package drafts

import (
	"fmt"

	"rmser/internal/domain/drafts"

	"github.com/google/uuid"
	"gorm.io/gorm"
)

type pgRepository struct {
	db *gorm.DB
}

func NewRepository(db *gorm.DB) drafts.Repository {
	return &pgRepository{db: db}
}

func (r *pgRepository) Create(draft *drafts.DraftInvoice) error {
	return r.db.Create(draft).Error
}

func (r *pgRepository) GetByID(id uuid.UUID) (*drafts.DraftInvoice, error) {
	var draft drafts.DraftInvoice
	err := r.db.
		Preload("Items", func(db *gorm.DB) *gorm.DB {
			return db.Order("draft_invoice_items.order ASC")
		}).
		Preload("Items.Product").
		Preload("Items.Product.MainUnit").
		Preload("Items.Container").
		Where("id = ?", id).
		First(&draft).Error

	if err != nil {
		return nil, err
	}
	return &draft, nil
}

func (r *pgRepository) GetByRMSInvoiceID(rmsInvoiceID uuid.UUID) (*drafts.DraftInvoice, error) {
	var draft drafts.DraftInvoice
	err := r.db.
		Where("rms_invoice_id = ?", rmsInvoiceID).
		First(&draft).Error
	if err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, nil
		}
		return nil, err
	}
	return &draft, nil
}

func (r *pgRepository) Update(draft *drafts.DraftInvoice) error {
	return r.db.Model(draft).Updates(map[string]interface{}{
		"status":                   draft.Status,
		"document_number":          draft.DocumentNumber,
		"incoming_document_number": draft.IncomingDocumentNumber,
		"date_incoming":            draft.DateIncoming,
		"supplier_id":              draft.SupplierID,
		"store_id":                 draft.StoreID,
		"comment":                  draft.Comment,
		"rms_invoice_id":           draft.RMSInvoiceID,
		"rms_server_id":            draft.RMSServerID,
		"updated_at":               gorm.Expr("NOW()"),
	}).Error
}

func (r *pgRepository) CreateItems(items []drafts.DraftInvoiceItem) error {
	if len(items) == 0 {
		return nil
	}
	return r.db.CreateInBatches(items, 100).Error
}

func (r *pgRepository) CreateItem(item *drafts.DraftInvoiceItem) error {
	return r.db.Create(item).Error
}

func (r *pgRepository) DeleteItem(itemID uuid.UUID) error {
	return r.db.Delete(&drafts.DraftInvoiceItem{}, itemID).Error
}

// GetItemByID - новый метод
func (r *pgRepository) GetItemByID(itemID uuid.UUID) (*drafts.DraftInvoiceItem, error) {
	var item drafts.DraftInvoiceItem
	err := r.db.Where("id = ?", itemID).First(&item).Error
	if err != nil {
		return nil, err
	}
	return &item, nil
}

// UpdateItem - обновленный метод, принимает map
func (r *pgRepository) UpdateItem(itemID uuid.UUID, updates map[string]interface{}) error {
	return r.db.Model(&drafts.DraftInvoiceItem{}).
		Where("id = ?", itemID).
		Updates(updates).Error
}

// UpdateItemOrder обновляет порядок позиции
func (r *pgRepository) UpdateItemOrder(itemID uuid.UUID, newOrder int) error {
	return r.db.Model(&drafts.DraftInvoiceItem{}).
		Where("id = ?", itemID).
		Update("order", newOrder).Error
}

// ReorderItems обновляет порядок нескольких элементов в одной транзакции
func (r *pgRepository) ReorderItems(draftID uuid.UUID, items []struct {
	ID    uuid.UUID
	Order int
}) error {
	return r.db.Transaction(func(tx *gorm.DB) error {
		for _, item := range items {
			// Проверяем, что элемент принадлежит указанному черновику
			var count int64
			if err := tx.Model(&drafts.DraftInvoiceItem{}).
				Where("id = ? AND draft_id = ?", item.ID, draftID).
				Count(&count).Error; err != nil {
				return err
			}
			if count == 0 {
				return fmt.Errorf("элемент с id %s не принадлежит черновику %s", item.ID.String(), draftID.String())
			}

			// Обновляем только колонку order
			if err := tx.Model(&drafts.DraftInvoiceItem{}).
				Where("id = ?", item.ID).
				Update("order", item.Order).Error; err != nil {
				return err
			}
		}
		return nil
	})
}

func (r *pgRepository) Delete(id uuid.UUID) error {
	return r.db.Delete(&drafts.DraftInvoice{}, id).Error
}

func (r *pgRepository) GetActive(serverID uuid.UUID) ([]drafts.DraftInvoice, error) {
	var list []drafts.DraftInvoice

	activeStatuses := []string{
		drafts.StatusProcessing,
		drafts.StatusReadyToVerify,
		drafts.StatusError,
		drafts.StatusCanceled,
	}

	err := r.db.
		Preload("Items").
		Preload("Store").
		Where("rms_server_id = ? AND status IN ?", serverID, activeStatuses).
		Order("created_at DESC").
		Find(&list).Error

	return list, err
}

func (r *pgRepository) GetLinkedDraftsMap(serverID uuid.UUID) (map[uuid.UUID]drafts.LinkedDraftInfo, error) {
	var draftsList []drafts.DraftInvoice
	err := r.db.
		Select("id", "rms_invoice_id", "sender_photo_url").
		Where("rms_server_id = ? AND rms_invoice_id IS NOT NULL", serverID).
		Find(&draftsList).Error
	if err != nil {
		return nil, err
	}

	result := make(map[uuid.UUID]drafts.LinkedDraftInfo)
	for _, d := range draftsList {
		if d.RMSInvoiceID != nil {
			result[*d.RMSInvoiceID] = drafts.LinkedDraftInfo{
				DraftID:  d.ID,
				PhotoURL: d.SenderPhotoURL,
			}
		}
	}
	return result, nil
}