// +build windows

/*
 * MinIO Cloud Storage, (C) 2016,2017 MinIO, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package sys

import (
	"syscall"
	"unsafe"

	"golang.org/x/sys/windows"
)

var (
	modkernel32              = windows.NewLazySystemDLL("kernel32.dll")
	procGlobalMemoryStatusEx = modkernel32.NewProc("GlobalMemoryStatusEx")
)

type memoryStatusEx struct {
	cbSize                  uint32
	dwMemoryLoad            uint32
	ullTotalPhys            uint64 // in bytes
	ullAvailPhys            uint64
	ullTotalPageFile        uint64
	ullAvailPageFile        uint64
	ullTotalVirtual         uint64
	ullAvailVirtual         uint64
	ullAvailExtendedVirtual uint64
}

// GetStats - return system statistics for windows.
func GetStats() (stats Stats, err error) {
	var memInfo memoryStatusEx
	memInfo.cbSize = uint32(unsafe.Sizeof(memInfo))
	if mem, _, _ := procGlobalMemoryStatusEx.Call(uintptr(unsafe.Pointer(&memInfo))); mem == 0 {
		err = syscall.GetLastError()
	} else {
		stats.TotalRAM = memInfo.ullTotalPhys
	}

	return stats, err
}