package gapi

import (
	"context"

	db "github.com/FernandoJVideira/simple_bank/internal/db/sqlc"
	"github.com/FernandoJVideira/simple_bank/internal/service"
	"github.com/FernandoJVideira/simple_bank/internal/val"
	"github.com/FernandoJVideira/simple_bank/pb"
	"google.golang.org/genproto/googleapis/rpc/errdetails"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
)

func (s *Server) CreateUser(ctx context.Context, req *pb.CreateUserRequest) (*pb.CreateUserResponse, error) {
	violations := validateCreateUserRequest(req)
	if violations != nil {
		return nil, invalidArgumentError(violations)
	}

	result, err := s.userService.CreateUser(ctx, service.RegisterUserRequest{
		Username: req.GetUsername(),
		Password: req.GetPassword(),
		FullName: req.GetFullName(),
		Email:    req.GetEmail(),
	})
	if err != nil {
		// Map service errors to gRPC status codes
		if db.ErrorCode(err) == db.UniqueViolation {
			return nil, status.Errorf(codes.AlreadyExists, "username already exists")
		}
		return nil, status.Errorf(codes.Internal, "failed to create user: %v", err)
	}

	resp := &pb.CreateUserResponse{
		User: convertUser(result.User),
	}
	return resp, nil
}

func validateCreateUserRequest(req *pb.CreateUserRequest) (violations []*errdetails.BadRequest_FieldViolation) {
	if err := val.ValidateUsername(req.GetUsername()); err != nil {
		violations = append(violations, fieldViolation("username", err))
	}

	if err := val.ValidateFullName(req.GetFullName()); err != nil {
		violations = append(violations, fieldViolation("full_name", err))
	}

	if err := val.ValidatePassword(req.GetPassword()); err != nil {
		violations = append(violations, fieldViolation("password", err))
	}

	if err := val.ValidateEmail(req.GetEmail()); err != nil {
		violations = append(violations, fieldViolation("email", err))
	}
	return violations
}