package ocr

import (
	"strings"
	"time"

	"gorm.io/gorm"
	"gorm.io/gorm/clause"

	"rmser/internal/domain/ocr"

	"github.com/google/uuid"
	"github.com/shopspring/decimal"
)

type pgRepository struct {
	db *gorm.DB
}

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

func (r *pgRepository) SaveMatch(serverID uuid.UUID, rawName string, productID uuid.UUID, quantity decimal.Decimal, containerID *uuid.UUID) error {
	normalized := strings.ToLower(strings.TrimSpace(rawName))

	match := ocr.ProductMatch{
		RMSServerID: serverID,
		RawName:     normalized,
		ProductID:   productID,
		Quantity:    quantity,
		ContainerID: containerID,
	}

	return r.db.Transaction(func(tx *gorm.DB) error {
		// Используем OnConflict по составному индексу (raw_name, rms_server_id)
		// Но GORM может потребовать названия ограничения.
		// Проще сделать через Where().Assign().FirstOrCreate() или явно указать Columns если индекс есть.
		// В Entity мы указали `uniqueIndex:idx_raw_server`.

		if err := tx.Clauses(clause.OnConflict{
			// Указываем оба поля, входящие в unique index
			Columns:   []clause.Column{{Name: "raw_name"}, {Name: "rms_server_id"}},
			DoUpdates: clause.AssignmentColumns([]string{"product_id", "quantity", "container_id", "updated_at"}),
		}).Create(&match).Error; err != nil {
			return err
		}

		// Удаляем из Unmatched для этого сервера
		if err := tx.Where("rms_server_id = ? AND raw_name = ?", serverID, normalized).Delete(&ocr.UnmatchedItem{}).Error; err != nil {
			return err
		}
		return nil
	})
}

func (r *pgRepository) DeleteMatch(serverID uuid.UUID, rawName string) error {
	normalized := strings.ToLower(strings.TrimSpace(rawName))
	return r.db.Where("rms_server_id = ? AND raw_name = ?", serverID, normalized).Delete(&ocr.ProductMatch{}).Error
}

func (r *pgRepository) FindMatch(serverID uuid.UUID, rawName string) (*ocr.ProductMatch, error) {
	normalized := strings.ToLower(strings.TrimSpace(rawName))
	var match ocr.ProductMatch

	err := r.db.Preload("Container").
		Where("rms_server_id = ? AND raw_name = ?", serverID, normalized).
		First(&match).Error

	if err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, nil
		}
		return nil, err
	}
	return &match, nil
}

func (r *pgRepository) GetAllMatches(serverID uuid.UUID) ([]ocr.ProductMatch, error) {
	var matches []ocr.ProductMatch
	err := r.db.
		Preload("Product").
		Preload("Product.MainUnit").
		Preload("Product.Containers").
		Preload("Container").
		Where("rms_server_id = ?", serverID).
		Order("updated_at DESC").
		Find(&matches).Error
	return matches, err
}

func (r *pgRepository) UpsertUnmatched(serverID uuid.UUID, rawName string) error {
	normalized := strings.ToLower(strings.TrimSpace(rawName))
	if normalized == "" {
		return nil
	}

	item := ocr.UnmatchedItem{
		RMSServerID: serverID,
		RawName:     normalized,
		Count:       1,
		LastSeen:    time.Now(),
	}

	return r.db.Clauses(clause.OnConflict{
		Columns: []clause.Column{{Name: "raw_name"}, {Name: "rms_server_id"}},
		DoUpdates: clause.Assignments(map[string]interface{}{
			"count":     gorm.Expr("unmatched_items.count + 1"),
			"last_seen": time.Now(),
		}),
	}).Create(&item).Error
}

func (r *pgRepository) GetTopUnmatched(serverID uuid.UUID, limit int) ([]ocr.UnmatchedItem, error) {
	var items []ocr.UnmatchedItem
	err := r.db.Where("rms_server_id = ?", serverID).
		Order("count DESC, last_seen DESC").
		Limit(limit).
		Find(&items).Error
	return items, err
}

func (r *pgRepository) DeleteUnmatched(serverID uuid.UUID, rawName string) error {
	normalized := strings.ToLower(strings.TrimSpace(rawName))
	return r.db.Where("rms_server_id = ? AND raw_name = ?", serverID, normalized).Delete(&ocr.UnmatchedItem{}).Error
}