package main

import (
	"crypto/md5"
	"crypto/sha256"
	"errors"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"strings"

	"go.wit.com/lib/debian"
	"go.wit.com/lib/gui/shell"
	"go.wit.com/lib/protobuf/zoopb"
	"google.golang.org/protobuf/types/known/timestamppb"
)

func populateDebInfo(p *zoopb.Package) error {
	// SIMPLE SANITY CHECKS
	if p.DebInfo != nil {
		// already added p.DebInfo
		return nil
	}
	fullname := filepath.Join(me.pb.BaseDir, p.Filename)
	cmd := []string{"dpkg", "-I", fullname}
	r := shell.Run(cmd)
	if r.Error != nil {
		return r.Error
	}
	if r.Exit != 0 {
		return errors.New("dpkg returned -1")
	}
	stat, err := os.Stat(fullname)
	if err != nil {
		return err
	}
	filedata, err := os.Open(fullname)
	if err != nil {
		return err
	}
	defer filedata.Close()
	// SIMPLE SANITY CHECKS END

	// SHA256 HASH
	p.DebInfo = new(zoopb.DebInfo)

	hSHA256 := sha256.New()
	hMD5 := md5.New() // probably deprecate, but love md5sum too much
	// hSHA1 := sha1.New() // deprecated

	// TeeReader allows writing to multiple hashers at once
	// multiWriter := io.MultiWriter(hMD5, hSHA1, hSHA256)
	multiWriter := io.MultiWriter(hSHA256, hMD5)
	if _, err := io.Copy(multiWriter, filedata); err != nil {
		return err
	}
	p.DebInfo.SHA256 = fmt.Sprintf("%x", hSHA256.Sum(nil)) // should be the standard now
	p.DebInfo.MD5SUM = fmt.Sprintf("%x", hMD5.Sum(nil))    // probably deprecate
	// p.DebInfo.SHA1 = fmt.Sprintf("%x", hSHA1.Sum(nil))     // deprecated
	// SHA256 HASH END

	// set file create time
	p.Ctime = timestamppb.New(stat.ModTime())

	// PARSE "dpkg -I <p.Filename>", then exit as we are done
	all := strings.Join(r.Stdout, "\n")
	debian.ParseDpkgOutputIntoPB(p, all)
	return nil
}