package dftool

import (
	"errors"
	"os/exec"
	"path/filepath"
	"runtime"
	"strconv"
	"strings"

	"imuslab.com/arozos/mod/disk/diskspace"
)

type Capacity struct {
	PhysicalDevice string //The ID of the physical device, like C:/ or /dev/sda1
	Used           int64  //Used capacity in bytes
	Available      int64  //Avilable capacity in bytes
	Total          int64  //Total capacity in bytes
}

func GetCapacityInfoFromPath(realpath string) (*Capacity, error) {
	rpathAbs, err := filepath.Abs(realpath)
	if err != nil {
		return nil, err
	}

	if runtime.GOOS == "windows" {
		//Windows
		//Extract disk ID from path
		rpathAbs = filepath.ToSlash(filepath.Clean(rpathAbs))
		diskRoot := strings.Split(rpathAbs, "/")[0]

		//Match the disk space info generated from diskspace
		logicDiskInfo := diskspace.GetAllLogicDiskInfo()
		for _, ldi := range logicDiskInfo {
			if strings.TrimSpace(ldi.Device) == strings.TrimSpace(diskRoot) {
				//Matching device ID
				return &Capacity{
					PhysicalDevice: ldi.Device,
					Used:           ldi.Used,
					Available:      ldi.Available,
					Total:          ldi.Volume,
				}, nil
			}
		}

	} else {
		//Assume Linux or Mac
		//Use command: df -P {abs_path}
		cmd := exec.Command("df", "-P", rpathAbs)
		out, err := cmd.CombinedOutput()
		if err != nil {
			return nil, err
		}

		//Get the last line of the output
		diskInfo := strings.TrimSpace(string(out))
		tmp := strings.Split(diskInfo, "\n")
		targetDiskInfo := strings.Join(tmp[len(tmp)-1:], " ")
		for strings.Contains(targetDiskInfo, "  ") {
			targetDiskInfo = strings.ReplaceAll(targetDiskInfo, "  ", " ")
		}

		diskInfoSlice := strings.Split(targetDiskInfo, " ")

		if len(diskInfoSlice) < 4 {
			return nil, errors.New("Malformed output for df -P")
		}

		//Extract capacity information from df output
		total, err := strconv.ParseInt(diskInfoSlice[1], 10, 64)
		if err != nil {
			return nil, errors.New("Malformed output for df -P")
		}

		used, err := strconv.ParseInt(diskInfoSlice[2], 10, 64)
		if err != nil {
			return nil, errors.New("Malformed output for df -P")
		}

		availbe, err := strconv.ParseInt(diskInfoSlice[3], 10, 64)
		if err != nil {
			return nil, errors.New("Malformed output for df -P")
		}

		//Return the capacity info struct, capacity is reported in 1024 bytes block
		return &Capacity{
			PhysicalDevice: diskInfoSlice[0],
			Used:           used * 1024,
			Available:      availbe * 1024,
			Total:          total * 1024,
		}, nil
	}

	return nil, errors.New("Unable to resolve matching disk capacity information")
}