search.go

package ud

import (
	"fmt"
	"github.com/golang/protobuf/proto"
	"github.com/pkg/errors"
	jww "github.com/spf13/jwalterweatherman"
	"gitlab.com/elixxir/crypto/contact"
	"gitlab.com/elixxir/crypto/factID"
	"gitlab.com/elixxir/primitives/fact"
	"gitlab.com/xx_network/primitives/id"
	"time"
)

// SearchTag specifies which callback to trigger when UD receives a search
// request.
const SearchTag = "xxNetwork_UdSearch"

// TODO: reconsider where this comes from
const maxSearchMessages = 20

type searchCallback func([]contact.Contact, error)

// Search searches for the passed Facts. The searchCallback will return a list
// of contacts, each having the facts it hit against. This is NOT intended to be
// used to search for multiple users at once; that can have a privacy reduction.
// Instead, it is intended to be used to search for a user where multiple pieces
// of information is known.
func (m *Manager) Search(list fact.FactList, callback searchCallback, timeout time.Duration) error {
	jww.INFO.Printf("ud.Search(%s, %s)", list.Stringify(), timeout)

	factHashes, factMap := hashFactList(list)

	// Build the request and marshal it
	request := &SearchSend{Fact: factHashes}
	requestMarshaled, err := proto.Marshal(request)
	if err != nil {
		return errors.WithMessage(err, "Failed to form outgoing search request.")
	}

	f := func(payload []byte, err error) {
		m.searchResponseHandler(factMap, callback, payload, err)
	}

	// Get UD contact
	c, err := m.getContact()
	if err != nil {
		return err
	}

	err = m.single.TransmitSingleUse(c, requestMarshaled, SearchTag,
		maxSearchMessages, f, timeout)
	if err != nil {
		return errors.WithMessage(err, "Failed to transmit search request.")
	}

	if m.client != nil {
		m.client.ReportEvent(1, "UserDiscovery", "SearchRequest",
			fmt.Sprintf("Sent: %+v", request))
	}

	return nil
}

func (m *Manager) searchResponseHandler(factMap map[string]fact.Fact,
	callback searchCallback, payload []byte, err error) {

	if err != nil {
		go callback(nil, errors.WithMessage(err, "Failed to search."))
		return