package win32api

import (
	"fmt"
	"sync"
	"syscall"
)

var (
	procCacheMu sync.Mutex
	dllCache    = map[string]syscall.Handle{}
	procCache   = map[string]uintptr{}
)

func getProcAddr(dllName, procName string) (uintptr, error) {
	cacheKey := dllName + "!" + procName

	procCacheMu.Lock()
	defer procCacheMu.Unlock()

	if proc, ok := procCache[cacheKey]; ok {
		return proc, nil
	}

	dll, ok := dllCache[dllName]
	if !ok {
		var err error
		dll, err = syscall.LoadLibrary(dllName)
		if err != nil {
			return 0, fmt.Errorf("load %s: %w", dllName, err)
		}
		dllCache[dllName] = dll
	}

	proc, err := syscall.GetProcAddress(syscall.Handle(dll), procName)
	if err != nil {
		return 0, fmt.Errorf("resolve %s!%s: %w", dllName, procName, err)
	}
	procCache[cacheKey] = proc
	return proc, nil
}