Rework config/flags (fixes #13)

config.go

@@ -0,0 +1,129 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"reflect"
+	"strconv"
+	"strings"
+	"text/template"
+	"time"
+)
+
+type Options struct {
+	Listen            string        `ini:"listen-address" default:":22000" description:"ip:port to for incoming sync connections"`
+	ReadOnly          bool          `ini:"read-only" description:"Allow changes to the local repository"`
+	Delete            bool          `ini:"allow-delete" default:"true" description:"Allow deletes of files in the local repository"`
+	Symlinks          bool          `ini:"follow-symlinks" default:"true" description:"Follow symbolic links at the top level of the repository"`
+	GUI               bool          `ini:"gui-enabled" default:"true" description:"Enable the HTTP GUI"`
+	GUIAddr           string        `ini:"gui-address" default:"127.0.0.1:8080" description:"ip:port for GUI connections"`
+	ExternalServer    string        `ini:"global-announce-server" default:"syncthing.nym.se:22025" description:"Global server for announcements"`
+	ExternalDiscovery bool          `ini:"global-announce-enabled" default:"true" description:"Announce to the global announce server"`
+	LocalDiscovery    bool          `ini:"local-announce-enabled" default:"true" description:"Announce to the local network"`
+	RequestsInFlight  int           `ini:"parallell-requests" default:"16" description:"Maximum number of blocks to request in parallell"`
+	LimitRate         int           `ini:"max-send-kbps" description:"Limit outgoing data rate (kbyte/s)"`
+	ScanInterval      time.Duration `ini:"rescan-interval" default:"60s" description:"Scan repository for changes this often"`
+	ConnInterval      time.Duration `ini:"reconnection-interval" default:"60s" description:"Attempt to (re)connect to peers this often"`
+	MaxChangeBW       int           `ini:"max-change-bw" default:"1000" description:"Suppress files changing more than this (kbyte/s)"`
+}
+
+func loadConfig(m map[string]string, data interface{}) error {
+	s := reflect.ValueOf(data).Elem()
+	t := s.Type()
+
+	for i := 0; i < s.NumField(); i++ {
+		f := s.Field(i)
+		tag := t.Field(i).Tag
+
+		name := tag.Get("ini")
+		if len(name) == 0 {
+			name = strings.ToLower(t.Field(i).Name)
+		}
+
+		v, ok := m[name]
+		if !ok {
+			v = tag.Get("default")
+		}
+		if len(v) > 0 {
+			switch f.Interface().(type) {
+			case time.Duration:
+				d, err := time.ParseDuration(v)
+				if err != nil {
+					return err
+				}
+				f.SetInt(int64(d))
+
+			case string:
+				f.SetString(v)
+
+			case int:
+				i, err := strconv.ParseInt(v, 10, 64)
+				if err != nil {
+					return err
+				}
+				f.SetInt(i)
+
+			case bool:
+				f.SetBool(v == "true")
+
+			default:
+				panic(f.Type())
+			}
+		}
+	}
+	return nil
+}
+
+type cfg struct {
+	Key     string
+	Value   string
+	Comment string
+}
+
+func structToValues(data interface{}) []cfg {
+	s := reflect.ValueOf(data).Elem()
+	t := s.Type()
+
+	var vals []cfg
+	for i := 0; i < s.NumField(); i++ {
+		f := s.Field(i)
+		tag := t.Field(i).Tag
+
+		var c cfg
+		c.Key = tag.Get("ini")
+		if len(c.Key) == 0 {
+			c.Key = strings.ToLower(t.Field(i).Name)
+		}
+		c.Value = fmt.Sprint(f.Interface())
+		c.Comment = tag.Get("description")
+		vals = append(vals, c)
+	}
+	return vals
+}
+
+var configTemplateStr = `[repository]
+{{if .comments}}; The directory to synchronize. Will be created if it does not exist.
+{{end}}dir = {{.dir}}
+
+[nodes]
+{{if .comments}}; Map of node ID to addresses, or "dynamic" for automatic discovery. Examples:
+; J3MZ4G5O4CLHJKB25WX47K5NUJUWDOLO2TTNY3TV3NRU4HVQRKEQ = 172.16.32.24:22000
+; ZNJZRXQKYHF56A2VVNESRZ6AY4ZOWGFJCV6FXDZJUTRVR3SNBT6Q = dynamic
+{{end}}{{range $n, $a := .nodes}}{{$n}} = {{$a}}
+{{end}}
+[settings]
+{{range $v := .settings}}; {{$v.Comment}}
+{{$v.Key}} = {{$v.Value}}
+{{end}}
+`
+
+var configTemplate = template.Must(template.New("config").Parse(configTemplateStr))
+
+func writeConfig(wr io.Writer, dir string, nodes map[string]string, opts Options, comments bool) {
+	configTemplate.Execute(wr, map[string]interface{}{
+		"dir":      dir,
+		"nodes":    nodes,
+		"settings": structToValues(&opts),
+		"comments": comments,
+	})
+}