1 files changed, 151 insertions, 0 deletions
diff --git a/cmd/extwiki/main.go b/cmd/extwiki/main.go
new file mode 100644
index 0000000..76e0f3a
--- /dev/null
+++ b/cmd/extwiki/main.go
@@ -0,0 +1,151 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"maps"
+	"os"
+	"path/filepath"
+	"slices"
+	"sort"
+	"text/template/parse"
+)
+
+var (
+	titles  = make(map[string]struct{})
+	configs = map[string]int{"Wikipedia": 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.Fprint(outfile, `// Code generated by extwiki.  DO NOT EDIT.
+
+package wikipedia
+
+var extractedTitles = [...]string{
+`)
+	xs := slices.Collect(maps.Keys(titles))
+	sort.Strings(xs)
+	for _, t := range xs {
+		fmt.Fprintf(outfile, "%q,\n", t)
+	}
+	fmt.Fprint(outfile, "}\n")
+}
+
+func process(path string) {
+	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]
+		}
+
+		i, ok := configs[funcname]
+		if !ok {
+			for _, pipe := range n.Args {
+				processNode(pipe)
+			}
+			break
+		}
+
+		if sn, ok := n.Args[i].(*parse.StringNode); ok {
+			titles[sn.Text] = struct{}{}
+		}
+	}
+}
+
+func processBranch(n parse.BranchNode) {
+	processNode(n.List)
+	if n.ElseList != nil {
+		processNode(n.ElseList)
+	}
+}
+
+func try(err error) {
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "%s: %s\n", filepath.Base(os.Args[0]), err)
+		os.Exit(1)
+	}
+}
+
+func try2[T any](val T, err error) T {
+	try(err)
+	return val
+}