Move completion package into cli

tools/cli/completion/main.go

@@ -0,0 +1,93 @@
+// License: GPLv3 Copyright: 2022, Kovid Goyal, <kovid at kovidgoyal.net>
+
+package completion
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+
+	"kitty/tools/tty"
+	"kitty/tools/utils"
+)
+
+func debug(args ...any) {
+	tty.DebugPrintln(args...)
+}
+
+func debugf(format string, args ...any) {
+	debug(fmt.Sprintf(format, args...))
+}
+
+func json_input_parser(data []byte, shell_state map[string]string) ([][]string, error) {
+	ans := make([][]string, 0, 32)
+	err := json.Unmarshal(data, &ans)
+	return ans, err
+}
+
+func json_output_serializer(completions []*Completions, shell_state map[string]string) ([]byte, error) {
+	return json.Marshal(completions)
+}
+
+type parser_func func(data []byte, shell_state map[string]string) ([][]string, error)
+type serializer_func func(completions []*Completions, shell_state map[string]string) ([]byte, error)
+
+var input_parsers = make(map[string]parser_func, 4)
+var output_serializers = make(map[string]serializer_func, 4)
+var init_completions = make(map[string]func(*Completions), 4)
+
+func init() {
+	input_parsers["json"] = json_input_parser
+	output_serializers["json"] = json_output_serializer
+}
+
+var registered_exes = make(map[string]func(root *Command))
+
+func Main(args []string) error {
+	output_type := "json"
+	if len(args) > 0 {
+		output_type = args[0]
+		args = args[1:]
+	}
+	n := len(args)
+	if n < 1 {
+		n = 1
+	}
+	shell_state := make(map[string]string, n)
+	for _, arg := range args {
+		k, v, found := utils.Cut(arg, "=")
+		if !found {
+			return fmt.Errorf("Invalid shell state specification: %s", arg)
+		}
+		shell_state[k] = v
+	}
+	input_parser := input_parsers[output_type]
+	output_serializer := output_serializers[output_type]
+	if input_parser == nil || output_serializer == nil {
+		return fmt.Errorf("Unknown output type: %s", output_type)
+	}
+	data, err := io.ReadAll(os.Stdin)
+	if err != nil {
+		return err
+	}
+	// debugf("%#v", string(data))
+	all_argv, err := input_parser(data, shell_state)
+	if err != nil {
+		return err
+	}
+	var root = Command{Options: make([]*Option, 0), Groups: make([]*CommandGroup, 0, 8)}
+	for _, re := range registered_exes {
+		re(&root)
+	}
+
+	all_completions := make([]*Completions, 0, 1)
+	for _, argv := range all_argv {
+		all_completions = append(all_completions, root.GetCompletions(argv, init_completions[output_type]))
+	}
+	output, err := output_serializer(all_completions, shell_state)
+	if err == nil {
+		_, err = os.Stdout.Write(output)
+	}
+	return err
+}