"              // 系统通知
	SysNotifyAnnounce          SystemNotificationType = "announce"            // 系统公告
	SysNotifyGroupInvite       SystemNotificationType = "group_invite"        // 群邀请
	SysNotifyGroupJoinApply    SystemNotificationType = "group_join_apply"    // 加群申请待审批
	SysNotifyGroupJoinApproved SystemNotificationType = "group_join_approved" // 加群申请通过
	SysNotifyGroupJoinRejected SystemNotificationType = "group_join_rejected" // 加群申请拒绝
)

// SystemNotificationExtra 额外数据
type SystemNotificationExtra struct {
	// 操作者信息
	ActorID    int64  `json:"actor_id,omitempty"`
	ActorIDStr string `json:"actor_id_str,omitempty"`
	ActorName  string `json:"actor_name,omitempty"`
	AvatarURL  string `json:"avatar_url,omitempty"`

	// 目标信息
	TargetID    string `json:"target_id,omitempty"` // 改为string类型以支持UUID
	TargetTitle string `json:"target_title,omitempty"`
	TargetType  string `json:"target_type,omitempty"`

	// 其他信息
	ActionURL  string `json:"action_url,omitempty"`
	ActionTime string `json:"action_time,omitempty"`

	// 群邀请/加群申请扩展字段
	GroupID          string `json:"group_id,omitempty"`
	GroupName        string `json:"group_name,omitempty"`
	GroupAvatar      string `json:"group_avatar,omitempty"`
	GroupDescription string `json:"group_description,omitempty"`
	Flag             string `json:"flag,omitempty"`
	RequestType      string `json:"request_type,omitempty"`
	RequestStatus    string `json:"request_status,omitempty"`
	Reason           string `json:"reason,omitempty"`
	TargetUserID     string `json:"target_user_id,omitempty"`
	TargetUserName   string `json:"target_user_name,omitempty"`
	TargetUserAvatar string `json:"target_user_avatar,omitempty"`
}

// Value 实现driver.Valuer接口
func (e SystemNotificationExtra) Value() (driver.Value, error) {
	return json.Marshal(e)
}

// Scan 实现sql.Scanner接口
func (e *SystemNotificationExtra) Scan(value interface{}) error {
	if value == nil {
		return nil
	}
	bytes, ok := value.([]byte)
	if !ok {
		return errors.New("type assertion to []byte failed")
	}
	return json.Unmarshal(bytes, e)
}

// SystemNotification 系统通知（独立表，与消息完全分离）
// 每个用户只能看到自己的系统通知
type SystemNotification struct {
	ID         int64                    `gorm:"primaryKey;autoIncrement:false" json:"id"`
	ReceiverID string                   `gorm:"column:receiver_id;type:varchar(50);not null;index:idx_sys_notifications_receiver_read_created,priority:1" json:"receiver_id"` // 接收者ID (UUID)
	Type       SystemNotificationType   `gorm:"type:varchar(30);not null" json:"type"`                                                                                        // 通知类型
	Title      string                   `gorm:"type:varchar(200)" json:"title,omitempty"`                                                                                     // 标题
	Content    string                   `gorm:"type:text;not null" json:"content"`                                                                                            // 内容
	ExtraData  *SystemNotificationExtra `gorm:"type:json" json:"extra_data,omitempty"`                                                                                        // 额外数据
	IsRead     bool                     `gorm:"default:false;index:idx_sys_notifications_receiver_read_created,priority:2" json:"is_read"`                                    // 是否已读
	ReadAt     *time.Time               `json:"read_at,omitempty"`                                                                                                            // 阅读时间

	// 软删除
	DeletedAt gorm.DeletedAt `json:"-" gorm:"index"`

	// 时间戳
	CreatedAt time.Time `json:"created_at" gorm:"autoCreateTime;index:idx_sys_notifications_receiver_read_created,priority:3,sort:desc"`
	UpdatedAt time.Time `json:"updated_at" gorm:"autoUpdateTime"`
}

// BeforeCreate 创建前生成雪花算法ID
func (n *SystemNotification) BeforeCreate(tx *gorm.DB) error {
	if n.ID == 0 {
		id, err := utils.GetSnowflake().GenerateID()
		if err != nil {
			return err
		}
		n.ID = id
	}
	return nil
}

// TableName 指定表名
func (SystemNotification) TableName() string {
	return "system_notifications"
}

// MarkAsRead 标记为已读
func (n *SystemNotification) MarkAsRead() {
	now := time.Now()
	n.IsRead = true
	n.ReadAt = &now
}