1// Package identity contains the identity data model and low-level related functions
2package identity
3
4import (
5 "encoding/json"
6 "fmt"
7 "os"
8 "strings"
9 "time"
10
11 "github.com/pkg/errors"
12
13 "github.com/MichaelMure/git-bug/repository"
14 "github.com/MichaelMure/git-bug/util/git"
15 "github.com/MichaelMure/git-bug/util/lamport"
16)
17
18const identityRefPattern = "refs/identities/"
19const identityRemoteRefPattern = "refs/remotes/%s/identities/"
20const versionEntryName = "version"
21const identityConfigKey = "git-bug.identity"
22
23const idLength = 40
24const humanIdLength = 7
25
26var ErrNonFastForwardMerge = errors.New("non fast-forward identity merge")
27var ErrNoIdentitySet = errors.New("user identity first needs to be created using \"git bug user create\" or \"git bug user adopt\"")
28var ErrMultipleIdentitiesSet = errors.New("multiple user identities set")
29
30var _ Interface = &Identity{}
31
32type Identity struct {
33 // Id used as unique identifier
34 id string
35
36 lastCommit git.Hash
37
38 // all the successive version of the identity
39 versions []*Version
40}
41
42func NewIdentity(name string, email string) *Identity {
43 return &Identity{
44 versions: []*Version{
45 {
46 name: name,
47 email: email,
48 nonce: makeNonce(20),
49 },
50 },
51 }
52}
53
54func NewIdentityFull(name string, email string, login string, avatarUrl string) *Identity {
55 return &Identity{
56 versions: []*Version{
57 {
58 name: name,
59 email: email,
60 login: login,
61 avatarURL: avatarUrl,
62 nonce: makeNonce(20),
63 },
64 },
65 }
66}
67
68// MarshalJSON will only serialize the id
69func (i *Identity) MarshalJSON() ([]byte, error) {
70 return json.Marshal(&IdentityStub{
71 id: i.Id(),
72 })
73}
74
75// UnmarshalJSON will only read the id
76// Users of this package are expected to run Load() to load
77// the remaining data from the identities data in git.
78func (i *Identity) UnmarshalJSON(data []byte) error {
79 panic("identity should be loaded with identity.UnmarshalJSON")
80}
81
82// ReadLocal load a local Identity from the identities data available in git
83func ReadLocal(repo repository.Repo, id string) (*Identity, error) {
84 ref := fmt.Sprintf("%s%s", identityRefPattern, id)
85 return read(repo, ref)
86}
87
88// ReadRemote load a remote Identity from the identities data available in git
89func ReadRemote(repo repository.Repo, remote string, id string) (*Identity, error) {
90 ref := fmt.Sprintf(identityRemoteRefPattern, remote) + id
91 return read(repo, ref)
92}
93
94// read will load and parse an identity from git
95func read(repo repository.Repo, ref string) (*Identity, error) {
96 refSplit := strings.Split(ref, "/")
97 id := refSplit[len(refSplit)-1]
98
99 if len(id) != idLength {
100 return nil, fmt.Errorf("invalid ref length")
101 }
102
103 hashes, err := repo.ListCommits(ref)
104
105 // TODO: this is not perfect, it might be a command invoke error
106 if err != nil {
107 return nil, ErrIdentityNotExist
108 }
109
110 i := &Identity{
111 id: id,
112 }
113
114 for _, hash := range hashes {
115 entries, err := repo.ListEntries(hash)
116 if err != nil {
117 return nil, errors.Wrap(err, "can't list git tree entries")
118 }
119
120 if len(entries) != 1 {
121 return nil, fmt.Errorf("invalid identity data at hash %s", hash)
122 }
123
124 entry := entries[0]
125
126 if entry.Name != versionEntryName {
127 return nil, fmt.Errorf("invalid identity data at hash %s", hash)
128 }
129
130 data, err := repo.ReadData(entry.Hash)
131 if err != nil {
132 return nil, errors.Wrap(err, "failed to read git blob data")
133 }
134
135 var version Version
136 err = json.Unmarshal(data, &version)
137
138 if err != nil {
139 return nil, errors.Wrapf(err, "failed to decode Identity version json %s", hash)
140 }
141
142 // tag the version with the commit hash
143 version.commitHash = hash
144 i.lastCommit = hash
145
146 i.versions = append(i.versions, &version)
147 }
148
149 return i, nil
150}
151
152type StreamedIdentity struct {
153 Identity *Identity
154 Err error
155}
156
157// ReadAllLocalIdentities read and parse all local Identity
158func ReadAllLocalIdentities(repo repository.ClockedRepo) <-chan StreamedIdentity {
159 return readAllIdentities(repo, identityRefPattern)
160}
161
162// ReadAllRemoteIdentities read and parse all remote Identity for a given remote
163func ReadAllRemoteIdentities(repo repository.ClockedRepo, remote string) <-chan StreamedIdentity {
164 refPrefix := fmt.Sprintf(identityRemoteRefPattern, remote)
165 return readAllIdentities(repo, refPrefix)
166}
167
168// Read and parse all available bug with a given ref prefix
169func readAllIdentities(repo repository.ClockedRepo, refPrefix string) <-chan StreamedIdentity {
170 out := make(chan StreamedIdentity)
171
172 go func() {
173 defer close(out)
174
175 refs, err := repo.ListRefs(refPrefix)
176 if err != nil {
177 out <- StreamedIdentity{Err: err}
178 return
179 }
180
181 for _, ref := range refs {
182 b, err := read(repo, ref)
183
184 if err != nil {
185 out <- StreamedIdentity{Err: err}
186 return
187 }
188
189 out <- StreamedIdentity{Identity: b}
190 }
191 }()
192
193 return out
194}
195
196// NewFromGitUser will query the repository for user detail and
197// build the corresponding Identity
198func NewFromGitUser(repo repository.Repo) (*Identity, error) {
199 name, err := repo.GetUserName()
200 if err != nil {
201 return nil, err
202 }
203 if name == "" {
204 return nil, errors.New("user name is not configured in git yet. Please use `git config --global user.name \"John Doe\"`")
205 }
206
207 email, err := repo.GetUserEmail()
208 if err != nil {
209 return nil, err
210 }
211 if email == "" {
212 return nil, errors.New("user name is not configured in git yet. Please use `git config --global user.email johndoe@example.com`")
213 }
214
215 return NewIdentity(name, email), nil
216}
217
218// IsUserIdentitySet tell if the user identity is correctly set.
219func IsUserIdentitySet(repo repository.RepoCommon) (bool, error) {
220 configs, err := repo.ReadConfigs(identityConfigKey)
221 if err != nil {
222 return false, err
223 }
224
225 if len(configs) > 1 {
226 return false, ErrMultipleIdentitiesSet
227 }
228
229 return len(configs) == 1, nil
230}
231
232// SetUserIdentity store the user identity's id in the git config
233func SetUserIdentity(repo repository.RepoCommon, identity *Identity) error {
234 return repo.StoreConfig(identityConfigKey, identity.Id())
235}
236
237// GetUserIdentity read the current user identity, set with a git config entry
238func GetUserIdentity(repo repository.Repo) (*Identity, error) {
239 configs, err := repo.ReadConfigs(identityConfigKey)
240 if err != nil {
241 return nil, err
242 }
243
244 if len(configs) == 0 {
245 return nil, ErrNoIdentitySet
246 }
247
248 if len(configs) > 1 {
249 return nil, ErrMultipleIdentitiesSet
250 }
251
252 var id string
253 for _, val := range configs {
254 id = val
255 }
256
257 i, err := ReadLocal(repo, id)
258 if err == ErrIdentityNotExist {
259 innerErr := repo.RmConfigs(identityConfigKey)
260 if innerErr != nil {
261 _, _ = fmt.Fprintln(os.Stderr, errors.Wrap(innerErr, "can't clear user identity").Error())
262 }
263 return nil, err
264 }
265
266 return i, nil
267}
268
269func (i *Identity) AddVersion(version *Version) {
270 i.versions = append(i.versions, version)
271}
272
273// Write the identity into the Repository. In particular, this ensure that
274// the Id is properly set.
275func (i *Identity) Commit(repo repository.ClockedRepo) error {
276 // Todo: check for mismatch between memory and commit data
277
278 if !i.NeedCommit() {
279 return fmt.Errorf("can't commit an identity with no pending version")
280 }
281
282 if err := i.Validate(); err != nil {
283 return errors.Wrap(err, "can't commit an identity with invalid data")
284 }
285
286 for _, v := range i.versions {
287 if v.commitHash != "" {
288 i.lastCommit = v.commitHash
289 // ignore already commit versions
290 continue
291 }
292
293 // get the times where new versions starts to be valid
294 v.time = repo.EditTime()
295 v.unixTime = time.Now().Unix()
296
297 blobHash, err := v.Write(repo)
298 if err != nil {
299 return err
300 }
301
302 // Make a git tree referencing the blob
303 tree := []repository.TreeEntry{
304 {ObjectType: repository.Blob, Hash: blobHash, Name: versionEntryName},
305 }
306
307 treeHash, err := repo.StoreTree(tree)
308 if err != nil {
309 return err
310 }
311
312 var commitHash git.Hash
313 if i.lastCommit != "" {
314 commitHash, err = repo.StoreCommitWithParent(treeHash, i.lastCommit)
315 } else {
316 commitHash, err = repo.StoreCommit(treeHash)
317 }
318
319 if err != nil {
320 return err
321 }
322
323 i.lastCommit = commitHash
324 v.commitHash = commitHash
325
326 // if it was the first commit, use the commit hash as the Identity id
327 if i.id == "" {
328 i.id = string(commitHash)
329 }
330 }
331
332 if i.id == "" {
333 panic("identity with no id")
334 }
335
336 ref := fmt.Sprintf("%s%s", identityRefPattern, i.id)
337 err := repo.UpdateRef(ref, i.lastCommit)
338
339 if err != nil {
340 return err
341 }
342
343 return nil
344}
345
346func (i *Identity) CommitAsNeeded(repo repository.ClockedRepo) error {
347 if !i.NeedCommit() {
348 return nil
349 }
350 return i.Commit(repo)
351}
352
353func (i *Identity) NeedCommit() bool {
354 for _, v := range i.versions {
355 if v.commitHash == "" {
356 return true
357 }
358 }
359
360 return false
361}
362
363// Merge will merge a different version of the same Identity
364//
365// To make sure that an Identity history can't be altered, a strict fast-forward
366// only policy is applied here. As an Identity should be tied to a single user, this
367// should work in practice but it does leave a possibility that a user would edit his
368// Identity from two different repo concurrently and push the changes in a non-centralized
369// network of repositories. In this case, it would result in some of the repo accepting one
370// version and some other accepting another, preventing the network in general to converge
371// to the same result. This would create a sort of partition of the network, and manual
372// cleaning would be required.
373//
374// An alternative approach would be to have a determinist rebase:
375// - any commits present in both local and remote version would be kept, never changed.
376// - newer commits would be merged in a linear chain of commits, ordered based on the
377// Lamport time
378//
379// However, this approach leave the possibility, in the case of a compromised crypto keys,
380// of forging a new version with a bogus Lamport time to be inserted before a legit version,
381// invalidating the correct version and hijacking the Identity. There would only be a short
382// period of time where this would be possible (before the network converge) but I'm not
383// confident enough to implement that. I choose the strict fast-forward only approach,
384// despite it's potential problem with two different version as mentioned above.
385func (i *Identity) Merge(repo repository.Repo, other *Identity) (bool, error) {
386 if i.id != other.id {
387 return false, errors.New("merging unrelated identities is not supported")
388 }
389
390 if i.lastCommit == "" || other.lastCommit == "" {
391 return false, errors.New("can't merge identities that has never been stored")
392 }
393
394 modified := false
395 for j, otherVersion := range other.versions {
396 // if there is more version in other, take them
397 if len(i.versions) == j {
398 i.versions = append(i.versions, otherVersion)
399 i.lastCommit = otherVersion.commitHash
400 modified = true
401 }
402
403 // we have a non fast-forward merge.
404 // as explained in the doc above, refusing to merge
405 if i.versions[j].commitHash != otherVersion.commitHash {
406 return false, ErrNonFastForwardMerge
407 }
408 }
409
410 if modified {
411 err := repo.UpdateRef(identityRefPattern+i.id, i.lastCommit)
412 if err != nil {
413 return false, err
414 }
415 }
416
417 return false, nil
418}
419
420// Validate check if the Identity data is valid
421func (i *Identity) Validate() error {
422 lastTime := lamport.Time(0)
423
424 if len(i.versions) == 0 {
425 return fmt.Errorf("no version")
426 }
427
428 for _, v := range i.versions {
429 if err := v.Validate(); err != nil {
430 return err
431 }
432
433 if v.commitHash != "" && v.time < lastTime {
434 return fmt.Errorf("non-chronological version (%d --> %d)", lastTime, v.time)
435 }
436
437 lastTime = v.time
438 }
439
440 // The identity ID should be the hash of the first commit
441 if i.versions[0].commitHash != "" && string(i.versions[0].commitHash) != i.id {
442 return fmt.Errorf("identity id should be the first commit hash")
443 }
444
445 return nil
446}
447
448func (i *Identity) lastVersion() *Version {
449 if len(i.versions) <= 0 {
450 panic("no version at all")
451 }
452
453 return i.versions[len(i.versions)-1]
454}
455
456// Id return the Identity identifier
457func (i *Identity) Id() string {
458 if i.id == "" {
459 // simply panic as it would be a coding error
460 // (using an id of an identity not stored yet)
461 panic("no id yet")
462 }
463 return i.id
464}
465
466// HumanId return the Identity identifier truncated for human consumption
467func (i *Identity) HumanId() string {
468 return FormatHumanID(i.Id())
469}
470
471func FormatHumanID(id string) string {
472 format := fmt.Sprintf("%%.%ds", humanIdLength)
473 return fmt.Sprintf(format, id)
474}
475
476// Name return the last version of the name
477func (i *Identity) Name() string {
478 return i.lastVersion().name
479}
480
481// Email return the last version of the email
482func (i *Identity) Email() string {
483 return i.lastVersion().email
484}
485
486// Login return the last version of the login
487func (i *Identity) Login() string {
488 return i.lastVersion().login
489}
490
491// AvatarUrl return the last version of the Avatar URL
492func (i *Identity) AvatarUrl() string {
493 return i.lastVersion().avatarURL
494}
495
496// Keys return the last version of the valid keys
497func (i *Identity) Keys() []Key {
498 return i.lastVersion().keys
499}
500
501// IsProtected return true if the chain of git commits started to be signed.
502// If that's the case, only signed commit with a valid key for this identity can be added.
503func (i *Identity) IsProtected() bool {
504 // Todo
505 return false
506}
507
508// ValidKeysAtTime return the set of keys valid at a given lamport time
509func (i *Identity) ValidKeysAtTime(time lamport.Time) []Key {
510 var result []Key
511
512 for _, v := range i.versions {
513 if v.time > time {
514 return result
515 }
516
517 result = v.keys
518 }
519
520 return result
521}
522
523// DisplayName return a non-empty string to display, representing the
524// identity, based on the non-empty values.
525func (i *Identity) DisplayName() string {
526 switch {
527 case i.Name() == "" && i.Login() != "":
528 return i.Login()
529 case i.Name() != "" && i.Login() == "":
530 return i.Name()
531 case i.Name() != "" && i.Login() != "":
532 return fmt.Sprintf("%s (%s)", i.Name(), i.Login())
533 }
534
535 panic("invalid person data")
536}
537
538// SetMetadata store arbitrary metadata along the last defined Version.
539// If the Version has been commit to git already, it won't be overwritten.
540func (i *Identity) SetMetadata(key string, value string) {
541 i.lastVersion().SetMetadata(key, value)
542}
543
544// ImmutableMetadata return all metadata for this Identity, accumulated from each Version.
545// If multiple value are found, the first defined takes precedence.
546func (i *Identity) ImmutableMetadata() map[string]string {
547 metadata := make(map[string]string)
548
549 for _, version := range i.versions {
550 for key, value := range version.metadata {
551 if _, has := metadata[key]; !has {
552 metadata[key] = value
553 }
554 }
555 }
556
557 return metadata
558}
559
560// MutableMetadata return all metadata for this Identity, accumulated from each Version.
561// If multiple value are found, the last defined takes precedence.
562func (i *Identity) MutableMetadata() map[string]string {
563 metadata := make(map[string]string)
564
565 for _, version := range i.versions {
566 for key, value := range version.metadata {
567 metadata[key] = value
568 }
569 }
570
571 return metadata
572}