package helpers

import (
	"strings"

	"forge.redroom.link/yves/meowlib"
	"forge.redroom.link/yves/meowlib/client"
)

// InvitationStep2GetMessage builds and returns the packed server message that retrieves
// the InvitationInitPayload from the server using the shortcode URL (STEP_2, invitee side).
func InvitationStep2GetMessage(invitationUrl string, serverPublicKey string, invitationPassword string) ([]byte, string, error) {
	meowurl := strings.Split(invitationUrl, "?")
	shortcode := meowurl[1]

	srv, err := client.CreateServerFromMeowUrl(meowurl[0])
	if err != nil {
		return nil, "InvitationStep2GetMessage: CreateServerFromMeowUrl", err
	}

	// Reuse the server entry if already known.
	dbsrv, err := client.GetConfig().GetIdentity().MessageServers.LoadServer(srv.Url)
	if err != nil {
		return nil, "InvitationStep2GetMessage: LoadServer", err
	}
	if dbsrv == nil {
		srv.PublicKey = serverPublicKey
		k, err := meowlib.NewKeyPair()
		if err != nil {
			return nil, "InvitationStep2GetMessage: NewKeyPair", err
		}
		srv.UserKp = k
		if err := client.GetConfig().GetIdentity().MessageServers.StoreServer(srv); err != nil {
			return nil, "InvitationStep2GetMessage: StoreServer", err
		}
	} else {
		if dbsrv.PublicKey != serverPublicKey {
			dbsrv.PublicKey = serverPublicKey
		}
		srv = dbsrv
	}

	toSrvMsg, err := srv.BuildToServerMessageInvitationRequest(shortcode, invitationPassword)
	if err != nil {
		return nil, "InvitationStep2GetMessage: BuildToServerMessageInvitationRequest", err
	}
	bytemsg, err := srv.ProcessOutboundMessage(toSrvMsg)
	if err != nil {
		return nil, "InvitationStep2GetMessage: ProcessOutboundMessage", err
	}
	return bytemsg, "", nil
}

// InvitationStep2ReadResponse decodes the server response to a Step2 get-message and returns
// the InvitationInitPayload sent by the initiator.
func InvitationStep2ReadResponse(invitationData []byte, invitationServerUid string) (*meowlib.InvitationInitPayload, string, error) {
	server, err := client.GetConfig().GetIdentity().MessageServers.LoadServer(invitationServerUid)
	if err != nil {
		return nil, "InvitationStep2ReadResponse: LoadServer", err
	}
	serverMsg, err := server.ProcessInboundServerResponse(invitationData)
	if err != nil {
		return nil, "InvitationStep2ReadResponse: ProcessInboundServerResponse", err
	}
	payload, err := meowlib.NewInvitationInitPayloadFromCompressed(serverMsg.Invitation.Payload)
	if err != nil {
		return nil, "InvitationStep2ReadResponse: NewInvitationInitPayloadFromCompressed", err
	}
	return payload, "", nil
}