From d28829ba288452dabf46cc42f45548dd54df64e9 Mon Sep 17 00:00:00 2001
From: Sergey Matveev <stargrave@stargrave.org>
Date: Sat, 1 May 2021 16:11:26 +0300
Subject: [PATCH] Simplify config read and arguments parsing

---
 cmd/sgblog/gopher.go | 20 ++------------------
 cmd/sgblog/http.go   | 20 +++-----------------
 cmd/sgblog/main.go   | 36 +++++++++++++++++++++++++++++++++---
 common.go            |  2 +-
 4 files changed, 39 insertions(+), 39 deletions(-)

diff --git a/cmd/sgblog/gopher.go b/cmd/sgblog/gopher.go
index 183914c..b12a2b8 100644
--- a/cmd/sgblog/gopher.go
+++ b/cmd/sgblog/gopher.go
@@ -19,11 +19,9 @@ package main
 
 import (
 	"bufio"
-	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"net/url"
 	"os"
@@ -34,7 +32,6 @@ import (
 	"github.com/go-git/go-git/v5"
 	"github.com/go-git/go-git/v5/plumbing"
 	"github.com/go-git/go-git/v5/plumbing/object"
-	"github.com/hjson/hjson-go"
 	"go.stargrave.org/sgblog"
 )
 
@@ -86,24 +83,11 @@ type TableMenuEntry struct {
 	Topics      []string
 }
 
-func serveGopher() {
-	cfgPath := os.Args[2]
-	cfgRaw, err := ioutil.ReadFile(cfgPath)
+func serveGopher(cfgPath string) {
+	cfg, err := readCfg(cfgPath)
 	if err != nil {
 		log.Fatalln(err)
 	}
-	var cfgGeneral map[string]interface{}
-	if err = hjson.Unmarshal(cfgRaw, &cfgGeneral); err != nil {
-		log.Fatalln(err)
-	}
-	cfgRaw, err = json.Marshal(cfgGeneral)
-	if err != nil {
-		log.Fatalln(err)
-	}
-	var cfg *Cfg
-	if err = json.Unmarshal(cfgRaw, &cfg); err != nil {
-		log.Fatalln(err)
-	}
 	if cfg.GopherDomain == "" {
 		log.Fatalln("GopherDomain is not configured")
 	}
diff --git a/cmd/sgblog/http.go b/cmd/sgblog/http.go
index bad1cb8..d039ed3 100644
--- a/cmd/sgblog/http.go
+++ b/cmd/sgblog/http.go
@@ -22,14 +22,12 @@ import (
 	"compress/gzip"
 	"crypto/sha1"
 	"encoding/hex"
-	"encoding/json"
 	"encoding/xml"
 	"errors"
 	"fmt"
 	"hash"
 	"html"
 	"io"
-	"io/ioutil"
 	"log"
 	"net/url"
 	"os"
@@ -40,7 +38,6 @@ import (
 	"github.com/go-git/go-git/v5"
 	"github.com/go-git/go-git/v5/plumbing"
 	"github.com/go-git/go-git/v5/plumbing/object"
-	"github.com/hjson/hjson-go"
 	"go.stargrave.org/sgblog"
 	"go.stargrave.org/sgblog/cmd/sgblog/atom"
 	"golang.org/x/crypto/blake2b"
@@ -260,22 +257,11 @@ func serveHTTP() {
 	if cfgPath == "" {
 		log.Fatalln("SGBLOG_CFG is not set")
 	}
-	cfgRaw, err := ioutil.ReadFile(cfgPath)
+	cfg, err := readCfg(cfgPath)
 	if err != nil {
-		makeErr(err)
-	}
-	var cfgGeneral map[string]interface{}
-	if err = hjson.Unmarshal(cfgRaw, &cfgGeneral); err != nil {
-		makeErr(err)
-	}
-	cfgRaw, err = json.Marshal(cfgGeneral)
-	if err != nil {
-		makeErr(err)
-	}
-	var cfg *Cfg
-	if err = json.Unmarshal(cfgRaw, &cfg); err != nil {
-		makeErr(err)
+		log.Fatalln(err)
 	}
+
 	pathInfo, exists := os.LookupEnv("PATH_INFO")
 	if !exists {
 		pathInfo = "/"
diff --git a/cmd/sgblog/main.go b/cmd/sgblog/main.go
index 7603d12..b373564 100644
--- a/cmd/sgblog/main.go
+++ b/cmd/sgblog/main.go
@@ -21,9 +21,10 @@ package main
 import (
 	"bytes"
 	"crypto/sha1"
+	"encoding/json"
+	"flag"
 	"fmt"
 	"io/ioutil"
-	"os"
 	"regexp"
 	"sort"
 	"strings"
@@ -32,6 +33,7 @@ import (
 	"github.com/go-git/go-git/v5"
 	"github.com/go-git/go-git/v5/plumbing"
 	"github.com/go-git/go-git/v5/plumbing/object"
+	"github.com/hjson/hjson-go"
 	"go.cypherpunks.ru/recfile"
 )
 
@@ -195,9 +197,37 @@ func initRepo(cfg *Cfg) (*plumbing.Hash, error) {
 	return &headHash, nil
 }
 
+func readCfg(cfgPath string) (*Cfg, error) {
+	cfgRaw, err := ioutil.ReadFile(cfgPath)
+	if err != nil {
+		return nil, err
+	}
+	var cfgGeneral map[string]interface{}
+	if err = hjson.Unmarshal(cfgRaw, &cfgGeneral); err != nil {
+		return nil, err
+	}
+	cfgRaw, err = json.Marshal(cfgGeneral)
+	if err != nil {
+		return nil, err
+	}
+	var cfg *Cfg
+	if err = json.Unmarshal(cfgRaw, &cfg); err != nil {
+		return nil, err
+	}
+	return cfg, nil
+}
+
 func main() {
-	if len(os.Args) == 3 && os.Args[1] == "-gopher" {
-		serveGopher()
+	gopherCfgPath := flag.String("gopher", "", "Path to gopher-related configuration file")
+	flag.Usage = func() {
+		fmt.Fprintf(flag.CommandLine.Output(), `Usage of sgblog:
+	sgblog -- run CGI HTTP backend
+	sgblog -gopher /path/to/cfg.hjson -- run UCSPI/inetd Gopher backend
+`)
+	}
+	flag.Parse()
+	if *gopherCfgPath != "" {
+		serveGopher(*gopherCfgPath)
 	} else {
 		serveHTTP()
 	}
diff --git a/common.go b/common.go
index ea1e7db..ebb5a9d 100644
--- a/common.go
+++ b/common.go
@@ -2,6 +2,6 @@
 package sgblog
 
 const (
-	Version = "0.16.0"
+	Version = "0.17.0"
 	WhenFmt = "2006-01-02 15:04:05Z07:00"
 )
-- 
2.44.0