package database

import (
	"gorm.io/gorm/clause"
	"strings"
)

type Tag struct {
	ID   int
	Name string
}

func ArticleTagsFromTagSlice(article Article, tags []Tag) (tagsTable []ArticleTags) {
	for _, tag := range tags {
		tagsTable = append(tagsTable, ArticleTags{
			ArticleID: article.ID,
			TagID:     tag.ID,
		})
	}
	return
}

type ArticleTags struct {
	ArticleID int
	TagID     int
}

func (db *Database) AddOrGetTags(names []string) (tags []Tag, err error) {
	for i, name := range names {
		names[i] = strings.ToLower(name)
	}

	err = db.gormDB.Table("tag").Clauses(clause.OnConflict{
		Columns:   []clause.Column{{Name: "name"}},
		DoNothing: true,
	}).Select("name").Create(&names).Error
	if err != nil {
		return nil, err
	}

	err = db.gormDB.Table("tag").Find(&tags).Where("name in (?)", &names).Error
	return
}

func (db *Database) SetTags(article Article, tags []Tag) error {
	return db.gormDB.Table("tags").Clauses(clause.OnConflict{
		Columns:   []clause.Column{{Name: "article_id"}, {Name: "tag_id"}},
		DoNothing: true,
	}).Create(ArticleTagsFromTagSlice(article, tags)).Error
}

func (db *Database) RemoveTags(article Article, tags []Tag) error {
	return db.gormDB.Table("tags").Delete(ArticleTagsFromTagSlice(article, tags)).Error
}