//go:build windows

// Package collector 提供 Windows 内存指标采集能力。 // Logan.Li
package collector

import (
	"fmt"
	"syscall"
	"unsafe"

	"ezops/agent/model"
)

type memoryStatusEx struct {
	Length               uint32
	MemoryLoad           uint32
	TotalPhys            uint64
	AvailPhys            uint64
	TotalPageFile        uint64
	AvailPageFile        uint64
	TotalVirtual         uint64
	AvailVirtual         uint64
	AvailExtendedVirtual uint64
}

type MemCollector struct{}

func NewMemCollector() *MemCollector {
	return &MemCollector{}
}

func (m *MemCollector) Collect() (model.MemoryStat, error) {
	var ms memoryStatusEx
	ms.Length = uint32(unsafe.Sizeof(ms))
	ret, _, err := syscall.NewLazyDLL("kernel32.dll").NewProc("GlobalMemoryStatusEx").Call(uintptr(unsafe.Pointer(&ms)))
	if ret == 0 {
		return model.MemoryStat{}, fmt.Errorf("GlobalMemoryStatusEx 失败: %w", err)
	}
	total := ms.TotalPhys
	avail := ms.AvailPhys
	used := total - avail
	swapTotal := ms.TotalPageFile
	swapAvail := ms.AvailPageFile
	swapUsed := uint64(0)
	if swapTotal > swapAvail {
		swapUsed = swapTotal - swapAvail
	}
	stat := model.MemoryStat{
		TotalGB:      bytesToGB(total),
		UsedGB:       bytesToGB(used),
		AvailableGB:  bytesToGB(avail),
		SwapUsedGB:   bytesToGB(swapUsed),
		UsagePercent: float64(ms.MemoryLoad),
	}
	return stat, nil
}