Config: Fix config version downgrade

Fixes thrasher-corp#1769

cmd/config/config.go

@@ -1,7 +1,7 @@
 package main
 
 import (
-	"errors"
+	"context"
 	"flag"
 	"fmt"
 	"os"
@@ -11,9 +11,10 @@ import (
 	"github.com/buger/jsonparser"
 	"github.com/thrasher-corp/gocryptotrader/common/file"
 	"github.com/thrasher-corp/gocryptotrader/config"
+	"github.com/thrasher-corp/gocryptotrader/config/versions"
 )
 
-var commands = []string{"upgrade", "encrypt", "decrypt"}
+var commands = []string{"upgrade", "downgrade", "encrypt", "decrypt"}
 
 func main() {
 	fmt.Println("GoCryptoTrader: config-helper tool")
@@ -22,13 +23,15 @@ func main() {
 
 	var in, out, keyStr string
 	var inplace bool
+	var version int
 
 	fs := flag.NewFlagSet("config", flag.ExitOnError)
 	fs.Usage = func() { usage(fs) }
 	fs.StringVar(&in, "in", defaultCfgFile, "The config input file to process")
 	fs.StringVar(&out, "out", "[in].out", "The config output file")
 	fs.BoolVar(&inplace, "edit", false, "Edit; Save result to the original file")
 	fs.StringVar(&keyStr, "key", "", "The key to use for AES encryption")
+	fs.IntVar(&version, "version", 0, "The version to downgrade to")
 
 	cmd, args := parseCommand(os.Args[1:])
 	if cmd == "" {
@@ -46,83 +49,59 @@ func main() {
 		out = in + ".out"
 	}
 
-	key := []byte(keyStr)
 	var err error
-	switch cmd {
-	case "upgrade":
-		err = upgradeFile(in, out, key)
-	case "decrypt":
-		err = encryptWrapper(in, out, key, false, decryptFile)
-	case "encrypt":
-		err = encryptWrapper(in, out, key, true, encryptFile)
-	}
+	key := []byte(keyStr)
+	data := readFile(in)
+	isEncrypted := config.IsEncrypted(data)
 
-	if err != nil {
-		fatal(err.Error())
+	if cmd == "encrypt" && isEncrypted {
+		fatal("Error: File is already encrypted")
 	}
 
-	fmt.Println("Success! File written to " + out)
-}
-
-func upgradeFile(in, out string, key []byte) error {
-	c := &config.Config{
-		EncryptionKeyProvider: func(_ bool) ([]byte, error) {
-			if len(key) != 0 {
-				return key, nil
-			}
-			return config.PromptForConfigKey(false)
-		},
+	if len(key) == 0 && (isEncrypted || cmd == "encrypt") {
+		if key, err = config.PromptForConfigKey(cmd == "encrypt"); err != nil {
+			fatal(err.Error())
+		}
 	}
 
-	if err := c.ReadConfigFromFile(in, true); err != nil {
-		return err
+	if isEncrypted {
+		if data, err = config.DecryptConfigData(data, key); err != nil {
+			fatal(err.Error())
+		}
 	}
 
-	return c.SaveConfigToFile(out)
-}
-
-type encryptFunc func(string, []byte) ([]byte, error)
-
-func encryptWrapper(in, out string, key []byte, confirmKey bool, fn encryptFunc) error {
-	if len(key) == 0 {
-		var err error
-		if key, err = config.PromptForConfigKey(confirmKey); err != nil {
-			return err
+	switch cmd {
+	case "decrypt":
+		if data, err = jsonparser.Set(data, []byte("-1"), "encryptConfig"); err != nil {
+			fatal("Unable to decrypt config data; Error: " + err.Error())
+		}
+	case "downgrade", "upgrade":
+		if version == 0 {
+			if cmd == "downgrade" {
+				fmt.Fprintln(os.Stderr, "Error: downgrade requires a version")
+				usage(fs)
+				os.Exit(3)
+			}
+			version = -1
+		}
+		if data, err = versions.Manager.Deploy(context.Background(), data, version); err != nil {
+			fatal("Unable to " + cmd + " config; Error: " + err.Error())
+		}
+		if !isEncrypted {
+			break
+		}
+		fallthrough
+	case "encrypt":
+		if data, err = config.EncryptConfigData(data, key); err != nil {
+			fatal("Unable to encrypt config data; Error: " + err.Error())
 		}
 	}
-	outData, err := fn(in, key)
-	if err != nil {
-		return err
-	}
-	if err := file.Write(out, outData); err != nil {
-		return fmt.Errorf("unable to write output file %s; Error: %w", out, err)
-	}
-	return nil
-}
 
-func encryptFile(in string, key []byte) ([]byte, error) {
-	if config.IsFileEncrypted(in) {
-		return nil, errors.New("file is already encrypted")
-	}
-	outData, err := config.EncryptConfigFile(readFile(in), key)
-	if err != nil {
-		return nil, fmt.Errorf("unable to encrypt config data. Error: %w", err)
+	if err := file.Write(out, data); err != nil {
+		fatal("Unable to write output file `" + out + "`; Error: " + err.Error())
 	}
-	return outData, nil
-}
 
-func decryptFile(in string, key []byte) ([]byte, error) {
-	if !config.IsFileEncrypted(in) {
-		return nil, errors.New("file is already decrypted")
-	}
-	outData, err := config.DecryptConfigFile(readFile(in), key)
-	if err != nil {
-		return nil, fmt.Errorf("unable to decrypt config data. Error: %w", err)
-	}
-	if outData, err = jsonparser.Set(outData, []byte("-1"), "encryptConfig"); err != nil {
-		return nil, fmt.Errorf("unable to decrypt config data. Error: %w", err)
-	}
-	return outData, nil
+	fmt.Println("Success! File written to " + out)
 }
 
 func readFile(in string) []byte {
@@ -152,7 +131,7 @@ func parseCommand(a []string) (cmd string, args []string) {
 	switch len(cmds) {
 	case 0:
 		fmt.Fprintln(os.Stderr, "No command provided")
-	case 1: //
+	case 1:
 		return cmds[0], rem
 	default:
 		fmt.Fprintln(os.Stderr, "Too many commands provided: "+strings.Join(cmds, ", "))
@@ -171,6 +150,7 @@ The commands are:
 	encrypt 	encrypt infile and write to outfile
 	decrypt 	decrypt infile and write to outfile
 	upgrade 	upgrade the version of a decrypted config file
+	downgrade 	downgrade the version of a decrypted config file to a specific version
 
 The arguments are:`)
 	fs.PrintDefaults()

config/config.go

@@ -1512,7 +1512,7 @@ func (c *Config) readConfig(d io.Reader) error {
 		}
 	}
 
-	if j, err = versions.Manager.Deploy(context.Background(), j); err != nil {
+	if j, err = versions.Manager.Deploy(context.Background(), j, -1); err != nil {
 		return err
 	}
 

config/versions/versions.go

@@ -13,9 +13,11 @@ package versions
 import (
 	"bytes"
 	"context"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"log"
+	"os"
 	"slices"
 	"strconv"
 	"sync"
@@ -55,16 +57,23 @@ type manager struct {
 var Manager = &manager{}
 
 // Deploy upgrades or downgrades the config between versions
-func (m *manager) Deploy(ctx context.Context, j []byte) ([]byte, error) {
+// version param -1 defaults to the latest version
+// Prints an error an exits if the config file version or version param is not registered
+func (m *manager) Deploy(ctx context.Context, j []byte, version int) ([]byte, error) {
 	if err := m.checkVersions(); err != nil {
 		return j, err
 	}
 
-	target, err := m.latest()
+	latest, err := m.latest()
 	if err != nil {
 		return j, err
 	}
 
+	target := latest
+	if version != -1 {
+		target = version
+	}
+
 	m.m.RLock()
 	defer m.m.RUnlock()
 
@@ -77,47 +86,59 @@ func (m *manager) Deploy(ctx context.Context, j []byte) ([]byte, error) {
 		return j, fmt.Errorf("%w `version`: %w", common.ErrGettingField, err)
 	case target == current:
 		return j, nil
+	case latest < current:
+		errVersionNotRegistered(current, latest, "Version in config file")
+	case target > latest:
+		errVersionNotRegistered(target, latest, "Target downgrade version")
 	}
 
 	for current != target {
-		next := current + 1
-		action := "upgrade"
+		patchVersion := current + 1
+		action := "upgrade to"
 		configMethod := ConfigVersion.UpgradeConfig
 		exchMethod := ExchangeVersion.UpgradeExchange
 
 		if target < current {
-			next = current - 1
-			action = "downgrade"
+			patchVersion = current
+			action = "downgrade from"
 			configMethod = ConfigVersion.DowngradeConfig
 			exchMethod = ExchangeVersion.DowngradeExchange
 		}
 
-		log.Printf("Running %s to config version %v\n", action, next)
+		log.Printf("Running %s config version %v\n", action, patchVersion)
 
-		patch := m.versions[next]
+		patch := m.versions[patchVersion]
 
 		if cPatch, ok := patch.(ConfigVersion); ok {
 			if j, err = configMethod(cPatch, ctx, j); err != nil {
-				return j, fmt.Errorf("%w %s to %v: %w", errApplyingVersion, action, next, err)
+				return j, fmt.Errorf("%w %s %v: %w", errApplyingVersion, action, patchVersion, err)
 			}
 		}
 
 		if ePatch, ok := patch.(ExchangeVersion); ok {
 			if j, err = exchangeDeploy(ctx, ePatch, exchMethod, j); err != nil {
-				return j, fmt.Errorf("%w %s to %v: %w", errApplyingVersion, action, next, err)
+				return j, fmt.Errorf("%w %s %v: %w", errApplyingVersion, action, patchVersion, err)
 			}
 		}
 
-		current = next
+		current = patchVersion
+		if target < current {
+			current = patchVersion - 1
+		}
 
 		if j, err = jsonparser.Set(j, []byte(strconv.Itoa(current)), "version"); err != nil {
-			return j, fmt.Errorf("%w `version` during %s to %v: %w", common.ErrSettingField, action, next, err)
+			return j, fmt.Errorf("%w `version` during %s %v: %w", common.ErrSettingField, action, patchVersion, err)
 		}
 	}
 
+	var out bytes.Buffer
+	if err = json.Indent(&out, j, "", " "); err != nil {
+		return j, fmt.Errorf("error formatting json: %w", err)
+	}
+
 	log.Println("Version management finished")
 
-	return j, nil
+	return out.Bytes(), nil
 }
 
 func exchangeDeploy(ctx context.Context, patch ExchangeVersion, method func(ExchangeVersion, context.Context, []byte) ([]byte, error), j []byte) ([]byte, error) {
@@ -196,3 +217,12 @@ func (m *manager) checkVersions() error {
 	}
 	return nil
 }
+
+func errVersionNotRegistered(current, latest int, msg string) {
+	fmt.Fprintf(os.Stderr, `
+%s '%d' is higher than latest available version '%d'
+Switch back to the version of GoCryptoTrader containing config version '%d' and run:
+$ cmd/config downgrade %d 
+`, msg, current, latest, current, latest)
+	os.Exit(1)
+}

config/versions/versions_test.go

@@ -13,45 +13,45 @@ import (
 func TestDeploy(t *testing.T) {
 	t.Parallel()
 	m := manager{}
-	_, err := m.Deploy(context.Background(), []byte(``))
+	_, err := m.Deploy(context.Background(), []byte(``), -1)
 	assert.ErrorIs(t, err, errNoVersions)
 
 	m.registerVersion(1, &TestVersion1{})
-	_, err = m.Deploy(context.Background(), []byte(``))
+	_, err = m.Deploy(context.Background(), []byte(``), -1)
 	require.ErrorIs(t, err, errVersionIncompatible)
 
 	m = manager{}
 
 	m.registerVersion(0, &Version0{})
-	_, err = m.Deploy(context.Background(), []byte(`not an object`))
+	_, err = m.Deploy(context.Background(), []byte(`not an object`), -1)
 	require.ErrorIs(t, err, jsonparser.KeyPathNotFoundError, "Must throw the correct error trying to add version to bad json")
 	require.ErrorIs(t, err, common.ErrSettingField, "Must throw the correct error trying to add version to bad json")
 	require.ErrorContains(t, err, "version", "Must throw the correct error trying to add version to bad json")
 
-	_, err = m.Deploy(context.Background(), []byte(`{"version":"not an int"}`))
+	_, err = m.Deploy(context.Background(), []byte(`{"version":"not an int"}`), -1)
 	require.ErrorIs(t, err, common.ErrGettingField, "Must throw the correct error trying to get version from bad json")
 
 	in := []byte(`{"version":0,"exchanges":[{"name":"Juan"}]}`)
-	j, err := m.Deploy(context.Background(), in)
+	j, err := m.Deploy(context.Background(), in, -1)
 	require.NoError(t, err)
 	require.Equal(t, string(in), string(j))
 
 	m.registerVersion(1, &Version1{})
-	j, err = m.Deploy(context.Background(), in)
+	j, err = m.Deploy(context.Background(), in, -1)
 	require.NoError(t, err)
 	require.Contains(t, string(j), `"version":1`)
 
 	m.versions = m.versions[:1]
-	j, err = m.Deploy(context.Background(), j)
+	j, err = m.Deploy(context.Background(), j, -1)
 	require.NoError(t, err)
 	require.Contains(t, string(j), `"version":0`)
 
 	m.versions = append(m.versions, &TestVersion2{ConfigErr: true, ExchErr: false}) // Bit hacky, but this will actually work
-	_, err = m.Deploy(context.Background(), j)
+	_, err = m.Deploy(context.Background(), j, -1)
 	require.ErrorIs(t, err, errUpgrade)
 
 	m.versions[1] = &TestVersion2{ConfigErr: false, ExchErr: true}
-	_, err = m.Deploy(context.Background(), in)
+	_, err = m.Deploy(context.Background(), in, -1)
 	require.Implements(t, (*ExchangeVersion)(nil), m.versions[1])
 	require.ErrorIs(t, err, errUpgrade)
 }
@@ -61,7 +61,7 @@ func TestDeploy(t *testing.T) {
 func TestExchangeDeploy(t *testing.T) {
 	t.Parallel()
 	m := manager{}
-	_, err := m.Deploy(context.Background(), []byte(``))
+	_, err := m.Deploy(context.Background(), []byte(``), -1)
 	assert.ErrorIs(t, err, errNoVersions)
 
 	v := &TestVersion2{}