Eliminate synccycles package [synccycles.DeviceIDGen() => syncclient.DeviceIDGenFromClient()]

syncclient/oneOff.go

@@ -1,10 +1,16 @@
 package syncclient
 
 import (
+	"encoding/json"
 	"errors"
+	"math/rand"
+	"os"
+	"strconv"
 	"strings"
+	"time"
 
 	"github.com/rwinkhart/go-boilerplate/back"
+	"github.com/rwinkhart/go-boilerplate/stringy"
 	"github.com/rwinkhart/libmutton/global"
 	"github.com/rwinkhart/libmutton/synccommon"
 )
@@ -154,3 +160,72 @@ end:
 	back.Exit(0)
 	return nil
 }
+
+// DeviceIDGenFromClient generates a new client device ID
+// and registers it with the server (will replace existing one).
+// Device IDs are only needed for online synchronization.
+// Device IDs are guaranteed unique as the current UNIX time is appended to them.
+// Leave prefix empty to use the current hostname as the prefix.
+// Returns: the remote EntryRoot, the remote AgeDir, and OS type indicator.
+func DeviceIDGenFromClient(oldDeviceID, prefix string) (string, string, string, error) {
+	// generate new device ID
+	if prefix == "" {
+		prefix, _ = os.Hostname()
+	}
+	newDeviceID := prefix + "-" + stringy.StringGen(rand.Intn(32)+48, 0.2, 1) + "-" + strconv.FormatInt(time.Now().Unix(), 10)
+
+	// create new device ID file (locally)
+	newDeviceIDPath := global.ConfigDir + global.PathSeparator + "devices" + global.PathSeparator + newDeviceID
+	oldDeviceIDPath := global.ConfigDir + global.PathSeparator + "devices" + global.PathSeparator + oldDeviceID
+	f, err := os.OpenFile(newDeviceIDPath, os.O_CREATE|os.O_WRONLY, 0600)
+	if err != nil {
+		return "", "", "", errors.New("unable to create local device ID file: " + err.Error())
+	}
+	_ = f.Close() // error ignored; if the file could be created, it can probably be closed
+
+	cleanupOnFail := func() {
+		// remove new device ID file
+		_ = os.RemoveAll(newDeviceIDPath)
+		if oldDeviceID != global.FSMisc {
+			// restore old device ID file (if it existed and has already been removed due to DirInit)
+			if isAccessible, _ := back.TargetIsFile(oldDeviceIDPath, true); !isAccessible {
+				f, _ := os.OpenFile(oldDeviceIDPath, os.O_CREATE|os.O_WRONLY, 0600)
+				_ = f.Close() // error ignored; if the file could be created, it can probably be closed
+			}
+		}
+	}
+
+	// register new device ID with server and fetch remote EntryRoot and OS type
+	// also removes the old device ID file (remotely)
+	// if registration fails, remove the new device ID file locally and return before removing the old one
+	sshClient, _, _, _, _, err := GetSSHClient()
+	if err != nil {
+		cleanupOnFail()
+		return "", "", "", errors.New("unable to connect to SSH client: " + err.Error())
+	}
+	output, err := GetSSHOutput(sshClient, "libmuttonserver register", newDeviceID+"\n"+oldDeviceID)
+	if err != nil {
+		cleanupOnFail()
+		return "", "", "", errors.New("unable to register device ID with server: " + err.Error())
+	}
+	var registerResp synccommon.RegisterResp
+	err = json.Unmarshal(output, &registerResp)
+	if err != nil {
+		cleanupOnFail()
+		return "", "", "", errors.New("unable to unmarshal server register response: " + err.Error())
+	}
+	if registerResp.ErrMsg != nil {
+		cleanupOnFail()
+		return "", "", "", errors.New("unable to complete register; server-side error occurred: " + strings.ReplaceAll(*registerResp.ErrMsg, global.FSSpace, "\n"))
+	}
+	_ = sshClient.Close() // ignore error; non-critical/unlikely/not much could be done about it
+
+	// remove old device ID file (locally; may not exist)
+	err = os.RemoveAll(oldDeviceIDPath)
+	if err != nil {
+		cleanupOnFail()
+		return "", "", "", errors.New("unable to remove old device ID file (locally): " + err.Error())
+	}
+
+	return registerResp.EntryRoot, registerResp.AgeDir, strconv.FormatBool(registerResp.IsWindows), nil
+}