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102 lines
2.2 KiB
Go

/*
Copyright (C) 2024 Pagefault Games
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
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 Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package daily
import (
"crypto/md5"
"crypto/rand"
"encoding/base64"
"encoding/binary"
"fmt"
"log"
"os"
"time"
"github.com/pagefaultgames/rogueserver/db"
"github.com/robfig/cron/v3"
)
const secondsPerDay = 60 * 60 * 24
var (
scheduler = cron.New(cron.WithLocation(time.UTC))
secret []byte
)
func Init() error {
var err error
secret, err = os.ReadFile("secret.key")
if err != nil {
if !os.IsNotExist(err) {
return fmt.Errorf("failed to read daily seed secret: %s", err)
}
newSecret := make([]byte, 32)
_, err := rand.Read(newSecret)
if err != nil {
return fmt.Errorf("failed to generate daily seed secret: %s", err)
}
err = os.WriteFile("secret.key", newSecret, 0400)
if err != nil {
return fmt.Errorf("failed to write daily seed secret: %s", err)
}
secret = newSecret
}
seed, err := db.TryAddDailyRun(Seed())
if err != nil {
log.Print(err)
}
log.Printf("Daily Run Seed: %s", seed)
_, err = scheduler.AddFunc("@daily", func() {
time.Sleep(time.Second)
seed, err = db.TryAddDailyRun(Seed())
if err != nil {
log.Printf("error while recording new daily: %s", err)
} else {
log.Printf("Daily Run Seed: %s", seed)
}
})
if err != nil {
return err
}
scheduler.Start()
return nil
}
func Seed() string {
return base64.StdEncoding.EncodeToString(deriveSeed(time.Now().UTC()))
}
func deriveSeed(seedTime time.Time) []byte {
day := make([]byte, 8)
binary.BigEndian.PutUint64(day, uint64(seedTime.Unix()/secondsPerDay))
hashedSeed := md5.Sum(append(day, secret...))
return hashedSeed[:]
}