package build

import (
	"archive/tar"
	"bytes"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"runtime"
)

func (b *Builder) GenerateTarball() error {
	buf := new(bytes.Buffer)

	tarW := tar.NewWriter(buf)

	err := tarW.WriteHeader(&tar.Header{
		Name: "bin/",
		Mode: int64(os.ModeDir) | 0o755,
	})
	if err != nil {
		return fmt.Errorf("writing bin directory: %w", err)
	}

	for _, bin := range b.Binaries {
		base := filepath.Base(bin)

		binB, err := os.ReadFile(bin)
		if err != nil {
			return fmt.Errorf("reading binary %v: %w", bin, err)
		}

		err = tarW.WriteHeader(&tar.Header{
			Name: filepath.Join("bin", base),
			Size: int64(len(binB)),
			Mode: 0o755,
		})
		if err != nil {
			return fmt.Errorf("writing header for binary %v: %w", bin, err)
		}

		_, err = tarW.Write(binB)
		if err != nil {
			return fmt.Errorf("writing binary %v: %w", bin, err)
		}
	}

	err = tarW.Close()
	if err != nil {
		return fmt.Errorf("writing tar footer: %w", err)
	}

	f, err := os.Create(filepath.Join(b.TempDir, fmt.Sprintf("%v-%v-%v.tar", b.Name, b.Version, runtime.GOARCH)))
	if err != nil {
		return fmt.Errorf("creating tarball: %w", err)
	}
	defer f.Close()

	_, err = io.Copy(f, buf)
	if err != nil {
		return fmt.Errorf("writing to tarball: %w", err)
	}

	fmt.Println("wrote tarball at", f.Name())

	return nil
}