// Fenrir console screen reader.
// Copyright (c) 2026 Storm Dragon
// SPDX-License-Identifier: GPL-3.0-or-later

package interaction

import (
	"strings"
	"unicode"

	"git.stormux.org/storm/fenrir/internal/i18n"
)

// Lists use Text as a prefix search without filtering or activating items.
func (s *Session) list(control *Control, key Key) Result {
	if key.Ctrl && key.Name != "backspace" {
		return Result{}
	}
	if key.Name == "backspace" || (key.Name == "" || key.Name == "space") && key.Text != "" && !key.Ctrl {
		prefix := []rune(control.Text)
		if key.Name == "backspace" {
			if key.Ctrl {
				prefix = nil
			} else if len(prefix) > 0 {
				prefix = prefix[:len(prefix)-1]
			}
		} else {
			for _, char := range key.Text {
				if !unicode.IsPrint(char) {
					return Result{}
				}
			}
			if len(prefix)+len([]rune(key.Text)) > 4096 {
				return Result{}
			}
			prefix = append(prefix, []rune(key.Text)...)
		}
		query := strings.ToLower(string(prefix))
		for index, item := range control.Items {
			if strings.HasPrefix(strings.ToLower(item), query) {
				control.Text, control.Selected = string(prefix), index
				return Result{Speech: item}
			}
		}
		// Reject unmatched input so a typo leaves the last valid search intact.
		return Result{Speech: i18n.T("No matches")}
	}
	switch key.Name {
	case "up":
		control.Selected = (control.Selected + len(control.Items) - 1) % len(control.Items)
	case "down":
		control.Selected = (control.Selected + 1) % len(control.Items)
	case "enter":
		return Result{Action: control.Action}
	default:
		return Result{}
	}
	control.Text = ""
	return Result{Speech: control.Items[control.Selected]}
}