package system

import (
	"os/exec"
	"runtime"
	"strconv"
	"strings"

	"github.com/shirou/gopsutil/disk"
)

// getDiskInfo 获取硬盘信息
func getDiskInfo() (string, string, string, error) {
	var diskTotalStr, diskUsageStr, bootPath string
	tempDiskTotal, tempDiskUsage := getDiskTotalAndUsed()
	diskTotalGB := float64(tempDiskTotal) / (1024 * 1024 * 1024)
	diskUsageGB := float64(tempDiskUsage) / (1024 * 1024 * 1024)
	// 字节为单位 进行单位转换
	if diskTotalGB < 1 {
		diskTotalStr = strconv.FormatFloat(diskTotalGB*1024, 'f', 2, 64) + " MB"
	} else {
		diskTotalStr = strconv.FormatFloat(diskTotalGB, 'f', 2, 64) + " GB"
	}
	if diskUsageGB < 1 {
		diskUsageStr = strconv.FormatFloat(diskUsageGB*1024, 'f', 2, 64) + " MB"
	} else {
		diskUsageStr = strconv.FormatFloat(diskUsageGB, 'f', 2, 64) + " GB"
	}
	if runtime.GOOS == "windows" {
		parts, err := disk.Partitions(true)
		if err != nil {
			bootPath = ""
		} else {
			for _, part := range parts {
				if part.Fstype == "tmpfs" {
					continue
				}
				usageStat, err := disk.Usage(part.Mountpoint)
				if err != nil {
					continue
				}
				if usageStat.Total > 0 {
					bootPath = part.Mountpoint
					break
				}
			}
		}
	} else {
		// df -x tmpfs / | awk "NR>1" | sed ":a;N;s/\\n//g;ta" | awk '{print $1}'
		cmd := exec.Command("df", "-x", "tmpfs", "/")
		output, err := cmd.Output()
		if err == nil {
			lines := strings.Split(string(output), "\n")
			if len(lines) >= 2 {
				fields := strings.Split(strings.TrimSpace(lines[1]), " ")
				var nonEmptyFields []string
				for _, field := range fields {
					if field != "" {
						nonEmptyFields = append(nonEmptyFields, field)
					}
				}
				if len(nonEmptyFields) > 0 && nonEmptyFields[0] != "" {
					bootPath = nonEmptyFields[0]
					if strings.Contains(bootPath, "overlay") && len(nonEmptyFields) >= 5 {
						tpDiskTotal, err1 := strconv.Atoi(nonEmptyFields[1])
						tpDiskUsage, err2 := strconv.Atoi(nonEmptyFields[2])
						if err1 == nil && err2 == nil {
							diskTotalGB = float64(tpDiskTotal) / (1024 * 1024)
							diskUsageGB = float64(tpDiskUsage) / (1024 * 1024)
							if diskTotalGB < 1 {
								diskTotalStr = strconv.FormatFloat(diskTotalGB*1024, 'f', 2, 64) + " MB" + " [" + nonEmptyFields[4] + "]"
							} else {
								diskTotalStr = strconv.FormatFloat(diskTotalGB, 'f', 2, 64) + " GB" + " [" + nonEmptyFields[4] + "]"
							}
							if diskUsageGB < 1 {
								diskUsageStr = strconv.FormatFloat(diskUsageGB*1024, 'f', 2, 64) + " MB"
							} else {
								diskUsageStr = strconv.FormatFloat(diskUsageGB, 'f', 2, 64) + " GB"
							}
						}
					}
				}
			}
		}
	}
	return diskTotalStr, diskUsageStr, bootPath, nil
}

func getDiskTotalAndUsed() (total uint64, used uint64) {
	devices := make(map[string]string)
	// 使用默认过滤规则
	diskList, _ := disk.Partitions(false)
	for _, d := range diskList {
		fsType := strings.ToLower(d.Fstype)
		// 不统计 K8s 的虚拟挂载点：https://github.com/shirou/gopsutil/issues/1007
		if devices[d.Device] == "" && isListContainsStr(expectDiskFsTypes, fsType) && !strings.Contains(d.Mountpoint, "/var/lib/kubelet") {
			devices[d.Device] = d.Mountpoint
		}
	}
	for _, mountPath := range devices {
		diskUsageOf, err := disk.Usage(mountPath)
		if err == nil {
			total += diskUsageOf.Total
			used += diskUsageOf.Used
		}
	}
	// Fallback 到这个方法,仅统计根路径,适用于OpenVZ之类的.
	if runtime.GOOS == "linux" && total == 0 && used == 0 {
		cmd := exec.Command("df")
		out, err := cmd.CombinedOutput()
		if err == nil {
			s := strings.Split(string(out), "\n")
			for _, c := range s {
				info := strings.Fields(c)
				if len(info) == 6 {
					if info[5] == "/" {
						total, _ = strconv.ParseUint(info[1], 0, 64)
						used, _ = strconv.ParseUint(info[2], 0, 64)
						// 默认获取的是1K块为单位的.
						total = total * 1024
						used = used * 1024
					}
				}
			}
		}
	}
	return
}

func isListContainsStr(list []string, str string) bool {
	for i := 0; i < len(list); i++ {
		if strings.Contains(str, list[i]) {
			return true
		}
	}
	return false
}