package usecase

import (
	"errors"
	"time"
	"users_management/m/model/dto/req"
	"users_management/m/model/entity"
	"users_management/m/repository"

	"github.com/go-playground/validator/v10"
	"github.com/google/uuid"
)

type TowerUseCase interface {
	Post(tower req.TowerDTO) error
	GetAll() ([]entity.Tower, error)
	GetByID(id uuid.UUID) (entity.Tower, error)
	UpdateTower(id uuid.UUID, tower req.UpdateTowerDTO) error
}

type towerUsecase struct {
	towerRepo repository.TowerRepo
	validate *validator.Validate
}

func NewTowerUseCase(towerRepo repository.TowerRepo) TowerUseCase {
	return &towerUsecase{
		towerRepo: towerRepo,
		validate: validator.New(),
	}
}

func (u *towerUsecase) Post(tower req.TowerDTO) error {
	err := u.validate.Struct(tower)
	if err != nil {
		return err
	}

	newTower := entity.Tower{
		ID: uuid.New(),
		DeviceID: tower.DeviceID,
		TowerCode: tower.TowerCode,
		Longitude: tower.Longitude,
		Latitude: tower.Latitude,
		CreatedAt: time.Now(),
		UpdatedAt: time.Now(),
	}

	return u.towerRepo.Post(newTower)
}

func (u *towerUsecase) GetAll() ([]entity.Tower, error) {
	towers, err := u.towerRepo.GetAll()
	if err != nil {
		return towers, err
	}
	return towers, nil
}


func (u *towerUsecase) GetByID(id uuid.UUID) (entity.Tower, error) {
	tower, err := u.towerRepo.GetByID(id)
	if err != nil {
		return tower, err
	}
	return tower, nil
}

func (u *towerUsecase) UpdateTower(id uuid.UUID, tower req.UpdateTowerDTO) error {
	err := u.validate.Struct(tower)
    if err != nil {
        return err // Return validation error
    }
	updates := make(map[string]interface{})

    if tower.DeviceID != nil {
        updates["DeviceID"] = *tower.DeviceID
    }
    if tower.TowerCode != nil {
        updates["TowerCode"] = *tower.TowerCode
    }
    if tower.Longitude != nil {
        updates["Longitude"] = *tower.Longitude
    }
    if tower.Latitude != nil {
        updates["Latitude"] = *tower.Latitude
    }

    // If no fields are updated, return an error
    if len(updates) == 0 {
        return errors.New("no fields to update")
    }

    updates["UpdatedAt"] = time.Now()

    return u.towerRepo.Update(id, updates)
}