package user

import (
	"context"
	"errors"
	"time"

	"gin_test/event"
	// repo 在本模块内，避免 user 模块依赖外部 model 层

	"golang.org/x/crypto/bcrypt"
)

type Service struct {
	repo *UserRepo
	bus  *event.Dispatcher
}

func NewService(repo *UserRepo, bus *event.Dispatcher) *Service {
	return &Service{repo: repo, bus: bus}
}

func (s *Service) Register(ctx context.Context, username, password string) error {
	if username == "" || password == "" {
		return errors.New("username/password required")
	}

	hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
	if err != nil {
		return err
	}

	return s.repo.Create(ctx, username, string(hash))
}

func (s *Service) Login(ctx context.Context, username, password string) (string, error) {
	u, err := s.repo.GetByUsername(ctx, username)
	if err != nil {
		return "", errors.New("invalid username or password")
	}

	if err := bcrypt.CompareHashAndPassword([]byte(u.PasswordHash), []byte(password)); err != nil {
		return "", errors.New("invalid username or password")
	}

	// 通过事件让 JWT 模块签发 token（request/reply）。
	reply := make(chan event.TokenIssueResult, 1)
	s.bus.Publish(event.TokenIssueRequested{
		At:       time.Now(),
		Username: u.Username,
		Reply:    reply,
	})

	select {
	case res := <-reply:
		if res.Err != "" {
			return "", errors.New(res.Err)
		}
		if res.Token == "" {
			return "", errors.New("empty token")
		}
		return res.Token, nil
	case <-time.After(2 * time.Second):
		return "", errors.New("token issue timeout")
	}
}