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/entity"
14 "github.com/MichaelMure/git-bug/repository"
15 "github.com/MichaelMure/git-bug/util/git"
16 "github.com/MichaelMure/git-bug/util/lamport"
17 "github.com/MichaelMure/git-bug/util/timestamp"
18)
19
20const identityRefPattern = "refs/identities/"
21const identityRemoteRefPattern = "refs/remotes/%s/identities/"
22const versionEntryName = "version"
23const identityConfigKey = "git-bug.identity"
24
25var ErrNonFastForwardMerge = errors.New("non fast-forward identity merge")
26var ErrNoIdentitySet = errors.New("No identity is set.\n" +
27 "To interact with bugs, an identity first needs to be created using " +
28 "\"git bug user create\"")
29var ErrMultipleIdentitiesSet = errors.New("multiple user identities set")
30
31var _ Interface = &Identity{}
32var _ entity.Interface = &Identity{}
33
34type Identity struct {
35 // Id used as unique identifier
36 id entity.Id
37
38 // all the successive version of the identity
39 versions []*Version
40
41 // not serialized
42 lastCommit git.Hash
43}
44
45func NewIdentity(name string, email string) *Identity {
46 return &Identity{
47 id: entity.UnsetId,
48 versions: []*Version{
49 {
50 name: name,
51 email: email,
52 nonce: makeNonce(20),
53 },
54 },
55 }
56}
57
58func NewIdentityFull(name string, email string, login string, avatarUrl string) *Identity {
59 return &Identity{
60 id: entity.UnsetId,
61 versions: []*Version{
62 {
63 name: name,
64 email: email,
65 login: login,
66 avatarURL: avatarUrl,
67 nonce: makeNonce(20),
68 },
69 },
70 }
71}
72
73// MarshalJSON will only serialize the id
74func (i *Identity) MarshalJSON() ([]byte, error) {
75 return json.Marshal(&IdentityStub{
76 id: i.id,
77 })
78}
79
80// UnmarshalJSON will only read the id
81// Users of this package are expected to run Load() to load
82// the remaining data from the identities data in git.
83func (i *Identity) UnmarshalJSON(data []byte) error {
84 panic("identity should be loaded with identity.UnmarshalJSON")
85}
86
87// ReadLocal load a local Identity from the identities data available in git
88func ReadLocal(repo repository.Repo, id entity.Id) (*Identity, error) {
89 ref := fmt.Sprintf("%s%s", identityRefPattern, id)
90 return read(repo, ref)
91}
92
93// ReadRemote load a remote Identity from the identities data available in git
94func ReadRemote(repo repository.Repo, remote string, id string) (*Identity, error) {
95 ref := fmt.Sprintf(identityRemoteRefPattern, remote) + id
96 return read(repo, ref)
97}
98
99// read will load and parse an identity from git
100func read(repo repository.Repo, ref string) (*Identity, error) {
101 refSplit := strings.Split(ref, "/")
102 id := entity.Id(refSplit[len(refSplit)-1])
103
104 if err := id.Validate(); err != nil {
105 return nil, errors.Wrap(err, "invalid ref")
106 }
107
108 hashes, err := repo.ListCommits(ref)
109
110 // TODO: this is not perfect, it might be a command invoke error
111 if err != nil {
112 return nil, ErrIdentityNotExist
113 }
114
115 i := &Identity{
116 id: id,
117 }
118
119 for _, hash := range hashes {
120 entries, err := repo.ListEntries(hash)
121 if err != nil {
122 return nil, errors.Wrap(err, "can't list git tree entries")
123 }
124
125 if len(entries) != 1 {
126 return nil, fmt.Errorf("invalid identity data at hash %s", hash)
127 }
128
129 entry := entries[0]
130
131 if entry.Name != versionEntryName {
132 return nil, fmt.Errorf("invalid identity data at hash %s", hash)
133 }
134
135 data, err := repo.ReadData(entry.Hash)
136 if err != nil {
137 return nil, errors.Wrap(err, "failed to read git blob data")
138 }
139
140 var version Version
141 err = json.Unmarshal(data, &version)
142
143 if err != nil {
144 return nil, errors.Wrapf(err, "failed to decode Identity version json %s", hash)
145 }
146
147 // tag the version with the commit hash
148 version.commitHash = hash
149 i.lastCommit = hash
150
151 i.versions = append(i.versions, &version)
152 }
153
154 return i, nil
155}
156
157type StreamedIdentity struct {
158 Identity *Identity
159 Err error
160}
161
162// ReadAllLocalIdentities read and parse all local Identity
163func ReadAllLocalIdentities(repo repository.ClockedRepo) <-chan StreamedIdentity {
164 return readAllIdentities(repo, identityRefPattern)
165}
166
167// ReadAllRemoteIdentities read and parse all remote Identity for a given remote
168func ReadAllRemoteIdentities(repo repository.ClockedRepo, remote string) <-chan StreamedIdentity {
169 refPrefix := fmt.Sprintf(identityRemoteRefPattern, remote)
170 return readAllIdentities(repo, refPrefix)
171}
172
173// Read and parse all available bug with a given ref prefix
174func readAllIdentities(repo repository.ClockedRepo, refPrefix string) <-chan StreamedIdentity {
175 out := make(chan StreamedIdentity)
176
177 go func() {
178 defer close(out)
179
180 refs, err := repo.ListRefs(refPrefix)
181 if err != nil {
182 out <- StreamedIdentity{Err: err}
183 return
184 }
185
186 for _, ref := range refs {
187 b, err := read(repo, ref)
188
189 if err != nil {
190 out <- StreamedIdentity{Err: err}
191 return
192 }
193
194 out <- StreamedIdentity{Identity: b}
195 }
196 }()
197
198 return out
199}
200
201// NewFromGitUser will query the repository for user detail and
202// build the corresponding Identity
203func NewFromGitUser(repo repository.Repo) (*Identity, error) {
204 name, err := repo.GetUserName()
205 if err != nil {
206 return nil, err
207 }
208 if name == "" {
209 return nil, errors.New("user name is not configured in git yet. Please use `git config --global user.name \"John Doe\"`")
210 }
211
212 email, err := repo.GetUserEmail()
213 if err != nil {
214 return nil, err
215 }
216 if email == "" {
217 return nil, errors.New("user name is not configured in git yet. Please use `git config --global user.email johndoe@example.com`")
218 }
219
220 return NewIdentity(name, email), nil
221}
222
223// SetUserIdentity store the user identity's id in the git config
224func SetUserIdentity(repo repository.RepoConfig, identity *Identity) error {
225 return repo.LocalConfig().StoreString(identityConfigKey, identity.Id().String())
226}
227
228// GetUserIdentity read the current user identity, set with a git config entry
229func GetUserIdentity(repo repository.Repo) (*Identity, error) {
230 configs, err := repo.LocalConfig().ReadAll(identityConfigKey)
231 if err != nil {
232 return nil, err
233 }
234
235 if len(configs) == 0 {
236 return nil, ErrNoIdentitySet
237 }
238
239 if len(configs) > 1 {
240 return nil, ErrMultipleIdentitiesSet
241 }
242
243 var id entity.Id
244 for _, val := range configs {
245 id = entity.Id(val)
246 }
247
248 if err := id.Validate(); err != nil {
249 return nil, err
250 }
251
252 i, err := ReadLocal(repo, id)
253 if err == ErrIdentityNotExist {
254 innerErr := repo.LocalConfig().RemoveAll(identityConfigKey)
255 if innerErr != nil {
256 _, _ = fmt.Fprintln(os.Stderr, errors.Wrap(innerErr, "can't clear user identity").Error())
257 }
258 return nil, err
259 }
260
261 return i, nil
262}
263
264// IsUserIdentitySet say if the user has set his identity
265func IsUserIdentitySet(repo repository.Repo) (bool, error) {
266 configs, err := repo.LocalConfig().ReadAll(identityConfigKey)
267 if err != nil {
268 return false, err
269 }
270
271 return len(configs) == 1, nil
272}
273
274func (i *Identity) AddVersion(version *Version) {
275 i.versions = append(i.versions, version)
276}
277
278// Write the identity into the Repository. In particular, this ensure that
279// the Id is properly set.
280func (i *Identity) Commit(repo repository.ClockedRepo) error {
281 // Todo: check for mismatch between memory and commit data
282
283 if !i.NeedCommit() {
284 return fmt.Errorf("can't commit an identity with no pending version")
285 }
286
287 if err := i.Validate(); err != nil {
288 return errors.Wrap(err, "can't commit an identity with invalid data")
289 }
290
291 for _, v := range i.versions {
292 if v.commitHash != "" {
293 i.lastCommit = v.commitHash
294 // ignore already commit versions
295 continue
296 }
297
298 // get the times where new versions starts to be valid
299 v.time = repo.EditTime()
300 v.unixTime = time.Now().Unix()
301
302 blobHash, err := v.Write(repo)
303 if err != nil {
304 return err
305 }
306
307 // Make a git tree referencing the blob
308 tree := []repository.TreeEntry{
309 {ObjectType: repository.Blob, Hash: blobHash, Name: versionEntryName},
310 }
311
312 treeHash, err := repo.StoreTree(tree)
313 if err != nil {
314 return err
315 }
316
317 var commitHash git.Hash
318 if i.lastCommit != "" {
319 commitHash, err = repo.StoreCommitWithParent(treeHash, i.lastCommit)
320 } else {
321 commitHash, err = repo.StoreCommit(treeHash)
322 }
323
324 if err != nil {
325 return err
326 }
327
328 i.lastCommit = commitHash
329 v.commitHash = commitHash
330
331 // if it was the first commit, use the commit hash as the Identity id
332 if i.id == "" || i.id == entity.UnsetId {
333 i.id = entity.Id(commitHash)
334 }
335 }
336
337 if i.id == "" {
338 panic("identity with no id")
339 }
340
341 ref := fmt.Sprintf("%s%s", identityRefPattern, i.id)
342 err := repo.UpdateRef(ref, i.lastCommit)
343
344 if err != nil {
345 return err
346 }
347
348 return nil
349}
350
351func (i *Identity) CommitAsNeeded(repo repository.ClockedRepo) error {
352 if !i.NeedCommit() {
353 return nil
354 }
355 return i.Commit(repo)
356}
357
358func (i *Identity) NeedCommit() bool {
359 for _, v := range i.versions {
360 if v.commitHash == "" {
361 return true
362 }
363 }
364
365 return false
366}
367
368// Merge will merge a different version of the same Identity
369//
370// To make sure that an Identity history can't be altered, a strict fast-forward
371// only policy is applied here. As an Identity should be tied to a single user, this
372// should work in practice but it does leave a possibility that a user would edit his
373// Identity from two different repo concurrently and push the changes in a non-centralized
374// network of repositories. In this case, it would result in some of the repo accepting one
375// version and some other accepting another, preventing the network in general to converge
376// to the same result. This would create a sort of partition of the network, and manual
377// cleaning would be required.
378//
379// An alternative approach would be to have a determinist rebase:
380// - any commits present in both local and remote version would be kept, never changed.
381// - newer commits would be merged in a linear chain of commits, ordered based on the
382// Lamport time
383//
384// However, this approach leave the possibility, in the case of a compromised crypto keys,
385// of forging a new version with a bogus Lamport time to be inserted before a legit version,
386// invalidating the correct version and hijacking the Identity. There would only be a short
387// period of time where this would be possible (before the network converge) but I'm not
388// confident enough to implement that. I choose the strict fast-forward only approach,
389// despite it's potential problem with two different version as mentioned above.
390func (i *Identity) Merge(repo repository.Repo, other *Identity) (bool, error) {
391 if i.id != other.id {
392 return false, errors.New("merging unrelated identities is not supported")
393 }
394
395 if i.lastCommit == "" || other.lastCommit == "" {
396 return false, errors.New("can't merge identities that has never been stored")
397 }
398
399 modified := false
400 for j, otherVersion := range other.versions {
401 // if there is more version in other, take them
402 if len(i.versions) == j {
403 i.versions = append(i.versions, otherVersion)
404 i.lastCommit = otherVersion.commitHash
405 modified = true
406 }
407
408 // we have a non fast-forward merge.
409 // as explained in the doc above, refusing to merge
410 if i.versions[j].commitHash != otherVersion.commitHash {
411 return false, ErrNonFastForwardMerge
412 }
413 }
414
415 if modified {
416 err := repo.UpdateRef(identityRefPattern+i.id.String(), i.lastCommit)
417 if err != nil {
418 return false, err
419 }
420 }
421
422 return false, nil
423}
424
425// Validate check if the Identity data is valid
426func (i *Identity) Validate() error {
427 lastTime := lamport.Time(0)
428
429 if len(i.versions) == 0 {
430 return fmt.Errorf("no version")
431 }
432
433 for _, v := range i.versions {
434 if err := v.Validate(); err != nil {
435 return err
436 }
437
438 if v.commitHash != "" && v.time < lastTime {
439 return fmt.Errorf("non-chronological version (%d --> %d)", lastTime, v.time)
440 }
441
442 lastTime = v.time
443 }
444
445 // The identity Id should be the hash of the first commit
446 if i.versions[0].commitHash != "" && string(i.versions[0].commitHash) != i.id.String() {
447 return fmt.Errorf("identity id should be the first commit hash")
448 }
449
450 return nil
451}
452
453func (i *Identity) lastVersion() *Version {
454 if len(i.versions) <= 0 {
455 panic("no version at all")
456 }
457
458 return i.versions[len(i.versions)-1]
459}
460
461// Id return the Identity identifier
462func (i *Identity) Id() entity.Id {
463 if i.id == "" {
464 // simply panic as it would be a coding error
465 // (using an id of an identity not stored yet)
466 panic("no id yet")
467 }
468 return i.id
469}
470
471// Name return the last version of the name
472func (i *Identity) Name() string {
473 return i.lastVersion().name
474}
475
476// Email return the last version of the email
477func (i *Identity) Email() string {
478 return i.lastVersion().email
479}
480
481// Login return the last version of the login
482func (i *Identity) Login() string {
483 return i.lastVersion().login
484}
485
486// AvatarUrl return the last version of the Avatar URL
487func (i *Identity) AvatarUrl() string {
488 return i.lastVersion().avatarURL
489}
490
491// Keys return the last version of the valid keys
492func (i *Identity) Keys() []Key {
493 return i.lastVersion().keys
494}
495
496// ValidKeysAtTime return the set of keys valid at a given lamport time
497func (i *Identity) ValidKeysAtTime(time lamport.Time) []Key {
498 var result []Key
499
500 for _, v := range i.versions {
501 if v.time > time {
502 return result
503 }
504
505 result = v.keys
506 }
507
508 return result
509}
510
511// DisplayName return a non-empty string to display, representing the
512// identity, based on the non-empty values.
513func (i *Identity) DisplayName() string {
514 switch {
515 case i.Name() == "" && i.Login() != "":
516 return i.Login()
517 case i.Name() != "" && i.Login() == "":
518 return i.Name()
519 case i.Name() != "" && i.Login() != "":
520 return fmt.Sprintf("%s (%s)", i.Name(), i.Login())
521 }
522
523 panic("invalid person data")
524}
525
526// IsProtected return true if the chain of git commits started to be signed.
527// If that's the case, only signed commit with a valid key for this identity can be added.
528func (i *Identity) IsProtected() bool {
529 // Todo
530 return false
531}
532
533// LastModificationLamportTime return the Lamport time at which the last version of the identity became valid.
534func (i *Identity) LastModificationLamport() lamport.Time {
535 return i.lastVersion().time
536}
537
538// LastModification return the timestamp at which the last version of the identity became valid.
539func (i *Identity) LastModification() timestamp.Timestamp {
540 return timestamp.Timestamp(i.lastVersion().unixTime)
541}
542
543// SetMetadata store arbitrary metadata along the last defined Version.
544// If the Version has been commit to git already, it won't be overwritten.
545func (i *Identity) SetMetadata(key string, value string) {
546 i.lastVersion().SetMetadata(key, value)
547}
548
549// ImmutableMetadata return all metadata for this Identity, accumulated from each Version.
550// If multiple value are found, the first defined takes precedence.
551func (i *Identity) ImmutableMetadata() map[string]string {
552 metadata := make(map[string]string)
553
554 for _, version := range i.versions {
555 for key, value := range version.metadata {
556 if _, has := metadata[key]; !has {
557 metadata[key] = value
558 }
559 }
560 }
561
562 return metadata
563}
564
565// MutableMetadata return all metadata for this Identity, accumulated from each Version.
566// If multiple value are found, the last defined takes precedence.
567func (i *Identity) MutableMetadata() map[string]string {
568 metadata := make(map[string]string)
569
570 for _, version := range i.versions {
571 for key, value := range version.metadata {
572 metadata[key] = value
573 }
574 }
575
576 return metadata
577}