package hot_key

import (
	"fmt"
	winapi "github.com/lxn/win"
	"syscall"
)

const (
	ModAlt = 1 << iota
	ModCtrl
	ModShift
	ModWin
)

var (
	user32           = syscall.NewLazyDLL("user32")
	registerHotKey   = user32.NewProc("RegisterHotKey")
	unregisterHotKey = user32.NewProc("UnregisterHotKey")
)

var keyHandle = map[int32]func(){0: func() {}}

func RegisterHotKey(Modifiers, KeyCode int, callback func()) (int, error) {
	uid := len(keyHandle)
	r1, _, err := registerHotKey.Call(0, uintptr(uid), uintptr(Modifiers), uintptr(KeyCode))
	if r1 == 1 {
		keyHandle[int32(uid)] = callback
		return uid, nil
	} else {
		return 0, err
	}
}

func UnregisterHotKey(uid int32) error {
	r1, _, err := unregisterHotKey.Call(0, uintptr(uid))
	if r1 == 1 {
		return nil
	} else {
		return err
	}
}

func UnregisterAllHotKey() {
	for id, _ := range keyHandle {
		_ = UnregisterHotKey(id)
	}
}

func ListenHotKey() {
	go func() {
		msg := &winapi.MSG{}
		fmt.Println("Start HotKey Listen...")
		for {
			winapi.GetMessage(msg, 0, 0, 0)
			if msg.Message == winapi.WM_HOTKEY {
				if fnc, ok := keyHandle[int32(msg.WParam)]; ok {
					fnc()
				}
			}
		}
	}()
}