// InitTargets initializes an empty targets, and returns the new empty target
func (tr *Repo) InitTargets(role string) (*data.SignedTargets, error) {
	if !data.IsDelegation(role) && role != data.CanonicalTargetsRole {
		return nil, data.ErrInvalidRole{
			Role:   role,
			Reason: fmt.Sprintf("role is not a valid targets role name: %s", role),
		}
	}
	targets := data.NewTargets()
	tr.Targets[role] = targets
	return targets, nil
}

func TestChecksumMatch(t *testing.T) {
	repo := tuf.NewRepo(nil, nil)
	localStorage := store.NewMemoryStore(nil, nil)
	remoteStorage := store.NewMemoryStore(nil, nil)
	client := NewClient(repo, remoteStorage, nil, localStorage)

	sampleTargets := data.NewTargets()
	orig, err := json.Marshal(sampleTargets)
	origSha256 := sha256.Sum256(orig)
	assert.NoError(t, err)

	remoteStorage.SetMeta("targets", orig)

	_, _, err = client.downloadSigned("targets", int64(len(orig)), origSha256[:])
	assert.NoError(t, err)
}

func TestRemoveUnusedKeys(t *testing.T) {
	targets := data.NewTargets()

	role, err := data.NewRole("targets/test", 1, []string{"123"}, []string{""})
	require.NoError(t, err)

	targets.Signed.Delegations.Keys["123"] = nil

	RemoveUnusedKeys(targets)
	require.Len(t, targets.Signed.Delegations.Keys, 0)

	// when role is present that uses key, it shouldn't get removed
	targets.Signed.Delegations.Roles = []*data.Role{role}
	targets.Signed.Delegations.Keys["123"] = nil

	RemoveUnusedKeys(targets)
	require.Len(t, targets.Signed.Delegations.Keys, 1)
}

func TestSizeMismatchShort(t *testing.T) {
	repo := tuf.NewRepo(nil)
	localStorage := store.NewMemoryStore(nil)
	remoteStorage := testutils.NewShortMemoryStore(nil)
	client := NewClient(repo, remoteStorage, localStorage)

	sampleTargets := data.NewTargets()
	orig, err := json.Marshal(sampleTargets)
	origSha256 := sha256.Sum256(orig)
	assert.NoError(t, err)
	l := int64(len(orig))

	remoteStorage.SetMeta("targets", orig)

	_, _, err = client.downloadSigned("targets", l, origSha256[:])
	// size just limits the data received, the error is caught
	// either during checksum verification or during json deserialization
	assert.IsType(t, ErrChecksumMismatch{}, err)
}

func TestUnusedDelegationKeys(t *testing.T) {
	targets := data.NewTargets()

	role, err := data.NewRole("targets/test", 1, []string{}, []string{""})
	require.NoError(t, err)

	discard := UnusedDelegationKeys(*targets)
	require.Len(t, discard, 0)

	targets.Signed.Delegations.Roles = []*data.Role{role}
	targets.Signed.Delegations.Keys["123"] = nil

	discard = UnusedDelegationKeys(*targets)
	require.Len(t, discard, 1)

	role.KeyIDs = []string{"123"}

	discard = UnusedDelegationKeys(*targets)
	require.Len(t, discard, 0)
}

// UpdateDelegations updates the appropriate delegations, either adding
// a new delegation or updating an existing one. If keys are
// provided, the IDs will be added to the role (if they do not exist
// there already), and the keys will be added to the targets file.
// The "before" argument specifies another role which this new role
// will be added in front of (i.e. higher priority) in the delegation list.
// An empty before string indicates to add the role to the end of the
// delegation list.
// A new, empty, targets file will be created for the new role.
func (tr *Repo) UpdateDelegations(role *data.Role, keys []data.PublicKey, before string) error {
	if !role.IsDelegation() || !role.IsValid() {
		return data.ErrInvalidRole{Role: role.Name}
	}
	parent := filepath.Dir(role.Name)
	p, ok := tr.Targets[parent]
	if !ok {
		return data.ErrInvalidRole{Role: role.Name}
	}
	for _, k := range keys {
		if !utils.StrSliceContains(role.KeyIDs, k.ID()) {
			role.KeyIDs = append(role.KeyIDs, k.ID())
		}
		p.Signed.Delegations.Keys[k.ID()] = k
		tr.keysDB.AddKey(k)
	}

	i := -1
	var r *data.Role
	for i, r = range p.Signed.Delegations.Roles {
		if r.Name == role.Name {
			break
		}
	}
	if i >= 0 {
		p.Signed.Delegations.Roles[i] = role
	} else {
		p.Signed.Delegations.Roles = append(p.Signed.Delegations.Roles, role)
	}
	p.Dirty = true

	roleTargets := data.NewTargets() // NewTargets always marked Dirty
	tr.Targets[role.Name] = roleTargets

	tr.keysDB.AddRole(role)

	return nil
}

// InitTargets initializes an empty targets
func (tr *Repo) InitTargets() error {
	targets := data.NewTargets()
	tr.Targets[data.ValidRoles["targets"]] = targets
	return nil
}