package files

import (
	"errors"
	"os"
	"strings"

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

// Step2ReadAndAnswer reads an InvitationInitPayload from a .mwiv file, creates the
// invitee's peer entry, and writes the invitee's ContactCard response to a .mwiv file.
func Step2ReadAndAnswer(invitationFile string, nickname string, myNickname string, serverUids []string) error {
	if _, err := os.Stat(invitationFile); os.IsNotExist(err) {
		return err
	}
	if !strings.HasSuffix(invitationFile, ".mwiv") {
		return errors.New("only .mwiv files are supported")
	}
	data, err := os.ReadFile(invitationFile)
	if err != nil {
		return err
	}
	payload, err := meowlib.NewInvitationInitPayloadFromCompressed(data)
	if err != nil {
		return err
	}

	mynick := myNickname
	if mynick == "" {
		mynick = client.GetConfig().GetIdentity().Nickname
	}

	response, err := messages.Step2InviteeCreatesInitiatorAndEncryptedContactCard(payload, nickname, mynick, serverUids)
	if err != nil {
		return err
	}

	c := client.GetConfig()
	filename := c.StoragePath + string(os.PathSeparator) + mynick + "-" + nickname + ".mwiv"
	return response.GetMyContact().WriteCompressed(filename)
}