package models

import (
	"time"

	"gorm.io/gorm"
)

// ArticleView represents a unique article view record.
// Each record tracks one unique visit (by IP or user) to an article.
type ArticleView struct {
	ID        uint      `gorm:"primarykey" json:"id"`
	CreatedAt time.Time `json:"created_at"`
	ArticleID uint      `gorm:"not null;index:idx_article_views_article" json:"article_id"`
	UserID    *uint     `gorm:"index:idx_article_views_user" json:"user_id"` // NULL for anonymous users
	IP        string    `gorm:"size:64;not null;index:idx_article_views_ip" json:"ip"`
	UserAgent string    `gorm:"size:512" json:"user_agent"`
	IsBot     bool      `gorm:"default:false;index:idx_article_views_bot" json:"is_bot"`
	Article   Article   `gorm:"foreignKey:ArticleID" json:"-"`
	User      *User     `gorm:"foreignKey:UserID" json:"-"`
}

// TableName overrides the default GORM table name.
func (ArticleView) TableName() string {
	return "article_views"
}

// BeforeCreate hook to ensure we don't create duplicate records.
// This is a safety check in addition to application-level deduplication.
func (av *ArticleView) BeforeCreate(tx *gorm.DB) error {
	var count int64
	query := tx.Model(&ArticleView{}).
		Where("article_id = ? AND ip = ?", av.ArticleID, av.IP)

	if av.UserID != nil {
		query = query.Where("user_id = ?", *av.UserID)
	} else {
		query = query.Where("user_id IS NULL")
	}

	query.Count(&count)
	if count > 0 {
		// Record already exists, skip creation
		return gorm.ErrDuplicatedKey
	}

	return nil
}