package service

import (
	"context"
	"errors"
	"fmt"
	"strings"

	"github.com/go-playground/validator/v10"
	"github.com/gofiber/fiber/v2"
	"github.com/sirupsen/logrus"
	common "gitlab.com/mbugroup/lti-api.git/internal/common/service"
	entity "gitlab.com/mbugroup/lti-api.git/internal/entities"
	m "gitlab.com/mbugroup/lti-api.git/internal/middleware"
	adjustmentStockRepo "gitlab.com/mbugroup/lti-api.git/internal/modules/inventory/adjustments/repositories"
	validation "gitlab.com/mbugroup/lti-api.git/internal/modules/inventory/adjustments/validations"
	ProductWarehouse "gitlab.com/mbugroup/lti-api.git/internal/modules/inventory/product-warehouses/repositories"
	productRepo "gitlab.com/mbugroup/lti-api.git/internal/modules/master/products/repositories"
	warehouseRepo "gitlab.com/mbugroup/lti-api.git/internal/modules/master/warehouses/repositories"
	projectFlockKandangRepo "gitlab.com/mbugroup/lti-api.git/internal/modules/production/project_flocks/repositories"
	stockLogsRepo "gitlab.com/mbugroup/lti-api.git/internal/modules/shared/repositories"
	"gitlab.com/mbugroup/lti-api.git/internal/utils"
	"gitlab.com/mbugroup/lti-api.git/internal/utils/fifo"
	"gorm.io/gorm"
)

type AdjustmentService interface {
	Adjustment(ctx *fiber.Ctx, req *validation.Create) (*entity.AdjustmentStock, error)
	GetOne(ctx *fiber.Ctx, id uint) (*entity.AdjustmentStock, error)
	AdjustmentHistory(ctx *fiber.Ctx, query *validation.Query) ([]*entity.AdjustmentStock, int64, error)
}

type adjustmentService struct {
	Log                       *logrus.Logger
	Validate                  *validator.Validate
	StockLogsRepository       stockLogsRepo.StockLogRepository
	WarehouseRepo             warehouseRepo.WarehouseRepository
	ProductWarehouseRepo      ProductWarehouse.ProductWarehouseRepository
	ProductRepo               productRepo.ProductRepository
	ProjectFlockKandangRepo   projectFlockKandangRepo.ProjectFlockKandangRepository
	AdjustmentStockRepository adjustmentStockRepo.AdjustmentStockRepository
	FifoSvc                   common.FifoService
}

func NewAdjustmentService(
	productRepo productRepo.ProductRepository,
	stockLogsRepo stockLogsRepo.StockLogRepository,
	warehouseRepo warehouseRepo.WarehouseRepository,
	productWarehouseRepo ProductWarehouse.ProductWarehouseRepository,
	adjustmentStockRepo adjustmentStockRepo.AdjustmentStockRepository,
	fifoSvc common.FifoService,
	validate *validator.Validate,
	projectFlockKandangRepo projectFlockKandangRepo.ProjectFlockKandangRepository,
) AdjustmentService {
	return &adjustmentService{
		Log:                       utils.Log,
		Validate:                  validate,
		StockLogsRepository:       stockLogsRepo,
		WarehouseRepo:             warehouseRepo,
		ProductWarehouseRepo:      productWarehouseRepo,
		ProductRepo:               productRepo,
		ProjectFlockKandangRepo:   projectFlockKandangRepo,
		AdjustmentStockRepository: adjustmentStockRepo,
		FifoSvc:                   fifoSvc,
	}
}

func (s *adjustmentService) withRelations(db *gorm.DB) *gorm.DB {
	return db.
		Preload("ProductWarehouse").
		Preload("ProductWarehouse.Product").
		Preload("ProductWarehouse.Warehouse").
		Preload("StockLog.CreatedUser")
}

func (s *adjustmentService) GetOne(c *fiber.Ctx, id uint) (*entity.AdjustmentStock, error) {
	adjustmentStock, err := s.AdjustmentStockRepository.GetByID(c.Context(), id, s.withRelations)
	if err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, fiber.NewError(fiber.StatusNotFound, "Adjustment not found")
		}
		s.Log.Errorf("Failed to get adjustment by id: %+v", err)
		return nil, err
	}

	return adjustmentStock, nil
}

func (s *adjustmentService) Adjustment(c *fiber.Ctx, req *validation.Create) (*entity.AdjustmentStock, error) {
	if err := s.Validate.Struct(req); err != nil {
		return nil, err
	}
	ctx := c.Context()
	actorID, err := m.ActorIDFromContext(c)
	if err != nil {
		return nil, err
	}
	if err := common.EnsureRelations(c.Context(),
		common.RelationCheck{Name: "Product", ID: &req.ProductID, Exists: s.ProductRepo.IdExists},
		common.RelationCheck{Name: "Warehouse", ID: &req.WarehouseID, Exists: s.WarehouseRepo.IdExists},
	); err != nil {
		return nil, err
	}

	if req.Quantity <= 0 {
		return nil, fiber.NewError(fiber.StatusBadRequest, "Quantity must be greater than zero")
	}

	transactionType := strings.ToUpper(req.TransactionType)
	if transactionType != string(utils.StockLogTransactionTypeIncrease) && transactionType != string(utils.StockLogTransactionTypeDecrease) {
		return nil, fiber.NewError(fiber.StatusBadRequest, "Invalid transaction type")
	}

	var createdAdjustmentStockId uint

	var projectFlockKandangID *uint
	pfkID, err := s.getActiveProjectFlockKandangID(ctx, uint(req.WarehouseID))
	if err == nil && pfkID > 0 {
		projectFlockKandangID = &pfkID
	}

	pw, err := s.ProductWarehouseRepo.FindByProductWarehouseAndPfk(ctx, uint(req.ProductID), uint(req.WarehouseID), projectFlockKandangID)
	if err != nil {
		if !errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, fiber.NewError(fiber.StatusInternalServerError, "Failed to get product warehouse")
		}

		newPW := &entity.ProductWarehouse{
			ProductId:             uint(req.ProductID),
			WarehouseId:           uint(req.WarehouseID),
			Quantity:              0,
			ProjectFlockKandangId: projectFlockKandangID,
		}

		if err := s.ProductWarehouseRepo.CreateOne(ctx, newPW, nil); err != nil {
			return nil, fiber.NewError(fiber.StatusInternalServerError, "Failed to create product warehouse")
		}
		pw = newPW
	}

	if err := common.EnsureProjectFlockNotClosedForProductWarehouses(
		ctx,
		s.StockLogsRepository.DB(),
		[]uint{pw.Id},
	); err != nil {
		return nil, err
	}
	err = s.StockLogsRepository.DB().WithContext(ctx).Transaction(func(tx *gorm.DB) error {

		productWarehouse, err := s.ProductWarehouseRepo.FindByProductWarehouseAndPfk(ctx, uint(req.ProductID), uint(req.WarehouseID), projectFlockKandangID)
		if err != nil {
			s.Log.Errorf("Failed to get product warehouse: %+v", err)
			return fiber.NewError(fiber.StatusInternalServerError, "Failed to get product warehouse")
		}

		afterQuantity := productWarehouse.Quantity
		newLog := &entity.StockLog{
			LoggableType:       string(utils.StockLogTypeAdjustment),
			LoggableId:         0,
			Notes:              req.Note,
			ProductWarehouseId: productWarehouse.Id,
			CreatedBy:          actorID,
		}

		stockLogs, err := s.StockLogsRepository.GetByProductWarehouse(ctx, productWarehouse.Id, 1)
		if err != nil {
			s.Log.Errorf("Failed to get stock logs: %+v", err)
			return fiber.NewError(fiber.StatusInternalServerError, "Failed to get stock logs")
		}

		if len(stockLogs) > 0 {
			latestStockLog := stockLogs[0]
			newLog.Stock = latestStockLog.Stock
		} else {
			newLog.Stock = 0
		}

		if transactionType == string(utils.StockLogTransactionTypeIncrease) {
			afterQuantity += req.Quantity
			newLog.Increase = req.Quantity
			newLog.Stock += newLog.Increase
		} else {
			if productWarehouse.Quantity < req.Quantity {
				return fiber.NewError(fiber.StatusBadRequest, fmt.Sprintf("Stok tidak mencukupi untuk pengurangan. Stok saat ini: %.2f, Jumlah yang akan dikurangi: %.2f", productWarehouse.Quantity, req.Quantity))
			}
			afterQuantity -= req.Quantity
			newLog.Decrease = req.Quantity
			newLog.Stock -= newLog.Decrease
		}

		if err := s.StockLogsRepository.WithTx(tx).CreateOne(ctx, newLog, nil); err != nil {
			return err
		}

		adjustmentStock := &entity.AdjustmentStock{
			ProductWarehouseId: productWarehouse.Id,
		}
		if err := s.AdjustmentStockRepository.WithTx(tx).CreateOne(ctx, adjustmentStock, nil); err != nil {

			return fiber.NewError(fiber.StatusInternalServerError, "Failed to create adjustment stock record")
		}

		newLog.LoggableType = string(utils.StockLogTypeAdjustment)
		newLog.LoggableId = adjustmentStock.Id
		if err := s.StockLogsRepository.WithTx(tx).UpdateOne(ctx, newLog.Id, newLog, nil); err != nil {
			return fiber.NewError(fiber.StatusInternalServerError, "Failed to link stock log")
		}

		if transactionType == string(utils.StockLogTransactionTypeIncrease) {

			note := fmt.Sprintf("Stock Adjustment IN #%d", newLog.Id)
			_, err := s.FifoSvc.Replenish(ctx, common.StockReplenishRequest{
				StockableKey:       fifo.StockableKeyAdjustmentIn,
				StockableID:        adjustmentStock.Id,
				ProductWarehouseID: uint(productWarehouse.Id),
				Quantity:           req.Quantity,
				Note:               &note,
				Tx:                 tx,
			})
			if err != nil {
				return fiber.NewError(fiber.StatusInternalServerError, fmt.Sprintf("Failed to replenish stock via FIFO: %v", err))
			}

		} else {
			_, err := s.FifoSvc.Consume(ctx, common.StockConsumeRequest{
				UsableKey:          fifo.UsableKeyAdjustmentOut,
				UsableID:           adjustmentStock.Id,
				ProductWarehouseID: uint(productWarehouse.Id),
				Quantity:           req.Quantity,
				AllowPending:       false,
				Tx:                 tx,
			})
			if err != nil {
				return fiber.NewError(fiber.StatusBadRequest, fmt.Sprintf("Failed to consume stock via FIFO: %v", err))
			}
		}

		productWarehouse.Quantity = afterQuantity
		if err := s.ProductWarehouseRepo.WithTx(tx).UpdateOne(ctx, productWarehouse.Id, productWarehouse, nil); err != nil {
			s.Log.Errorf("Failed to update product warehouse quantity: %+v", err)
			return err
		}

		createdAdjustmentStockId = adjustmentStock.Id
		return nil
	})

	if err != nil {
		s.Log.Errorf("Transaction failed in CreateOne: %+v", err)
		var fiberErr *fiber.Error
		if errors.As(err, &fiberErr) {
			return nil, err
		}
		return nil, fiber.NewError(fiber.StatusInternalServerError, "Failed to process adjustment transaction")
	}

	return s.GetOne(c, createdAdjustmentStockId)
}

func (s *adjustmentService) getActiveProjectFlockKandangID(ctx context.Context, warehouseID uint) (uint, error) {
	warehouse, err := s.WarehouseRepo.GetByID(ctx, warehouseID, nil)
	if err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return 0, fiber.NewError(fiber.StatusNotFound, fmt.Sprintf("Gudang dengan ID %d tidak ditemukan", warehouseID))
		}
		s.Log.Errorf("Failed to get warehouse %d: %+v", warehouseID, err)
		return 0, fiber.NewError(fiber.StatusInternalServerError, "Gagal mengambil data gudang")
	}

	if warehouse.KandangId == nil || *warehouse.KandangId == 0 {
		return 0, fiber.NewError(fiber.StatusBadRequest, fmt.Sprintf("Gudang %d belum terhubung ke kandang", warehouseID))
	}

	projectFlockKandang, err := s.ProjectFlockKandangRepo.GetActiveByKandangID(ctx, uint(*warehouse.KandangId))
	if err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return 0, fiber.NewError(fiber.StatusBadRequest, fmt.Sprintf("Kandang %d belum memiliki project flock aktif", *warehouse.KandangId))
		}
		s.Log.Errorf("Failed to get active project flock for kandang %d: %+v", *warehouse.KandangId, err)
		return 0, fiber.NewError(fiber.StatusInternalServerError, "Gagal mengambil project flock kandang")
	}

	return uint(projectFlockKandang.Id), nil
}

func (s *adjustmentService) AdjustmentHistory(c *fiber.Ctx, query *validation.Query) ([]*entity.AdjustmentStock, int64, error) {
	if err := s.Validate.Struct(query); err != nil {
		return nil, 0, err
	}
	offset := (query.Page - 1) * query.Limit

	var isProductsExist bool
	isWarehousesExist, err := s.WarehouseRepo.IdExists(c.Context(), uint(query.WarehouseID))

	if err != nil {
		return nil, 0, fiber.NewError(fiber.StatusInternalServerError, "Failed to validate warehouse")
	}
	if query.WarehouseID > 0 && !isWarehousesExist {
		return nil, 0, fiber.NewError(fiber.StatusNotFound, "Warehouse not found")
	}

	isProductsExist, err = s.ProductRepo.IdExists(c.Context(), uint(query.ProductID))

	if err != nil {
		s.Log.Errorf("Failed to check product existence: %+v", err)
		return nil, 0, fiber.NewError(fiber.StatusInternalServerError, "Failed to validate product")
	}
	if query.ProductID > 0 && !isProductsExist {
		return nil, 0, fiber.NewError(fiber.StatusNotFound, "Product not found")
	}

	var adjustmentStocks []entity.AdjustmentStock
	var total int64

	q := s.AdjustmentStockRepository.DB().WithContext(c.Context()).Model(&entity.AdjustmentStock{}).
		Preload("ProductWarehouse").
		Preload("ProductWarehouse.Product").
		Preload("ProductWarehouse.Warehouse").
		Preload("StockLog.CreatedUser")

	if query.ProductID > 0 {
		q = q.Joins("JOIN product_warehouses ON product_warehouses.id = adjustment_stocks.product_warehouse_id").
			Where("product_warehouses.product_id = ?", query.ProductID)
	}

	if query.WarehouseID > 0 {
		q = q.Joins("JOIN product_warehouses ON product_warehouses.id = adjustment_stocks.product_warehouse_id").
			Where("product_warehouses.warehouse_id = ?", query.WarehouseID)
	}

	if query.TransactionType != "" {
		q = q.Joins("JOIN stock_logs ON stock_logs.loggable_type = ? AND stock_logs.loggable_id = adjustment_stocks.id", "ADJUSTMENT").
			Where("stock_logs.transaction_type = ?", strings.ToUpper(query.TransactionType))
	}

	if err = q.Count(&total).Error; err != nil {
		s.Log.Errorf("Failed to get adjustments: %+v", err)
		return nil, 0, fiber.NewError(fiber.StatusInternalServerError, "Failed to get adjustment history")
	}

	err = q.Offset(offset).Limit(query.Limit).Order("created_at DESC").Find(&adjustmentStocks).Error

	if err != nil {
		s.Log.Errorf("Failed to get adjustments: %+v", err)
		return nil, 0, fiber.NewError(fiber.StatusInternalServerError, "Failed to get adjustment history")
	}

	result := make([]*entity.AdjustmentStock, len(adjustmentStocks))
	for i := range adjustmentStocks {
		result[i] = &adjustmentStocks[i]
	}

	return result, total, nil
}