package tools

import (
	"bytes"
	"encoding/base64"
	"errors"
	"fmt"
	"github.com/avast/apkverifier"
	"github.com/shogo82148/androidbinary"
	"github.com/shogo82148/androidbinary/apk"
	"image"
	"image/png"
	"os"
)

type ApkInfo struct {
	Label         string
	PackageName   string
	VersionName   string
	VersionCode   int32
	SignatureSha1 string
	IconPath      string
	IconMD5       string
}

func ParserApk(apkPath string) (*ApkInfo, error) {
	//先验证签名
	signatureSha1, err := getApkSignatureSha1(apkPath)
	if err != nil {
		return nil, err
	}
	//打开Apk
	app, err := apk.OpenFile(apkPath)
	if err != nil {
		return nil, err
	}
	//延后释放
	defer func(app *apk.Apk) {
		_ = app.Close()
	}(app)
	icon, _ := app.Icon(&androidbinary.ResTableConfig{SDKVersion: 25, Density: 720})
	label, _ := app.Label(&androidbinary.ResTableConfig{Language: [2]uint8{uint8('z'), uint8('h')}})
	packageName := app.PackageName()
	versionName, _ := app.Manifest().VersionName.String()
	versionCode, _ := app.Manifest().VersionCode.Int32()
	//生成icon png
	iconPath, _ := makePng(label, icon)
	iconMD5, _ := imageToBase64(icon)
	return &ApkInfo{
		Label:         label,
		PackageName:   packageName,
		VersionName:   versionName,
		VersionCode:   versionCode,
		SignatureSha1: signatureSha1,
		IconPath:      iconPath,
		IconMD5:       iconMD5,
	}, nil
}

func getApkSignatureSha1(apkPath string) (string, error) {
	res, err := apkverifier.Verify(apkPath, nil)
	if err != nil {
		return "", err
	}
	certInfo, _ := apkverifier.PickBestApkCert(res.SignerCerts)
	if certInfo == nil {
		return "", errors.New("no certificate found")
	}
	return certInfo.Sha1, nil
}

func makePng(label string, img image.Image) (string, error) {
	if img == nil {
		return "", errors.New("nil image")
	}
	dir, err := CreateDirIfNotExist("./temp/icon/")
	if err != nil {
		return "", err
	}
	pngPath := fmt.Sprintf("%s%s.png", dir, label)
	pngFile, err := os.Create(pngPath)
	if err != nil {
		return "", err
	}
	defer func(pngFile *os.File) {
		_ = pngFile.Close()
	}(pngFile)
	err = png.Encode(pngFile, img)
	if err != nil {
		return "", err
	}
	return pngFile.Name(), nil
}

func imageToBase64(img image.Image) (string, error) {
	buffer := new(bytes.Buffer)
	err := png.Encode(buffer, img)
	if err != nil {
		return "", err
	}
	base64Str := base64.StdEncoding.EncodeToString(buffer.Bytes())
	return base64Str, nil
}