package validate

import (
	"context"

	"github.com/go-kratos/kratos/v2/errors"
	"github.com/go-kratos/kratos/v2/middleware"
	"go.einride.tech/aip/fieldbehavior"
	"google.golang.org/protobuf/proto"
)

// Middleware is a middleware that validates the request message with [FieldBehavior](https://google.aip.dev/203)
func Middleware() middleware.Middleware {
	return func(handler middleware.Handler) middleware.Handler {
		return func(ctx context.Context, req any) (reply any, err error) {
			if msg, ok := req.(proto.Message); ok {
				if err := fieldbehavior.ValidateRequiredFields(msg); err != nil {
					return nil, errors.BadRequest("VALIDATOR", err.Error()).WithCause(err)
				}
			}
			return handler(ctx, req)
		}
	}
}