package utils

import (
	"crypto/rand"
	"fmt"
	"math"
	"os"
	"os/exec"
	"strings"
	"time"

	"github.com/sirupsen/logrus"
)

// Logger 全局日志实例
var Logger *logrus.Logger

// InitLogger 初始化日志系统
func InitLogger(logFile string, level logrus.Level) {
	Logger = logrus.New()
	Logger.SetLevel(level)

	// 设置日志格式
	Logger.SetFormatter(&logrus.TextFormatter{
		FullTimestamp:   true,
		TimestampFormat: "2006-01-02 15:04:05",
	})

	// 如果提供了日志文件，则输出到文件
	if logFile != "" {
		file, err := os.OpenFile(logFile, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
		if err == nil {
			Logger.SetOutput(file)
		} else {
			Logger.Info("无法写入日志文件，使用标准输出")
		}
	}
}

// GenerateRandomData 生成指定大小的随机数据
func GenerateRandomData(size int) ([]byte, error) {
	data := make([]byte, size)
	_, err := rand.Read(data)
	if err != nil {
		return nil, err
	}
	return data, nil
}

// BytesToMB 将字节转换为MB
func BytesToMB(bytes int) float64 {
	return float64(bytes) / (1024 * 1024)
}

// MBToBytes 将MB转换为字节
func MBToBytes(mb float64) int {
	return int(mb * 1024 * 1024)
}

// KBToBytes 将KB转换为字节
func KBToBytes(kb float64) int {
	return int(kb * 1024)
}

// FormatDuration 格式化持续时间
func FormatDuration(d time.Duration) string {
	if d < time.Minute {
		return fmt.Sprintf("%.2f秒", d.Seconds())
	} else if d < time.Hour {
		minutes := math.Floor(d.Minutes())
		seconds := d.Seconds() - minutes*60
		return fmt.Sprintf("%.0f分%.2f秒", minutes, seconds)
	} else {
		hours := math.Floor(d.Hours())
		minutes := math.Floor(d.Minutes()) - hours*60
		seconds := d.Seconds() - hours*3600 - minutes*60
		return fmt.Sprintf("%.0f时%.0f分%.2f秒", hours, minutes, seconds)
	}
}

// CalculatePercentage 计算百分比
func CalculatePercentage(part, total float64) float64 {
	if total == 0 {
		return 0
	}
	return (part / total) * 100
}

// ExecuteCommand 执行系统命令
func ExecuteCommand(command string, args ...string) (string, error) {
	cmd := exec.Command(command, args...)
	output, err := cmd.CombinedOutput()
	if err != nil {
		return string(output), err
	}
	return string(output), nil
}

// IsMounted 检查指定路径是否已挂载
func IsMounted(mountPoint string) bool {
	output, err := ExecuteCommand("mount")
	if err != nil {
		return false
	}
	return strings.Contains(output, mountPoint)
}

// FileExists 检查文件是否存在
func FileExists(path string) bool {
	_, err := os.Stat(path)
	return !os.IsNotExist(err)
}

// CreateDirIfNotExist 如果目录不存在则创建
func CreateDirIfNotExist(path string) error {
	if !FileExists(path) {
		return os.MkdirAll(path, 0755)
	}
	return nil
}

// CalculateWriteSpeed 计算写入速度
func CalculateWriteSpeed(bytesWritten int, duration time.Duration) float64 {
	if duration.Seconds() == 0 {
		return 0
	}
	return BytesToMB(bytesWritten) / duration.Seconds()
}

// CalculateIOPS 计算IOPS
func CalculateIOPS(operations int, duration time.Duration) float64 {
	if duration.Seconds() == 0 {
		return 0
	}
	return float64(operations) / duration.Seconds()
}