WIP: Waifufetch by JGH0 working in windows-bash

cmd/bash/main.go

@@ -60,12 +60,7 @@ func historyFile() string {
 func interactive() error {
 	sh := shell.New()
 
-	// Build completer
-	completer := readline.NewPrefixCompleter(
-		readline.PcItemDynamic(func(line string) []string {
-			return dynamicComplete(sh, line)
-		}),
-	)
+	completer := &shellCompleter{sh: sh}
 
 	rl, err := readline.NewEx(&readline.Config{
 		HistoryFile:            historyFile(),
@@ -183,6 +178,56 @@ func buildPrompt(sh *shell.Shell) string {
 	return pwd + suffix
 }
 
+// shellCompleter implements readline.AutoCompleter.
+// readline's built-in PrefixCompleter matches candidates against the full
+// line, so "C:\workspace" never matches "cd C:\w". This implementation
+// extracts the last token and returns only the suffix to append.
+type shellCompleter struct{ sh *shell.Shell }
+
+func (c *shellCompleter) Do(line []rune, pos int) (newLine [][]rune, offset int) {
+	lineStr := string(line[:pos])
+	last := lastToken(lineStr)
+	for _, comp := range dynamicComplete(c.sh, lineStr) {
+		if !strings.HasPrefix(comp, last) {
+			continue
+		}
+		suffix := []rune(comp[len(last):])
+		// Add a trailing space for non-directory completions.
+		if len(suffix) > 0 && suffix[len(suffix)-1] != '/' && suffix[len(suffix)-1] != '\\' {
+			suffix = append(suffix, ' ')
+		}
+		newLine = append(newLine, suffix)
+	}
+	return newLine, len([]rune(last))
+}
+
+// lastToken returns the last whitespace-delimited token from s,
+// respecting single and double quotes.
+func lastToken(s string) string {
+	if strings.HasSuffix(s, " ") || strings.HasSuffix(s, "\t") {
+		return ""
+	}
+	inSingle, inDouble := false, false
+	start := 0
+	for i := 0; i < len(s); i++ {
+		switch s[i] {
+		case '\'':
+			if !inDouble {
+				inSingle = !inSingle
+			}
+		case '"':
+			if !inSingle {
+				inDouble = !inDouble
+			}
+		case ' ', '\t':
+			if !inSingle && !inDouble {
+				start = i + 1
+			}
+		}
+	}
+	return s[start:]
+}
+
 // dynamicComplete provides tab completion for commands and paths.
 func dynamicComplete(sh *shell.Shell, line string) []string {
 	line = strings.TrimLeft(line, " \t")
@@ -241,7 +286,7 @@ func dynamicComplete(sh *shell.Shell, line string) []string {
 				if strings.HasPrefix(name, base) {
 					p := filepath.Join(dir, name)
 					if e.IsDir() {
-						p += "/"
+						p += string(filepath.Separator)
 					}
 					completions = append(completions, p)
 				}