package messages

import (
	"errors"

	"forge.redroom.link/yves/meowlib"
	"forge.redroom.link/yves/meowlib/client"
	"google.golang.org/protobuf/proto"
)

// Step4InviteeFinalizesInitiator is called by the invitee's message processor when a
// UserMessage with invitation.step == 3 arrives. It unmarshals the initiator's ContactCard
// and completes the invitee's peer entry with the initiator's real keys.
func Step4InviteeFinalizesInitiator(usermsg *meowlib.UserMessage) (*client.Peer, error) {
	if usermsg.Invitation == nil || usermsg.Invitation.Step != 3 {
		return nil, errors.New("expected invitation step 3")
	}
	var initiatorCC meowlib.ContactCard
	if err := proto.Unmarshal(usermsg.Invitation.Payload, &initiatorCC); err != nil {
		return nil, err
	}
	// Patch the invitation ID from the outer message in case it was not set in the CC.
	if initiatorCC.InvitationId == "" {
		initiatorCC.InvitationId = usermsg.Invitation.Uuid
	}
	if err := client.GetConfig().GetIdentity().InvitationStep4(&initiatorCC); err != nil {
		return nil, err
	}
	client.GetConfig().GetIdentity().Save()
	peer := client.GetConfig().GetIdentity().Peers.GetFromInvitationId(initiatorCC.InvitationId)
	return peer, nil
}