soju/config/config.go
2020-03-13 18:13:03 +01:00

185 lines
3.2 KiB
Go

package config
import (
"bufio"
"fmt"
"io"
"os"
"strings"
"unicode"
)
type TLS struct {
CertPath, KeyPath string
}
type Server struct {
Addr string
Hostname string
TLS *TLS
SQLDriver string
SQLSource string
}
func Defaults() *Server {
hostname, err := os.Hostname()
if err != nil {
hostname = "localhost"
}
return &Server{
Addr: ":6667",
Hostname: hostname,
SQLDriver: "sqlite3",
SQLSource: "soju.db",
}
}
func Load(path string) (*Server, error) {
f, err := os.Open(path)
if err != nil {
return nil, err
}
defer f.Close()
return Parse(f)
}
func Parse(r io.Reader) (*Server, error) {
p := parser{br: bufio.NewReader(r)}
directives, err := p.file()
if err != nil {
return nil, fmt.Errorf("failed to parse config file: %v", err)
}
srv := Defaults()
for _, d := range directives {
switch d.Name {
case "listen":
if err := d.parseParams(&srv.Addr); err != nil {
return nil, err
}
case "hostname":
if err := d.parseParams(&srv.Hostname); err != nil {
return nil, err
}
case "tls":
tls := &TLS{}
if err := d.parseParams(&tls.CertPath, &tls.KeyPath); err != nil {
return nil, err
}
srv.TLS = tls
case "sql":
if err := d.parseParams(&srv.SQLDriver, &srv.SQLSource); err != nil {
return nil, err
}
default:
return nil, fmt.Errorf("unknown directive %q", d.Name)
}
}
return srv, nil
}
type directive struct {
Name string
Params []string
}
func (d *directive) parseParams(out ...*string) error {
if len(d.Params) != len(out) {
return fmt.Errorf("directive %q has wrong number of parameters: expected %v, got %v", d.Name, len(out), len(d.Params))
}
for i := range out {
*out[i] = d.Params[i]
}
return nil
}
type parser struct {
br *bufio.Reader
}
func (p *parser) skipSpace() error {
for {
r, _, err := p.br.ReadRune()
if err == io.EOF {
break
} else if err != nil {
return err
}
if !unicode.IsSpace(r) || r == '\n' {
p.br.UnreadRune()
break
}
}
return nil
}
func (p *parser) atom() (string, error) {
var sb strings.Builder
for {
r, _, err := p.br.ReadRune()
if err == io.EOF && sb.Len() > 0 {
break
} else if err != nil {
return "", err
}
if unicode.IsSpace(r) {
p.br.UnreadRune()
if err := p.skipSpace(); err != nil {
return "", err
}
break
}
sb.WriteRune(r)
}
return sb.String(), nil
}
func (p *parser) directive() (*directive, error) {
name, err := p.atom()
if err == io.EOF {
return nil, io.EOF
} else if err != nil {
return nil, fmt.Errorf("failed to read directive name: %v", err)
}
var params []string
for {
r, _, err := p.br.ReadRune()
if err == io.EOF {
break
} else if err != nil {
return nil, err
}
if r == '\n' {
break
}
p.br.UnreadRune()
param, err := p.atom()
if err == io.EOF {
break
} else if err != nil {
return nil, fmt.Errorf("failed to read directive param: %v", err)
}
params = append(params, param)
}
return &directive{name, params}, nil
}
func (p *parser) file() ([]directive, error) {
var l []directive
for {
d, err := p.directive()
if err == io.EOF {
break
} else if err != nil {
return nil, err
}
l = append(l, *d)
}
return l, nil
}