func prereqDevAccount(c *C, storeDB assertstest.SignerDB, db *asserts.Database) {
	dev1Acct := assertstest.NewAccount(storeDB, "developer1", map[string]interface{}{
		"account-id": "dev-id1",
	}, "")
	err := db.Add(dev1Acct)
	c.Assert(err, IsNil)
}

func makeNewSnapRevision(orig, new *info, targetDir string, db *asserts.Database) error {
	a, err := db.Find(asserts.SnapRevisionType, map[string]string{
		"snap-sha3-384": orig.digest,
	})
	if err != nil {
		return err
	}
	origSnapRev := a.(*asserts.SnapRevision)

	headers := map[string]interface{}{
		"authority-id":  "testrootorg",
		"snap-sha3-384": new.digest,
		"snap-id":       origSnapRev.SnapID(),
		"snap-size":     fmt.Sprintf("%d", new.size),
		"snap-revision": fmt.Sprintf("%d", origSnapRev.SnapRevision()+1),
		"developer-id":  origSnapRev.DeveloperID(),
		"timestamp":     time.Now().Format(time.RFC3339),
	}
	a, err = db.Sign(asserts.SnapRevisionType, headers, nil, systestkeys.TestStoreKeyID)
	if err != nil {
		return err
	}

	return writeAssert(a, targetDir)
}

func prereqSnapDecl2(c *C, storeDB assertstest.SignerDB, db *asserts.Database) {
	snapDecl, err := storeDB.Sign(asserts.SnapDeclarationType, map[string]interface{}{
		"series":       "16",
		"snap-id":      "snap-id-2",
		"snap-name":    "bar",
		"publisher-id": "dev-id1",
		"timestamp":    time.Now().Format(time.RFC3339),
	}, nil, "")
	c.Assert(err, IsNil)
	err = db.Add(snapDecl)
	c.Assert(err, IsNil)
}

func setup3rdPartySigning(c *C, username string, storeDB *assertstest.SigningDB, checkDB *asserts.Database) (signingDB *assertstest.SigningDB) {
	privKey := testPrivKey2

	acct := assertstest.NewAccount(storeDB, username, map[string]interface{}{
		"account-id": username,
	}, "")
	accKey := assertstest.NewAccountKey(storeDB, acct, nil, privKey.PublicKey(), "")

	err := checkDB.Add(acct)
	c.Assert(err, IsNil)
	err = checkDB.Add(accKey)
	c.Assert(err, IsNil)

	return assertstest.NewSigningDB(acct.AccountID(), privKey)
}

// StoreAssertionFetcher creates an asserts.Fetcher for assertions against the given store using dlOpts for authorization, the fetcher will add assertions in the given database and after that also call save for each of them.
func StoreAssertionFetcher(sto Store, dlOpts *DownloadOptions, db *asserts.Database, save func(asserts.Assertion) error) asserts.Fetcher {
	retrieve := func(ref *asserts.Ref) (asserts.Assertion, error) {
		return sto.Assertion(ref.Type, ref.PrimaryKey, dlOpts.User)
	}
	save2 := func(a asserts.Assertion) error {
		// for checking
		err := db.Add(a)
		if err != nil {
			if _, ok := err.(*asserts.RevisionError); ok {
				return nil
			}
			return fmt.Errorf("cannot add assertion %v: %v", a.Ref(), err)
		}
		return save(a)
	}
	return asserts.NewFetcher(db, retrieve, save2)
}

func (aks *accountKeySuite) prereqAccount(c *C, db *asserts.Database) {
	trustedKey := testPrivKey0

	headers := map[string]interface{}{
		"authority-id": "canonical",
		"display-name": "Acct1",
		"account-id":   "acc-id1",
		"username":     "acc-id1",
		"validation":   "unproven",
		"timestamp":    aks.since.Format(time.RFC3339),
	}
	acct1, err := asserts.AssembleAndSignInTest(asserts.AccountType, headers, nil, trustedKey)
	c.Assert(err, IsNil)

	// prereq
	db.Add(acct1)
}