package internal

import (
	"github.com/godbus/dbus/v5"
	"sort"
)

type Scanner struct {
	conn *dbus.Conn
}

func NewScanner() (*Scanner, error) {
	conn, err := dbus.SystemBus()
	if err != nil {
		return nil, err
	}
	return &Scanner{conn: conn}, nil
}

func (s *Scanner) GetDevices() ([]Device, error) {
	var result map[dbus.ObjectPath]map[string]map[string]dbus.Variant
	err := s.conn.Object("org.bluez", "/").Call("org.freedesktop.DBus.ObjectManager.GetManagedObjects", 0).Store(&result)
	if err != nil {
		return nil, err
	}

	var devices []Device
	for path, interfaces := range result {
		if props, ok := interfaces["org.bluez.Device1"]; ok {
			name, hasName := props["Name"]
			address, hasAddress := props["Address"]
			if hasName && hasAddress {
				nameStr, _ := name.Value().(string)
				addrStr, _ := address.Value().(string)
				if nameStr != "" && nameStr != addrStr {
					devices = append(devices, Device{nameStr, addrStr, path})
				}
			}
		}
	}

	sort.Slice(devices, func(i, j int) bool { return devices[i].Name < devices[j].Name })
	return devices, nil
}

func (s *Scanner) FindDevice(address string) (Device, dbus.ObjectPath, error) {
	devices, err := s.GetDevices()
	if err != nil {
		return Device{}, "", err
	}
	for _, device := range devices {
		if device.Address == address {
			return device, device.Path, nil
		}
	}
	return Device{}, "", nil
}

func (s *Scanner) IsConnected(path dbus.ObjectPath) bool {
	var connected bool
	err := s.conn.Object("org.bluez", path).Call("org.freedesktop.DBus.Properties.Get", 0, "org.bluez.Device1", "Connected").Store(&connected)
	return err == nil && connected
}

func (s *Scanner) GetManagedObjects() (map[dbus.ObjectPath]map[string]map[string]dbus.Variant, error) {
	var result map[dbus.ObjectPath]map[string]map[string]dbus.Variant
	err := s.conn.Object("org.bluez", "/").Call("org.freedesktop.DBus.ObjectManager.GetManagedObjects", 0).Store(&result)
	return result, err
}

func (s *Scanner) ReadCharacteristic(path dbus.ObjectPath) ([]byte, error) {
	call := s.conn.Object("org.bluez", path).Call("org.bluez.GattCharacteristic1.ReadValue", 0, map[string]dbus.Variant{})
	if call.Err != nil {
		return nil, call.Err
	}
	if len(call.Body) > 0 {
		if data, ok := call.Body[0].([]byte); ok {
			return data, nil
		}
	}
	return nil, nil
}

func (s *Scanner) GetLegacyBattery(path dbus.ObjectPath) (int, error) {
	var level byte
	err := s.conn.Object("org.bluez", path).Call("org.freedesktop.DBus.Properties.Get", 0, "org.bluez.Battery1", "Percentage").Store(&level)
	return int(level), err
}

func (s *Scanner) Close() {
	if s.conn != nil {
		s.conn.Close()
	}
}