package steam

import (
	"archive/tar"
	"io"
	"path/filepath"
	"time"
)

const (
	defaultDirectoryMode = 0775
	defaultFileMode      = 0644
)

func (l *Library) Package(game string, wr io.Writer) error {
	l.m.Lock()
	if _, ok := l.Games()[game]; !ok {
		l.m.Unlock()
		return E_GameDoesNotExist
	}

	g := l.Games()[game]
	j := newJob("package", g)
	defer j.done()

	l.status.addJob(j)

	j.setSize(g.GetSizeBytes())

	// Invert the writer, so we can break up the copy and get progress
	// information in here
	rdr, pwrtr := io.Pipe()
	go func() {
		err := l.packagePrimitive(j, g, pwrtr)
		if err != nil {
			j.addError(err)
		}
	}()

	var total int64
	for {
		n, err := io.CopyN(wr, rdr, updateEveryNBytes)

		if err == io.EOF {
			break
		}
		if err != nil {
			j.addError(err)
			return err
		}

		total += n
		j.setTransferred(total)

		elapsedSeconds := time.Since(*j.StartTime()).Seconds()

		rate := float64(total) / elapsedSeconds

		// fmt.Println("rate in bytes/second: ", formatBytes(int64(rate)))

		estSize := j.GetSize()

		if estSize == nil {
			j.addError(E_NoEstimatedSize)
			continue
		}

		remainingBytes := float64(*estSize - total)
		// fmt.Println("remaining bytes: ", formatBytes(int64(remainingBytes)))

		seconds := remainingBytes / rate

		duration := time.Duration(seconds * 1000 * 1000 * 1000)
		// fmt.Println("Raw duration: ", duration)

		j.setETA(duration)
	}

	return nil
}

// Package writes the package to wr, returning errors if any
func (l *Library) packagePrimitive(g *Game, wr io.WriteCloser) error {

	acf, err := FindACF(l.folder, g.Name)
	if err != nil {
		j.addError(err)
		return err
	}

	twriter := tar.NewWriter(wr)

	paths := []string{
		filepath.Join(l.folder, "common", g.Name),
		acf,
	}
	for _, pth := range paths {
		err := filepath.Walk(pth, tarWalkfn(twriter, l.folder))
		if err != nil {
			j.addError(err)
			return err
		}
	}

	err = twriter.Flush()
	if err != nil {
		j.addError(err)
		return err
	}

	err = twriter.Close()
	if err != nil {
		j.addError(err)
		return err
	}

	err = wr.Close()
	if err != nil {
		j.addError(err)
		return err
	}

	return err
}