1 files changed, 305 insertions, 0 deletions
diff --git a/cmd/extpo/main.go b/cmd/extpo/main.go
new file mode 100644
index 0000000..6aa1503
--- /dev/null
+++ b/cmd/extpo/main.go
@@ -0,0 +1,305 @@
+package main
+
+import (
+	"bytes"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"slices"
+	"strings"
+	"text/template/parse"
+	"time"
+)
+
+type config struct {
+	arg     int
+	plural  int
+	context int
+	domain  int
+}
+
+type translation struct {
+	msgid       string
+	msgidPlural string
+	msgctxt     string
+	domain      string
+}
+
+type transinfo struct {
+	comment string
+	locs    []loc
+}
+
+type loc struct {
+	file string
+	line int
+}
+
+func (l loc) String() string {
+	return fmt.Sprintf("%s:%d", l.file, l.line)
+}
+
+var (
+	currentFile  []byte
+	currentPath  string
+	lastComment  string
+	translations = make(map[translation]transinfo)
+	configs      = map[string]config{
+		"Get":    {1, -1, -1, -1},
+		"GetC":   {1, -1, 2, -1},
+		"GetD":   {2, -1, -1, 1},
+		"GetDC":  {2, -1, 3, 1},
+		"GetN":   {1, 2, -1, -1},
+		"GetNC":  {1, 2, 4, -1},
+		"GetND":  {2, 3, -1, 1},
+		"GetNDC": {2, 3, 5, 1},
+	}
+)
+
+func usage() {
+	fmt.Fprintf(os.Stderr, "Usage: %s [flags] template...\n",
+		filepath.Base(os.Args[0]))
+	flag.PrintDefaults()
+}
+
+func main() {
+	try(os.Chdir(filepath.Dir(os.Args[0])))
+
+	outpath := flag.String("out", "-", "output file")
+	flag.Usage = usage
+	flag.Parse()
+
+	if flag.NArg() < 1 {
+		flag.Usage()
+		os.Exit(1)
+	}
+
+	var outfile *os.File
+	if *outpath == "-" {
+		outfile = os.Stdout
+	} else {
+		outfile = try2(os.Create(*outpath))
+	}
+
+	for _, f := range flag.Args() {
+		process(f)
+	}
+
+	fmt.Fprintf(outfile, `# SOME DESCRIPTIVE TITLE.
+# Copyright (C) YEAR THE PACKAGE'S COPYRIGHT HOLDER
+# This file is distributed under the same license as the PACKAGE package.
+# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
+#
+#, fuzzy
+msgid ""
+msgstr ""
+"Project-Id-Version: PACKAGE VERSION\n"
+"Report-Msgid-Bugs-To: \n"
+"POT-Creation-Date: %s\n"
+"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
+"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
+"Language-Team: LANGUAGE <LL@li.org>\n"
+"Language: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+`, time.Now().Format("2006-01-02 15:04-0700"))
+
+	for tl, ti := range translations {
+		if ti.comment != "" {
+			fmt.Fprintln(outfile, "#.", ti.comment)
+		}
+
+		slices.SortFunc(ti.locs, func(a, b loc) int {
+			if x := strings.Compare(a.file, b.file); x != 0 {
+				return x
+			}
+			return a.line - b.line
+		})
+		for _, x := range ti.locs {
+			fmt.Fprintln(outfile, "#:", x)
+		}
+
+		if tl.msgctxt != "" {
+			writeField(outfile, "msgctxt", tl.msgctxt)
+		}
+		writeField(outfile, "msgid", tl.msgid)
+		if tl.msgidPlural != "" {
+			writeField(outfile, "msgid_plural", tl.msgidPlural)
+			writeField(outfile, "msgstr[0]", "")
+			writeField(outfile, "msgstr[1]", "")
+		} else {
+			writeField(outfile, "msgstr", "")
+		}
+		fmt.Fprint(outfile, "\n")
+	}
+}
+
+func process(path string) {
+	currentPath = path
+	currentFile = try2(os.ReadFile(path))
+	trees := make(map[string]*parse.Tree)
+	t := parse.New(path)
+	t.Mode |= parse.ParseComments | parse.SkipFuncCheck
+	try2(t.Parse(string(currentFile), "", "", trees))
+	for _, t := range trees {
+		processNode(t.Root)
+	}
+}
+
+func processNode(node parse.Node) {
+	switch n := node.(type) {
+	case *parse.ListNode:
+		for _, m := range n.Nodes {
+			processNode(m)
+		}
+	case *parse.PipeNode:
+		for _, m := range n.Cmds {
+			processNode(m)
+		}
+	case *parse.TemplateNode:
+		processNode(n.Pipe)
+	case *parse.IfNode:
+		processBranch(n.BranchNode)
+	case *parse.RangeNode:
+		processBranch(n.BranchNode)
+	case *parse.WithNode:
+		processBranch(n.BranchNode)
+	case *parse.BranchNode:
+		processBranch(*n)
+	case *parse.ActionNode:
+		processNode(n.Pipe)
+	case *parse.CommandNode:
+		if len(n.Args) == 0 {
+			break
+		}
+
+		var funcname string
+		f, ok := n.Args[0].(*parse.FieldNode)
+		if !ok || len(f.Ident) == 0 {
+			ff, ok := n.Args[0].(*parse.VariableNode)
+			if !ok || len(ff.Ident) == 0 {
+				fff, ok := n.Args[0].(*parse.IdentifierNode)
+				if !ok {
+					for _, pipe := range n.Args {
+						processNode(pipe)
+					}
+					break
+				}
+				funcname = fff.Ident
+			} else {
+				funcname = ff.Ident[len(ff.Ident)-1]
+			}
+		} else {
+			funcname = f.Ident[len(f.Ident)-1]
+		}
+
+		cfg, ok := configs[funcname]
+		if !ok {
+			for _, pipe := range n.Args {
+				processNode(pipe)
+			}
+			break
+		}
+
+		var (
+			tl     translation
+			linenr int
+		)
+
+		if sn, ok := n.Args[cfg.arg].(*parse.StringNode); ok {
+			tl.msgid = sn.Text
+			linenr = getlinenr(sn.Pos.Position())
+		} else {
+			break
+		}
+		if cfg.plural != -1 {
+			if sn, ok := n.Args[cfg.plural].(*parse.StringNode); ok {
+				tl.msgidPlural = sn.Text
+			}
+		}
+		if cfg.context != -1 {
+			if sn, ok := n.Args[cfg.context].(*parse.StringNode); ok {
+				tl.msgctxt = sn.Text
+			}
+		}
+
+		ti := translations[tl]
+		if lastComment != "" {
+			ti.comment = lastComment
+			lastComment = ""
+		}
+		ti.locs = append(ti.locs, loc{currentPath, linenr})
+		translations[tl] = ti
+	case *parse.CommentNode:
+		if strings.HasPrefix(n.Text, "/* TRANSLATORS:") {
+			lastComment = strings.TrimSpace(n.Text[2 : len(n.Text)-2])
+		}
+	}
+}
+
+func processBranch(n parse.BranchNode) {
+	processNode(n.List)
+	if n.ElseList != nil {
+		processNode(n.ElseList)
+	}
+}
+
+func writeField(w io.Writer, pfx, s string) {
+	fmt.Fprintf(w, "%s ", pfx)
+	if strings.ContainsRune(s, '\n') {
+		fmt.Fprintln(w, "\"\"")
+		lines := strings.SplitAfter(s, "\n")
+		n := len(lines)
+		if n > 1 && lines[n-1] == "" {
+			lines = lines[:n-1]
+		}
+		for _, ss := range lines {
+			writeLine(w, ss)
+		}
+		fmt.Fprintln(w, "\"\"")
+	} else {
+		writeLine(w, s)
+	}
+}
+
+func writeLine(w io.Writer, s string) {
+	fmt.Fprint(w, "\"")
+	for _, c := range s {
+		switch c {
+		case '\\', '"':
+			fmt.Fprintf(w, "\\%c", c)
+		case '\n':
+			fmt.Fprint(w, "\\n")
+		default:
+			fmt.Fprintf(w, "%c", c)
+		}
+	}
+	fmt.Fprintln(w, "\"")
+}
+
+func getlinenr(p parse.Pos) int {
+	return bytes.Count(currentFile[:p], []byte{'\n'}) + 1
+}
+
+func try(err error) {
+	if err != nil {
+		die(err)
+	}
+}
+
+func try2[T any](val T, err error) T {
+	try(err)
+	return val
+}
+
+func warn(err any) {
+	fmt.Fprintf(os.Stderr, "%s: %s\n", filepath.Base(os.Args[0]), err)
+}
+
+func die(err any) {
+	warn(err)
+	os.Exit(1)
+}