package query

import (
	"git.artlef.fr/bibliomane/internal/model"
	"gorm.io/gorm"
)

type CollectionHeader struct {
	Name   string
	UserID uint
}

// collection header without the books
func FetchCollectionHeader(db *gorm.DB, collectionId uint) (CollectionHeader, error) {
	var collection CollectionHeader
	query := db.Model(&model.Collection{})
	query = query.Select("collections.name, collections.user_id")
	query = query.Where("collections.id = ?", collectionId)
	res := query.Find(&collection)
	return collection, res.Error
}

type CollectionsQueryResult struct {
	ID        uint
	UserID    uint
	Name      string
	BookId    uint
	BookTitle string
	CoverPath string
}

type collectionId struct {
	ID uint
}

func FetchAllCollections(db *gorm.DB, userId uint, limit int, offset int) ([]CollectionsQueryResult, error) {
	var collections []CollectionsQueryResult
	var collectionIds []collectionId
	res := fetchCollections(db, userId).Limit(limit).Offset(offset).Order("collections.id DESC").Find(&collectionIds)
	if res.Error != nil {
		return collections, res.Error
	}
	for _, collectionId := range collectionIds {
		//only takes first 8 books
		queryResults, err := fetchCollectionItemBook(db, collectionId.ID, 8, 0)
		if err != nil {
			return collections, res.Error
		}
		collections = append(collections, queryResults...)
	}
	return collections, res.Error
}

func fetchCollectionItemBook(db *gorm.DB, collectionId uint, limit int, offset int) ([]CollectionsQueryResult, error) {
	var collections []CollectionsQueryResult
	query := fetchCollectionItemBooksQuery(db, collectionId)
	query = query.Limit(limit)
	query = query.Offset(offset)
	res := query.Find(&collections)
	return collections, res.Error
}

func fetchCollectionItemBooksQuery(db *gorm.DB, collectionId uint) *gorm.DB {
	query := db.Model(&model.Collection{})
	query = query.Select("collections.id, collections.user_id, collections.name, books.id as book_id, books.title as book_title, " + selectStaticFilesPath())
	query = query.Joins("left join collection_items on (collection_items.collection_id = collections.id)")
	query = query.Joins("left join books on (books.id = collection_items.book_id)")
	query = joinStaticFiles(query)
	query = query.Where("collections.id = ?", collectionId)
	return query
}

func FetchAllCollectionsCount(db *gorm.DB, userId uint) (int64, error) {
	var count int64
	res := fetchCollections(db, userId).Count(&count)
	return count, res.Error
}

func fetchCollections(db *gorm.DB, userId uint) *gorm.DB {
	return db.Model(&model.Collection{}).Where("collections.user_id = ?", userId)
}

type CollectionItemQueryResult struct {
	Position            uint
	ID                  uint
	Title               string
	Author              string
	Description         string
	InventaireID        string
	IsInventaireEdition bool
	Rating              int
	Read                bool
	StartReadDate       string
	WantRead            bool
	CoverPath           string
}

func FetchCollectionItems(db *gorm.DB, userId uint, collectionId uint, limit int, offset int) ([]CollectionItemQueryResult, error) {
	var collectionitems []CollectionItemQueryResult
	query := fetchCollectionBooksQuery(db, userId, collectionId)
	query = query.Limit(limit)
	query = query.Offset(offset)
	query = query.Order("collection_items.position")
	res := query.Find(&collectionitems)
	return collectionitems, res.Error
}

func FetchCollectionBooksCount(db *gorm.DB, userId uint, collectionId uint) (int64, error) {
	var count int64
	res := fetchCollectionBooksQuery(db, userId, collectionId).Count(&count)
	return count, res.Error
}

func fetchCollectionBooksQuery(db *gorm.DB, userId uint, collectionId uint) *gorm.DB {
	query := db.Model(&model.CollectionItem{})
	query = query.Select("collection_items.position, " + selectBookItem())
	query = query.Joins("left join collections on (collection_items.collection_id = collections.id)")
	query = query.Joins("left join books on (books.id = collection_items.book_id)")
	query = joinAuthors(query)
	query = query.Joins("left join user_books on (user_books.book_id = books.id and user_books.user_id = ?)", userId)
	query = joinStaticFiles(query)
	query = query.Order("collection_items.position")
	query = query.Where("collections.id = ?", collectionId)
	return query
}