package grpc

import (
	"context"
	"log"

	"datarush/internal/auth/domain"
	"datarush/internal/auth/service"
	pb "datarush/pkg/api/auth"

	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
)

type AuthHandler struct {
	pb.UnimplementedAuthServiceServer
	authService *service.AuthService
}

func NewAuthHandler(authService *service.AuthService) *AuthHandler {
	return &AuthHandler{
		authService: authService,
	}
}

func (h *AuthHandler) SignUp(ctx context.Context, req *pb.SignUpRequest) (*pb.SignUpResponse, error) {
	token, err := h.authService.SignUp(ctx, req.Email, req.Username, req.Password)
	if err != nil {
		log.Printf("signup error: %v", err)
		switch err {
		case domain.ErrUserAlreadyExists:
			return nil, status.Error(codes.AlreadyExists, "user already exists")
		default:
			return nil, status.Error(codes.Internal, "internal error")
		}
	}

	return &pb.SignUpResponse{Token: token}, nil
}

func (h *AuthHandler) SignIn(ctx context.Context, req *pb.SignInRequest) (*pb.SignInResponse, error) {
	token, err := h.authService.SignIn(ctx, req.Email, req.Password)
	if err != nil {
		log.Printf("signin error: %v", err)
		switch err {
		case domain.ErrInvalidPassword, domain.ErrUserNotFound:
			return nil, status.Error(codes.Unauthenticated, "invalid credentials")
		default:
			return nil, status.Error(codes.Internal, "internal error")
		}
	}

	return &pb.SignInResponse{Token: token}, nil
}

func (h *AuthHandler) ValidateToken(
	ctx context.Context,
	req *pb.ValidateTokenRequest,
) (*pb.ValidateTokenResponse, error) {
	token := req.Token

	if token == "" {
		return nil, status.Error(codes.Unauthenticated, "missing token")
	}

	if token == "" {
		return nil, status.Error(codes.Unauthenticated, "missing token")
	}

	user, err := h.authService.ValidateToken(ctx, token)
	if err != nil {
		log.Printf("validate token error: %v", err)
		return nil, status.Error(codes.Unauthenticated, "invalid token")
	}

	return &pb.ValidateTokenResponse{UserId: user.ID.String()}, nil
}