//go:build windows

// Package collector 提供 Windows 逻辑磁盘使用率采集能力。 // Logan.Li
package collector

import (
	"fmt"
	"syscall"
	"unsafe"

	"ezops/agent/model"
)

type DiskCollector struct{}

func NewDiskCollector() *DiskCollector {
	return &DiskCollector{}
}

func (d *DiskCollector) Collect() ([]model.DiskStat, error) {
	mask, _, err := syscall.NewLazyDLL("kernel32.dll").NewProc("GetLogicalDrives").Call()
	if mask == 0 {
		return nil, fmt.Errorf("GetLogicalDrives 失败: %w", err)
	}
	var disks []model.DiskStat
	for i := 0; i < 26; i++ {
		if mask&(1<<uint(i)) == 0 {
			continue
		}
		root := string(rune('A'+i)) + `:\`
		var freeAvail, totalBytes, totalFree uint64
		pathPtr, _ := syscall.UTF16PtrFromString(root)
		ret, _, _ := syscall.NewLazyDLL("kernel32.dll").NewProc("GetDiskFreeSpaceExW").Call(
			uintptr(unsafe.Pointer(pathPtr)),
			uintptr(unsafe.Pointer(&freeAvail)),
			uintptr(unsafe.Pointer(&totalBytes)),
			uintptr(unsafe.Pointer(&totalFree)),
		)
		if ret == 0 || totalBytes == 0 {
			continue
		}
		used := totalBytes - totalFree
		disks = append(disks, model.DiskStat{
			Mount:        root,
			Device:       root,
			TotalGB:      bytesToGB(totalBytes),
			UsedGB:       bytesToGB(used),
			UsagePercent: float64(used) / float64(totalBytes) * 100.0,
		})
	}
	return disks, nil
}