new config infrastructure

- adds config get and config set commands
- supports arbitrary k/v strings set at top and host level
- supports writing an updated config, preserving comments
- supports mostly lazy evaluation of yaml

context/config_file.go

@@ -10,57 +10,159 @@ import (
 	"gopkg.in/yaml.v3"
 )
 
-const defaultHostname = "github.com"
-
-type configEntry struct {
-	User  string
-	Token string `yaml:"oauth_token"`
-}
-
-func parseOrSetupConfigFile(fn string) (*configEntry, error) {
-	entry, err := parseConfigFile(fn)
+func parseOrSetupConfigFile(fn string) (Config, error) {
+	config, err := ParseConfig(fn)
 	if err != nil && errors.Is(err, os.ErrNotExist) {
 		return setupConfigFile(fn)
 	}
-	return entry, err
+	return config, err
 }
 
-func parseConfigFile(fn string) (*configEntry, error) {
+func ParseDefaultConfig() (Config, error) {
+	return ParseConfig(configFile())
+}
+
+var ReadConfigFile = func(fn string) ([]byte, error) {
 	f, err := os.Open(fn)
 	if err != nil {
 		return nil, err
 	}
 	defer f.Close()
-	return parseConfig(f)
-}
 
-// ParseDefaultConfig reads the configuration file
-func ParseDefaultConfig() (*configEntry, error) {
-	return parseConfigFile(configFile())
-}
-
-func parseConfig(r io.Reader) (*configEntry, error) {
-	data, err := ioutil.ReadAll(r)
+	data, err := ioutil.ReadAll(f)
 	if err != nil {
 		return nil, err
 	}
-	var config yaml.Node
-	err = yaml.Unmarshal(data, &config)
+
+	return data, nil
+}
+
+var WriteConfigFile = func(fn string, data []byte) error {
+	cfgFile, err := os.OpenFile(configFile(), os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600) // cargo coded from setup
 	if err != nil {
-		return nil, err
+		return err
 	}
-	if len(config.Content) < 1 {
-		return nil, fmt.Errorf("malformed config")
+	defer cfgFile.Close()
+
+	n, err := cfgFile.Write(data)
+	if err == nil && n < len(data) {
+		err = io.ErrShortWrite
 	}
-	for i := 0; i < len(config.Content[0].Content)-1; i = i + 2 {
-		if config.Content[0].Content[i].Value == defaultHostname {
-			var entries []configEntry
-			err = config.Content[0].Content[i+1].Decode(&entries)
-			if err != nil {
-				return nil, err
-			}
-			return &entries[0], nil
+
+	return err
+}
+
+var BackupConfigFile = func(fn string) error {
+	return os.Rename(fn, fn+".bak")
+}
+
+func parseConfigFile(fn string) ([]byte, *yaml.Node, error) {
+	data, err := ReadConfigFile(fn)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	var root yaml.Node
+	err = yaml.Unmarshal(data, &root)
+	if err != nil {
+		return data, nil, err
+	}
+	if len(root.Content) < 1 {
+		return data, &root, fmt.Errorf("malformed config")
+	}
+	if root.Content[0].Kind != yaml.MappingNode {
+		return data, &root, fmt.Errorf("expected a top level map")
+	}
+
+	return data, &root, nil
+}
+
+func isLegacy(root *yaml.Node) bool {
+	for _, v := range root.Content[0].Content {
+		if v.Value == "hosts" {
+			return false
 		}
 	}
-	return nil, fmt.Errorf("could not find config entry for %q", defaultHostname)
+
+	return true
+}
+
+func migrateConfig(fn string, root *yaml.Node) error {
+	// TODO i'm sorry
+	newConfigData := map[string]map[string]map[string]string{}
+	newConfigData["hosts"] = map[string]map[string]string{}
+
+	topLevelKeys := root.Content[0].Content
+
+	for i, x := range topLevelKeys {
+		if x.Value == "" {
+			continue
+		}
+		if i+1 == len(topLevelKeys) {
+			break
+		}
+		hostname := x.Value
+		newConfigData["hosts"][hostname] = map[string]string{}
+
+		authKeys := topLevelKeys[i+1].Content[0].Content
+
+		for j, y := range authKeys {
+			if j+1 == len(authKeys) {
+				break
+			}
+			switch y.Value {
+			case "user":
+				newConfigData["hosts"][hostname]["user"] = authKeys[j+1].Value
+			case "oauth_token":
+				newConfigData["hosts"][hostname]["oauth_token"] = authKeys[j+1].Value
+			}
+		}
+	}
+
+	if _, ok := newConfigData["hosts"][defaultHostname]; !ok {
+		return errors.New("could not find default host configuration")
+	}
+
+	defaultHostConfig := newConfigData["hosts"][defaultHostname]
+
+	if _, ok := defaultHostConfig["user"]; !ok {
+		return errors.New("default host configuration missing user")
+	}
+
+	if _, ok := defaultHostConfig["oauth_token"]; !ok {
+		return errors.New("default host configuration missing oauth_token")
+	}
+
+	newConfig, err := yaml.Marshal(newConfigData)
+	if err != nil {
+		return err
+	}
+
+	err = BackupConfigFile(fn)
+	if err != nil {
+		return fmt.Errorf("failed to back up existing config: %s", err)
+	}
+
+	return WriteConfigFile(fn, newConfig)
+}
+
+func ParseConfig(fn string) (Config, error) {
+	_, root, err := parseConfigFile(fn)
+	if err != nil {
+		return nil, err
+	}
+
+	if isLegacy(root) {
+		err = migrateConfig(fn, root)
+		if err != nil {
+			return nil, err
+		}
+
+		_, root, err = parseConfigFile(fn)
+		if err != nil {
+			return nil, fmt.Errorf("failed to reparse migrated config: %s", err)
+		}
+	}
+
+	return NewConfig(root), nil
 }