/*
GoCheese -- Python private package repository and caching proxy
Copyright (C) 2019 Sergey Matveev <stargrave@stargrave.org>

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, version 3 of the License.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

package main

import (
	"bytes"
	"crypto/sha256"
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"path/filepath"
	"strings"
)

func goodIntegrity() bool {
	dirs, err := ioutil.ReadDir(*root)
	if err != nil {
		log.Fatal(err)
	}
	hasher := sha256.New()
	digest := make([]byte, sha256.Size)
	isGood := true
	var data []byte
	var pkgName string
	for _, dir := range dirs {
		files, err := ioutil.ReadDir(filepath.Join(*root, dir.Name()))
		if err != nil {
			log.Fatal(err)
		}
		for _, file := range files {
			if !strings.HasSuffix(file.Name(), "."+HashAlgoSHA256) {
				continue
			}
			pkgName = strings.TrimSuffix(file.Name(), "."+HashAlgoSHA256)
			data, err = ioutil.ReadFile(filepath.Join(*root, dir.Name(), pkgName))
			if err != nil {
				if os.IsNotExist(err) {
					continue
				}
				log.Fatal(err)
			}
			hasher.Write(data)
			data, err = ioutil.ReadFile(filepath.Join(*root, dir.Name(), file.Name()))
			if err != nil {
				log.Fatal(err)
			}
			if bytes.Compare(hasher.Sum(digest[:0]), data) == 0 {
				fmt.Println(pkgName, "GOOD")
			} else {
				isGood = false
				fmt.Println(pkgName, "BAD")
			}
			hasher.Reset()
		}
	}
	return isGood
}