package main

/*
#cgo LDFLAGS: -ldl
#include <stdio.h>
#include <dlfcn.h>
#include <stdlib.h>
#include <errno.h>

void* load_so(char* path) {
	void* handle = dlopen(path, RTLD_LAZY);
	if (!handle) {
        fprintf(stderr, "failed to open so:%s, error:%d\n", path, errno);
        return NULL;
    }

	printf("succeeded to load so:%s\n", path);

	return handle;
}

int so_incr(void* handle, int i) {
	typedef int (*p_inc)(int i);
	p_inc f = (p_inc)dlsym(handle, "printlog");

	return f(i);
}

void release_so(void* handle) {
	dlclose(handle);
}

*/
import "C"
import (
	"fmt"
	"io"
	"os"
	"unsafe"
	"embed"
)

//go:embed static
var local embed.FS

func main() {
	in, err := local.Open("static/libs/libtest.so")
	if nil != err {
		fmt.Println("failed to read file", err)
	} else {
		fmt.Println("load dll okay")
	}

	path := "./embed-" + "libtest.so"
	out, err := os.Create(path)
	if nil != err {
		fmt.Println("create backup failed")
	}

	_, err = io.Copy(out, in)
	_ = in.Close()
	_ = out.Close()
	if nil == err {
		fmt.Println("copy file failed")
	}

	soFile := C.CString(path)
	defer C.free(unsafe.Pointer(soFile))

	handle := C.load_so(soFile)
	if nil != handle {
		v := C.so_incr(handle, C.int(5))
		C.release_so(handle)

		fmt.Println("return value from so:", int(v))
	}
}