package service

import (
	"errors"
	"narasi-ahli-be/app/database/entity"
	"narasi-ahli-be/app/module/user_agent/repository"

	"github.com/rs/zerolog"
)

type UserAgentService interface {
	UpdateUserAgents(userID uint, agentIDs []uint) error
	GetAgentsByUser(userID uint) ([]entity.Agent, error)
}

type userAgentService struct {
	Repo repository.UserAgentRepository
	Log  zerolog.Logger
}


func NewUserAgentService(repo repository.UserAgentRepository, log zerolog.Logger) UserAgentService {
	return &userAgentService{Repo: repo, Log: log}
}

func (s *userAgentService) UpdateUserAgents(userID uint, agentIDs []uint) error {

	// kosong → valid (lepas semua agent)
	if len(agentIDs) == 0 {
		return s.Repo.ReplaceUserAgents(userID, agentIDs)
	}

	validIDs, err := s.Repo.ValidateAgents(agentIDs)
	if err != nil {
		return err
	}

	// cek apakah ada agent yang tidak exist
	if len(validIDs) != len(agentIDs) {
		return errors.New("one or more agent_id not found")
	}

	return s.Repo.ReplaceUserAgents(userID, agentIDs)
}

func (s *userAgentService) GetAgentsByUser(userID uint) ([]entity.Agent, error) {
	return s.Repo.GetAgentsByUser(userID)
}