abzcoding / hget

package main

import (

	"encoding/json"

	"os"

	"os/user"

	"path/filepath"

)

var dataFolder = ".hget/"

var stateFileName = "state.json"

// State holds information about url Parts

type State struct {

	URL   string

	Parts []Part

}

// Part represents a chunk of downloaded file

type Part struct {

	Index     int64

	URL       string

	Path      string

	RangeFrom int64

	RangeTo   int64

}

// Save stores downloaded file into disk

func (s *State) Save() error {

	//make temp folder

	//only working in unix with env HOME

	folder := FolderOf(s.URL)

	Printf("Saving current download data in %s\n", folder)

	if err := MkdirIfNotExist(folder); err != nil {

		return err

	}

	//move current downloading file to data folder

	for _, part := range s.Parts {

		err := os.Rename(part.Path, filepath.Join(folder, filepath.Base(part.Path)))

		if err != nil {

			return err

		}

	}

	//save state file

	j, err := json.Marshal(s)

	if err != nil {

		return err

	}

	return os.WriteFile(filepath.Join(folder, stateFileName), j, 0644)

}

// Read loads data about the state of downloaded files

func Read(task string) (*State, error) {

	usr, err := user.Current()

	FatalCheck(err)

	homeDir := usr.HomeDir

	// extract filename from task

	taskName := TaskFromURL(task)

	file := filepath.Join(homeDir, dataFolder, taskName, stateFileName)

	Printf("Getting data from %s\n", file)

	bytes, err := os.ReadFile(file)

	if err != nil {

		return nil, err

	}

	s := new(State)

	err = json.Unmarshal(bytes, s)

	return s, err

}