Initial commit

1 files changed, 73 insertions, 0 deletions

diff --git a/complete.go b/complete.go
new file mode 100644
index 0000000..eedaa81
--- /dev/null
+++ b/complete.go
@@ -0,0 +1,73 @@
+package complete
+
+import (
+	"fmt"
+	"os"
+	"strings"
+)
+
+const (
+	envComplete = "COMP_LINE"
+	envDebug    = "COMP_DEBUG"
+)
+
+type Completer struct {
+	Command
+	log func(format string, args ...interface{})
+}
+
+func New(c Command) *Completer {
+	return &Completer{
+		Command: c,
+		log:     logger(),
+	}
+}
+
+func (c *Completer) Complete() {
+	args := getLine()
+	c.log("Completing args: %s", args)
+
+	options := c.complete(args)
+
+	c.log("Completion: %s", options)
+	output(options)
+}
+
+func (c *Completer) complete(args []string) []string {
+	all, _ := c.options(args[:len(args)-1])
+	return c.chooseRelevant(last(args), all)
+}
+
+func (c *Completer) chooseRelevant(last string, list []string) (opts []string) {
+	if last == "" {
+		return list
+	}
+	for _, sub := range list {
+		if strings.HasPrefix(sub, last) {
+			opts = append(opts, sub)
+		}
+	}
+	return
+}
+
+func getLine() []string {
+	line := os.Getenv(envComplete)
+	if line == "" {
+		panic("should be run as a complete script")
+	}
+	return strings.Split(line, " ")
+}
+
+func last(args []string) (last string) {
+	if len(args) > 0 {
+		last = args[len(args)-1]
+	}
+	return
+}
+
+func output(options []string) {
+	// stdout of program defines the complete options
+	for _, option := range options {
+		fmt.Println(option)
+	}
+}