Fix CLI args (#66)

Signed-off-by: kayos@tcp.direct <kayos@tcp.direct>

go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/spf13/afero v1.9.3
 	github.com/spf13/viper v1.15.0
 	github.com/valyala/fasthttp v1.44.0
+	golang.org/x/term v0.0.0-20210927222741-03fcf44c2211
 )
 
 require (

go.sum

@@ -337,6 +337,7 @@ golang.org/x/sys v0.0.0-20220908164124-27713097b956/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.3.0 h1:w8ZOecv6NaNa/zC8944JTU3vz4u6Lagfk4RPQxv92NQ=
 golang.org/x/sys v0.3.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/term v0.0.0-20210927222741-03fcf44c2211 h1:JGgROgKl9N8DuW20oFS5gxc+lE67/N3FcwmBPMe7ArY=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
 golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

heffalump/markov.go

@@ -5,7 +5,6 @@ import (
 	"io"
 	"math/rand"
 	"strings"
-	"time"
 	"unicode"
 	"unicode/utf8"
 
@@ -15,7 +14,6 @@ import (
 var DefaultMarkovMap MarkovMap
 
 func init() {
-	rand.Seed(time.Now().UnixNano())
 	// DefaultMarkovMap is a Markov chain based on src.
 	src, err := squish.UnpackStr(srcGz)
 	if err != nil {

internal/config/arguments.go

@@ -1,44 +1,33 @@
 package config
 
-import "os"
-
-var usage = []string{
-	"\n" + Title + " v" + Version + " Usage\n",
-	"-c <config.toml> - Specify config file",
-	"--nocolor - disable color and banner ",
-	"--banner - show banner + version and exit",
-	"--genconfig - write default config to 'default.toml' then exit",
-}
-
-func printUsage() {
-	println(usage)
-	os.Exit(0)
-}
+import (
+	"os"
+)
 
 var (
 	forceDebug = false
 	forceTrace = false
 )
 
+var argBoolMap = map[string]*bool{
+	"--debug": &forceDebug, "-v": &forceDebug, "--trace": &forceTrace, "-vv": &forceTrace,
+	"--nocolor": &noColorForce, "--banner": &BannerOnly, "--genconfig": &GenConfig,
+}
+
 // TODO: should probably just make a proper CLI with flags or something
 func argParse() {
 	for i, arg := range os.Args {
+		if t, ok := argBoolMap[arg]; ok {
+			*t = true
+			continue
+		}
 		switch arg {
 		case "-h":
-			printUsage()
-		case "--genconfig":
-			GenConfig = true
-		case "--debug", "-v":
-			forceDebug = true
-		case "--trace", "-vv":
-			forceTrace = true
-		case "--nocolor":
-			noColorForce = true
-		case "--banner":
-			BannerOnly = true
+			CLI.printUsage()
 		case "-c", "--config":
-			if len(os.Args) <= i-1 {
-				panic("syntax error! expected file after -c")
+			if len(os.Args) < i+2 {
+				println("missing config file after -c/--config")
+				os.Exit(1)
 			}
 			loadCustomConfig(os.Args[i+1])
 		default:

internal/config/globals.go

@@ -16,6 +16,7 @@ func init() {
 	for _, v := range info.Settings {
 		binInfo[v.Key] = v.Value
 	}
+
 	if gitrev, ok := binInfo["vcs.revision"]; ok && Version == "dev" {
 		Version = gitrev[:7]
 	}

internal/config/help.go

@@ -0,0 +1,123 @@
+package config
+
+import (
+	"io"
+	"os"
+	"strings"
+
+	"golang.org/x/term"
+)
+
+type help struct {
+	title, version string
+	usage          map[int][]string
+	out            io.Writer
+}
+
+var CLI = help{
+	title:   Title,
+	version: Version,
+	usage: map[int][]string{
+		0: {0: "--config", 1: "<file>", 2: "Specify config file"},
+		1: {0: "--nocolor", 1: "disable color and banner"},
+		2: {0: "--banner", 1: "show banner + version and exit"},
+		3: {0: "--genconfig", 1: "write default config to 'default.toml' then exit"},
+		4: {0: "--help", 1: "show this help and exit"},
+	},
+	out: os.Stdout,
+}
+
+func (cli help) secondColStart(index int) (max int) {
+	l := cli.firstColEnd() + 2
+	if len(cli.usage[index]) > 2 && cli.usage[index][2] != "" {
+		l -= len(cli.usage[index][1])
+	}
+	if l > max {
+		max = l
+	}
+	return max
+}
+
+func (cli help) firstColEnd() (max int) {
+	for n := range cli.usage {
+		l := len(cli.usage[n][0])
+		if l > max {
+			max = l
+		}
+	}
+	return max
+}
+
+func (cli help) stdout(s ...string) {
+	for _, v := range s {
+		_, _ = cli.out.Write([]byte(v))
+	}
+}
+
+func (cli help) lb(n int) {
+	for n > 0 {
+		cli.stdout("\n")
+		n--
+	}
+}
+
+func (cli help) printUsage() {
+	if !term.IsTerminal(int(os.Stdout.Fd())) {
+		os.Exit(1)
+	}
+	cli.header()
+
+	for n := 0; n < len(cli.usage); n++ {
+		line := &strings.Builder{}
+		buf := &strings.Builder{}
+		usageAt := 1
+		tlen := cli.secondColStart(n)
+		switch {
+		case cli.usage[n][0] == "":
+			cli.lb(1)
+		case cli.usage[n][1] == "":
+			cli.stdout(cli.usage[n][0])
+			cli.lb(2)
+		case len(cli.usage[n]) > 2 && cli.usage[n][2] != "":
+			tlen = cli.firstColEnd() - len(cli.usage[n][1])
+			usageAt = 2
+			fallthrough
+		default:
+			buf.WriteString(cli.usage[n][0])
+		}
+		if tlen < 0 {
+			tlen = 2
+		}
+		tab := strings.Repeat(" ", tlen)
+		line.WriteString(" ")
+		if buf.Len() < cli.firstColEnd() {
+			line.WriteString(strings.Repeat(" ", cli.firstColEnd()-buf.Len()))
+		}
+		if usageAt == 2 {
+			buf.WriteString(strings.Repeat(" ", tlen/2))
+			buf.WriteString(cli.usage[n][1])
+		}
+		buf.WriteString(tab)
+		buf.Write([]byte(" (" + cli.usage[n][usageAt] + ")"))
+		buf.Write([]byte{'\n'})
+		line.Write([]byte(buf.String()))
+		cli.stdout(line.String())
+	}
+	os.Exit(0)
+
+}
+
+func (cli help) header() {
+	cli.stdout("\n")
+	s := &strings.Builder{}
+	s.Write([]byte(cli.title))
+	s.Write([]byte(" v["))
+	s.Write([]byte(cli.version))
+	s.Write([]byte("]"))
+	tab := cli.firstColEnd() - (s.Len() % 2) + 1
+	if tab > 0 {
+		cli.stdout(strings.Repeat(" ", tab))
+	}
+	cli.stdout(s.String())
+	cli.lb(2)
+}