package repository

import (
	"git.mchus.pro/mchus/quoteforge/internal/localdb"
	"gorm.io/gorm"
)

// PartnumberBookRepository provides read-only access to local partnumber book snapshots.
type PartnumberBookRepository struct {
	db *gorm.DB
}

func NewPartnumberBookRepository(db *gorm.DB) *PartnumberBookRepository {
	return &PartnumberBookRepository{db: db}
}

// GetActiveBook returns the most recently active local partnumber book.
func (r *PartnumberBookRepository) GetActiveBook() (*localdb.LocalPartnumberBook, error) {
	var book localdb.LocalPartnumberBook
	err := r.db.Where("is_active = 1").Order("created_at DESC, id DESC").First(&book).Error
	if err != nil {
		return nil, err
	}
	return &book, nil
}

// GetBookItems returns all items for the given local book ID.
func (r *PartnumberBookRepository) GetBookItems(bookID uint) ([]localdb.LocalPartnumberBookItem, error) {
	var items []localdb.LocalPartnumberBookItem
	err := r.db.Where("book_id = ?", bookID).Find(&items).Error
	return items, err
}

// GetBookItemsPage returns items for the given local book ID with optional search and pagination.
func (r *PartnumberBookRepository) GetBookItemsPage(bookID uint, search string, page, perPage int) ([]localdb.LocalPartnumberBookItem, int64, error) {
	if page < 1 {
		page = 1
	}
	if perPage < 1 {
		perPage = 100
	}

	query := r.db.Model(&localdb.LocalPartnumberBookItem{}).Where("book_id = ?", bookID)
	trimmedSearch := "%" + search + "%"
	if search != "" {
		query = query.Where("partnumber LIKE ? OR lot_name LIKE ?", trimmedSearch, trimmedSearch)
	}

	var total int64
	if err := query.Count(&total).Error; err != nil {
		return nil, 0, err
	}

	var items []localdb.LocalPartnumberBookItem
	err := query.
		Order("partnumber ASC, lot_name ASC, id ASC").
		Offset((page - 1) * perPage).
		Limit(perPage).
		Find(&items).Error
	return items, total, err
}

// FindLotByPartnumber looks up a partnumber in the active book and returns the matching items.
func (r *PartnumberBookRepository) FindLotByPartnumber(bookID uint, partnumber string) ([]localdb.LocalPartnumberBookItem, error) {
	var items []localdb.LocalPartnumberBookItem
	err := r.db.Where("book_id = ? AND partnumber = ?", bookID, partnumber).Find(&items).Error
	return items, err
}

// ListBooks returns all local partnumber books ordered newest first.
func (r *PartnumberBookRepository) ListBooks() ([]localdb.LocalPartnumberBook, error) {
	var books []localdb.LocalPartnumberBook
	err := r.db.Order("created_at DESC, id DESC").Find(&books).Error
	return books, err
}

// SaveBook saves a new partnumber book snapshot.
func (r *PartnumberBookRepository) SaveBook(book *localdb.LocalPartnumberBook) error {
	return r.db.Save(book).Error
}

// SaveBookItems bulk-inserts items for a book snapshot.
func (r *PartnumberBookRepository) SaveBookItems(items []localdb.LocalPartnumberBookItem) error {
	if len(items) == 0 {
		return nil
	}
	return r.db.CreateInBatches(items, 500).Error
}

// CountBookItems returns the number of items for a given local book ID.
func (r *PartnumberBookRepository) CountBookItems(bookID uint) int64 {
	var count int64
	r.db.Model(&localdb.LocalPartnumberBookItem{}).Where("book_id = ?", bookID).Count(&count)
	return count
}

func (r *PartnumberBookRepository) CountDistinctLots(bookID uint) int64 {
	var count int64
	r.db.Model(&localdb.LocalPartnumberBookItem{}).
		Where("book_id = ?", bookID).
		Distinct("lot_name").
		Count(&count)
	return count
}

func (r *PartnumberBookRepository) CountPrimaryItems(bookID uint) int64 {
	var count int64
	r.db.Model(&localdb.LocalPartnumberBookItem{}).
		Where("book_id = ? AND is_primary_pn = ?", bookID, true).
		Count(&count)
	return count
}