Support config file

flags.go

@@ -0,0 +1,101 @@
+package main
+
+import (
+	"errors"
+	"reflect"
+	"strings"
+
+	"github.com/codegangsta/cli"
+	"github.com/fatih/structs"
+
+	"github.com/yudai/gotty/app"
+)
+
+type flag struct {
+	name        string
+	shortName   string
+	description string
+}
+
+func generateFlags(flags []flag, hint map[string]string) ([]cli.Flag, error) {
+	o := structs.New(app.DefaultOptions)
+
+	results := make([]cli.Flag, len(flags))
+
+	for i, flag := range flags {
+		fieldName := fieldName(flag.name, hint)
+
+		field, ok := o.FieldOk(fieldName)
+		if !ok {
+			return nil, errors.New("No such field: " + fieldName)
+		}
+
+		flagName := flag.name
+		if flag.shortName != "" {
+			flagName += ", " + flag.shortName
+		}
+		envName := "GOTTY_" + strings.ToUpper(strings.Join(strings.Split(flag.name, "-"), "_"))
+
+		switch field.Kind() {
+		case reflect.String:
+			results[i] = cli.StringFlag{
+				Name:   flagName,
+				Value:  field.Value().(string),
+				Usage:  flag.description,
+				EnvVar: envName,
+			}
+		case reflect.Bool:
+			results[i] = cli.BoolFlag{
+				Name:   flagName,
+				Usage:  flag.description,
+				EnvVar: envName,
+			}
+		case reflect.Int:
+			results[i] = cli.IntFlag{
+				Name:   flagName,
+				Value:  field.Value().(int),
+				Usage:  flag.description,
+				EnvVar: envName,
+			}
+		default:
+			return nil, errors.New("Unsupported type: " + fieldName)
+		}
+	}
+
+	return results, nil
+}
+
+func applyFlags(
+	options *app.Options,
+	flags []flag,
+	mappingHint map[string]string,
+	c *cli.Context,
+) {
+	o := structs.New(options)
+	for _, flag := range flags {
+		if c.IsSet(flag.name) {
+			field := o.Field(fieldName(flag.name, mappingHint))
+			var val interface{}
+			switch field.Kind() {
+			case reflect.String:
+				val = c.String(flag.name)
+			case reflect.Bool:
+				val = c.Bool(flag.name)
+			case reflect.Int:
+				val = c.Int(flag.name)
+			}
+			field.Set(val)
+		}
+	}
+}
+
+func fieldName(name string, hint map[string]string) string {
+	if fieldName, ok := hint[name]; ok {
+		return fieldName
+	}
+	nameParts := strings.Split(name, "-")
+	for i, part := range nameParts {
+		nameParts[i] = strings.ToUpper(part[0:1]) + part[1:]
+	}
+	return strings.Join(nameParts, "")
+}