package query

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

// collection header without the books
func FetchCollectionHeader(db *gorm.DB, collectionId uint) (dto.CollectionGet, error) {
	var collection dto.CollectionGet
	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_books on (collection_books.collection_id = collections.id)")
	query = query.Joins("left join books on (books.id = collection_books.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)
}

func FetchCollectionBooks(db *gorm.DB, userId uint, collectionId uint, limit int, offset int) ([]dto.BookItemGet, error) {
	var books []dto.BookItemGet
	query := fetchCollectionBooksQuery(db, userId, collectionId)
	query = query.Limit(limit)
	query = query.Offset(offset)
	query = query.Order("books.id DESC")
	res := query.Find(&books)
	return books, 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 := fetchBookQueryBuilder(db, userId)
	query = query.Joins("left join collection_books on (collection_books.book_id = books.id)")
	query = query.Where("collection_books.collection_id = ?", collectionId)
	return query
}